Publications

Abstract

"Event realisation" refers to the normal final state of the affected entity of an activity described by a verb. For example, the sentence John killed the mosquito entails that the mosquito is afterwards dead – this is the full realisation of a killing event. By contrast, a sentence such as John hit the mosquito does not entail the mosquito’s death (even though we might assume this to be a likely result). In using a certain verb, which features of event realisation are entailed and which are just likely? This questionnaire supports cross-linguistic exploration of event realisation for a range of event types.

Abstract

In a within-subject design we investigated the levels-of-processing (LOP) effect using visual material in a behavioral and a corresponding PET study. In the behavioral study we characterize a generalized LOP effect, using pleasantness and graphical quality judgments in the encoding situation, with two types of visual material, figurative and nonfigurative line drawings. In the PET study we investigate the related pattern of brain activations along these two dimensions. The behavioral results indicate that instruction and material contribute independently to the level of recognition performance. Therefore the LOP effect appears to stem both from the relative relevance of the stimuli (encoding opportunity) and an altered processing of stimuli brought about by the explicit instruction (encoding mode). In the PET study, encoding of visual material under the pleasantness (deep) instruction yielded left lateralized frontoparietal and anterior temporal activations while surface-based perceptually oriented processing (shallow instruction) yielded right lateralized frontoparietal, posterior temporal, and occipitotemporal activations. The result that deep encoding was related to the left prefrontal cortex while shallow encoding was related to the right prefrontal cortex, holding the material constant, is not consistent with the HERA model. In addition, we suggest that the anterior medial superior frontal region is related to aspects of self-referential semantic processing and that the inferior parts of the anterior cingulate as well as the medial orbitofrontal cortex is related to affective processing, in this case pleasantness evaluation of the stimuli regardless of explicit semantic content. Finally, the left medial temporal lobe appears more actively engaged by elaborate meaning-based processing and the complex response pattern observed in different subregions of the MTL lends support to the suggestion that this region is functionally segregated.

Abstract

The objectives of this article are to characterize the performance and to discuss the performance differences between literate and illiterate participants in a well-defined study population.We describe the participant-selection procedure used to investigate this population. Three groups with similar sociocultural backgrounds living in a relatively homogeneous fishing community in southern Portugal were characterized in terms of socioeconomic and sociocultural background variables and compared on a simple neuropsychological test battery; specifically, a literate group with more than 4 years of education (n = 9), a literate group with 4 years of education (n = 26), and an illiterate group (n = 31) were included in this study.We compare and discuss our results with other similar studies on the effects of literacy and illiteracy. The results indicate that naming and identification of real objects, verbal fluency using ecologically relevant semantic criteria, verbal memory, and orientation are not affected by literacy or level of formal education. In contrast, verbal working memory assessed with digit span, verbal abstraction, long-term semantic memory, and calculation (i.e., multiplication) are significantly affected by the level of literacy. We indicate that it is possible, with proper participant-selection procedures, to exclude general cognitive impairment and to control important sociocultural factors that potentially could introduce bias when studying the specific effects of literacy and level of formal education on cognitive brain function.

Abstract

Is there a relation between socioeconomic factors and aphasia severity and recovery? Connor, Obler, Tocco, Fitzpatrick, and Albert (2001) describe correlations between the educational level and socioeconomic status of aphasic subjects with aphasia severity and subsequent recovery. As stated in the introduction by Connor et al. (2001), studies of the influence of educational level and literacy (or illiteracy) on aphasia severity have yielded conflicting results, while no significant link between socioeconomic status and aphasia severity and recovery has been established. In this brief note, we will comment on their findings and conclusions, beginning first with a brief review of literacy and aphasia research, and complexities encountered in these fields of investigation. This serves as a general background to our specific comments on Connor et al. (2001), which will be focusing on methodological issues and the importance of taking normative values in consideration when subjects with different socio-cultural or socio-economic backgrounds are assessed.

