Auditory-cortex lesions impair contralateral tone-pattern detection under informational masking

Cortex ◽  
2017 ◽  
Vol 95 ◽  
pp. 1-14
Author(s):  
Lisa Prilop ◽  
Alexander Gutschalk
Keyword(s):  
Auditory Cortex ◽  
Pattern Detection ◽  
Informational Masking ◽  
Tone Pattern

scholarly journals Effects of Cross-modal Asynchrony on Informational Masking in Human Cortex

2017 ◽  
Vol 29 (6) ◽  
pp. 980-990 ◽  
Author(s):  
Lars Hausfeld ◽  
Alexander Gutschalk ◽  
Elia Formisano ◽  
Lars Riecke
Keyword(s):  
Auditory Cortex ◽  
Visual Input ◽  
Auditory Target ◽  
Informational Masking ◽  
Visual Stream ◽  
Human Cortex ◽  
Target Sound ◽  
Audible Sound ◽  
Audiovisual Stimuli ◽  
Neural Effect

In many everyday listening situations, an otherwise audible sound may go unnoticed amid multiple other sounds. This auditory phenomenon, called informational masking (IM), is sensitive to visual input and involves early (50–250 msec) activity in the auditory cortex (the so-called awareness-related negativity). It is still unclear whether and how the timing of visual input influences the neural correlates of IM in auditory cortex. To address this question, we obtained simultaneous behavioral and neural measures of IM from human listeners in the presence of a visual input stream and varied the asynchrony between the visual stream and the rhythmic auditory target stream (in-phase, antiphase, or random). Results show effects of cross-modal asynchrony on both target detectability (RT and sensitivity) and the awareness-related negativity measured with EEG, which were driven primarily by antiphasic audiovisual stimuli. The neural effect was limited to the interval shortly before listeners' behavioral report of the target. Our results indicate that the relative timing of visual input can influence the IM of a target sound in the human auditory cortex. They further show that this audiovisual influence occurs early during the perceptual buildup of the target sound. In summary, these findings provide novel insights into the interaction of IM and multisensory interaction in the human brain.

scholarly journals Auditory cortex is susceptible to lexical influence as revealed by informational vs. energetic masking of speech categorization

2020 ◽  
Author(s):  
Jared A. Carter ◽  
Gavin M. Bidelman
Keyword(s):  
Speech Perception ◽  
Auditory Cortex ◽  
Categorical Perception ◽  
Inferior Frontal Gyrus ◽  
Informational Masking ◽  
Linguistic Interference ◽  
Source Level ◽  
Speech Categorization ◽  
Energetic Masking ◽  
Lexical Interference

ABSTRACTSpeech perception requires the grouping of acoustic information into meaningful phonetic units via the process of categorical perception (CP). Environmental masking influences speech perception and CP. However, it remains unclear at which stage of processing (encoding, decision, or both) masking affects listeners’ categorization of speech signals. The purpose of this study was to determine whether linguistic interference influences the early acoustic-phonetic conversion process inherent to CP. To this end, we measured source level, event related brain potentials (ERPs) from auditory cortex (AC) and inferior frontal gyrus (IFG) as listeners rapidly categorized speech sounds along a /da/ to /ga/ continuum presented in three listening conditions: quiet, and in the presence of forward (informational masker) and time-reversed (energetic masker) 2-talker babble noise. Maskers were matched in overall SNR and spectral content and thus varied only in their degree of linguistic interference (i.e., informational masking). We hypothesized a differential effect of informational versus energetic masking on behavioral and neural categorization responses, where we predicted increased activation of frontal regions when disambiguating speech from noise, especially during lexical-informational maskers. We found (1) informational masking weakens behavioral speech phoneme identification above and beyond energetic masking; (2) low-level AC activity not only codes speech categories but is susceptible to higher-order lexical interference; (3) identifying speech amidst noise recruits a cross hemispheric circuit (ACleft → IFGright) whose engagement varies according to task difficulty. These findings provide corroborating evidence for top-down influences on the early acoustic-phonetic analysis of speech through a coordinated interplay between frontotemporal brain areas.

The Development of Informational Masking

2013 ◽  
Author(s):  
Rochelle S. Newman ◽  
Gerald D. Kidd ◽  
Faraz Ahsan ◽  
Giovanna Morini
Keyword(s):  
Informational Masking
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