Three-dimensional coherence of the conscious body image
Longo, Matthew R. (2015) Three-dimensional coherence of the conscious body image. Quarterly Journal of Experimental Psychology 68 (6), pp. 1116-1123. ISSN 1747-0218.
We experience our body as a coherent object in the three-dimensional (3-D) world. In contrast, the body is represented in somatosensory cortex as a fragmented collection of two-dimensional (2-D) maps. Recent results have suggested that some forms of higher-level body representations maintain this fragmentation, for example by showing different patterns of distortion for two surfaces of a single body part, such as the palmar and dorsal hand surfaces. This study investigated the 3-D coherence of the conscious body image of the hand by comparing perceptual biases of perceived hand shape on the dorsal and palmar surfaces. Participants made forced-choice judgments of whether observed hand images were thinner or wider than their own left or right hand, and perceptual distortions of the hand image were assessed by fitting psychometric functions. The results suggested that the hand is consciously represented as a fully coherent, 3-D object. Specifically: (1) similar overall levels of distortion were found on the palmar and dorsal hand surfaces, (2) comparable laterality effects were found on both surfaces (left hand represented as wider than right hand), and (3) the magnitude of distortions were strongly correlated across the two surfaces. Whereas other recent results have suggested that perceptual abilities such as position sense, tactile size perception, and tactile localisation may rely on fragmented, 2-D representations of individual skin surfaces, the present results suggest that, in striking contrast, the conscious body image represents the body (or, at least the hand) as a coherent, 3-D object.
|Additional Information:||This is an Accepted Manuscript of an article published in Quarterly Journal of Experimental Psychology on October 14th 2014, available online: http://www.tandfonline.com/10.1080/17470218.2014.975731|
|School:||Birkbeck Schools and Departments > School of Science > Psychological Sciences|
|Research Centre:||Brain and Cognitive Development, Centre for (CBCD)|
|Depositing User:||Matthew Longo|
|Date Deposited:||16 Oct 2014 07:41|
|Last Modified:||02 Dec 2016 11:52|
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