Joost Rommers

Using the visual world paradigm to study language processing: A review and critical evaluation

We describe the key features of the visual world paradigm and review the main research areas where it has been used. In our discussion we highlight that the paradigm provides information about the way language users integrate linguistic information with information derived from the visual environment. Therefore the paradigm is well suited to study one of the key issues of current cognitive psychology, namely the interplay between linguistic and visual information processing. However, conclusions about linguistic processing (e.g., about activation, competition, and timing of access of linguistic representations) in the absence of relevant visual information must be drawn with caution.

Context-dependent semantic processing in the human brain: Evidence from idiom comprehension

Language comprehension involves activating word meanings and integrating them with the sentence context. This study examined whether these routines are carried out even when they are theoretically unnecessary, namely, in the case of opaque idiomatic expressions, for which the literal word meanings are unrelated to the overall meaning of the expression. Predictable words in sentences were replaced by a semantically related or unrelated word. In literal sentences, this yielded previously established behavioral and electrophysiological signatures of semantic processing: semantic facilitation in lexical decision, a reduced N400 for semantically related relative to unrelated words, and a power increase in the gamma frequency band that was disrupted by semantic violations. However, the same manipulations in idioms yielded none of these effects. Instead, semantic violations elicited a late positivity in idioms. Moreover, gamma band power was lower in correct idioms than in correct literal sentences. It is argued that the brains semantic expectancy and literal word meaning integration operations can, to some extent, be “switched off” when the context renders them unnecessary. Furthermore, the results lend support to models of idiom comprehension that involve unitary idiom representations.

Beta Oscillations Reflect Memory and Motor Aspects of Spoken Word Production

Two major components form the basis of spoken word production: the access of conceptual and lexical/phonological information in long‐term memory, and motor preparation and execution of an articulatory program. Whereas the motor aspects of word production have been well characterized as reflected in alpha‐beta desynchronization, the memory aspects have remained poorly understood. Using magnetoencephalography, we investigated the neurophysiological signature of not only motor but also memory aspects of spoken‐word production. Participants named or judged pictures after reading sentences. To probe the involvement of the memory component, we manipulated sentence context. Sentence contexts were either constraining or nonconstraining toward the final word, presented as a picture. In the judgment task, participants indicated with a left‐hand button press whether the picture was expected given the sentence. In the naming task, they named the picture. Naming and judgment were faster with constraining than nonconstraining contexts. Alpha‐beta desynchronization was found for constraining relative to nonconstraining contexts pre‐picture presentation. For the judgment task, beta desynchronization was observed in left posterior brain areas associated with conceptual processing and in right motor cortex. For the naming task, in addition to the same left posterior brain areas, beta desynchronization was found in left anterior and posterior temporal cortex (associated with memory aspects), left inferior frontal cortex, and bilateral ventral premotor cortex (associated with motor aspects). These results suggest that memory and motor components of spoken word production are reflected in overlapping brain oscillations in the beta band. Hum Brain Mapp 36:2767–2780, 2015.

Object Shape and Orientation Do Not Routinely Influence Performance During Language Processing

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.

Verbal and nonverbal predictors of language-mediated anticipatory eye movements

During language comprehension, listeners often anticipate upcoming information. This can draw listeners’ overt attention to visually presented objects before the objects are referred to. We investigated to what extent the anticipatory mechanisms involved in such language-mediated attention rely on specific verbal factors and on processes shared with other domains of cognition. Participants listened to sentences ending in a highly predictable word (e.g., “In 1969 Neil Armstrong was the first man to set foot on the moon”) while viewing displays containing three unrelated distractor objects and a critical object, which was either the target object (e.g., a moon), an object with a similar shape (e.g., a tomato), or an unrelated control object (e.g., rice). Language-mediated anticipatory eye movements were observed to targets and to shape competitors. Importantly, looks to the shape competitor were systematically related to individual differences in anticipatory attention, as indexed by a spatial cueing task: Participants whose responses were most strongly facilitated by predictive arrow cues also showed the strongest effects of predictive language input on their eye movements. By contrast, looks to the target were related to individual differences in vocabulary size and verbal fluency. The results suggest that verbal and nonverbal factors contribute to different types of language-mediated eye movements. The findings are consistent with multiple-mechanism accounts of predictive language processing.

Lateralized electrical brain activity reveals covert attention allocation during speaking

ABSTRACT Speakers usually begin to speak while only part of the utterance has been planned. Earlier work has shown that speech planning processes are reflected in speakers’ eye movements as they describe visually presented objects. However, to‐be‐named objects can be processed to some extent before they have been fixated upon, presumably because attention can be allocated to objects covertly, without moving the eyes. The present study investigated whether EEG could track speakers’ covert attention allocation as they produced short utterances to describe pairs of objects (e.g., “dog and chair”). The processing difficulty of each object was varied by presenting it in upright orientation (easy) or in upside down orientation (difficult). Background squares flickered at different frequencies in order to elicit steady‐state visual evoked potentials (SSVEPs). The N2pc component, associated with the focusing of attention on an item, was detectable not only prior to speech onset, but also during speaking. The time course of the N2pc showed that attention shifted to each object in the order of mention prior to speech onset. Furthermore, greater processing difficulty increased the time speakers spent attending to each object. This demonstrates that the N2pc can track covert attention allocation in a naming task. In addition, an effect of processing difficulty at around 200–350 ms after stimulus onset revealed early attention allocation to the second to‐be‐named object. The flickering backgrounds elicited SSVEPs, but SSVEP amplitude was not influenced by processing difficulty. These results help complete the picture of the coordination of visual information uptake and motor output during speaking. HIGHLIGHTSParticipants described pairs of objects while their EEG was recorded.Covert attention shifted to each object in the order of mention.Objects that were more difficult to process were attended to longer.The second to‐be‐named object was processed at an early stage.