Chiara Renzi1, Chiara Ferrari1, Susanna Schiavi2, Alberto Pisoni2, Costanza Papagno2, Tomaso Vecchi1, Andrea Antal3, Zaira Cattaneo4. 1. Brain Connectivity Center, National Neurological Institute C. Mondino. 2. Department of Psychology, University of Milano-Bicocca. 3. Department of Clinical Neurophysiology, Georg-August University. 4. Department of Psychology, University of Milano-Bicocca, Brain Connectivity Center, National Neurological Institute C. Mondino.
Abstract
OBJECTIVE: The aim of this study was to examine the role of occipital face area (OFA) in mediating observers' tendency to perceive faces as "wholes" (holistic processing) both when detecting and discriminating faces. To investigate this issue, we modulated OFA activity using transcranial direct current stimulation (tDCS). METHOD: In Experiment 1, participants performed a face detection task (the Mooney faces task) and a face discrimination task (the Composite faces task), which both assess holistic face processing. In Experiment 2, participants were asked to detect both Mooney faces and Mooney objects, to test face selectivity of OFA. In each experimental session, the tasks were presented once before (pre) and once after (post) administration of 20 min of excitability increasing anodal tDCS (real) and sham stimulation over the putative OFA. RESULTS: Compared with sham stimulation, we found that real anodal tDCS interfered with both Mooney faces and objects detection, whereas it had no effect on holistic processing involved in face discrimination, as measured by the Composite faces task. CONCLUSIONS: Our results suggest that OFA is causally implicated in facial detection at least in degraded conditions (i.e., when the "face" signal needs to be extracted from a noisy background). In turn, our data do not implicate OFA in holistic processing in face discrimination. Finally, our data suggest a possible role of OFA in categorization of other nonface stimuli, a conclusion that must be taken with caution, as stimulation over OFA may affect object-selective adjacent regions. (c) 2015 APA, all rights reserved).
OBJECTIVE: The aim of this study was to examine the role of occipital face area (OFA) in mediating observers' tendency to perceive faces as "wholes" (holistic processing) both when detecting and discriminating faces. To investigate this issue, we modulated OFA activity using transcranial direct current stimulation (tDCS). METHOD: In Experiment 1, participants performed a face detection task (the Mooney faces task) and a face discrimination task (the Composite faces task), which both assess holistic face processing. In Experiment 2, participants were asked to detect both Mooney faces and Mooney objects, to test face selectivity of OFA. In each experimental session, the tasks were presented once before (pre) and once after (post) administration of 20 min of excitability increasing anodal tDCS (real) and sham stimulation over the putative OFA. RESULTS: Compared with sham stimulation, we found that real anodal tDCS interfered with both Mooney faces and objects detection, whereas it had no effect on holistic processing involved in face discrimination, as measured by the Composite faces task. CONCLUSIONS: Our results suggest that OFA is causally implicated in facial detection at least in degraded conditions (i.e., when the "face" signal needs to be extracted from a noisy background). In turn, our data do not implicate OFA in holistic processing in face discrimination. Finally, our data suggest a possible role of OFA in categorization of other nonface stimuli, a conclusion that must be taken with caution, as stimulation over OFA may affect object-selective adjacent regions. (c) 2015 APA, all rights reserved).
Authors: Elizabeth Heinrichs-Graham; Timothy J McDermott; Mackenzie S Mills; Nathan M Coolidge; Tony W Wilson Journal: Cortex Date: 2016-12-07 Impact factor: 4.027
Authors: Tony W Wilson; Timothy J McDermott; Mackenzie S Mills; Nathan M Coolidge; Elizabeth Heinrichs-Graham Journal: Cereb Cortex Date: 2018-05-01 Impact factor: 5.357