Publications

Abstract

Many accounts of working memory posit specialized storage mechanisms for the maintenance of serial order. We explore an alternative, that maintenance is achieved through temporary activation in the language production architecture. Four experiments examined the extent to which the phonological similarity effect can be explained as a sublexical speech error. Phonologically similar nonword stimuli were ordered to create tongue twister or control materials used in four tasks: reading aloud, immediate spoken recall, immediate typed recall, and serial recognition. Dependent measures from working memory (recall accuracy) and language production (speech errors) fields were used. Even though lists were identical except for item order, robust effects of tongue twisters were observed. Speech error analyses showed that errors were better described as phoneme rather than item ordering errors. The distribution of speech errors was comparable across all experiments and exhibited syllable-position effects, suggesting an important role for production processes. Implications for working memory and language production are discussed.

Abstract

Verbal working memory (WM) tasks typically involve the language production architecture for recall; however, language production processes have had a minimal role in theorizing about WM. A framework for understanding verbal WM results is presented here. In this framework, domain-specific mechanisms for serial ordering in verbal WM are provided by the language production architecture, in which positional, lexical, and phonological similarity constraints are highly similar to those identified in the WM literature. These behavioral similarities are paralleled in computational modeling of serial ordering in both fields. The role of long-term learning in serial ordering performance is emphasized, in contrast to some models of verbal WM. Classic WM findings are discussed in terms of the language production architecture. The integration of principles from both fields illuminates the maintenance and ordering mechanisms for verbal information.

Abstract

Speakers vary their speech rate considerably during a conversation, and listeners are able to quickly adapt to these variations in speech rate. Adaptation to fast speech rates is usually measured using artificially time-compressed speech. This study examined adaptation to two types of fast speech: artificially time-compressed speech and natural fast speech. Listeners performed a speeded sentence verification task on three series of sentences: normal-speed sentences, time-compressed sentences, and natural fast sentences. Listeners were divided into two groups to evaluate the possibility of transfer of learning between the time-compressed and natural fast conditions. The first group verified the natural fast before the time-compressed sentences, while the second verified the time-compressed before the natural fast sentences. The results showed transfer of learning when the time-compressed sentences preceded the natural fast sentences, but not when natural fast sentences preceded the time-compressed sentences. The results are discussed in the framework of theories on perceptual learning. Second, listeners show adaptation to the natural fast sentences, but performance for this type of fast speech does not improve to the level of time-compressed sentences.

Abstract

Interleukin 6 (IL-6) is a multifunctional cytokine with both pro- and anti-inflammatory properties with a heritability estimate of up to 61%. The circulating levels of IL-6 in blood have been associated with an increased risk of complex disease pathogenesis. We conducted a two-staged, discovery and replication meta genome-wide association study (GWAS) of circulating serum IL-6 levels comprising up to 67 428 (ndiscovery = 52 654 and nreplication = 14 774) individuals of European ancestry. The inverse variance fixed effects based discovery meta-analysis, followed by replication led to the identification of two independent loci, IL1F10/IL1RN rs6734238 on chromosome (Chr) 2q14, (Pcombined = 1.8 × 10−11), HLA-DRB1/DRB5 rs660895 on Chr6p21 (Pcombined = 1.5 × 10−10) in the combined meta-analyses of all samples. We also replicated the IL6R rs4537545 locus on Chr1q21 (Pcombined = 1.2 × 10−122). Our study identifies novel loci for circulating IL-6 levels uncovering new immunological and inflammatory pathways that may influence IL-6 pathobiology.

Abstract

How do bilingual speakers represent and use information that guides the assembly of the words into phrases and sentences (i.e., sentence structures) for languages that have different word orders? Cross-language syntactic priming effects provide mixed evidence on whether bilinguals access sentence structures from both languages even when speaking just one. Here, we compared English monolinguals, Korean-immersed Korean-English bilinguals, and English-immersed Korean-English bilinguals while they produced noun phrases (“the lemon below the lobster”), which have different word orders in English and Korean (the Korean translation word order is [lobster][below][lemon]). We examined when speakers plan each noun using an extended picture-word interference paradigm, by measuring articulation times for each word in the phrase with either the distractor word “apple” (which slows the planning of “lemon”) or “crab” (which slows the planning of “lobster”). Results suggest that for phrases that are different in linear word order across languages, bilinguals only access the sentence structure of the one language they are actively speaking at the time, even when switching languages between trials.

Abstract

Bilinguals are remarkable at language control—switching between languages only when they want. However, language control in production can involve switch costs. That is, switching to another language takes longer than staying in the same language. Moreover, bilinguals sometimes produce language intrusion errors, mistakenly producing words in an unintended language (e.g., Spanish–English bilinguals saying “pero” instead of “but”). Switch costs are also found in comprehension. For example, reading times are longer when bilinguals read sentences with language switches compared to sentences with no language switches. Given that both production and comprehension involve switch costs, some language–control mechanisms might be shared across modalities. To test this, we compared language switch costs found in eye–movement measures during silent sentence reading (comprehension) and intrusion errors produced when reading aloud switched words in mixed–language paragraphs (production). Bilinguals who made more intrusion errors during the read–aloud task did not show different switch cost patterns in most measures in the silent–reading task, except on skipping rates. We suggest that language switching is mostly controlled by separate, modality–specific processes in production and comprehension, although some points of overlap might indicate the role of domain general control and how it can influence individual differences in bilingual language control.

Abstract

We hypothesized that areas in the temporal lobe that have been implicated in the phonological processing of spoken words would also be activated during the generation and phonological processing of imagined speech. We tested this hypothesis using functional magnetic resonance imaging during a behaviorally controlled task of metrical stress evaluation. Subjects were presented with bisyllabic words and had to determine the alternation of strong and weak syllables. Thus, they were required to discriminate between weak-initial words and strong-initial words. In one condition, the stimuli were presented auditorily to the subjects (by headphones). In the other condition the stimuli were presented visually on a screen and subjects were asked to imagine hearing the word. Results showed activation of the supplementary motor area, inferior frontal gyrus (Broca's area) and insula in both conditions. In the superior temporal gyrus (STG) and in the superior temporal sulcus (STS) strong activation was observed during the auditory (perceptual) condition. However, a region located in the posterior part of the STS/STG also responded during the imagery condition. No activation of this same region of the STS was observed during a control condition which also involved processing of visually presented words, but which required a semantic decision from the subject. We suggest that processing of metrical stress, with or without auditory input, relies in part on cortical interface systems located in the posterior part of STS/STG. These results corroborate behavioral evidence regarding phonological loop involvement in auditory–verbal imagery.

Abstract

Continuous vector word representations (or
word embeddings) have shown success in cap-turing semantic relations between words, as evidenced by evaluation against behavioral data of adult performance on semantic tasks (Pereira et al., 2016). Adult semantic knowl-edge is the endpoint of a language acquisition process; thus, a relevant question is whether these models can also capture emerging word
representations of young language learners. However, the data for children’s semantic knowledge across development is scarce. In this paper, we propose to bridge this gap by using Age of Acquisition norms to evaluate word embeddings learnt from child-directed input. We present two methods that evaluate word embeddings in terms of (a) the semantic neighbourhood density of learnt words, and (b) con-
vergence to adult word associations. We apply our methods to bag-of-words models, and find that (1) children acquire words with fewer semantic neighbours earlier, and (2) young learners only attend to very local context. These findings provide converging evidence for validity of our methods in understanding the prerequisite features for a distributional model of word learning.

