Multiple routes from occipital to temporal cortices during reading

Area of Science:

• Neuroscience
• Cognitive Science
• Psycholinguistics

Background:

• Current reading models emphasize ventral occipitotemporal cortex (vOT) influencing language areas.
• Alternative pathways from visual cortex to temporal lobe language regions require investigation.

Purpose of the Study:

• To explore alternative neural routes supporting reading beyond established models.
• To investigate the connectivity between visual and language areas during word processing using fMRI and DCM.

Main Methods:

• Functional magnetic resonance imaging (fMRI) to identify brain regions involved in reading.
• Dynamic causal modeling (DCM) to analyze effective connectivity between identified brain areas.
• Three DCM analyses tested specific directional influences between occipital and temporal regions.

Main Results:

• Reading activated posterior inferior occipital (iO) and vOT areas more than listening.
• Increased connectivity was observed from iO to pSTS and vOT during reading.
• Connectivity to aSTS was enhanced from both vOT and pSTS, and to pSTS from both iO and vOT.

Conclusions:

• Identified three distinct processing streams in the occipitotemporal cortex: iO→pSTS→aSTS, iO→vOT→aSTS, and iO→vOT→pSTS→aSTS.
• These pathways contribute to the neural basis of reading.
• Efficient reading likely depends on the integrity of these multiple interconnected pathways.