A model-guided dissociation between subcortical and cortical contributions to word recognition

Area of Science:

• Neuroscience
• Cognitive Psychology
• Computational Linguistics

Background:

• Visual word recognition research explores brain activity related to orthographic processing.
• Orthographic neighborhood density has been linked to global lexical activity (GLA) in computational models.

Purpose of the Study:

• To investigate the neural correlates of orthographic processing using GLA from the multiple read-out model (MROM).
• To examine the relationship between GLA and brain activity during visual word recognition via fMRI.

Main Methods:

• Utilized functional magnetic resonance imaging (fMRI) to measure brain activity.
• Employed the multiple read-out model (MROM) to calculate global lexical activity (GLA) for words and nonwords.

Main Results:

• Cortical BOLD responses showed linear decreases with increasing GLA for both words and nonwords.
• Subcortical regions (hippocampus, globus pallidus, caudate nucleus) exhibited increasing linear BOLD responses with increasing GLA for words.

Conclusions:

• The basal ganglia, particularly the globus pallidus and caudate nucleus, may play a role in visual word recognition.
• These regions might support the matching of orthographic input to long-term memory representations and working memory maintenance.