Abstract

The present paper assesses discourse-pragmatic factors as a potential explanation for the subject-object assymetry in early child language. It identifies a set of factors which characterize typical situations of informativeness (Greenfield & Smith, 1976), and uses these factors to identify informative arguments in data from four children aged 2;0 through 3;6 learning Inuktitut as a first language. In addition, it assesses the extent of the links between features of informativeness on one hand and lexical vs. null and subject vs. object arguments on the other. Results suggest that a pragmatics account of the subject-object asymmetry can be upheld to a greater extent than previous research indicates, and that several of the factors characterizing informativeness are good indicators of those arguments which tend to be omitted in early child language.

Abstract

Infants learn the meaning of words from accumulated experiences of real-time interactions with their caregivers. To study the effects of visual sensory input on word learning, we recorded infant's view of the world using head-mounted eye trackers during free-flowing play with a caregiver. While playing, infants were exposed to novel label-object mappings and later learning outcomes for these items were tested after the play session. In this study we use a classification based approach to link properties of infants' visual scenes during naturalistic labeling moments to their word learning outcomes. We find that a model which integrates both highly informative and ambiguous sensory evidence is a better fit to infants' individual learning outcomes than models where either type of evidence is taken alone, and that raw labeling frequency is unable to account for the word learning differences we observe. Here we demonstrate how a computational model, using only raw pixels taken from the egocentric scene image, can derive insights on human language learning.

Abstract

Previous studies have shown that children retreat from argument-structure overgeneralization errors (e.g., *Don’t giggle me) by inferring that frequently encountered verbs are unlikely to be grammatical in unattested constructions, and by making use of syntax-semantics correspondences (e.g., verbs denoting internally caused actions such as giggling cannot normally be used causatively). The present study tested a new account based on a unitary learning mechanism that combines both of these processes. Seventy-two participants (ages 5–6, 9–10, and adults) rated overgeneralization errors with higher (*The funny man’s joke giggled Bart) and lower (*The funny man giggled Bart) degrees of direct external causation. The errors with more-direct causation were rated as less unacceptable than those with less-direct causation. This finding is consistent with the new account, under which children acquire—in an incremental and probabilistic fashion—the meaning of particular constructions (e.g., transitive causative = direct external causation) and particular verbs, rejecting generalizations where the incompatibility between the two is too great.

Abstract

A central question in language acquisition is how children master sentence types that they have seldom, if ever, heard. Here we report the findings of a pre-registered, randomised, single-blind intervention study designed to test the prediction that, for one such sentence type, complex questions (e.g., Is the crocodile who’s hot eating?), children could combine schemas learned, on the basis of the input, for complex noun phrases (the [THING] who’s [PROPERTY]) and simple questions (Is [THING] [ACTION]ing?) to yield a complex-question schema (Is [the [THING] who’s [PROPERTY]] ACTIONing?). Children aged 4;2 to 6;8 (M = 5;6, SD = 7.7 months) were trained on simple questions (e.g., Is the bird cleaning?) and either (Experimental group, N = 61) complex noun phrases (e.g., the bird who’s sad) or (Control group, N = 61) matched simple noun phrases (e.g., the sad bird). In general, the two groups did not differ on their ability to produce novel complex questions at test. However, the Experimental group did show (a) some evidence of generalising a particular complex NP schema (the [THING] who’s [PROPERTY] as opposed to the [THING] that’s [PROPERTY]) from training to test, (b) a lower rate of auxiliary-doubling errors (e.g., *Is the crocodile who’s hot is eating?), and (c) a greater ability to produce complex questions on the first test trial. We end by suggesting some different methods – specifically artificial language learning and syntactic priming – that could potentially be used to better test the present account.

Abstract

Positive and negative what, why and yes/no questions with the 3sg auxiliaries can and does were elicited from 50 children aged 3;3–4;3. In support of the constructivist “schema-combination” account, only children who produced a particular positive question type correctly (e.g., What does she want?) produced a characteristic “auxiliary-doubling” error (e.g., *What does she doesn't want?) for the corresponding negative question type. This suggests that these errors are formed by superimposing a positive question frame (e.g., What does THING PROCESS?) and an inappropriate negative frame (e.g., She doesn't PROCESS) learned from declarative utterances. In addition, a significant correlation between input frequency and correct production was observed for 11 of the 12 lexical frames (e.g., What does THING PROCESS?), although some negative question types showed higher rates of error than one might expect based on input frequency alone. Implications for constructivist and generativist theories of question-acquisition are discussed.

Abstract

Particles are little words that speakers use to signal the illocutionary force of utterances and/or express their attitude towards elements of the communicative situation, e.g. the addresses. This paper presents an overview of the classification, meaning and use of utterance particles in Ewe. It argues that they constitute a grammatical word class on functional and distributional grounds. The paper calls for a cross-cultural investigation of particles, especially in Africa, where they have been neglected for far too long.

Abstract

This paper briefly presents the current situation of bilingualism in the Philippines,
specifically that of Tagalog-English bilingualism. More importantly, it describes the process of adapting the Multilingual Assessment Instrument for Narratives (LITMUS-MAIN) to Tagalog, the basis of Filipino, which is the country’s national language.
Finally, the results of a pilot study conducted on Tagalog-English bilingual children and
adults (N=27) are presented. The results showed that Story Structure is similar across the
two languages and that it develops significantly with age.

Abstract

There are some historical divisions in methods, rationales, and purposes between
studies on comparative cognition and behavioural ecology. In turn, the interaction between
these two branches and studies from mathematics, computation and neuroscience is not
usual. In this short piece, we attempt to build bridges among these disciplines. We present a
series of interconnected vignettes meant to illustrate how a more interdisciplinary approach
looks like when successful, and its advantages. Concretely, we focus on a recent topic,
namely animal rhythms in interaction, studied under different approaches. We showcase 5
research efforts, which we believe successfully link 5 particular Scientific areas of rhythm
research conceptualized as: Social neuroscience, Detailed rhythmic quantification,
Ontogeny, Computational approaches and Spontaneous interactions. Our suggestions will
hopefully spur a ‘Comparative rhythms in interaction’ field, which can integrate and
capitalize on knowledge from zoology, comparative psychology, neuroscience, and
computation.

