Object-based attentional selection modulates anticipatory alpha oscillations.

Balã¡Zs Knakker,Zoltã¡N Vidnyã¡Nszky,Bã©La Weiss

doi:10.3389/fnhum.2014.01048

Abstract

Visual cortical alpha oscillations are involved in attentional gating of incoming visual information. It has been shown that spatial and feature-based attentional selection result in increased alpha oscillations over the cortical regions representing sensory input originating from the unattended visual field and task-irrelevant visual features, respectively. However, whether attentional gating in the case of object based selection is also associated with alpha oscillations has not been investigated before. Here we measured anticipatory electroencephalography (EEG) alpha oscillations while participants were cued to attend to foveal face or word stimuli, the processing of which is known to have right and left hemispheric lateralization, respectively. The results revealed that in the case of simultaneously displayed, overlapping face and word stimuli, attending to the words led to increased power of parieto-occipital alpha oscillations over the right hemisphere as compared to when faces were attended. This object category-specific modulation of the hemispheric lateralization of anticipatory alpha oscillations was maintained during sustained attentional selection of sequentially presented face and word stimuli. These results imply that in the case of object-based attentional selection—similarly to spatial and feature-based attention—gating of visual information processing might involve visual cortical alpha oscillations.

Highlights

A remarkable ability of the visual system is that it can deal with the clutter of visual objects in our environment
ELECTROPHYSIOLOGY The results revealed that anticipatory alpha activity measured on parieto-occipital electrodes was modulated depending on whether participants were cued to attend to faces or words (Figure 2, thick lines; Figure 3), regardless of the presence of distractors (Figure 2, solid and dashed thin lines)
Our results revealed that during sequential presentation of word and face stimuli, the power of parieto-occipital alpha oscillations increased when attending to words, as compared to when faces were attended

Summary

Introduction

A remarkable ability of the visual system is that it can deal with the clutter of visual objects in our environment. A prominent neural signature of attentional distractor suppression is enhanced oscillatory activity in the alpha frequency band (Klimesch et al, 2007; Jensen and Mazaheri, 2010; Foxe and Snyder, 2011), which can be measured in human subjects non-invasively by means of electroencephalography (EEG) It is well-established that during spatial attentional tasks, the representation of the unattended visual space is inhibited through enhanced alpha activity in the corresponding parts of the visual cortex (Worden et al, 2000; Sauseng et al, 2005; Kelly et al, 2006; Thut et al, 2006; Rihs et al, 2007). It has been shown that this generalizes to feature-based attention: Snyder and Foxe (2010) demonstrated that anticipatory alpha band power increases can be localized more ventrally when the motion of the presented dot field was task-relevant, as compared to more dorsal sources when attending the color of the same dots

Methods

Results

Conclusion