Neural Activations During Feedback-Based and Paired Associate Probabilistic Category Learning in Aphasia

Sofia Vallila-Rohter¹, Swathi Kiran²
¹Boston University, ²Boston University


For decades cognitive neuroscientists have explored probabilistic category learning to better understand learning systems in healthy and clinical populations (Ashby & Moddox, 2005), yet little remains known about probabilistic category learning in aphasia. In the current study, we used functional magnetic resonance imaging (fMRI) to examine the neural regions involved when post-stroke persons with aphasia (PWA) completed feedback-based (FB) and paired associated (PA) nonlinguistic category learning tasks.

Three PWA in the chronic stages of aphasia completed our study. Participants learned to categorize novel fictional animals as belonging to one of two categories established along a continuum based on the number of features shared with each of the two prototypes. In one condition (FB) participants had to guess each animal’s category affiliation via button press, receiving feedback related to accuracy after each trial. In the second condition (PA), animals appeared along with a label indicating their category membership.

PWA were found to engage a network of frontal, parietal and occipital regions. Activations were predominantly in the right hemisphere, including the right IFG, and could not be explained simply by legion size in the left hemisphere. The role of the right IFG has been extensively probed in examinations of language recovery, with current results supporting the hypothesis that the right IFG plays a role in processes which include monitoring, selective attention, and executive actions (Vigneau et al., 2011)


Keywords: Category-Learning, Aphasia, Feedback

 

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