Abstract

Four form-preparation experiments investigated whether aspects of phonological encoding processes and representations are shared between languages in bilingual speakers. The participants were Dutch--English bilinguals. Experiment 1 showed that the basic rightward incrementality revealed in studies for the first language is also observed for second-language words. In Experiments 2 and 3, speakers were given words to produce that did or did not share onset segments, and that came or did not come from different languages. It was found that when onsets were shared among the response words, those onsets were prepared, even when the words came from different languages. Experiment 4 showed that preparation requires prior knowledge of the segments and that knowledge about their phonological features yields no effect. These results suggest that both first- and second-language words are phonologically planned through the same serial order mechanism and that the representations of segments common to the languages are shared.

Abstract

This article presents a new account of the color-word Stroop phenomenon ( J. R. Stroop, 1935) based on an implemented model of word production, WEAVER++ ( W. J. M. Levelt, A. Roelofs, & A. S. Meyer, 1999b; A. Roelofs, 1992, 1997c). Stroop effects are claimed to arise from processing interactions within the language-production architecture and explicit goal-referenced control. WEAVER++ successfully simulates 16 classic data sets, mostly taken from the review by C. M. MacLeod (1991), including incongruency, congruency, reverse-Stroop, response-set, semantic-gradient, time-course, stimulus, spatial, multiple-task, manual, bilingual, training, age, and pathological effects. Three new experiments tested the account against alternative explanations. It is shown that WEAVER++ offers a more satisfactory account of the data than other models.

Abstract

Accounts that specify semantic and/or syntactic complexity as the primary determinant of the order in which children acquire particular words or grammatical constructions have been highly influential in the literature on question acquisition. One explanation of wh-question acquisition in particular suggests that the order in which English speaking children acquire wh-questions is determined by two interlocking linguistic factors; the syntactic function of the wh-word that heads the question and the semantic generality (or ‘lightness’) of the main verb (Bloom, Merkin & Wootten, 1982; Bloom, 1991). Another more recent view, however, is that acquisition is influenced by the relative frequency with which children hear particular wh-words and verbs in their input (e.g. Rowland & Pine, 2000). In the present study over 300 hours of naturalistic data from twelve two- to three-year-old children and their mothers were analysed in order to assess the relative contribution of complexity and input frequency to wh-question acquisition. The analyses revealed, first, that the acquisition order of wh-questions could be predicted successfully from the frequency with which particular wh-words and verbs occurred in the children's input and, second, that syntactic and semantic complexity did not reliably predict acquisition once input frequency was taken into account. These results suggest that the relationship between acquisition and complexity may be a by-product of the high correlation between complexity and the frequency with which mothers use particular wh-words and verbs. We interpret the results in terms of a constructivist view of language acquisition.

Abstract

Van Valin (Journal of Child Language29, 2002, 161–75) presents a critique of Rowland & Pine (Journal of Child Language27, 2000, 157–81) and argues that the wh-question data from Adam (in Brown, A first language, Cambridge, MA, 1973) cannot be explained in terms of input frequencies as we suggest. Instead, he suggests that the data can be more successfully accounted for in terms of Role and Reference Grammar. In this note we re-examine the pattern of inversion and uninversion in Adam's wh-questions and argue that the RRG explanation cannot account for some of the developmental facts it was designed to explain.

Abstract

In this article, we present the spatial logistics task (SLOT) platform for investigating multimodal communication between 2 human participants. Presented are the SLOT communication task and the software and hardware that has been developed to run SLOT experiments and record the participants’ multimodal behavior. SLOT offers a high level of flexibility in varying the context of the communication and is particularly useful in studies of the relationship between pen gestures and speech. We illustrate the use of the SLOT platform by discussing the results of some early experiments. The first is an experiment on negotiation with a one-way mirror between the participants, and the second is an exploratory study of automatic recognition of spontaneous pen gestures. The results of these studies demonstrate the usefulness of the SLOT platform for conducting multimodal communication research in both human– human and human–computer interactions.

