The asymmetrical influence of increasing time-on-task on attentional disengagement

Abstract

Increasing time-on-task leads to fatigue and, as shown by previous research, differentially affects the deployment of visual attention towards the left and the right visual space. In healthy participants, an increasing rightward bias is commonly observed with increasing time-on-task. Yet, it is unclear whether specific mechanisms involved in the spatial deployment of visual attention are differentially affected by increasing time-on-task. The aim of the present study was to investigate whether prolonged time-on-task would affect a specific mechanism of visuospatial attentional deployment, namely attentional disengagement, in an asymmetrical fashion. For this purpose, we administered to healthy participants a prolonged gap/overlap saccadic paradigm, with left- and right-sided target stimuli. This oculomotor paradigm allowed to quantify disengagement costs according to the direction of the subsequent attentional shifts, and to evaluate the temporal development of disengagement costs with increasing time-on-task. Our results show that, with increasing time-on-task, participants demonstrated significantly lower disengagement costs for rightward compared to leftward saccades. These effects were specific, since concurring side differences of saccadic latencies were found for overlap trials (requiring attentional disengagement), but not for gap trials (requiring no or less attentional disengagement). Moreover, the results were paralleled by a non-lateralised decrease in saccadic peak velocity with increasing time-on-task, a common finding indicating an increasing level of fatigue. Our findings support the idea that non-spatial attentional aspects, such as fatigue due to increasing time-on-task, can have a substantial influence on the spatial deployment of visual attention, in particular on its disengagement, depending on the direction of the subsequent attentional shift.

Trial‐by‐trial co‐variation of pre‐stimulusEEGalpha power and visuospatial bias reflects a mixture of stochastic and deterministic effects

“…It has been suggested that rightward shifts in spatial attention with time‐on‐task occur due to an interaction between spatial and non‐spatial aspects of attention such as alertness/fatigue (Manly et al ., ; Fimm et al ., ; Dufour et al ., ; Paladini et al ., , ; see also Newman et al ., , ). In Corbetta & Shulman's () neuroanatomical attention model, depletion of the primarily right lateralized ‘alertness’ network (Sturm & Willmes, ) results in decreased recruitment of the RH dorsal frontoparietal attention network (DAN) which would be expected to reduce pseudoneglect, that is to induce a rightward shift in spatial bias.…”

The Influence of Alertness on the Spatial Deployment of Visual Attention is Mediated by the Excitability of the Posterior Parietal Cortices

“…These spatial and non-spatial aspects of attention are thought to interact with each other, whereby non-spatial attention can modulate the deployment of visual attention in space. In fact, previous research has shown that, with a reduced level of alertness (triggered by different manipulations, such as sleep deprivation, circadian rhythmicity, or increasing time-on-task), healthy participants typically show a rightward shift when deploying visual attention in space (e.g., Manly et al 2005 ; Fimm et al 2006 ; Dufour et al 2007 ; Heber et al 2008 ; Matthias et al 2009 ; Benwell et al 2013 ; Newman et al 2013 ; Dorrian et al 2015 ; Paladini et al 2016 ). However, to date, the neural basis of this interaction between spatial and non-spatial attentional aspects is poorly understood, and the neurophysiological substrate of the above-mentioned rightward attentional shift with a reduced level of alertness is largely unknown.…”

Spatial and non-spatial aspects of visual attention: Interactive cognitive mechanisms and neural underpinnings

“…Two papers included in this special issue analysed eye movements in order to assess the effects of a manipulation of non-spatial attentional aspects (i.e., fatigue or decreasing arousal) on the spatial deployment of visual attention. Paladini, et al (2016) manipulated the level of fatigue in healthy individuals by means of increasing time-on-task, and measured spatial attentional deployment by means of a saccadic paradigm, in which horizontal left-and right-sided saccades had to be produced. The authors showed that, with increasing time-on-task and fatigue, the attentional deployment was affected asymmetrically, in that attentional disengagement costs became significantly lower for rightward than for leftward saccades.…”

“…A direct comparison of the paradigms applied by Paladini et al (2016) and Fimm et al (2016) reveals at least two central differences: i) the type of manipulation of non-attentional aspects, i.e., increasing fatigue due to increasing time on task vs. decreasing arousal due to sleep deprivation; and, ii) the amount of trials administered during a testing session (with lateralized effects on attentional disengagement seeming to appear only after a conspicuous amount of trials). Overall, the results seem thus to support the idea that eye movement analysis can reveal interactions between nonspatial attentional aspects and spatial ones.…”