In pursuit of visual attention: SSVEP frequency-tagging moving targets

Abstract

Previous research has shown that visual attention does not always exactly follow gaze direction, leading to the concepts of overt and covert attention. However, it is not yet clear how such covert shifts of visual attention to peripheral regions impact the processing of the targets we directly foveate as they move in our visual field. The current study utilised the coregistration of eye-position and EEG recordings while participants tracked moving targets that were embedded with a 30 Hz frequency tag in a Steady State Visually Evoked Potentials (SSVEP) paradigm. When the task required attention to be divided between the moving target (overt attention) and a peripheral region where a second target might appear (covert attention), the SSVEPs elicited by the tracked target at the 30 Hz frequency band were significantly, but transiently, lower than when participants did not have to covertly monitor for a second target. Our findings suggest that neural responses of overt attention are only briefly reduced when attention is divided between covert and overt areas. This neural evidence is in line with theoretical accounts describing attention as a pool of finite resources, such as the perceptual load theory. Altogether, these results have practical implications for many real-world situations where covert shifts of attention may discretely reduce visual processing of objects even when they are directly being tracked with the eyes.

Neuropsychological and Neurophysiological Mechanisms behind Flickering Light Stimulus Processing

“…De Lissa et al [ 83 ] used the frequency tagging method to assess visual attention in the smooth-pursuit paradigm, where 17 participants had to follow a moving target and react when it reached the goal area (1st paradigm) or follow this target and switch their attention when the second one, flickering at 30 Hz, occurs and follow it until it reaches the goal area (2nd paradigm). Researchers found that SSVEP power decreased early and rapidly when the individuals had to divide their attention.…”

An investigation of inattentional blindness using gaze and frequency tagging.

“…The novelty of the SSVEP effect observed is likely due to complications inherent to the sustained IB paradigm. SSVEP magnitude is attenuated when attention is divided across hemifields (Toffanin et al, 2009), directed to moving targets (De Lissa et al, 2020), and/ or is directed to targets in the periphery (Chen et al, 2017). Parsing out the isolated signal of each concurrent stimulus within the aggregate neural response also remains a challenge with the presentation of multiple simultaneous moving stimuli.…”

The Relative Contribution of Executive Functions and Aging on Attentional Control During Road Crossing

“…It remains undetermined whether, in the present study, participants' overt attention was automatically attracted toward the pedestrian distractors, or conversely whether they voluntarily gazed at pedestrian distractors and covertly attended to cars. This question could be addressed using the approach based on eye-tracking and Steady State Visual Evoked Potentials that we recently developed, and which allowed us to demonstrate that covert shifts of attention reduce visual processing of objects even when they are directly tracked with the eyes (de Lissa et al, 2020 ).…”