Dissociating the functions of superior and inferior parts of the left ventral occipito-temporal cortex during visual word and object processing

Publication date: Available online 6 June 2019Source: NeuroImageAuthor(s): Philipp Ludersdorfer, Cathy J. Price, Keith J. Kawabata Duncan, Kristina DeDuck, Nicholas H. Neufeld, Mohamed L. SeghierAbstractDuring word and object recognition, extensive activation has consistently been observed in the left ventral occipito-temporal cortex (vOT), focused around the occipito-temporal sulcus (OTs). Previous studies have shown that there is a hierarchy of responses from posterior to anterior vOT regions (along the y-axis) that corresponds with increasing levels of recognition - from perceptual to semantic processing, respectively. In contrast, the functional differences between superior and inferior vOT responses (i.e. along the z-axis) have not yet been elucidated. To investigate, we conducted an extensive review of the literature and found that peak activation for reading varies by more than 1 cm in the z-axis. In addition, we investigated functional differences between superior and inferior parts of left vOT by analysing functional MRI data from 58 neurologically normal skilled readers performing 8 different visual processing tasks. We found that group activation in superior vOT was significantly more sensitive than inferior vOT to the type of task, with more superior vOT activation when participants were matching visual stimuli for their semantic or perceptual content than producing speech to the same stimuli. This functional difference along the z-axis was compared to existing ...

Source: NeuroImage - June 6, 2019 Category: Neuroscience Source Type: research