Abstract

Participants' eye movements were monitored as they heard sentences and saw four pictured objects on a computer screen. Participants were instructed to click on the object mentioned in the sentence. There were more transitory fixations to pictures representing monosyllabic words (e.g. ham) when the first syllable of the target word (e.g. hamster) had been replaced by a recording of the monosyllabic word than when it came from a different recording of the target word. This demonstrates that a phonemically identical sequence can contain cues that modulate its lexical interpretation. This effect was governed by the duration of the sequence, rather than by its origin (i.e. which type of word it came from). The longer the sequence, the more monosyllabic-word interpretations it generated. We argue that cues to lexical-embedding disambiguation, such as segmental lengthening, result from the realization of a prosodic boundary that often but not always follows monosyllabic words, and that lexical candidates whose word boundaries are aligned with prosodic boundaries are favored in the word-recognition process.

Abstract

This letter evaluates potential benefits of combining human speech recognition ~HSR! and automatic speech recognition by building a joint model of an automatic phone recognizer ~APR! and a computational model of HSR, viz., Shortlist @Norris, Cognition 52, 189–234 ~1994!#. Experiments based on ‘‘real-life’’ speech highlight critical limitations posed by some of the simplifying assumptions made in models of human speech recognition. These limitations could be overcome by avoiding hard phone decisions at the output side of the APR, and by using a match between the input and the internal lexicon that flexibly copes with deviations from canonical phonemic representations.

Abstract

In this paper, we present an automatic speech recognition (ASR) system based on the combination of an automatic phone recogniser and a computational model of human speech recognition – SpeM – that is capable of computing ‘word activations’ during the recognition process, in addition to doing normal speech recognition, a task in which conventional ASR architectures only provide output after the end of an utterance. We explain the notion of word activation and show that it can be used for ‘early recognition’, i.e. recognising a word before the end of the word is available. Our ASR system was tested on 992 continuous speech utterances, each containing at least one target word: a city name of at least two syllables. The results show that early recognition was obtained for 72.8% of the target words that were recognised correctly. Also, it is shown that word activation can be used as an effective confidence measure.

Abstract

We have recently developed a new model of human speech recognition, based on automatic speech recognition techniques [1]. The present paper has two goals. First, we show that the new model performs well in the recognition of lexically ambiguous input. These demonstrations suggest that the model is able to operate in the same optimal way as human listeners. Second, we discuss how to relate the behaviour of a recogniser, designed to discover the optimum path through a word lattice, to data from human listening experiments. We argue that this requires a metric that combines both path-based and word-based measures of recognition performance. The combined metric varies continuously as the input speech signal unfolds over time.

Abstract

In this paper, we present a novel computational model of human speech recognition – called SpeM – based on the theory underlying Shortlist. We will show that SpeM, in combination with an automatic phone recogniser (APR), is able to simulate the human speech recognition process from the acoustic signal to the ultimate recognition of words. This joint model takes an acoustic speech file as input and calculates the activation flows of candidate words on the basis of the degree of fit of the candidate words with the input. Experiments showed that SpeM outperforms Shortlist on the recognition of ‘real-life’ input. Furthermore, SpeM performs only slightly worse than an off-the-shelf full-blown automatic speech recogniser in which all words are equally probable, while it provides a transparent computationally elegant paradigm for modelling word activations in human word recognition.

Abstract

During language production and comprehension, information about a word's syntactic properties is sometimes needed. While the decision about the grammatical gender of a word requires access to syntactic knowledge, it has also been hypothesized that semantic (i.e., biological gender) or phonological information (i.e., sound regularities) may influence this decision. Event-related potentials (ERPs) were measured while native speakers of German processed written words that were or were not semantically and/or phonologically marked for gender. Behavioral and ERP results showed that participants were faster in making a gender decision when words were semantically and/or phonologically gender marked than when this was not the case, although the phonological effects were less clear. In conclusion, our data provide evidence that even though participants performed a grammatical gender decision, this task can be influenced by semantic and phonological factors.