Abstract

The meaning of a sentence can be understood, whether presented in written or spoken form. Therefore it is highly probable that brain processes supporting language comprehension are at least partly independent of sensory modality. To identify where and when in the brain language processing is independent of sensory modality, we directly compared neuromagnetic brain signals of 200 human subjects (102 males) either reading or listening to sentences. We used multiset canonical correlation analysis to align individual subject data in a way that boosts those aspects of the signal that are common to all, allowing us to capture word-by-word signal variations, consistent across subjects and at a fine temporal scale. Quantifying this consistency in activation across both reading and listening tasks revealed a mostly left hemispheric cortical network. Areas showing consistent activity patterns include not only areas previously implicated in higher-level language processing, such as left prefrontal, superior & middle temporal areas and anterior temporal lobe, but also parts of the control-network as well as subcentral and more posterior temporal-parietal areas. Activity in this supramodal sentence processing network starts in temporal areas and rapidly spreads to the other regions involved. The findings do not only indicate the involvement of a large network of brain areas in supramodal language processing, but also indicate that the linguistic information contained in the unfolding sentences modulates brain activity in a word-specific manner across subjects.

Abstract

This eye-tracking study explored how phonological encoding and speech production planning for successive words are coordinated in adult readers with dyslexia (N = 22) and control readers (N = 25) during rapid automatized naming (RAN). Using an object-RAN task, we orthogonally manipulated the word-form frequency and phonological neighborhood density of the object names and assessed the effects on speech and eye movements and their temporal coordination. In both groups, there was a significant interaction between word frequency and neighborhood density: shorter fixations for dense than for sparse neighborhoods were observed for low-, but not for high-frequency words. This finding does not suggest a specific difficulty in lexical phonological access in dyslexia. However, in readers with dyslexia only, these lexical effects percolated to the late processing stages, indicated by longer offset eye-speech lags. We close by discussing potential reasons for this finding, including suboptimal specification of phonological representations and deficits in attention control or in multi-item coordination.

Abstract

Native-speaker listeners constantly predict upcoming units of speech as part of language processing, using various cues.
However, this process is impeded in second-language listeners, as well as when the speaker has an unfamiliar accent.
Whereas previous research has largely concentrated on the pronunciation of individual segments in foreign-accented speech,
we show that regional accent impedes higher levels of language processing, making native listeners’ processing resemble that of
second-language listeners.
In Experiment 1, 42 native speakers of Canadian English followed instructions spoken in British English to move objects on a
screen while their eye movements were tracked. Native listeners use prosodic cues to information status to disambiguate between
two possible referents, a new and a previously mentioned one, before they have heard the complete word. By contrast, the
Canadian participants, similarly to second-language speakers, were not able to make full use of prosodic cues in the way native
British listeners do.
In Experiment 2, 19 native speakers of Canadian English rated the British English instructions used in Experiment 1, as well as
the same instructions spoken by a Canadian imitating the British English prosody. While information status had no effect for the
Canadian imitations, the original stimuli received higher ratings when prosodic realization and information status of the referent
matched than for mismatches, suggesting a native-like competence in these offline ratings.
These findings underline the importance of expanding psycholinguistic models of second language/dialect processing and
representation to include both prosody and regional variation.

Abstract

Across diverse lineages, animals communicate using chemosignals, but only humans communicate about chemical signals. Many studies have observed that compared with other sensory modalities, communication about smells is relatively rare and not always reliable. Recent cross-cultural studies, on the other hand, suggest some communities are more olfactorily oriented than previously supposed. Nevertheless, across the globe a general trend emerges where olfactory communication is relatively hard. We suggest here that this is in part because olfactory representations are different in kind: they have a low degree of embodiment, and are not easily expressed as primitives, thereby limiting the mental manipulations that can be performed with them. New exploratory data from Dutch children (9–12 year-olds) and adults support that mental imagery from olfaction is weak in comparison with vision and audition, and critically this is not affected by language development. Specifically, while visual and auditory imagery becomes more vivid with age, olfactory imagery shows no such development. This is consistent with the idea that olfactory representations are different in kind from representations from the other senses.

Abstract

Luria (1976) famously observed that people who never learnt to read and write do not perceive visual illusions. We conducted a conceptual replication of the Luria study of the effect of literacy on the processing of visual illusions. We designed two carefully controlled experiments with 161 participants with varying literacy levels ranging from complete illiterates to high literates in Chennai, India. Accuracy and reaction time in the identification of two types of visual shape and color illusions and the identification of appropriate control images were measured. Separate statistical analyses of Experiments 1 and 2 as well as pooled analyses of both experiments do not provide any support for the notion that literacy effects the perception of visual illusions. Our large sample, carefully controlled study strongly suggests that literacy does not meaningfully affect the identification of visual illusions and raises some questions about other reports about cultural effects on illusion perception.

Abstract

The term “uptalk” describes utterance-final pitch rises that carry no sentence-structural information. Uptalk is usually dialectal or sociolectal, and Australian English (AusEng) is particularly known for this attribute. We ask here whether experience with an uptalk variety affects listeners’ ability to categorise rising pitch contours on the basis of the timing and height of their onset and offset. Listeners were two groups of English-speakers (AusEng, and American English), and three groups of listeners with L2 English: one group with Mandarin as L1 and experience of listening to AusEng, one with German as L1 and experience of listening to AusEng, and one with German as L1 but no AusEng experience. They heard nouns (e.g. flower, piano) in the framework “Got a NOUN”, each ending with a pitch rise artificially manipulated on three contrasts: low vs. high rise onset, low vs. high rise offset and early vs. late rise onset. Their task was to categorise the tokens as “question” or “statement”, and we analysed the effect of the pitch contrasts on their judgements. Only the native AusEng listeners were able to use the pitch contrasts systematically in making these categorisations.

Abstract

This paper investigates whether there are changes in gesture rate when speakers of two languages with different gesture rates (Turkish-high gesture; Dutch-low gesture) come into daily contact. We analyzed gestures produced by second-generation heritage speakers of Turkish in the Netherlands in each language, comparing them to monolingual baselines. We did not find differences between bilingual and monolingual speakers, possibly because bilinguals were proficient in both languages and used them frequently – in line with a usage-based approach to language. However, bilinguals produced more deictic gestures than monolinguals in both Turkish and Dutch, which we interpret as a bilingual strategy. Deictic gestures may help organize discourse by placing entities in gesture space and help reduce the cognitive load associated with being bilingual, e.g., inhibition cost. Therefore, gesture rate does not necessarily change in contact situations but might be modulated by frequency of language use, proficiency, and cognitive factors related to being bilingual.

Abstract

Aim:

This paper examines whether second-generation Turkish heritage speakers in the Netherlands follow language-specific patterns of reference tracking in Turkish and Dutch, focusing on discourse status and pragmatic contexts as factors that may modulate the choice of referring expressions (REs), that is, the noun phrase (NP), overt pronoun and null pronoun.
Methodology:

Two short silent videos were used to elicit narratives from 20 heritage speakers of Turkish, both in Turkish and in Dutch. Monolingual baseline data were collected from 20 monolingually raised speakers of Turkish in Turkey and 20 monolingually raised speakers of Dutch in the Netherlands. We also collected language background data from bilinguals with an extensive survey.
Data and analysis:

Using generalised logistic mixed-effect regression, we analysed the influence of discourse status and pragmatic context on the choice of subject REs in Turkish and Dutch, comparing bilingual data to the monolingual baseline in each language.
Findings:

Heritage speakers used overt versus null pronouns in Turkish and stressed versus reduced pronouns in Dutch in pragmatically appropriate contexts. There was, however, a slight increase in the proportions of overt pronouns as opposed to NPs in Turkish and as opposed to null pronouns in Dutch. We suggest an explanation based on the degree of entrenchment of differential RE types in relation to discourse status as the possible source of the increase.
Originality:

This paper provides data from an understudied language pair in the domain of reference tracking in language contact situations. Unlike several studies of pronouns in language contact, we do not find differences across monolingual and bilingual speakers with regard to pragmatic constraints on overt pronouns in the minority pro-drop language.
Significance:

Our findings highlight the importance of taking language proficiency and use into account while studying bilingualism and combining formal approaches to language use with usage-based approaches for a more complete understanding of bilingual language production.

