Publications

Abstract

Contemporary accounts of anticipatory language processing assume that individuals predict upcoming information at multiple levels of representation. Research investigating language-mediated anticipatory eye gaze typically assumes that linguistic input restricts the domain of subsequent reference (visual target objects). Here, we explored the converse case: Can visual input restrict the dynamics of anticipatory language processing? To this end, we recorded participants’ eye movements as they listened to sentences in which an object was predictable based on the verb’s selectional restrictions (“The man peels a banana”). While listening, participants looked at different types of displays: The target object (banana) was either present or it was absent. On target-absent trials, the displays featured objects that had a similar visual shape as the target object (canoe) or objects that were semantically related to the concepts invoked by the target (monkey). Each trial was presented in a long preview version, where participants saw the displays for approximately 1.78 seconds before the verb was heard (pre-verb condition), and a short preview version, where participants saw the display approximately 1 second after the verb had been heard (post-verb condition), 750 ms prior to the spoken target onset. Participants anticipated the target objects in both conditions. Importantly, robust evidence for predictive looks to objects related to the (absent) target objects in visual shape and semantics was found in the post-verb but not in the pre-verb condition. These results suggest that visual information can restrict language-mediated anticipatory gaze and delineate theoretical accounts of predictive processing in the visual world.

Abstract

Previous studies have shown that during comprehension readers activate words beyond the unfolding sentence. An open question concerns the mechanisms underlying this behavior. One proposal is that readers mentally simulate the described event and activate related words that might be referred to as the discourse further unfolds. Another proposal is that activation between words spreads in an automatic, associative fashion. The empirical support for these proposals is mixed. Therefore, theoretical accounts differ with regard to how much weight they place on the contributions of these sources to sentence comprehension. In the present study, we attempted to assess the contributions of event simulation and lexical associations to discourse reading, using event-related brain potentials (ERPs). Participants read target words, which were preceded by associatively related words either appearing in a coherent discourse event (Experiment 1) or in sentences that did not form a coherent discourse event (Experiment 2). Contextually unexpected target words that were associatively related to the described events elicited a reduced N400 amplitude compared to contextually unexpected target words that were unrelated to the events (Experiment 1). In Experiment 2, a similar but reduced effect was observed. These findings support the notion that during discourse reading event simulation and simple word associations jointly contribute to language comprehension by activating words that are beyond contextually congruent sentence continuations.

Abstract

A main challenge for theories of embodied cognition is to understand the task dependency of embodied language processing. One possibility is that perceptual representations (e.g., typical colour of objects mentioned in spoken sentences) are not activated routinely but the influence of perceptual representation emerges only when context strongly supports their involvement in language. To explore this question, we tested the effects of colour representations during language processing in three visual- world eye-tracking experiments. On critical trials, participants listened to sentence- embedded words associated with a prototypical colour (e.g., ‘...spinach...’) while they inspected a visual display with four printed words (Experiment 1), coloured or greyscale line drawings (Experiment 2) and a ‘blank screen’ after a preview of coloured or greyscale line drawings (Experiment 3). Visual context always presented a word/object (e.g., frog) associated with the same prototypical colour (e.g. green) as the spoken target word and three distractors. When hearing spinach participants did not prefer the written word frog compared to other distractor words (Experiment 1). In Experiment 2, colour competitors attracted more overt attention compared to average distractors, but only for the coloured condition and not for greyscale trials. Finally, when the display was removed at the onset of the sentence, and in contrast to the previous blank-screen experiments with semantic competitors, there was no evidence of colour competition in the eye-tracking record (Experiment 3). These results fit best with the notion that the main role of perceptual representations in language processing is to contextualize language in the immediate environment.

Abstract

Composing sentence meaning is easier for predictable words than for unpredictable words. Are predictable words genuinely predicted, or simply more plausible and therefore easier to integrate with sentence context? We addressed this persistent and fundamental question using data from a recent, large-scale (N = 334) replication study, by investigating the effects of word predictability and sentence plausibility on the N400, the brain’s electrophysiological index of semantic processing. A spatiotemporally fine-grained mixed-effects multiple regression analysis revealed overlapping effects of predictability and plausibility on the N400, albeit with distinct spatiotemporal profiles. Our results challenge the view that the predictability-dependent N400 reflects the effects of either prediction or integration, and suggest that semantic facilitation of predictable words arises from a cascade of processes that activate and integrate word meaning with context into a sentence-level meaning.