Abstract

This study investigated the time course of phonological encoding during speech production planning. Previous research has shown that conceptual/semantic information precedes syntactic information in the planning of speech production and that syntactic information is available earlier than phonological information. Here, we studied the relative time courses of the two different processes within phonological encoding, i.e. metrical encoding and syllabification. According to one prominent theory of language production, metrical encoding involves the retrieval of the stress pattern of a word, while syllabification is carried out to construct the syllabic structure of a word. However, the relative timing of these two processes is underspecified in the theory. We employed an implicit picture naming task and recorded event-related brain potentials to obtain fine-grained temporal information about metrical encoding and syllabification. Results revealed that both tasks generated effects that fall within the time window of phonological encoding. However, there was no timing difference between the two effects, suggesting that they occur approximately at the same time.

Abstract

In this study, we investigated grammatical feature selection during noun phrase production in German and Dutch. More specifically, we studied the conditions under which different grammatical genders select either the same or different determiners or suffixes. Pictures of one or two objects paired with a gender-congruent or a gender-incongruent distractor word were presented. Participants named the pictures using a singular or plural noun phrase with the appropriate determiner and/or adjective in German or Dutch. Significant effects of gender congruency were only obtained in the singular condition where the selection of determiners is governed by the target’s gender, but not in the plural condition where the determiner is identical for all genders. When different suffixes were to be selected in the gender-incongruent condition, no gender congruency effect was obtained. The results suggest that the so-called gender congruency effect is really a determiner congruency effect. The overall pattern of results is interpreted as indicating that grammatical feature selection is an automatic consequence of lexical node selection and therefore not subject to interference from other grammatical features. This implies that lexical node and grammatical feature selection operate with distinct principles.

Abstract

This study investigated the encoding of metrical information during speech production in Dutch. In Experiment 1, participants were asked to judge whether bisyllabic picture names had initial or final stress. Results showed significantly faster decision times for initially stressed targets (e.g., LEpel 'spoon') than for targets with final stress (e.g., liBEL 'dragon fly'; capital letters indicate stressed syllables) and revealed that the monitoring latencies are not a function of the picture naming or object recognition latencies to the same pictures. Experiments 2 and 3 replicated the outcome of the first experiment with bi- and trisyllabic picture names. These results demonstrate that metrical information of words is encoded rightward incrementally during phonological encoding in speech production. The results of these experiments are in line with Levelt's model of phonological encoding.

Abstract

The basic idea behind this task is to find out how languages encode basic shape distinctions such as dimensionality, axial geometry, relative size, etc. More specifically, we want to find out (i) which formal means are used cross linguistically to encode basic shape distinctions, and (ii) which are the semantic distinctions that are made in this domain. In languages with many shape-classifiers, these distinctions are encoded (at least partially) in classifiers. In other languages, positional verbs, descriptive modifiers, such as “flat”, “round”, or nouns such as “cube”, “ball”, etc. might be the preferred means. In this context, we also want to investigate what other “grammatical work” shapeencoding expressions possibly do in a given language, e.g. unitization of mass nouns, or anaphoric uses of shape-encoding classifiers, etc. This task further seeks to determine the role of shape-related parameters which underlie the design of objects in the semantics of the system under investigation.

Abstract

This project aims to investigate how speakers of various languages in indigenous cultures verbally reason about moral issues. The ways in which a solution for a moral problem is found, phrased and justified will be taken as the basis for researching reasoning processes that manifest themselves verbally in the speakers’ arguments put forward to solve a number of moral problems which will be presented to them in the form of unfinished story plots or scenarios that ask for a solution. The plots chosen attempt to present common problems in human society and human behaviour. They should function to elicit moral discussion and/or moral arguments in groups of consultants of at least three persons.