Abstract

it is widely believed that the difference between regular and irregular verbs is restricted to form. This study questions that belief. We report a series of lexical statistics showing that irregular verbs cluster in denser regions in semantic space. Compared to regular verbs, irregular verbs tend to have more semantic neighbors that in turn have relatively many other semantic neighbors that are morphologically irregular. We show that this greater semantic density for irregulars is reflected in association norms, familiarity ratings, visual lexical-decision latencies, and word-naming latencies. Meta-analyses of the materials of two neuroimaging studies show that in these studies, regularity is confounded with differences in semantic density. Our results challenge the hypothesis of the supposed formal encapsulation of rules of inflection and support lines of research in which sensitivity to probability is recognized as intrinsic to human language.

Abstract

Autism is characterized by impairments in reciprocal social interaction and communication, and restricted and sterotyped patterns of interests and activities. Developmental difficulties are apparent before 3 years of age and there is evidence for strong genetic influences most likely involving more than one susceptibility gene. A two-stage genome search for susceptibility loci in autism was performed on 87 affected sib pairs plus 12 non-sib affected relative-pairs, from a total of 99 families identified by an international consortium. Regions on six chromosomes (4, 7, 10, 16, 19 and 22) were identified which generated a multipoint maximum lod score (MLS) > 1. A region on chromosome 7q was the most significant with an MLS of 3.55 near markers D7S530 and D7S684 in the subset of 56 UK affected sib-pair families, and an MLS of 2.53 in all 87 affected sib-pair families. An area on chromosome 16p near the telomere was the next most significant, with an MLS of 1.97 in the UK families, and 1.51 in all families. These results are an important step towards identifying genes predisposing to autism; establishing their general applicability requires further study.

Abstract

This study investigated how bilingual experience alters neural mechanisms supporting novel word learning. We hypothesised that novel words elicit increased semantic activation in the larger bilingual lexicon, potentially stimulating stronger memory integration than in monolinguals. English monolinguals and Spanish–English bilinguals were trained on two sets of written Swahili–English word pairs, one set on each of two consecutive days, and performed a recognition task in the MRI-scanner. Lexical integration was measured through visual primed lexical decision. Surprisingly, no group difference emerged in explicit word memory, and priming occurred only in the monolingual group. This difference in lexical integration may indicate an increased need for slow neocortical interleaving of old and new information in the denser bilingual lexicon. The fMRI data were consistent with increased use of cognitive control networks in monolinguals and of articulatory motor processes in bilinguals, providing further evidence for experience-induced neural changes: monolinguals and bilinguals reached largely comparable behavioural performance levels in novel word learning, but did so by recruiting partially overlapping but non-identical neural systems to acquire novel words.

Abstract

In multilevel data, units at level 1 are nested in clusters at level 2, which in turn may be nested in even larger clusters at level 3, and so on. For continuous data, several authors have shown how to model multilevel data in a ‘wide’ or ‘multivariate’ format approach. We provide a general framework to analyze random intercept multilevel SEM in the ‘wide format’ (WF) and extend this approach for discrete data. In a simulation study, we vary response scale (binary, four response options), covariate presence (no, between-level, within-level), design (balanced, unbalanced), model misspecification (present, not present), and the number of clusters (small, large) to determine accuracy and efficiency of the estimated model parameters. With a small number of observations in a cluster, results indicate that the WF approach is a preferable approach to estimate multilevel data with discrete response options.

Abstract

Machine-learned computer vision algorithms for tagging images are increasingly used by developers and researchers, having become popularized as easy-to-use "cognitive services." Yet these tools struggle with gender recognition, particularly when processing images of women, people of color and non-binary individuals. Socio-technical researchers have cited data bias as a key problem; training datasets often over-represent images of people and contexts that convey social stereotypes. The social psychology literature explains that people learn social stereotypes, in part, by observing others in particular roles and contexts, and can inadvertently learn to associate gender with scenes, occupations and activities. Thus, we study the extent to which image tagging algorithms mimic this phenomenon. We design a controlled experiment, to examine the interdependence between algorithmic recognition of context and the depicted person's gender. In the spirit of auditing to understand machine behaviors, we create a highly controlled dataset of people images, imposed on gender-stereotyped backgrounds. Our methodology is reproducible and our code publicly available. Evaluating five proprietary algorithms, we find that in three, gender inference is hindered when a background is introduced. Of the two that "see" both backgrounds and gender, it is the one whose output is most consistent with human stereotyping processes that is superior in recognizing gender. We discuss the accuracy--fairness trade-off, as well as the importance of auditing black boxes in better understanding this double-edged sword.

Abstract

The frontal lobe is central to distinctive aspects of human cognition and behavior. Some comparative studies link this to a larger frontal cortex and even larger frontal white matter in humans compared with other primates, yet others dispute these findings. The discrepancies between studies could be explained by limitations of the methods used to quantify volume differences across species, especially when applied to white matter connections. In this study, we used a novel tractography approach to demonstrate that frontal lobe networks, extending within and beyond the frontal lobes, occupy 66% of total brain white matter in humans and 48% in three monkey species: vervets (Chlorocebus aethiops), rhesus macaque (Macaca mulatta) and cynomolgus macaque (Macaca fascicularis), all male. The simian–human differences in proportional frontal tract volume were significant for projection, commissural, and both intralobar and interlobar association tracts. Among the long association tracts, the greatest difference was found for tracts involved in motor planning, auditory memory, top-down control of sensory information, and visuospatial attention, with no significant differences in frontal limbic tracts important for emotional processing and social behaviour. In addition, we found that a nonfrontal tract, the anterior commissure, had a smaller volume fraction in humans, suggesting that the disproportionally large volume of human frontal lobe connections is accompanied by a reduction in the proportion of some nonfrontal connections. These findings support a hypothesis of an overall rearrangement of brain connections during human evolution.

Abstract

To ensure short gaps between turns in conversation, next speakers regularly start planning their utterance in overlap with the incoming turn. Three experiments investigate which stages of utterance planning are executed in overlap. E1 establishes effects of associative and phonological relatedness of pictures and words in a switch-task from picture naming to lexical decision. E2 focuses on effects of phonological relatedness and investigates potential shifts in the time-course of production planning during background speech. E3 required participants to verbally answer questions as a base task. In critical trials, however, participants switched to visual lexical decision just after they began planning their answer. The task-switch was time-locked to participants' gaze for response planning. Results show that word form encoding is done as early as possible and not postponed until the end of the incoming turn. Hence, planning a response during the incoming turn is executed at least until word form activation.

