Biology subjects

Hagoort, P.

Publications and source records attributed to Hagoort, P..

6 recordsLinked to original sources

bioRxiv2018

Do we predict upcoming speech content in naturalistic environments?

The ability to predict upcoming actions is a characteristic hallmark of cognition and therefore not surprisingly a central topic in cognitive science. It remains unclear, however, whether the predictive behaviour commonly observed in strictly controlled lab environments generalizes to rich, everyday settings. In four virtual reality experiments, we tested whether a well-established marker of linguistic prediction (i.e. anticipatory eye movements as observed in the visual world paradigm) replicated when increasing the naturalness of the paradigm by means of i) immersing participants in naturalistic everyday scenes, ii) increasing the number of distractor objects present, iii) manipulating the location of referents in central versus peripheral vision, and iv) modifying the proportion of predictable nounreferents in the experiment. Robust anticipatory eye movements were observed, even in the presence of 10 objects (hereby testing working memory) and when only 25% of all sentences contained a visually present referent (hereby testing error-based learning). The anticipatory effect disappeared, however, when referents were placed in peripheral vision. Together, our findings suggest that working memory may play an important role in predictive processing in everyday communication, but only in contexts where upcoming referents have been explicitly attended to prior to encountering the spoken referential act. Methodologically, our study confirms that ecological validity and experimental control may go hand in hand in future studies of human predictive behaviour.

neuroscience↗

bioRxiv2018

Distracting linguistic information impairs neural entrainment to attended speech

Listening to speech is difficult in noisy environments, and is even harder when the interfering noise consists of intelligible speech as compared to unintelligible sounds. This suggests that the competing linguistic information interferes with the neural processing of target speech. Interference could either arise from a degradation of the neural representation of the target speech, or from increased representation of distracting speech that enters in competition with the target speech. We tested these alternative hypotheses using magnetoencephalography (MEG) while participants listened to a target clear speech in the presence of distracting noise-vocoded speech. Crucially, the distractors were initially unintelligible but became more intelligible after a short training session. Results showed that the comprehension of the target speech was poorer after training than before training. The neural tracking of target speech in the delta range (1-4 Hz) reduced in strength in the presence of a more intelligible distractor. In contrast, the neural tracking of distracting signals was not significantly modulated by intelligibility. These results suggest that the presence of distracting speech signals degrades the linguistic representation of target speech carried by delta oscillations.

neuroscience↗

bioRxiv2017

Changes in alpha activity reveal that social opinion modulates attention allocation during face processing

AbstractParticipants performance differs when conducting a task in the presence of a secondary individual, moreover the opinion the participant has of this individual also plays a role. Using EEG, we investigated how previous interactions with, and evaluations of, an avatar in virtual reality subsequently influenced attentional allocation to the face of that avatar. We focused on changes in the alpha activity as an index of attentional allocation. We found that the onset of an avatars face whom the participant had developed a rapport with induced greater alpha suppression. This suggests greater attentional resources allocated to the interacted-with avatars. The evaluative ratings of the avatar induced a U-shaped change in alpha suppression, such that participants paid most attention when the avatar was rated as average. These results suggest that attentional allocation is thus an important element of how behaviour is altered in the presence of a secondary individual.

neuroscience↗

bioRxiv2017

Binding language: Structuring sentences through precisely timed oscillatory mechanisms

Syntactic binding refers to combining words into larger structures. Using EEG, we investigated the neural processes involved in syntactic binding. Participants were auditorily presented two-word sentences (i.e. a pronoun and pseudoverb such as she dotches, for which syntactic binding can take place) and wordlists (i.e. two pseudoverbs such as pob dotches, for which no binding can occur). Comparing these two conditions, we targeted syntactic binding while minimizing contributions of semantic binding and of other cognitive processes such as working memory. We found a converging pattern of results using two distinct analysis approaches: one approach using frequency bands as defined in previous literature, and one data-driven approach in which we looked at the entire range of frequencies between 3-30 Hz without the constraints of pre-defined frequency bands. In the syntactic binding (relative to the wordlist) condition, a power increase was observed in the alpha and beta frequency range shortly preceding the presentation of the target word that requires binding, which was maximal over frontal-central electrodes. Our interpretation is that these signatures reflect that language comprehenders expect the need for binding to occur. Following the presentation of the target word in a syntactic binding context (relative to the wordlist condition), an increase in alpha power maximal over a left lateralized cluster of frontal-temporal electrodes was observed. We suggest that this alpha increase relates to syntactic binding taking place. Taken together, our findings suggest that increases in alpha and beta power are reflections of distinct the neural processes underlying syntactic binding.

neuroscience↗

bioRxiv2017

Neural entrainment determines the words we hear

Low-frequency neural entrainment to rhythmic input has been hypothesized as a canonical mechanism that shapes sensory perception in time. Neural entrainment is deemed particularly relevant for speech analysis, as it would contribute to the extraction of discrete linguistic elements from continuous acoustic signals. Yet, its causal influence in speech perception has been difficult to establish. Here, we provide evidence that oscillations build temporal predictions about the duration of speech tokens that directly influence perception. Using magnetoencephalography (MEG), we studied neural dynamics during listening to sentences that changed in speech rate. We observed neural entrainment to preceding speech rhythms persisting for several cycles after the change in rate. The sustained entrainment was associated with changes in the perceived duration of the last words vowel, resulting in the perception of words with radically different meanings. These findings support oscillatory models of speech processing, suggesting that neural oscillations actively shape speech perception.

neuroscience↗

bioRxiv2017

Frequency-specific directed interactions in the human brain network for language

The brains remarkable capacity for language requires bidirectional interactions between functionally specialized brain regions. We used magnetoencephalography to investigate interregional interactions in the brain network for language, while 102 participants were reading sentences. Using Granger causality analysis, we identified inferior frontal cortex and anterior temporal regions to receive widespread input, and middle temporal regions to send widespread output. This fits well with the notion that these regions play a central role in language processing. Characterization of the functional topology of this network, using data-driven matrix factorization, which allowed for partitioning into a set of subnetworks, revealed directed connections at distinct frequencies of interaction. Connections originating from temporal regions peaked at alpha frequency, whereas connections originating from frontal and parietal regions peaked at beta frequency. These findings indicate that processing different types of linguistic information may depend on the contributions of distinct brain rhythms.\n\nOne Sentence SummaryCommunication between language relevant areas in the brain is supported by rhythmic synchronization, where different rhythms reflect the direction of information flow.

neuroscience↗