Presentations

Abstract

In sentence comprehension, readers and listeners often anticipate upcoming information (e.g., Altmann & Kamide, 1999). We investigated two aspects of this process, namely 1) what is pre-activated when anticipating an upcoming word (the contents of predictions), and 2) which cognitive mechanisms are involved. The contents of predictions at the level of meaning could be restricted to functional semantic attributes (e.g., edibility; Altmann & Kamide, 1999). However, when words are processed other types of information can also be activated, such as object shape representations. It is unknown whether this type of information is already activated when upcoming words are predicted. Forty-five adult participants listened to predictable words in sentence contexts (e.g., "In 1969 Neil Armstrong was the first man to set foot on the moon.") while looking at visual displays of four objects. Their eye movements were recorded. There were three conditions: target present (e.g., a moon and three distractor objects that were unrelated to the predictable word in terms of semantics, shape, and phonology), shape competitor (e.g., a tomato and three unrelated distractors), and distractors only (e.g., rice and three other unrelated objects). Across lists, the same pictures and sentences were used in the different conditions. We found that participants already showed a significant bias for the target object (moon) over unrelated distractors several seconds before the target was mentioned, demonstrating that they were predicting. Importantly, there was also a smaller but significant shape competitor (tomato) preference starting at about a second before critical word onset, consistent with predictions involving the referent’s shape. The mechanisms of predictions could be specific to language tasks, or language could use processing principles that are also used in other domains of cognition. We investigated whether performance in non-linguistic prediction is related to prediction in language processing, taking an individual differences approach. In addition to the language processing task, the participants performed a simple cueing task (after Posner, Nissen, & Ogden, 1978). They pressed one of two buttons (left/right) to indicate the location of an X symbol on the screen. On half of the trials, the X was preceded by a neutral cue (+). On the other half, an arrow cue pointing left (<) or right (>) indicated the upcoming X's location with 80% validity (i.e., the arrow cue was correct 80% of the time). The SOA between cue and target was 500 ms. Prediction was quantified as the mean response latency difference between the neutral and valid condition. This measure correlated positively with individual participants' anticipatory target and shape competitor preference (r = .27; r = .45), and was a significant predictor of anticipatory looks in linear mixed-effects regression models of the data. Participants who showed more facilitation from the arrow cues predicted to a higher degree in the linguistic task. This suggests that prediction in language processing may use mechanisms that are also used in other domains of cognition. References Altmann, G. T. M., & Kamide, Y. (1999). Incremental interpretation at verbs: Restricting the domain of subsequent reference. Cognition, 73(3), 247-264. Posner, M. I., Nissen, M. J., & Ogden, W. C. (1978). Attended and unattended processing modes: The role of set for spatial location. In: H.L. Pick, & I.J. Saltzman (Eds.), Modes of perceiving and processing information. Hillsdale, N.J.: Lawrence Erlbaum Associates.

Abstract

Hub-and-spoke models of semantic processing which integrate modality specific information within a central resource have proven successful in capturing a range of neuropsychological phenomena (Rogers et al, 2004; Dilkina et al, 2008). Within our study we investigate whether the scope of the Hub-and-spoke architectural framework can be extended to capture behavioural phenomena in other areas of cognition. The visual world paradigm (VWP) has contributed significantly to our understanding of the information and processes involved in spoken word recognition. In particular it has highlighted the importance of non-linguistic influences during language processing, indicating that combined information from vision, phonology, and semantics is evident in performance on such tasks (see Huettig, Rommers & Meyer, 2011). Huettig & McQueen (2007) demonstrated that participants’ fixations to objects presented within a single visual display varied systematically according to their phonological, semantic and visual relationship to a spoken target word. The authors argue that only an explanation allowing for influence from all three knowledge types is capable of accounting for the observed behaviour. To date computational models of the VWP (Allopenna et al, 1998; Mayberry et al, 2009; Kukona et al, 2011) have focused largely on linguistic aspects of the task and have therefore been unable to offer explanations for the growing body of experimental evidence emphasising the influence of non-linguistic information on spoken word recognition. Our study demonstrates that an emergent connectionist model, based on the Hub-and-spoke models of semantic processing, which integrates visual, phonological and functional information within a central resource, is able to capture the intricate time course dynamics of eye fixation behaviour reported in Huettig & McQueen (2007). Our findings indicate that such language mediated visual attention phenomena can emerge largely due to the statistics of the problem domain and may not require additional domain specific processing constraints.

