%A Xu,Yang %A D'Lauro,Christopher %A Pyles,John %A Kass,Robert %A Tarr,Michael %D 2013 %J Frontiers in Psychology %C %F %G English %K visual category learning,subordinate categorization,visually-similar categories,the ventral visual pathway,Prefrontal Cortex,cortical time course,category discriminability,Decoding,MEG %Q %R 10.3389/fpsyg.2013.00684 %W %L %M %P %7 %8 2013-October-17 %9 Original Research %+ Mr Yang Xu,Carnegie Mellon University,Machine Learning Department,Pittsburgh,United States,yang_xu_ch@yahoo.com %+ Mr Yang Xu,Center for The Neural Basis of Cognition,Pittsburgh,Pennsylvania,United States,yang_xu_ch@yahoo.com %+ Dr Christopher D'Lauro,Center for The Neural Basis of Cognition,Pittsburgh,Pennsylvania,United States,christopher.dlauro@gmail.com %+ Dr Christopher D'Lauro,United States Air Force Academy,Department of Behavioral Sciences and Leadership,Colorado Springs,CO,United States,christopher.dlauro@gmail.com %# %! Temporal coding of visually-similar categories with MEG %* %< %T Fine-grained temporal coding of visually-similar categories in the ventral visual pathway and prefrontal cortex %U https://www.frontiersin.org/articles/10.3389/fpsyg.2013.00684 %V 4 %0 JOURNAL ARTICLE %@ 1664-1078 %X Humans are remarkably proficient at categorizing visually-similar objects. To better understand the cortical basis of this categorization process, we used magnetoencephalography (MEG) to record neural activity while participants learned–with feedback–to discriminate two highly-similar, novel visual categories. We hypothesized that although prefrontal regions would mediate early category learning, this role would diminish with increasing category familiarity and that regions within the ventral visual pathway would come to play a more prominent role in encoding category-relevant information as learning progressed. Early in learning we observed some degree of categorical discriminability and predictability in both prefrontal cortex and the ventral visual pathway. Predictability improved significantly above chance in the ventral visual pathway over the course of learning with the left inferior temporal and fusiform gyri showing the greatest improvement in predictability between 150 and 250 ms (M200) during category learning. In contrast, there was no comparable increase in discriminability in prefrontal cortex with the only significant post-learning effect being a decrease in predictability in the inferior frontal gyrus between 250 and 350 ms (M300). Thus, the ventral visual pathway appears to encode learned visual categories over the long term. At the same time these results add to our understanding of the cortical origins of previously reported signature temporal components associated with perceptual learning.