Abstract

In conversation, production and comprehension processes may overlap, causing interference. In 3 experiments, we investigated whether repetition priming can work as a supporting device, reducing costs associated with linguistic dual-tasking. Experiment 1 established the rate of decay of repetition priming from spoken words to picture naming for primes embedded in sentences. Experiments 2 and 3 investigated whether the rate of decay was faster when participants comprehended the prime while planning to name unrelated pictures. In all experiments, the primed picture followed the sentences featuring the prime on the same trial, or 10 or 50 trials later. The results of the 3 experiments were strikingly similar: robust repetition priming was observed when the primed picture followed the prime sentence. Thus, repetition priming was observed even when the primes were processed while the participants prepared an unrelated spoken utterance. Priming might, therefore, support utterance planning in conversation, where speakers routinely listen while planning their utterances.

Abstract

Oscillatory neuronal dynamics, observed in the human electroencephalogram (EEG) during language processing, have been related to the dynamic formation of functionally coherent networks that serve the role of integrating the different sources of information needed for understanding the linguistic input. To further explore the functional role of oscillatory synchrony during language processing, we quantified event-related EEG power changes induced by the presentation of open-class (OC) words and closed-class (CC) words in a wide range of frequencies (from 1 to 30 Hz), while subjects read a short story. Word presentation induced three oscillatory components: a theta power increase (4–7 Hz), an alpha power decrease (10–12 Hz), and a beta power decrease (16–21 Hz). Whereas the alpha and beta responses showed mainly quantitative differences between the two word classes, the theta responses showed qualitative differences between OC words and CC words: A theta power increase was found over left temporal areas for OC words, but not for CC words. The left temporal theta increase may index the activation of a network involved in retrieving the lexical–semantic properties of the OC items.

Abstract

This article argues that with the original emphasis on dialectal variation, using primarily literary texts from various regions, analysis of Old French has routinely neglected social variation, providing an incomplete picture of its grammar. Accordingly, Old French has been identified as typically featuring e.g. “pro-drop”, brace constructions, and single negation. Yet examination of these features in informal texts, as opposed to the formal texts typically dealt with, demonstrates that these documents do not corroborate the picture of Old French that is commonly presented in the linguistic literature. Our reconstruction of Old French grammar therefore needs adjustment and further refinement, in particular by implementing sociolinguistic data. With a broader scope, the call for inclusion of sociolinguistic variation may resonate in the investigation of other early languages, resulting in the reassessment of the sources used, and reopening the debate about social variation in dead languages and its role in language evolution.

Abstract

The Romance languages have a rich numeral system that includes cardinals—providing the bases on which the other types of numeral series are built—ordinals, fractions, collectives, approximatives, distributives, and multiplicatives. Latin plays a decisive and continued role in their formation, both as the language to which many numerals go back directly and as an ongoing source for lexemes and formatives. While the Latin numeral system was synthetic, with a distinct ending for each type of numeral, the Romance numerals often feature more than one (unevenly distributed) marker or structure per series, which feature varying degrees of inherited, borrowed, or innovative elements. Formal consistency is strongest in cardinals, followed by ordinals and then the other types of numeral, which also tend to be more analytic or periphrastic. From a morphological perspective, Romance numerals overall have moved away from the inherited syntheticity, but several series continue to be synthetic formations—at least in part—with morphological markers drawn from Latin that may have undergone functional change (e.g. distributive > ordinal > collective). The underlying syntax of Romance numerals is in line with the overall grammatical patterns of Romance languages, as reflected in the prevalence of word order (with arithmetical correlates), connectors, (partial) loss of agreement, and analyticity. Innovation is prominent in the formation of higher numerals with bases beyond ‘thousand’, of teens and decads in Romanian, and of vigesimals in numerous Romance varieties.

Abstract

To form a more reliable percept of the environment, the brain needs to estimate its own sensory uncertainty. Current theories of perceptual inference assume that the brain computes sensory uncertainty instantaneously and independently for each stimulus. We evaluated this assumption in four psychophysical experiments, in which human observers localized auditory signals that were presented synchronously with spatially disparate visual signals. Critically, the visual noise changed dynamically over time continuously or with intermittent jumps. Our results show that observers integrate audiovisual inputs weighted by sensory uncertainty estimates that combine information from past and current signals consistent with an optimal Bayesian learner that can be approximated by exponential discounting. Our results challenge leading models of perceptual inference where sensory uncertainty estimates depend only on the current stimulus. They demonstrate that the brain capitalizes on the temporal dynamics of the external world and estimates sensory uncertainty by combining past experiences with new incoming sensory signals.

Abstract

In many tasks the effects of frequency and age of acquisition (AoA) on reaction latencies are similar in size. However, in picture naming the AoA-effect is often significantly larger than expected on the basis of the frequency-effect. Previous explanations of this frequency-independent AoA-effect have attributed it to the organisation of the semantic system or to the way phonological word forms are stored in the mental lexicon. Using a semantic blocking paradigm, we show that semantic context effects on naming latencies are more pronounced for late-acquired than for early-acquired words. This interaction between AoA and naming context is likely to arise during lexical-semantic encoding, which we put forward as the locus for the frequency-independent AoA-effect.

Abstract

In the cyclic semantic blocking paradigm participants repeatedly name sets of objects with semantically related names (homogeneous sets) or unrelated names (heterogeneous sets). The naming latencies are typically longer in related than in unrelated sets. In we replicated this semantic blocking effect and demonstrated that the effect only arose after all objects of a set had been shown and named once. In , the objects of a set were presented simultaneously (instead of on successive trials). Evidence for semantic blocking was found in the naming latencies and in the gaze durations for the objects, which were longer in homogeneous than in heterogeneous sets. For the gaze-to-speech lag between the offset of gaze on an object and the onset of the articulation of its name, a repetition priming effect was obtained but no blocking effect. showed that the blocking effect for speech onset latencies generalized to new, previously unnamed lexical items. We propose that the blocking effect is due to refractory behaviour in the semantic system.

Abstract

In early deaf individuals, the auditory deprived temporal brain regions become engaged in visual processing. In our study we tested further the hypothesis that intrinsic functional specialization guides the expression of cross-modal responses in the deprived auditory cortex. We used functional MRI to characterize the brain response to horizontal, radial and stochastic visual motion in early deaf and hearing individuals matched for the use of oral or sign language. Visual motion showed enhanced response in the ‘deaf’ mid-lateral planum temporale, a region selective to auditory motion as demonstrated by a separate auditory motion localizer in hearing people. Moreover, multivariate pattern analysis revealed that this reorganized temporal region showed enhanced decoding of motion categories in the deaf group, while visual motion-selective region hMT+/V5 showed reduced decoding when compared to hearing people. Dynamic Causal Modelling revealed that the ‘deaf’ motion-selective temporal region shows a specific increase of its functional interactions with hMT+/V5 and is now part of a large-scale visual motion selective network. In addition, we observed preferential responses to radial, compared to horizontal, visual motion in the ‘deaf’ right superior temporal cortex region that also show preferential response to approaching/receding sounds in the hearing brain. Overall, our results suggest that the early experience of auditory deprivation interacts with intrinsic constraints and triggers a large-scale reallocation of computational load between auditory and visual brain regions that typically support the multisensory processing of motion information.