Abstract

Three experiments examined whether infants recognise functors in phrases, and whether their representations of functors are phonetically well specified. Eight- and 13- month-old English infants heard monosyllabic lexical words preceded by real functors (e.g., the, his) versus nonsense functors (e.g., kuh); the latter were minimally modified segmentally (but not prosodically) from real functors. Lexical words were constant across conditions; thus recognition of functors would appear as longer listening time to sequences with real functors. Eightmonth- olds' listening times to sequences with real versus nonsense functors did not significantly differ, suggesting that they did not recognise real functors, or functor representations lacked phonetic specification. However, 13-month-olds listened significantly longer to sequences with real functors. Thus, somewhere between 8 and 13 months of age infants learn familiar functors and represent them with segmental detail. We propose that accumulated frequency of functors in input in general passes a critical threshold during this time.

Abstract

A t(X;1)(p11.2;q21.2) has been reported in cases of papillary renal cell tumors arising in males. In this study two cell lines derived from this tumor type have been used to indicate the breakpoint region on the X chromosome. Both cell lines have the translocation in addition to other rearrangements and one is derived from the first female case to be reported with the t(X;1)(p11.2;q21.2). Fluorescence in situ hybridization (FISH) has been used to position YACs belonging to contigs in the Xp11.2 region relative to the breakpoint. When considered together with detailed mapping information from the Xp11.2 region the position of the breakpoint in both cell lines was suggested as follows: Xpter-->Xp11.23-OATL1-GATA1-WAS-TFE3-SY P-t(X;1)-DXS255-CLCN5-DXS146-OATL2- Xp11.22-->Xcen. The breakpoint was determined to lie in an uncloned region between SYP and a YAC called FTDM/1 which extends 1 Mb distal to DXS255. These results are contrary to the conclusion from previous FISH studies that the breakpoint was near the OATL2 locus, but are consistent with, and considerably refine, the position that had been established by molecular analysis.

Abstract

The present experiment tested the suggestion that human listeners may exploit durational information in speech to parse continuous utterances into words. Listeners were presented with six-syllable unpredictable utterances under noise-masking, and were required to judge between alternative word strings as to which best matched the rhythm of the masked utterances. For each utterance there were four alternative strings: (a) an exact rhythmic and word boundary match, (b) a rhythmic mismatch, and (c) two utterances with the same rhythm as the masked utterance, but different word boundary locations. Listeners were clearly able to perceive the rhythm of the masked utterances: The rhythmic mismatch was chosen significantly less often than any other alternative. Within the three rhythmically matched alternatives, the exact match was chosen significantly more often than either word boundary mismatch. Thus, listeners both perceived speech rhythm and used durational cues effectively to locate the position of word boundaries.

Abstract

We present the results of a large-scale study on speech perception, assessing the number and type of perceptual hypotheses which listeners entertain about possible phoneme sequences in their language. Dutch listeners were asked to identify gated fragments of all 1179 diphones of Dutch, providing a total of 488 520 phoneme categorizations. The results manifest orderly uptake of acoustic information in the signal. Differences across phonemes in the rate at which fully correct recognition was achieved arose as a result of whether or not potential confusions could occur with other phonemes of the language ~long with short vowels, affricates with their initial components, etc.!. These data can be used to improve models of how acoustic phonetic information is mapped onto the mental lexicon during speech comprehension.