Abstract

Existing computational models of the Visual World Paradigm (VWP) have simulated the connection between language processing and eye gaze behavior, and consequently have provided insight into the cognitive processes underlying lexical and sentence comprehension. Allopenna, Magnuson and Tanenhaus (1998), demonstrated that fixation probabilities during spoken word processing can be predicted by lexical activations in the TRACE model of spoken word recognition. Recent computational models have extended this work to predict fixation behavior during sentence processing from the integration of visual and linguistic information. Recent empirical investigation of word level effects in VWP support claims that language mediated eye gaze is not only influenced by overlap at a phonological level (Allopenna, Magnuson & Tanenhaus, 1998) but also by relationships in terms of visual and semantic similarity. Huettig and McQueen (2007) found that when participants heard a word and viewed a scene containing objects phonologically, visually, or semantically similar to the target, then all competitors exerted an effect on fixations, but fixations to phonological competitors preceded those to other competitors. Current models of VWP that simulate the interaction between visual and linguistic information do so with representations that are unable to capture fine-grained semantic, phonological or visual feature relationships. They are therefore limited in their ability to examine effects of multimodal interactions in language processing. Our research extends that of previous models by implementing representations in each modality that are sufficiently rich to capture similarities and distinctions in visual, phonological and semantic representations. Our starting point was to determine the extent to which multimodal interactions between these modalities in the VWP would be emergent from the nature of the representations themselves, rather than determined by architectural constraints. We constructed a recurrent connectionist model, based on Hub-and-spoke models of semantic processing, which integrates visual, phonological and semantic information within a central resource. We trained and tested the model on viewing scenes as in Huettig and McQueen’s (2007) study, and found that the model replicated the complex behaviour and time course dynamics of multimodal interaction, such that the model activated phonological competitors prior to activating visual and semantic competitors. Our approach enables us to determine that differences in the computational properties of each modality’s representational structure is sufficient to produce behaviour consistent with the VWP. The componential nature of phonological representations and the holistic structure of visual and semantic representations result in fixations to phonological competitors preceding those to other competitors. Our findings suggest such language-mediated visual attention phenomena can emerge due to the statistics of the problem domain, with observed behaviour emerging as a natural consequence of differences in the structure of information within each modality, without requiring additional modality specific architectural constraints.

Abstract

Sinking about boats and brains: activation of word meaning in foreign-accented speech by native and non-native listeners Andrea Weber, Meghan Sumner, Andrea Krott, Falk Huettig, Adriana Hanulikova Understanding foreign-accented speech requires from listeners the correct interpretation of segmental variation as in German-accented [s]eft for English theft. The task difficulty increases when the accented word forms resemble existing words as in [s]ink for think. In two English priming experiments, we investigated the activation of the meanings of intended and unintended words by accented primes. American native (L1) and German non-native (L2) participants listened to auditory primes followed by visual targets to which they made lexical decisions. Primes were produced by a native German speaker and were either nonsense words ([s]eft for theft), unintended words ([s]ink for think), or words in their canonical forms (salt for salt). Furthermore, primes were strongly associated to targets, with the co-occurrence being high either between the surface form of the prime and the target ([s]ink-BOAT, salt-PEPPER) or the underlying form and the target ([s]ink-BRAIN, seft-PRISON). L1 listeners responded faster when the underlying form was associated with the target (in comparison to unrelated primes), but L2 listeners responded faster when the surface form was associated. Seemingly, L1 listeners interpreted all primes as being mispronounced – facilitating the activation of think when hearing the unintended word [s]ink, but erroneously preventing the activation of salt when hearing the canonical form salt. L2 listeners, though, took primes at face value and failed to activate the meaning of think when hearing [s]ink but did activate the meaning of salt when hearing salt. This asymmetry suggests an interesting difference in the use of high-level information, with L1 listeners, but not L2 listeners, using knowledge about segmental variations for immediate meaning activation.