Abstract

Psycholinguistic studies of metaphor processing must control their stimuli not just for word frequency but also for the frequency with which a term is used metaphorically. Thus, we consider the task of metaphor frequency estimation, which predicts how often target words will be used metaphorically. We develop metaphor classifiers which represent metaphorical domains through Latent Dirichlet Allocation, and apply these classifiers to the target words, aggregating their decisions to estimate the metaphorical frequencies. Training on only 400 sentences, our models are able to achieve 61.3 % accuracy on metaphor classification and 77.8 % accuracy on HIGH vs. LOW metaphorical frequency estimation.

Abstract

We used a multi-method approach to investigate how children avoid (or retreat from) argument structure overgeneralisation errors (e.g., *You giggled me). Experiment 1 investigated how semantic and statistical constraints (preemption and entrenchment) influence children’s and adults’ judgments of the grammatical acceptability of 120 verbs in transitive and intransitive sentences. Experiment 2 used syntactic priming to elicit overgeneralisation errors from children (aged 5–6) to investigate whether the same constraints operate in production. For judgments, the data showed effects of preemption, entrenchment, and semantics for all ages. For production, only an effect of preemption was observed, and only for transitivisation errors with intransitive-only verbs (e.g., *The man laughed the girl). We conclude that preemption, entrenchment, and semantic effects are real, but are obscured by particular features of the present production task.

Abstract

All accounts of language acquisition agree that, by around age 4, children’s knowledge of grammatical constructions is abstract, rather than tied solely to individual lexical items. The aim of the present research was to investigate, focusing on the passive, whether children’s and adults’ performance is additionally semantically constrained, varying according to the distance between the semantics of the verb and those of the construction. In a forced‐choice pointing study (Experiment 1), both 4‐ to 6‐year olds (N = 60) and adults (N = 60) showed support for the prediction of this semantic construction prototype account of an interaction such that the observed disadvantage for passives as compared to actives (i.e., fewer correct points/longer reaction time) was greater for experiencer‐theme verbs than for agent‐patient and theme‐experiencer verbs (e.g., Bob was seen/hit/frightened by Wendy). Similarly, in a production/priming study (Experiment 2), both 4‐ to 6‐year olds (N = 60) and adults (N = 60) produced fewer passives for experiencer‐theme verbs than for agent‐patient/theme‐experiencer verbs. We conclude that these findings are difficult to explain under accounts based on the notion of A(rgument) movement or of a monostratal, semantics‐free, level of syntax, and instead necessitate some form of semantic construction prototype account.

Abstract

Four experiments investigated the role of frequency information in compound production by independently varying the frequencies of the first and second constituent as well as the frequency of the compound itself. Pairs of Dutch noun-noun compounds were selected such that there was a maximal contrast for one frequency while matching the other two frequencies. In a position-response association task, participants first learned to associate a compound with a visually marked position on a computer screen. In the test phase, participants had to produce the associated compound in response to the appearance of the position mark, and we measured speech onset latencies. The compound production latencies varied significantly according to factorial contrasts in the frequencies of both constituting morphemes but not according to a factorial contrast in compound frequency, providing further evidence for decompositional models of speech production. In a stepwise regression analysis of the joint data of Experiments 1-4, however, compound frequency was a significant nonlinear predictor, with facilitation in the low-frequency range and a trend toward inhibition in the high-frequency range. Furthermore, a combination of structural measures of constituent frequencies and entropies explained significantly more variance than a strict decompositional model, including cumulative root frequency as the only measure of constituent frequency, suggesting a role for paradigmatic relations in the mental lexicon.

Abstract

This article sets out our perspective on how to begin the journey of decolonising computational fi elds, such as data and cognitive sciences. We see this struggle as requiring two basic steps: a) realisation that the present-day system has inherited, and still enacts, hostile, conservative, and oppressive behaviours and principles towards women of colour; and b) rejection of the idea that centring individual people is a solution to system-level problems. The longer we ignore these two steps, the more “our” academic system maintains its toxic structure, excludes, and harms Black women and other minoritised groups. This also keeps the door open to discredited pseudoscience, like eugenics and physiognomy. We propose that grappling with our fi elds’ histories and heritage holds the key to avoiding mistakes of the past. In contrast to, for example, initiatives such as “diversity boards”, which can be harmful because they superfi cially appear reformatory but nonetheless center whiteness and maintain the status quo. Building on the work of many women of colour, we hope to advance the dialogue required to build both a grass-roots and a top-down re-imagining of computational sciences — including but not limited to psychology, neuroscience, cognitive science, computer science, data science, statistics, machine learning, and artifi cial intelligence. We aspire to progress away from
these fi elds’ stagnant, sexist, and racist shared past into an ecosystem that welcomes and nurtures
demographically diverse researchers and ideas that critically challenge the status quo.

Abstract

Recent work has considered the relationship between value and confidence in both behavioural and neural representation. Here we evaluated whether the brain organises value and confidence signals in a systematic fashion that reflects the overall desirability of options. If so, regions that respond to either increases or decreases in both value and confidence should be widespread. We strongly confirmed these predictions through a model-based fMRI analysis of a mixed gambles task that assessed subjective value (SV) and inverse decision entropy (iDE), which is related to confidence. Purported value areas more strongly signalled iDE than SV, underscoring how intertwined value and confidence are. A gradient tied to the desirability of actions transitioned from positive SV and iDE in ventromedial prefrontal cortex to negative SV and iDE in dorsal medial prefrontal cortex. This alignment of SV and iDE signals could support retrospective evaluation to guide learning and subsequent decisions.

