Simultaneous cortical responses to multiple written words

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Reading Research

Background:

• Previous research focused on single-word processing in reading.
• Limited understanding of how the brain processes multiple words concurrently.
• The simultaneous suppression paradigm reveals reduced responses to simultaneous stimuli.

Purpose of the Study:

• To investigate brain activity during simultaneous versus sequential word processing.
• To determine how the number of words affects neural responses in reading networks.
• To explore interference during simultaneous lexical access.

Main Methods:

• Functional magnetic resonance imaging (fMRI) study.
• Participants viewed sequences of zero, one, or two words (simultaneously or sequentially).
• Visual stimulation was held constant across conditions.

Main Results:

• Behavioral accuracy decreased when detecting two words simultaneously versus sequentially.
• Blood-oxygen-level-dependent (BOLD) responses increased linearly with word count in left hemisphere reading regions.
• Ventral temporal regions showed reduced sensitivity to lexical frequency when words were presented simultaneously.

Conclusions:

• The reading network can detect simultaneous letter strings.
• Simultaneous word presentation leads to interference during lexical access.
• This study elucidates neural mechanisms of multi-word processing.