*Article* **Left-Hemispheric Asymmetry for Object-Based Attention: an ERP Study**

#### **Andrea Orlandi \* and Alice Mado Proverbio**

Neuro-MI, Milan Center for Neuroscience, Dept. of Psychology, University of Milano - Bicocca, Milan 20126, Italy; mado.proverbio@unimib.it

**\*** Correspondence: a.orlandi5@campus.unimib.it; Tel.: +39-02-64483866

Received: 26 September 2019; Accepted: 6 November 2019; Published: 8 November 2019

**Abstract:** It has been shown that selective attention enhances the activity in visual regions associated with stimulus processing. The left hemisphere seems to have a prominent role when non-spatial attention is directed towards specific stimulus features (e.g., color, spatial frequency). The present electrophysiological study investigated the time course and neural correlates of object-based attention, under the assumption of left-hemispheric asymmetry. Twenty-nine right-handed participants were presented with 3D graphic images representing the shapes of different object categories (wooden dummies, chairs, structures of cubes) which lacked detail. They were instructed to press a button in response to a target stimulus indicated at the beginning of each run. The perception of non-target stimuli elicited a larger anterior N2 component, which was likely associated with motor inhibition. Conversely, target selection resulted in an enhanced selection negativity (SN) response lateralized over the left occipito-temporal regions, followed by a larger centro-parietal P300 response. These potentials were interpreted as indexing attentional selection and categorization processes, respectively. The standardized weighted low-resolution electromagnetic tomography (swLORETA) source reconstruction showed the engagemen<sup>t</sup> of a fronto-temporo-limbic network underlying object-based visual attention. Overall, the SN scalp distribution and relative neural generators hinted at a left-hemispheric advantage for non-spatial object-based visual attention.

**Keywords:** selective attention; object-based attention; hemispheric asymmetry; ERP; selection negativity; swLORETA; anterior cingulate cortex; visual recognition