Abstract

A wealth of research has demonstrated that prediction is a core feature of human information processing. Much less is known, however, about the nature and the extent of predictive processing abilities. Here we investigated whether high levels of language expertise attained through formal literacy are related to anticipatory language-mediated visual orienting. Indian low and high literates listened to simple spoken sentences containing a target word (e.g., "door") while at the same time looking at a visual display of four objects (a target, i.e. the door, and three distractors). The spoken sentences were constructed to encourage anticipatory eye movements to visual target objects. High literates started to shift their eye gaze to the target object well before target word onset. In the low literacy group this shift of eye gaze occurred more than a second later, well after the onset of the target. Our findings suggest that formal literacy is crucial for the fine-tuning of language-mediated anticipatory mechanisms, abilities which proficient language users can then exploit for other cognitive activities such as language-mediated visual orienting.

Abstract

Eye movements made by listeners during language-mediated visual search reveal a strong link between visual processing and conceptual processing. For example, upon hearing the word for a missing referent with a characteristic colour (e.g., “strawberry”), listeners tend to fixate a colour-matched distractor (e.g., a red plane) more than a colour-mismatched distractor (e.g., a yellow plane). We ask whether these shifts in visual attention are mediated by the retrieval of lexically stored colour labels. Do children who do not yet possess verbal labels for the colour attribute that spoken and viewed objects have in common exhibit language-mediated eye movements like those made by older children and adults? That is, do toddlers look at a red plane when hearing “strawberry”? We observed that 24-month-olds lacking colour-term knowledge nonetheless recognised the perceptual-conceptual commonality between named and seen objects. This indicates that language-mediated visual search need not depend on stored labels for concepts.

Abstract

How do listeners recognize reduced forms that occur in spontaneous speech, such as “puter” for “computer”? To this end, eye-tracking experiments were performed in which participants heard a sentence and saw four printed words on a computer screen. The auditory stimuli contained canonical and reduced forms from a spontaneous speech corpus in different amounts of linguistic context. The four printed words were a “canonical form” competitor e.g., “companion”, phonologically similar to “computer”, a “reduced form” competitor e.g., “pupil”, phonologically similar to “puter” and two unrelated distractors. The results showed, first, that reduction inhibits word recognition overall. Second, listeners look more often to the “reduced form” competitor than to the “canonical form” competitor when reduced forms are presented in isolation or in a phonetic context. In full context, however, both competitors attracted looks: early rise of the “reduced form” competitor and late rise of the “canonical form” competitor. This “late rise” of the “canonical form” competitor was not observed when we replaced the original /p/ from “puter” with a real onset /p/. This indicates that phonetic detail and semantic/syntactic context are necessary for the recognition of reduced forms.