Abstract

Studies have shown that cross-linguistically, consonants at the left edge of higher-level prosodic boundaries tend to be more forcefully articulated than those at lower-level boundaries, a phenomenon known as domain-initial strengthening. This study tests whether similar effects occur in Turkish, using the Autosegmental-Metrical model proposed by Ipek & Jun [1, 2] as the basis for assessing boundary strength. Productions of /t/ and /d/ were elicited in four domain-initial prosodic positions corresponding to progressively higher-level boundaries: syllable, word, intermediate phrase, and Intonational Phrase. A fifth position, nuclear word, was included in order to better situate it within the prosodic hierarchy. Acoustic correlates of articulatory strength were measured, including closure duration for /d/ and /t/, as well as voice onset time and burst energy for /t/. Our results show that closure duration increases cumulatively from syllable to intermediate phrase, while voice onset time and burst energy are not influenced by boundary strength. These findings provide corroborating evidence for Ipek & Jun’s model, particularly for the distinction between word and intermediate phrase boundaries. Additionally, articulatory strength at the left edge of the nuclear word patterned closely with word-initial position, supporting the view that the nuclear word is not associated with a distinct phrasing domain

Abstract

One of the most controversial hypotheses in cognitive science is the Chomskyan evolutionary conjecture that language arose instantaneously in humans through a single mutation. Here we analyze the evolutionary dynamics implied by this hypothesis, which has never been formalized before. The hypothesis supposes the emergence and fixation of a single mutant (capable of the syntactic operation Merge) during a narrow historical window as a result of frequency-independent selection under a huge fitness advantage in a population of an effective size no larger than ~15 000 individuals. We examine this proposal by combining diffusion analysis and extreme value theory to derive a probabilistic formulation of its dynamics. We find that although a macro-mutation is much more likely to go to fixation if it occurs, it is much more unlikely a priori than multiple mutations with smaller fitness effects. The most likely scenario is therefore one where a medium number of mutations with medium fitness effects accumulate. This precise analysis of the probability of mutations occurring and going to fixation has not been done previously in the context of the evolution of language. Our results cast doubt on any suggestion that evolutionary reasoning provides an independent rationale for a single-mutant theory of language.

Abstract

The present study extends neuro-imaging into conversation through studying dialogue comprehension. Conversation entails rapid responses, with negative semiotics for delay. We explored how expectations about the valence of the forthcoming response develop during the silence before the response and whether negative responses have mainly cognitive or social-emotional consequences. EEG-participants listened to questions from a spontaneous spoken corpus, cross-spliced with short/long gaps and “yes”/“no” responses. Preceding contexts biased listeners to expect the eventual response, which was hypothesised to translate to expectations for a shorter or longer gap. “No” responses showed a trend towards an early positivity, suggesting socio-emotional consequences. Within the long gap, expecting a “yes” response led to an earlier negativity, as well as a trend towards stronger theta-oscillations, after 300 milliseconds. This suggests that listeners anticipate/predict “yes” responses to come earlier than “no” responses, showing strong sensitivities to timing, which presumably promote hastening the pace of verbal interaction.

Abstract

This study investigated the role of contextual and prosodic information in turn-end estimation by means of a button-press task. We presented participants with turns extracted from a corpus of telephone calls visually (i.e., in transcribed form, word-by-word) and auditorily, and asked them to anticipate turn ends by pressing a button. The availability of the previous conversational context was generally helpful for turn-end estimation in short turns only, and more clearly so in the visual task than in the auditory task. To investigate the role of prosody, we examined whether participants in the auditory task pressed the button close to turn-medial points likely to constitute turn ends based on lexico-syntactic information alone. We observed that the vast majority of such button presses occurred in the presence of an intonational boundary rather than in its absence. These results are consistent with the view that prosodic cues in the proximity of turn ends play a relevant role in turn-end estimation.

Abstract

Conversation is generally characterized by smooth transitions between turns, with only very short gaps. This entails that responders often begin planning their response before the ongoing turn is finished. However, controversy exists about whether they start planning as early as they can, to make sure they respond on time, or as late as possible, to minimize the overlap between comprehension and production planning. Two earlier EEG studies have found neural correlates of response planning (positive ERP and alpha decrease) as soon as listeners could start planning their response, already midway through the current turn. However, in these studies, the questions asked were highly controlled with respect to the position where planning could start (e.g., very early) and required short and easy responses. The present study measured participants' EEG while an experimenter interviewed them in a spontaneous interaction. Coding the questions in the interviews showed that, under these natural circumstances, listeners can, in principle, start planning a response relatively early, on average after only about one third of the question has passed. Furthermore, ERP results showed a large positivity, interpreted before as an early neural signature of response planning, starting about half a second after the start of the word that allowed listeners to start planning a response. A second neural signature of response planning, an alpha decrease, was not replicated as reliably. In conclusion, listeners appear to start planning their response early during the ongoing turn, also under natural circumstances, presumably in order to keep the gap between turns short and respond on time. These results have several important implications for turn-taking theories, which need to explain how interlocutors deal with the overlap between comprehension and production, how they manage to come in on time, and the sources that lead to variability between conversationalists in the start of planning.

Abstract

Objective: Ample behavioral evidence suggests that distributional properties of the language environment influence the processing of speech. Yet, how these characteristics are reflected in neural processes remains largely unknown. The present ERP study investigates neurophysiological correlates of phonotactic probability: the distributional frequency of phoneme combinations. Methods: We employed an ERP measure indicative of experience-dependent auditory memory traces, the mismatch negativity (MMN). We presented pairs of non-words that differed by the degree of phonotactic probability in a codified passive oddball design that minimizes the contribution of acoustic processes. Results: In Experiment 1 the non-word with high phonotactic probability (notsel) elicited a significantly enhanced MMN as compared to the non-word with low phonotactic probability (notkel). In Experiment 2 this finding was replicated with a non-word pair with a smaller acoustic difference (notsel–notfel). An MMN enhancement was not observed in a third acoustic control experiment with stimuli having comparable phonotactic probability (so–fo). Conclusions: Our data suggest that auditory cortical responses to phoneme clusters are modulated by statistical regularities of phoneme combinations. Significance: This study indicates that the language environment is relevant in shaping the neural processing of speech. Furthermore, it provides a potentially useful design for investigating implicit phonological processing in children with anomalous language functions like dyslexia.

Abstract

Many studies of speech perception assess the intelligibility of spoken sentence stimuli by means
of transcription tasks (‘type out what you hear’). The intelligibility of a given stimulus is then often
expressed in terms of percentage of words correctly reported from the target sentence. Yet scoring
the participants’ raw responses for words correctly identified from the target sentence is a time-
consuming task, and hence resource-intensive. Moreover, there is no consensus among speech
scientists about what specific protocol to use for the human scoring, limiting the reliability of
human scores. The present paper evaluates various forms of fuzzy string matching between
participants’ responses and target sentences, as automated metrics of listener transcript accuracy.
We demonstrate that one particular metric, the Token Sort Ratio, is a consistent, highly efficient,
and accurate metric for automated assessment of listener transcripts, as evidenced by high
correlations with human-generated scores (best correlation: r = 0.940) and a strong relationship to
acoustic markers of speech intelligibility. Thus, fuzzy string matching provides a practical tool for
assessment of listener transcript accuracy in large-scale speech intelligibility studies. See
https://tokensortratio.netlify.app for an online implementation.

