Biology subjects

Husta, C.

Publications and source records attributed to Husta, C..

3 recordsLinked to original sources

bioRxiv2026

Speech clarity shapes auditory attention and visual-signal coupling during multimodal sentence comprehension

Face-to-face communication requires listeners to attend, integrate, and weigh multiple communicative signals, including auditory speech, mouth movements, and co-speech gestures. The contribution of these signals may depend on the reliability of auditory input and the informativeness of the available signals. We utilized rapid invisible frequency tagging (RIFT) with EEG to examine how participants attend to and integrate these different signals in clear and adverse listening conditions. Participants watched videos of an actress producing clear or noise-vocoded sentences. Auditory speech was amplitude-modulated at 58Hz, while the luminance of the gesture and mouth regions was frequency-tagged at 63Hz and 65Hz. Degraded speech elicited stronger responses at the auditory tagged frequency, suggesting increased attentional gain to the auditory signal when listening was challenging. In contrast, clear speech elicited stronger responses at the gesture tagged frequency and a stronger 2Hz intermodulation response (65-63Hz), reflecting enhanced nonlinear coupling between mouth movements and gestures. Finally, in degraded speech, the informativeness of mouth movement, but not gesture, was associated with intermodulation strength, suggesting that the informativeness of mouth movements plays a greater role in multisensory interaction when listening is challenging. Our findings demonstrate that both signal reliability and informativeness shape multisensory integration during spoken language comprehension.

neuroscience↗

bioRxiv2024

Using rapid invisible frequency tagging (RIFT) to probe the attentional distribution between speech planning and comprehension

Interlocutors often use the semantics of comprehended speech to inform the semantics of planned speech. Do representations of the comprehension and planning stimuli interact on a neural level? We used rapid invisible frequency tagging (RIFT) and EEG to probe the attentional distribution between spoken distractor words and target pictures in the picture-word interference (PWI) paradigm. We presented participants with auditory distractor nouns (auditory (f1); tagged at 54Hz) together with categorically related or unrelated pictures (visual (f2); tagged at 68Hz), which had to be named after a delay. RIFT elicits steady-state evoked potentials, which reflect attentional allocation to the tagged stimuli. When representations of the tagged stimuli interact, integrative effects have been observed at the intermodulation frequency resulting from an interaction of the base frequencies (f2{+/-}f1; Drijvers et al., 2021). Our results showed clear power increases at 54Hz and 68Hz during the tagging window, but no differences between related or unrelated conditions. More interestingly, we observed a larger power difference in the unrelated compared to the related condition at the intermodulation frequency (68Hz - 54Hz: 14Hz), indicating stronger interaction between the auditory and visual representations when they were unrelated. Our results go beyond standard PWI results (e.g., Burki et al., 2020) by showing that participants do not have more difficulty visually attending to the related pictures or inhibiting the related auditory distractors. Instead, processing difficulties arise when the representations of the stimuli interact, meaning that participants might be trying to prevent integration between the auditory and visual representations in the related condition. Significance statementStudying speech planning during comprehension with EEG has been difficult due to a lack of appropriate methodology. This study demonstrates that rapid invisible frequency tagging (RIFT) can explore attentional allocation to speech planning and comprehension stimuli, as well as their interaction. Our results show that the content of the speech planning and comprehension representations affects their interaction in the neural signal, which should always be considered when these processes are studied jointly. In future work, RIFT could be used to investigate speech planning and comprehension in more conversational settings, as tagging can be added to videos or speech segments. This is the first study that demonstrates that RIFT can be used together with EEG to study cognitive phenomena.

neuroscience↗

bioRxiv2018

The Pupillary Light Response Reflects Visual Working Memory Content

Recent studies have shown that the pupillary light response (PLR) is modulated by higher cognitive functions, presumably through activity in visual sensory brain areas. Here we use the PLR to test the involvement of sensory areas in visual working memory (VWM). In two experiments, participants memorized either bright or dark stimuli. We found that pupils were smaller when a pre-stimulus cue indicated that a bright stimulus should be memorized; this reflects a covert shift of attention during encoding of items into VWM. Crucially, we obtained the same result with a post-stimulus cue, which shows that internal shifts of attention within VWM affect pupil size as well. Strikingly, pupil size reflected VWM content only briefly. This suggests that a shift of attention within VWM momentarily activates an \"active\" memory representation, but that this representation quickly transforms into a \"hidden\" state that does not rely on sensory areas.

neuroscience↗