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1. chinaXiv:202010.00076 [pdf]

Multisensory Signals Inhibit Pupillary Light Reflex: Evidence from Pupil Oscillation

Xiangyong Yuan; Yuhui Cheng; Yi Jiang
Subjects: Psychology >> Cognitive Psychology

Multisensory integration, which enhances the stimulus saliency at the early stage of processing hierarchy, is recently shown to produce a larger pupil size than its unisensory constituents. Theoretically, any modulation on pupil size ought to be associated with the sympathetic and parasympathetic pathways that are sensitive to lights. But it remains poorly understood how pupillary light reflex is changed in a multisensory context. The present study evoked an oscillation of pupillary light reflex by periodically changing the luminance of a visual stimulus at 1.25 Hz. It was found that such induced pupil oscillation was substantially attenuated when the bright but not the dark phase of the visual flicker was periodically and synchronously presented with a burst of tones. This inhibition effect persisted when the visual flicker was task-irrelevant and out of attentional focus, but disappeared when the visual flicker was moved from the central field to the periphery. These findings not only offer a comprehensive characterization of the multisensory impact on pupil response to lightness, but also provide valuable clues to the individual contributions of the sympathetic and parasympathetic pathways to multisensory modulation of pupil size.

submitted time 2021-04-27 Hits9181Downloads986 Comment 0

2. chinaXiv:202102.00085 [pdf]

An electrophysiological investigation of the temporal asynchrony effect on character-speech sound integration in Chinese typically developing children and children with dyslexia

Du, Yingchun; Li, Yizhen; Qin, Li; Bi, Hongyan
Subjects: Psychology >> Developmental Psychology

The neural mechanism of orthographic-phonological integration was influenced by the temporal relationship of cross-modal stimuli. However, previous studies mainly investigated the neural mechanism of letter-speech sound integration in precise temporal synchrony or small temporal asynchrony conditions. In this study, character-speech sound integration was investigated in a relatively wide temporal window. Chinese characters were presented synchronously to the onset of speech sounds or before speech sound by 300 or 600 ms (referred as AV0, AV300 and AV600). ERP responses evoked by congruent condition (speech sounds were paired with congruent visual characters) and baseline condition (speech sounds were paired with Korean characters) were compared. Different electrophysiological markers were found in the temporal synchrony and temporal asynchrony conditions. In the AV0 condition, developing dyslexia (DD) and typically developing (TD) children showed similar congruency effect on P1, N170 and N300 components, demonstrating the influence of speech sound on visual character processing. In the AV300 condition, DD group showed left-lateralized congruency effect on N200, whereas TD children showed bilateral congruency effect on N200. Both groups showed bilateral congruency effect on N200 in the AV600 condition. We speculate that the insufficient character-speech sound integration exhibited by dyslexic children in the AV300 condition was probably caused by their slow visual processing speed. The results provide unique insight into the neural mechanism of print-speech integration in a wide temporal window and point out the necessity to investigate neural mechanism of print-speech integration in a relatively wide temporal window.

submitted time 2021-02-25 Hits3347Downloads787 Comment 0

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