Abstract

Spoken language comprehension requires rapid integration of information from multiple linguistic sources. In the present study we addressed the temporal aspects of this integration process by focusing on the time course of the selection of the appropriate meaning of lexical ambiguities (“bank”) in sentence contexts. Successful selection of the contextually appropriate meaning of the ambiguous word is dependent upon the rapid binding of the contextual information in the sentence to the appropriate meaning of the ambiguity. We used the N400 to identify the time course of this binding process. The N400 was measured to target words that followed three types of context sentences. In the concordant context, the sentence biased the meaning of the sentence-final ambiguous word so that it was related to the target. In the discordant context, the sentence context biased the meaning so that it was not related to the target. In the unrelated control condition, the sentences ended in an unambiguous noun that was unrelated to the target. Half of the concordant sentences biased the dominant meaning, and the other half biased the subordinate meaning of the sentence-final ambiguous words. The ISI between onset of the target word and offset of the sentence-final word of the context sentence was 100 ms in one version of the experiment, and 1250 ms in the second version. We found that (i) the lexically dominant meaning is always partly activated, independent of context, (ii) initially both dominant and subordinate meaning are (partly) activated, which suggests that contextual and lexical factors both contribute to sentence interpretation without context completely overriding lexical information, and (iii) strong lexical influences remain present for a relatively long period of time.

Abstract

Although infants show remarkable sensitivity to linguistically relevant phonetic variation in speech, young children sometimes appear not to make use of this sensitivity. Here, children's knowledge of the sound-forms of familiar words was assessed using a visual fixation task. Dutch 19-month-olds were shown pairs of pictures and heard correct pronunciations and mispronunciations of familiar words naming one of the pictures. Mispronunciations were word-initial in Experiment 1 and word-medial in Experiment 2, and in both experiments involved substituting one segment with [d] (a common sound in Dutch) or [g] (a rare sound). In both experiments, word recognition performance was better for correct pronunciations than for mispronunciations involving either substituted consonant. These effects did not depend upon children's knowledge of lexical or nonlexical phonological neighbors of the tested words. The results indicate the encoding of phonetic detail in words at 19 months.

Abstract

The roles which word class (open/closed) and sentential stress play in the sentence comprehension processes of both agrammatic (Broca's) aphasics and normal listeners were examined with a word monitoring task. Overall, normal listeners responded more quickly to stressed than to unstressed items, but showed no effect of word class. Aphasics also responded more quickly to stressed than to unstressed materials, but, unlike the normals, responded faster to open than to closed class words regardless of their stress. The results are interpreted as support for the theory that Broca's aphasics lack the functional underlying open/closed class word distinction used in word recognition by normal listeners.

Abstract

This paper discusses the development of an orthography for the Touo language (Solomon Islands). Various orthographies have been proposed for this language in the past, and the paper discusses why they are perceived by the community to have failed. Current opinion about orthography development within the Touo-speaking community is divided along religious, political, and geographical grounds; and the development of a successful orthography must take into account a variety of opinions. The paper examines the social, historical, and linguistic obstacles that have hitherto prevented the development of an accepted Touo orthography, and presents a new proposal which has thus far gained acceptance with community leaders. The fundamental issue is that creating an orthography for a language takes place in a social, political, and historical context; and for an orthography to be acceptable for the speakers of a language, all these factors must be taken into account.

Abstract

The extent to which linguistic borrowing can be used to shed light on the existence and nature of early contact between Papuan and Oceanic speakers is examined. The question is addressed by taking one Papuan language, Lavukaleve, spoken in the Russell Islands, central Solomon Islands and examining lexical borrowings between it and nearby Oceanic languages, and with reconstructed forms of Proto Oceanic. Evidence from ethnography, culture history and archaeology, when added to the linguistic evidence provided in this study, indicates long-standing cultural links between other (non-Russell) islands. The composite picture is one of a high degree of cultural contact with little linguistic mixing, i.e., little or no changes affecting the structure of the languages and actually very little borrowed vocabulary.