Abstract

Language processing does not take place in isolation from the sensory environment. Listeners are able to recognise spoken words in many different situations, ranging from carefully articulated and noise-free laboratory speech, through casual conversational speech in a quiet room, to degraded conversational speech in a busy train-station. For listeners to be able to recognize speech optimally in each of these listening situations, they must be able to adapt to the constraints of each situation. We investigated this flexibility by comparing the dynamics of the spoken-word recognition process in clear speech and speech disrupted by radio noise. In Experiment 1, Dutch participants listened to clearly articulated spoken Dutch sentences which each included a critical word while their eye movements to four visual objects presented on a computer screen were measured. There were two critical conditions. In the first, the objects included a cohort competitor (e.g., parachute, “parachute”) with the same onset as the critical spoken word (e.g., paraplu, “umbrella”) and three unrelated distractors. In the second condition, a rhyme competitor (e.g., hamer, “hammer”) of the critical word (e.g., kamer, “room”) was present in the display, again with three distractors. To maximize competitor effects pictures of the critical words themselves were not present in the displays on the experimental trials (e.g.,there was no umbrella in the display with the 'paraplu' sentence) and a passive listening task was used (Huettig McQueen, 2007). Experiment 2 was identical to Experiment 1 except that phonemes in the spoken sentences were replaced with radio-signal noises (as in AM radio listening conditions). In each sentence, two,three or four phonemes were replaced with noises. The sentential position of these replacements was unpredictable, but the adjustments were always made to onset phonemes. The critical words (and the immediately surrounding words) were not changed. The question was whether listeners could learn that, under these circumstances, onset information is less reliable. We predicted that participants would look less at the cohort competitors (the initial match to the competitor is less good) and more at the rhyme competitors (the initial mismatch is less bad). We observed a significant experiment by competitor type interaction. In Experiment 1 participants fixated both kinds competitors more than unrelated distractors, but there were more and earlier looks to cohort competitors than to rhyme competitors (Allopenna et al., 1998). In Experiment 2 participants still fixated cohort competitors more than rhyme competitors but the early cohort effect was reduced and the rhyme effect was stronger and occurred earlier. These results suggest that AM radio noise changes the dynamics of spoken word recognition. The well-attested finding of stronger reliance on word onset overlap in speech recognition appears to be due in part to the use of clear speech in most experiments. When onset information becomes less reliable, listeners appear to depend on it less. A core feature of the speech-recognition system thus appears to be its flexibility. Listeners are able to adjust the perceptual weight they assign to different parts of incoming spoken language.

Abstract

If a Mandarin speaker had walked past two rivers and wished to describe how many he had seen, he would have to say “two tiao river”, where tiao designates long, rope-like objects such as rivers, snakes and legs. Tiao is one of several hundred classifiers – a grammatical category in Mandarin. In two eye-tracking studies we presented Mandarin speakers with simple Mandarin sentences through headphones while monitoring their eye-movements to objects presented on a computer monitor. The crucial question is what participants look at while listening to a pre-specified target noun. If classifier categories influence general conceptual processing then on hearing the target noun participants should look at objects that are also members of the same classifier category – even when the classifier is not explicitly present. For example, on hearing scissors, Mandarin speakers should look more at a picture of a chair than at an unrelated object because scissors and chair share the classifier ba. This would be consistent with a Strong Whorfian position, according to which language is a major determinant in shaping conceptual thought (Sapir, 1921; Whorf, 1956). A weaker influence of language-on-thought could be predicted, where language shapes cognitive processing, but only when the language-specific category is actively being processed (Slobin, 1996). According to this account, eye-movements are not necessarily drawn to chair when a participant hears scissors, but they would be on hearing ba scissors. This is because hearing ba activates the linguistic category that both scissors and chair belong to. A third logical possibility is that classifiers are purely formal markers (cf. Greenberg, 1972; Lehman, 1979) that do not influence attentional processing even when they are explicitly present. The data showed that when participants heard a spoken word from the same classifier category as a visually depicted object (e.g. scissors-chair), but the classifier was not explicitly presented in the speech, overt attention to classifier-match objects (e.g. chair) and distractor objects did not differ (Experiment 1). But when the classifier was explicitly presented (e.g. ba, Experiment 2), participants shifted overt attention significantly more to classifier-match objects (e.g. chair) than to distractors. These data are incompatible with the Strong Whorfian hypothesis. Instead the findings support the Weak Whorfian hypothesis that linguistic distinctions force attention to properties of the world but only during active linguistic processing of that distinction (cf. Slobin, 1996).