Abstract

Speech in everyday conversations is riddled with discourse markers (DMs), such as well, you know, and like. However, in many lab-based studies of speech comprehension, such DMs are typically absent from the carefully articulated and highly controlled speech stimuli. As such, little is known about how these DMs influence online word recognition. The present study specifically investigated the online processing of DM like and how it influences the activation of words in the mental lexicon. We specifically targeted the cohort competitor (CC) effect in the Visual World Paradigm: Upon hearing spoken instructions to “pick up the beaker,” human listeners also typically fixate—next to the target object—referents that overlap phonologically with the target word (cohort competitors such as beetle; CCs). However, several studies have argued that CC effects are constrained by syntactic, semantic, pragmatic, and discourse constraints. Therefore, the present study investigated whether DM like influences online word recognition by activating its cohort competitors (e.g., lightbulb). In an eye-tracking experiment using the Visual World Paradigm, we demonstrate that when participants heard spoken instructions such as “Now press the button for the, like … unicycle,” they showed anticipatory looks to the CC referent (lightbulb)well before hearing the target. This CC effect was sustained for a relatively long period of time, even despite hearing disambiguating information (i.e., the /k/ in like). Analysis of the reaction times also showed that participants were significantly faster to select CC targets (lightbulb) when preceded by DM like. These findings suggest that seemingly trivial DMs, such as like, activate their CCs, impacting online word recognition. Thus, we advocate a more holistic perspective on spoken language comprehension in naturalistic communication, including the processing of DMs.

Abstract

Beat gestures—spontaneously produced biphasic movements of the hand—
are among the most frequently encountered co-speech gestures in human
communication. They are closely temporally aligned to the prosodic charac-
teristics of the speech signal, typically occurring on lexically stressed
syllables. Despite their prevalence across speakers of the world’s languages,
how beat gestures impact spoken word recognition is unclear. Can these
simple ‘flicks of the hand’ influence speech perception? Across a range
of experiments, we demonstrate that beat gestures influence the explicit
and implicit perception of lexical stress (e.g. distinguishing OBject from
obJECT), and in turn can influence what vowels listeners hear. Thus, we pro-
vide converging evidence for a manual McGurk effect: relatively simple and
widely occurring hand movements influence which speech sounds we hear

Abstract

Speakers adjust their voice when talking in noise, which is known as Lombard speech. These acoustic adjustments facilitate speech comprehension in noise relative to plain speech (i.e., speech produced in quiet). However, exactly which characteristics of Lombard speech drive this intelligibility benefit in noise remains unclear. This study assessed the contribution of enhanced amplitude modulations to the Lombard speech intelligibility benefit by demonstrating that (1) native speakers of Dutch in the Nijmegen Corpus of Lombard Speech (NiCLS) produce more pronounced amplitude modulations in noise vs. in quiet; (2) more enhanced amplitude modulations correlate positively with intelligibility in a speech-in-noise perception experiment; (3) transplanting the amplitude modulations from Lombard speech onto plain speech leads to an intelligibility improvement, suggesting that enhanced amplitude modulations in Lombard speech contribute towards intelligibility in noise. Results are discussed in light of recent neurobiological models of speech perception with reference to neural oscillators phase-locking to the amplitude modulations in speech, guiding the processing of speech.

Abstract

Spoken words are highly variable and therefore listeners interpret speech sounds relative to the surrounding acoustic context, such as the speech rate of a preceding sentence. For instance, a vowel midway between short /ɑ/ and long /a:/ in Dutch is perceived as short /ɑ/ in the context of preceding slow speech, but as long /a:/ if preceded by a fast context. Despite the well-established influence of visual articulatory cues on speech comprehension, it remains unclear whether visual cues to speech rate also influence subsequent spoken word recognition. In two ‘Go Fish’-like experiments, participants were presented with audio-only (auditory speech + fixation cross), visual-only (mute videos of talking head), and audiovisual (speech + videos) context sentences, followed by ambiguous target words containing vowels midway between short /ɑ/ and long /a:/. In Experiment 1, target words were always presented auditorily, without visual articulatory cues. Although the audio-only and audiovisual contexts induced a rate effect (i.e., more long /a:/ responses after fast contexts), the visual-only condition did not. When, in Experiment 2, target words were presented audiovisually, rate effects were observed in all three conditions, including visual-only. This suggests that visual cues to speech rate in a context sentence influence the perception of following visual target cues (e.g., duration of lip aperture), which at an audiovisual integration stage bias participants’ target categorization responses. These findings contribute to a better understanding of how what we see influences what we hear.

Abstract

Two fundamental properties of perception are selective attention and perceptual contrast, but how these two processes interact remains unknown. Does an attended stimulus history exert a larger contrastive influence on the perception of a following target than unattended stimuli? Dutch listeners categorized target sounds with a reduced prefix “ge-” marking tense (e.g., ambiguous between gegaan-gaan “gone-go”). In ‘single talker’ Experiments 1–2, participants perceived the reduced syllable (reporting gegaan) when the target was heard after a fast sentence, but not after a slow sentence (reporting gaan). In ‘selective attention’ Experiments 3–5, participants listened to two simultaneous sentences from two different talkers, followed by the same target sounds, with instructions to attend only one of the two talkers. Critically, the speech rates of attended and unattended talkers were found to equally influence target perception – even when participants could watch the attended talker speak. In fact, participants’ target perception in ‘selective attention’ Experiments 3–5 did not differ from participants who were explicitly instructed to divide their attention equally across the two talkers (Experiment 6). This suggests that contrast effects of speech rate are immune to selective attention, largely operating prior to attentional stream segregation in the auditory processing hierarchy.

Abstract

Speech contains pronounced amplitude modulations in the 1–9 Hz range, correlating with the syllabic rate of speech. Recent models of speech perception propose that this rhythmic nature of speech is central to speech recognition and has beneficial effects on language processing. Here, we investigated the contribution of amplitude modulations to the subjective impression listeners have of public speakers. The speech from US presidential candidates Hillary Clinton and Donald Trump in the three TV debates of 2016 was acoustically analyzed by means of modulation spectra. These indicated that Clinton’s speech had more pronounced amplitude modulations than Trump’s speech, particularly in the 1–9 Hz range. A subsequent perception experiment, with listeners rating the perceived charisma of (low-pass filtered versions of) Clinton’s and Trump’s speech, showed that more pronounced amplitude modulations (i.e., more ‘rhythmic’ speech) increased perceived charisma ratings. These outcomes highlight the important contribution of speech rhythm to charisma perception.

Abstract

Speech sounds are perceived relative to spectral properties of surrounding speech. For instance, target words ambiguous between /bɪt/ (with low F1) and /bɛt/ (with high F1) are more likely to be perceived as “bet” after a ‘low F1’ sentence, but as “bit” after a ‘high F1’ sentence. However, it is unclear how these spectral contrast effects (SCEs) operate in multi-talker listening conditions. Recently, Feng and Oxenham [(2018b). J.Exp.Psychol.-Hum.Percept.Perform. 44(9), 1447–1457] reported that selective attention affected SCEs to a small degree, using two simultaneously presented sentences produced by a single talker. The present study assessed the role of selective attention in more naturalistic ‘cocktail party’ settings, with 200 lexically unique sentences, 20 target words, and different talkers. Results indicate that selective attention to one talker in one ear (while ignoring another talker in the other ear) modulates SCEs in such a way that only the spectral properties of the attended talker influences target perception. However, SCEs were much smaller in multi-talker settings (Experiment 2) than those in single-talker settings (Experiment 1). Therefore, the influence of SCEs on speech comprehension in more naturalistic settings (i.e., with competing talkers) may be smaller than estimated based on studies without competing talkers.