Abstract

In two eye-tracking experiments we examined whether wider discourse information helps
the recognition of reduced pronunciations (e.g., 'puter') more than the recognition of
canonical pronunciations of spoken words (e.g., 'computer'). Dutch participants listened to
sentences from a casual speech corpus containing canonical and reduced target words. Target
word recognition was assessed by measuring eye fixation proportions to four printed words
on a visual display: the target, a "reduced form" competitor, a "canonical form" competitor
and an unrelated distractor. Target sentences were presented in isolation or with a wider
discourse context. Experiment 1 revealed that target recognition was facilitated by wider
discourse information. Importantly, the recognition of reduced forms improved significantly
when preceded by strongly rather than by weakly supportive discourse contexts. This was not
the case for canonical forms: listeners' target word recognition was not dependent on the
degree of supportive context. Experiment 2 showed that the differential context effects in
Experiment 1 were not due to an additional amount of speaker information. Thus, these data
suggest that in natural settings a strongly supportive discourse context is more important for
the recognition of reduced forms than the recognition of canonical forms.

Abstract

The Perceptual Loop Theory of speech monitoring assumes that speakers routinely inspect their inner speech. In contrast, Huettig and Hartsuiker (2010) observed that listening to one’s own speech during language production drives eye-movements to phonologically related printed words with a similar time-course as listening to someone else’s speech does in speech perception experiments. This suggests that speakers listen to their own overt speech, but not to their inner speech. However, a direct comparison between production and perception with the same stimuli and participants is lacking so far. The current printed word eye-tracking experiment therefore used a within-subjects design, combining production and perception. Displays showed four words, of which one, the target, either had to be named or was presented auditorily. Accompanying words were phonologically related, semantically related, or unrelated to the target. There were small increases in looks to phonological competitors with a similar time-course in both production and perception. Phonological effects in perception however lasted longer and had a much larger magnitude. We conjecture that this difference is related to a difference in predictability of one’s own and someone else’s speech, which in turn has consequences for lexical competition in other-perception and possibly suppression of activation in self-perception.

Abstract

Although we agree with Pickering & Garrod (P&G) that prediction-by-simulation and prediction-by-association are important mechanisms of anticipatory language processing, this commentary suggests that they: (1) overlook other potential mechanisms that might underlie prediction in language processing, (2) overestimate the importance of prediction-by-association in early childhood, and (3) underestimate the complexity and significance of several factors that might mediate prediction during language processing.

Abstract

What is the relative salience of different aspects of word meaning in the developing lexicon? The current study examines the time-course of retrieval of semantic and color knowledge associated with words during toddler word recognition: at what point do toddlers orient towards an image of a yellow cup upon hearing color-matching words such as “banana” (typically yellow) relative to unrelated words (e.g., “house”)? Do children orient faster to semantic matching images relative to color matching images, e.g., orient faster to an image of a cookie relative to a yellow cup upon hearing the word “banana”? The results strongly suggest a prioritization of semantic information over color information in children’s word-referent mappings. This indicates that, even for natural objects (e.g., food, animals that are more likely to have a prototypical color), semantic knowledge is a more salient aspect of toddler's word meaning than color knowledge. For 24-month-old Dutch toddlers, bananas are thus more edible than they are yellow.

