Right but not left angular gyrus modulates the metric component of the mental body representation: a tDCS study

Abstract

The parietal lobes contribute to body-space representation. The present work aims at characterizing the functional role of the inferior parietal lobe in body-space representation and at studying the different roles of the angular gyrus in the right and left hemisphere. We conducted three separate transcranial direct current stimulation (tDCS) experiments using “tactile distance task” as an implicit measure of body representation. Whereas anodal tDCS on the right angular gyrus influences vocal reaction times (vRT) for stimuli delivered on the ipsilateral body parts without changes of accuracy, right tDCS improved both vRT and accuracy for tactile stimuli on the contralateral limbs. Sham or left parietal anodal tDCS had no effect. These evidences support the view that right parietal areas have a crucial role in the metric component of the body representation.

The two dimensions of the body representation in women suffering from Anorexia Nervosa

“…Serino and Haggard (2010) proposed that body representations are constructed from and reciprocally influenced by touch stimulations, so that the structure of the physical body organizes tactile sensations contributing to form body representations, which, in Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/psychres turn influence primary tactile processing and mediate the formation of object representation from primary tactile sensations. In line with this view, we and other authors have suggested that primary tactile processing responsible for detecting an object in contact with the skin, can be anatomically and functionally dissociated from a secondary higher-order tactile processing, such as the discrimination of the sizes of objects touching different body parts (Serino et al, 2008;Gallace and Spence, 2009;Spitoni et al, 2010Spitoni et al, , 2013 We have proposed that, in order to extract metric information from the skin surface, the brain has to link information related to the single locations on the skin where touch is applied with a representation of the stimulated body part, and therefore, a "tactile size estimation task" can be used as an implicit proxy of the body representations. (Keizer et al, 2011(Keizer et al, , 2012) used a tactile size estimation task to study tactile performance in patients suffering from AN and they found that relative to controls, AN patients overestimated the distance between two tactile stimuli for the stimulated body parts.…”

Increased Gray Matter Volume and Resting-State Functional Connectivity in Somatosensory Cortex and their Relationship with Autistic Symptoms in Young Boys with Autism Spectrum Disorder

“…Our finding of abnormal connectivity between right AG and left PCG may be the neural substrates leading to the deficit in integrating and coordinating multiple cognitive domains in ASD children. More specifically, research has demonstrated that the right AG plays a key role in tactile processing (Spitoni et al, 2013 ). Hypo- or hyper-sensitivity to touch and dysfunction of tactile discrimination have been commonly existed in ASD children, seriously affects their normal development and daily life.…”

Poor judgment of distance between nociceptive stimuli

“…These rescaling transformations are computed by several regions in the posterior parietal cortex (Azanon & Haggard, 2009; Cohen & Andersen, 2002; Longo et al, 2010; Maravita et al, 2003). In particular, the angular gyrus is involved in the estimation of tactile spatial distances (Spitoni, Galati, Antonucci, Haggard, & Pizzamiglio, 2010; Spitoni et al, 2013). The angular gyrus is also thought to play a role in the representation of magnitude (Walsh, 2003), which may be closely linked to the representation of spatial extent, or distance.…”