Visual search under physical effort is faster but more vulnerable to distractor interference

Abstract

Cognition and action are often intertwined in everyday life. It is thus pivotal to understand how cognitive processes operate with concurrent actions. The present study aims to assess how simple physical effort operationalized as isometric muscle contractions affects visual attention and inhibitory control. In a dual-task paradigm, participants performed a singleton search task and a handgrip task concurrently. In the search task, the target was a shape singleton among distractors with a homogeneous but different shape. A salient-but-irrelevant distractor with a unique color (i.e., color singleton) appeared on half of the trials (Singleton distractor present condition), and its presence often captures spatial attention. Critically, the visual search task was performed by the participants with concurrent hand grip exertion, at 5% or 40% of their maximum strength (low vs. high physical load), on a hand dynamometer. We found that visual search under physical effort is faster, but more vulnerable to distractor interference, potentially due to arousal and reduced inhibitory control, respectively. The two effects further manifest in different aspects of RT distributions that can be captured by different components of the ex-Gaussian model using hierarchical Bayesian method. Together, these results provide behavioral evidence and a novel model for two dissociable cognitive mechanisms underlying the effects of simple muscle exertion on the ongoing visual search process on a moment-by-moment basis.

Detrimental Effects of Effortful Physical Exertion on Cognitive Control in Younger and Older Adults

“…More importantly, the decline in cognitive inhibition in older adults seems amplified by the concurrent high physical load. This effect may be accompanied by an arousal-based enhancement effect (also see Park et al, 2021) which manifested as opposite patterns in μ and τ components of the ex-Gaussian analyses of the WM task RTs in the present study. It is however possible that the two effects may stem from the same neurocognitive mechanism.…”

“…For instance, engaging in a concurrent handgrip task during long-term memory encoding can impair later retrieval in young adults (Tomporowski et al, 2017). More importantly, task-irrelevant distractors can more easily capture visual attention (Park et al, 2021) and get encoded into WM (Cappiello et al, 2018) under concurrent physical effort. These inhibition-based effects of physical effort provide an intriguing perspective to look at functional declines in older adults given the widely observed age-related declines in cognitive control.…”

“…Physical load was operationalized as handgrip force exertion at different subject-specific maximum voluntary contraction (MVC, 5% versus 30%), independent of individual differences in muscular strength and fitness level. Given that high physical load impairs inhibitory control (Park et al, 2021), it is hypothesized that 1) inhibitory control of access to WM will be compromised under high physical load and 2) this effect will be amplified by age. Accordingly, it was predicted that 1) worse performance in the WM task will manifest in the 5-distractor condition than the 0-distractor condition under high physical load, but similar performance between the two distractor conditions under low physical load; and 2) this two-way interaction will be more pronounced in the older adults than younger adults, yielding a significant three-way interaction.…”

Examining the ability to track multiple moving targets as a function of postural stability: a comparison between team sports players and sedentary individuals

“…Of note, the cognition-action interaction in the domain of visual attention involves arousal processes ( Davranche & Audiffren, 2004 ), but also, inhibitory control processes play a role in this activity ( Tiego et al, 2018 ). Recently, Park, Ahn & Zhang (2021) examined the impact of performing physical effort (handgrip exertion) at two intensity levels on visual search. They found a faster behavioral performance with physical effort due to the arousing effects of handgrip exertion, however, the most physically demanding condition caused a heightened interference from the singleton distractor and impaired cognitive performance as consequence of the reduced inhibitory control.…”

Effortfulness of Visual Working Memory: Gauged by Physical Exertion

“…These study items were randomly presented on an invisible circle with a radius of 6.5° visual angle from the center of the screen. For the handgrip task, a digital hand dynamometer (Vernier Software & Technology, Beaverton, OR) was used to collect participants hand force (Docx et al, 2015;Park, Ahn, & Zhang, 2021;Stanek & Richter, 2016).…”