Abstract

Recent eye-tracking research has revealed that spoken language can guide eye gaze very rapidly (and closely time-locked to the unfolding speech) toward referents in the visual world. We discuss whether, and to what extent, such language-mediated eye movements are automatic rather than subject to conscious and controlled decision-making. We consider whether language-mediated eye movements adhere to four main criteria of automatic behavior, namely, whether they are fast and efficient, unintentional, unconscious, and overlearned (i.e., arrived at through extensive practice). Current evidence indicates that language-driven oculomotor behavior is fast but not necessarily always efficient. It seems largely unintentional though there is also some evidence that participants can actively use the information in working memory to avoid distraction in search. Language-mediated eye movements appear to be for the most part unconscious and have all the hallmarks of an overlearned behavior. These data are suggestive of automatic mechanisms linking language to potentially referred-to visual objects, but more comprehensive and rigorous testing of this hypothesis is needed.

Abstract

The role of visual representations during language processing remains unclear: They could be activated as a necessary part of the comprehension process, or they could be less crucial and influence performance in a task-dependent manner. In the present experiments, participants read sentences about an object. The sentences implied that the object had a specific shape or orientation. They then either named a picture of that object (Experiments 1 and 3) or decided whether the object had been mentioned in the sentence (Experiment 2). Orientation information did not reliably influence performance in any of the experiments. Shape representations influenced performance most strongly when participants were asked to compare a sentence with a picture or when they were explicitly asked to use mental imagery while reading the sentences. Thus, in contrast to previous claims, implied visual information often does not contribute substantially to the comprehension process during normal reading.

Abstract

When comprehending concrete words, listeners and readers can activate specific visual information such as the shape of the words’ referents. In two experiments we examined whether such information can be activated in an anticipatory fashion. In Experiment 1, listeners’ eye movements were tracked while they were listening to sentences that were predictive of a specific critical word (e.g., “moon” in “In 1969 Neil Armstrong was the first man to set foot on the moon”). 500 ms before the acoustic onset of the critical word, participants were shown four-object displays featuring three unrelated distractor objects and a critical object, which was either the target object (e.g., moon), an object with a similar shape (e.g., tomato), or an unrelated control object (e.g., rice). In a time window before shape information from the spoken target word could be retrieved, participants already tended to fixate both the target and the shape competitors more often than they fixated the control objects, indicating that they had anticipatorily activated the shape of the upcoming word's referent. This was confirmed in Experiment 2, which was an ERP experiment without picture displays. Participants listened to the same lead-in sentences as in Experiment 1. The sentence-final words corresponded to the predictable target, the shape competitor, or the unrelated control object (yielding, for instance, “In 1969 Neil Armstrong was the first man to set foot on the moon/tomato/rice”). N400 amplitude in response to the final words was significantly attenuated in the shape-related compared to the unrelated condition. Taken together, these results suggest that listeners can activate perceptual attributes of objects before they are referred to in an utterance.

Abstract

Language-mediated visual attention describes the interaction of two fundamental components of the human cognitive system, language and vision. Within this paper we present an amodal shared resource model of language-mediated visual attention that offers a description of the information and processes involved in this complex multimodal behavior and a potential explanation for how this ability is acquired. We demonstrate that the model is not only sufficient to account for the experimental effects of Visual World Paradigm studies but also that these effects are emergent properties of the architecture of the model itself, rather than requiring separate information processing channels or modular processing systems. The model provides an explicit description of the connection between the modality-specific input from language and vision and the distribution of eye gaze in language-mediated visual attention. The paper concludes by discussing future applications for the model, specifically its potential for investigating the factors driving observed individual differences in language-mediated eye gaze.

Abstract

Recent empirical evidence suggests that language-mediated eye gaze is partly determined by level of formal literacy training. Huettig, Singh and Mishra (2011) showed that high-literate individuals' eye gaze was closely time locked to phonological overlap between a spoken target word and items presented in a visual display. In contrast, low-literate individuals' eye gaze was not related to phonological overlap, but was instead strongly influenced by semantic relationships between items. Our present study tests the hypothesis that this behavior is an emergent property of an increased ability to extract phonological structure from the speech signal, as in the case of high-literates, with low-literates more reliant on more coarse grained structure. This hypothesis was tested using a neural network model, that integrates linguistic information extracted from the speech signal with visual and semantic information within a central resource. We demonstrate that contrasts in fixation behavior similar to those observed between high and low literates emerge when models are trained on speech signals of contrasting granularity.