Getting a Grip on Memory: Unilateral Hand Clenching Alters Episodic Recall

Abstract

Unilateral hand clenching increases neuronal activity in the frontal lobe of the contralateral hemisphere. Such hand clenching is also associated with increased experiencing of a given hemisphere’s “mode of processing.” Together, these findings suggest that unilateral hand clenching can be used to test hypotheses concerning the specializations of the cerebral hemispheres during memory encoding and retrieval. We investigated this possibility by testing effects of unilateral hand clenching on episodic memory. The hemispheric Encoding/Retrieval Asymmetry (HERA) model proposes left prefrontal regions are associated with encoding, and right prefrontal regions with retrieval, of episodic memories. It was hypothesized that right hand clenching (left hemisphere activation) pre-encoding, and left hand clenching (right hemisphere activation) pre-recall, would result in superior memory. Results supported the HERA model. Also supported was that simple unilateral hand clenching can be used as a means by which the functional specializations of the cerebral hemispheres can be investigated in intact humans.

Unilateral Left-Hand Contractions Produce Widespread Depression of Cortical Activity after Their Execution

“…These effects have been attributed to an induced shift in activation asymmetry to the contralateral hemisphere induced through the contractions, hence enhancing the functions in which that hemisphere specializes and affecting performance in a subsequent task. Among the reported effects are heightened approach motivation after right contractions [ 1 , 2 , 4 ]; increased processing to global visual stimuli after left, and local stimuli after right contractions [ 5 ]; enhanced memory encoding after right, and retrieval after left contractions [ 3 ]; and prevention of motor skill failure under pressure after left hand contractions [ 6 ]. In the above studies, it is assumed that the activation asymmetry towards the contralateral hemisphere induced through unilateral hand contractions persists even after their termination (referred to hereafter as a persistent activity model ).…”

The impact of isometric handgrip exercise and training on health‐related factors: A review

“…Furthermore, the order of hands used for unilateral handgrip exercise may influence the episodic memory recall performance. The hypothesis was made on the basis of the hemispheric encoding/retrieval asymmetry model (Propper et al, 2013). This model proposes that the left prefrontal cortex plays an important role in memory encoding, whereas the right prefrontal cortex plays an important role in memory retrieval.…”

“…Six studies reported on the acute effect of isometric handgrip exercise on interference control (Stroop task and Flanker task) (Brown & Bray, 2015; Thibault et al, 2019) and episodic memory (word list free recall, and logical memory subtest of the Wechsler Memory Scale III, and Benton visual retention test) (Loprinzi et al, 2020; Nielson et al, 2014; Propper et al, 2013; Tomporowski et al, 2017) (Table 4). One study reported chronic changes in the performance of cognitive tasks associated with perception and motor speed (Trail making Test A) and overall executive functioning (Trail making Test B and controlled oral word association task) following isometric handgrip training (Dempster et al, 2018) (Table 4).…”

“I never imagined” pronunciation as “such an interesting thing”: Student teacher perception of innovative practices

“…The third source is current neurophysiological research on the role of movement and touch in learning (Minogue & Jones, 2006). That is, touch serves to bond a speaker's senses together (Fredembach, de Boisferon, & Gentaz, 2009) and enhances memory of events and language (Propper, McGraw, Brunyé, & Weiss, 2013). The fourth source is the proposition that kinaesthetic approaches to L2 pronunciation instruction facilitate learning (Acton, 1984).…”