Anisotropy of lateral peripersonal space is linked to handedness

Abstract

The space immediately surrounding our bodies, i.e., peripersonal space (PPS), is a critical area for the interaction with the external world, be it to deal with imminent threat or to attain objects of interest. In the brain, a dedicated system codes PPS in motor terms for the purpose of action. Yet, humans have asymmetric motor abilities: the dominant hand has an advantage in term of movements' precision and reaction time. Furthermore, spatial attention is asymmetric and seems to be linked to a right hemispheric dominance for spatial processing. Here, we tested whether handedness and attentional asymmetries impact the detection of a tactile stimulus when an irrelevant auditory stimulus is looming towards the individual from the right or left hemispace. We examined the distance at which sound started speeding up tactile detection to estimate the morphometry of peri-trunk PPS. Our results show that right-handers' PPS is larger in the left than in the right hemispace, whereas left-handers' PPS is symmetric. The expansion of right-handers' PPS on the side of the non-dominant hand is coherent with a protective function of PPS. Left-handers' symmetric PPS can be related to the symmetric request of their motor abilities induced by living in a right-handers' world. These findings reveal that PPS is not uniform and suggest that general mechanisms of spatial processing as well as motor skills could play a role in the representation of peri-trunk PPS.

Capturing the dynamics of peripersonal space by integrating expectancy effects and sound propagation properties

“…Thus, PPS might not be an inor-out zone. In line with this result, previous studies suggested that, within PPS, the distance between an auditory or visual stimuli continues to influence tactile detection (de Haan et al, 2016;Hobeika et al, 2018) and action preparation (Camponogara et al, 2015) This logarithmic function is also coherent with the theoretical framework proposed by Bufacchi and Iannetti, who described PPS as an action field, in which responses are graded with proximity (Bufacchi and Iannetti, 2018).…”

“…All of them were right-handed. As PPS is linked to handedness (Hobeika et al, 2018), participants' handedness was verified with a questionnaire measuring skilled hand preference. The scores on this questionnaire, called the Flinders Handedness survey (FLANDERS) (Nicholls et al, 2013), range from -10 for strong left-handed individuals to +10 for strong right-handed individuals.…”

Capturing the dynamics of peripersonal space by integrating sound propagation properties and expectancy effects

“…Thus, PPS might not be an in-or-out zone. In line with this result, previous studies suggested that, within PPS, the distance between an auditory or visual stimuli continues to influence tactile detection (de Haan et al, 2016;Hobeika et al, 2018) and action preparation (Camponogara et al, 2015) This logarithmic function is also coherent with the theoretical framework proposed by Bufacchi and Iannetti, who described PPS as an action field, in which responses are graded with proximity (Bufacchi and Iannetti, 2018).…”

Lower limb peripersonal space and the desire to amputate a leg

“…Although, asymmetries in left and right PPS have been revealed before. One study showed that right-handed people have a larger PPS on their left side, whereas left-handed people have a similar PPS for both sides of the body (Hobeika, Viaud-Delmon, & Taffou, 2018). Moreover, people who have had an upper limb amputation have a smaller PPS around the stump than for the intact limb (Canzoneri et al, 2013a).…”