Finger agnosia refers to a neurological condition in which patients with left posterior parietal lesions fail to identify their fingers, despite having relatively preserved abilities in sensation and skilled action. This dissociation suggests that the structural body representations (BSRs) may be distinct from sensorimotor representations. However, recent research has reported that postural changes modulate representation of hand structure, revealing dynamic interactions between structural and sensorimotor body representations. However, it is unknown how and to what extent anatomical and spatial proximity contribute to shape the hand structural representation. We investigate this question using the "in-between" test in which participants estimate how many unstimulated fingers are in-between two touched fingers of the left hand placed palm down. The first phalange of the participants' fingers was touched on the left or right side. Judged finger numerosity was greater when fingers were stimulated on far sides (i.e., opposite sides of the two fingers) compared to when they were stimulated on close (i.e., sides facing each other's) or mid-distance (i.e., sides facing in the same direction) sides. Therefore, fingers identification was modulated both by anatomical and spatial proximity in external space between touches. This demonstrates that BSRs rely on both anatomical and external reference frames.
The original version of this Article contained an error in the spelling of the author Karina Dolgilevica, which was incorrectly given as Karina Dolgevica.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.