Effects of the unilateral dynamic handgrip on resting cortical activity levels: A replication and extension

Effects of unilateral dynamic handgrip on reaction time and error rate

“…This has been termed left-hand dynamic handgrip or LDH. The data from these studies also showed that a depression of cortical excitability (i.e., increase power in alpha waves) in both hemispheres after the left-hand (but not the right hand) intervention was terminated (Cross-Villasana et al 2015;Mirifar et al 2020). Thus, LDH appeared to generate a relaxation effect that can reduce or eliminate performance deterioration in motor tasks under pressure (Beckmann et al 2013;Gröpel and Beckmann 2017).…”

“…Therefore, we hypothesize that LDH will have different effects on SRT and CRT. This hypothesis is based on the fact that the LDH has been shown to increase alpha power across the whole cortex (a finding that has been robustly shown in several EEG studies, e.g., Cross-Villasana et al 2015;Hirao and Masaki 2018;Mirifar et al 2020), which might influence perception and the underlying internal motor-cognitive processes-notably attentive sensory-motor mapping and response selection-in response time tasks. An accumulating body of data suggests that interareal alpha-phase synchronization could support attentional, executive, and contextual functions (Palva and Palva 2011).…”

“…As a result, researchers have been looking for ways to improve reaction times using different techniques, ranging from simple cognitive training (see e.g., Simpson et al 2012) to more complicated approaches such as brain stimulation (see e.g., Angelakis et al 2007), to treat impairments in these abilities caused by mental disorders and/or to optimize individual performance (see e.g., Hashemian et al 2013;Hatfield et al 2009;Jeunet et al 2019). Embodied interventions-bodily actions intended to change cortical activity in order to change behaviors (Beckmann et al 2013;Mirifar et al 2020)-have also attracted attention in this area because they offer a practical, easily accessible, and affordable approach. One such simple but effective embodied intervention is dynamic handgrip; Editors: Alessandro D'Ausilio (University of Ferrara); Arran Reader (University of Stirling) Reviewers: two researchers who prefer to remain anonymous.…”

“…This phenomenon was mostly tested during the contraction phase and, based on the behavioral outcomes, was usually assumed to persist after termination of contractions (see e.g., Harmon-Jones 2006). However, no secondary resting states had been assessed post-contraction, until Cross-Villasana et al (2015) and Mirifar et al (2020), who tested the neurophysiological after effects of such unilateral hand contractions. These studies showed a long lasting reduction in cortical activity (indicated by an increase in the power/amplitude of alpha waves) after unilateral upper limb contractions, a change which was especially evident when the left hand was dynamically contracted.…”

Preventing a loss of accuracy of the tennis serve under pressure

“…In the control groups of all three studies, participants squeezed the ball with the right hand, which did not eliminate choking. However, EEG studies [21,22] showed that the hand clenching does not produce a shift of activation from the left to the right brain hemisphere but triggers relaxation (high alpha wave) that spreads across the whole cortex, producing a state of reduced cortical activity in the left brain hemisphere. In line with this, Hoskens et al [23] argue that an engagement in movement control is associated with verbal-analytical processing (i.e., the planning and reasoning of an action framed in words).…”