Auditory selective attention to speech modulates activity in the visual word form area

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Auditory Perception

Background:

• Top-down attentional modulation influences cortical processing of complex auditory input.
• Previous research links auditory and visual word perception to specific cortical regions.

Purpose of the Study:

• To isolate top-down attentional effects on cortical regions involved in speech and word perception.
• To investigate how selective attention to auditory speech versus nonspeech signals impacts brain activity.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activity.
• Participants performed two challenging active listening tasks: rhyme judgment (attending to speech) and tone-triplet matching (attending to melody).
• Complex auditory stimuli consisted of words overlaid with tone sequences.

Main Results:

• Selective attention to speech, compared to melody, increased blood oxygenation level-dependent (BOLD) signals in the left inferior frontal gyrus, temporal regions, and the visual word form area (VWFA).
• Both attention conditions showed overall deactivation in visual regions relative to rest.
• Attending to speech specifically modulated extrastriate cortex, deactivating fusiform regions except the VWFA, while attending to melody caused uniform deactivation across fusiform regions.

Conclusions:

• Selective attention to speech can specifically tune extrastriate cortex activity.
• Increased activity in the VWFA when attending to speech, relative to surrounding regions, supports connectivity between spoken and visual word processing areas.
• These findings highlight the dynamic interplay between attention and sensory processing in the brain.