Abstract

Repeated exposure to objects improves our ability to identify and name them, even after a long delay. Previous brain imaging studies have demonstrated that this experience-related facilitation of object naming is associated with neural changes in distinct brain regions. We used event-related functional magnetic resonance imaging (fMRI) to examine the modulation of neural activity in the object naming system as a function of experience and time. Pictures of common objects were presented repeatedly for naming at different time intervals (1 h, 6 h and 3 days) before scanning, or at 30 s intervals during scanning. The results revealed that as objects became more familiar with experience, activity in occipitotemporal and left inferior frontal regions decreased while activity in the left insula and basal ganglia increased. In posterior regions, reductions in activity as a result of multiple repetitions did not interact with time, whereas in left inferior frontal cortex larger decreases were observed when repetitions were spaced out over time. This differential modulation of activity in distinct brain regions provides support for the idea that long-lasting object priming is mediated by two neural mechanisms. The first mechanism may involve changes in object-specific representations in occipitotemporal cortices, the second may be a form of procedural learning involving a reorganization in brain circuitry that leads to more efficient name retrieval.

Abstract

In two ERP experiments, we assessed the impact of discourse-level information on the processing of an unfolding spoken sentence. Subjects listened to sentences like Jane told her brother that he was exceptionally quick/slow, designed such that the alternative critical words were equally acceptable within the local sentence context. In Experiment 1, these sentences were embedded in a discourse that rendered one of the critical words anomalous (e.g. because Jane’s brother had in fact done something very quickly). Relative to the coherent alternative, these discourse-anomalous words elicited a standard N400 effect that started at 150–200 ms after acoustic word onset. Furthermore, when the same sentences were heard in isolation in Experiment 2, the N400 effect disappeared. The results demonstrate that our listeners related the unfolding spoken words to the wider discourse extremely rapidly, after having heard the first two or three phonemes only, and in many cases well before the end of the word. In addition, the identical nature of discourse- and sentence-dependent N400 effects suggests that from the perspective of the word-elicited comprehension process indexed by the N400, the interpretive context delineated by a single unfolding sentence and a larger discourse is functionally identical.

Abstract

This Field Manual entry has been superceded by the published version: Van Staden, M., & Majid, A. (2006). Body colouring task. Language Sciences, 28(2-3), 158-161. doi:10.1016/j.langsci.2005.11.004.

Abstract

An introductory study of the perception of stochastically specified events is reported. The initial problem was to determine whether the perceiver can split visual input data of this kind into random and determined components. The inability of subjects to do so with the stimulus material used (a filmlike sequence of dot patterns), led to the more general question of how subjects code this kind of visual material. To meet the difficulty of defining the subjects' responses, two experiments were designed. In both, patterns were presented as a rapid sequence of dots on a screen. The patterns were more or less disturbed by “noise,” i.e. the dots did not appear exactly at their proper places. In the first experiment the response was a rating on a semantic scale, in the second an identification from among a set of alternative patterns. The results of these experiments give some insight in the coding systems adopted by the subjects. First, noise appears to be detrimental to pattern recognition, especially to patterns with little spread. Second, this shows connections with the factors obtained from analysis of the semantic ratings, e.g. easily disturbed patterns show a large drop in the semantic regularity factor, when only a little noise is added.

Abstract

In two experiments, we explored the use of event-related brain potentials to selectively track the processes that establish reference during spoken language comprehension. Subjects listened to stories in which a particular noun phrase like "the girl" either uniquely referred to a single referent mentioned in the earlier discourse, or ambiguously referred to two equally suitable referents. Referentially ambiguous nouns ("the girl" with two girls introduced in the discourse context) elicited a frontally dominant and sustained negative shift in brain potentials, emerging within 300–400 ms after acoustic noun onset. The early onset of this effect reveals that reference to a discourse entity can be established very rapidly. Its morphology and distribution suggest that at least some of the processing consequences of referential ambiguity may involve an increased demand on memory resources. Furthermore, because this referentially induced ERP effect is very different from that of well-known ERP effects associated with the semantic (N400) and syntactic (e.g., P600/SPS) aspects of language comprehension, it suggests that ERPs can be used to selectively keep track of three major processes involved in the comprehension of an unfolding piece of discourse.