Content area
Full Text
Brain Struct Funct (2012) 217:735746 DOI 10.1007/s00429-011-0369-y
ORIGINAL ARTICLE
The role of temporo-parietal junction (TPJ) in global Gestalt perception
Elisabeth Huberle Hans-Otto Karnath
Received: 16 August 2011 / Accepted: 1 December 2011 / Published online: 23 December 2011 Springer-Verlag 2011
Abstract Grouping processes enable the coherent perception of our environment. A number of brain areas has been suggested to be involved in the integration of elements into objects including early and higher visual areas along the ventral visual pathway as well as motion-processing areas of the dorsal visual pathway. However, integration not only is required for the cortical representation of individual objects, but is also essential for the perception of more complex visual scenes consisting of several different objects and/or shapes. The present fMRI experiments aimed to address such integration processes. We investigated the neural correlates underlying the global Gestalt perception of hierarchically organized stimuli that allowed parametrical degrading of the object at the global level. The comparison of intact versus disturbed perception of the global Gestalt revealed a network of cortical areas including the temporo-parietal junction (TPJ), anterior cingulate cortex and the precuneus. The TPJ location corresponds well with the areas known to be typically lesioned in stroke patients with simultanagnosia following bilateral brain damage. These patients typically show a decit in identifying the global Gestalt of a visual scene. Further, we found the closest relation between behavioral performance and fMRI activation for the TPJ. Our data thus argue for a signicant role of the TPJ in human global Gestalt perception.
Keywords fMRI Global/Local Perception
Simultanagnosia Temporal cortex Parietal cortex
Human
Introduction
Several decades ago, Gestalt psychologists (Wertheimer 1923; Koffka 1935) suggested that grouping processes enable the intact perception of our environment. Meanwhile, perceptual grouping has been accepted as a main principle in object recognition. Early work by Treisman and Gelade (1980) suggested that beneath conscious awareness, individual objects (so-called features) are represented in a master map and features such as proximity, motion and orientation group together (Kramer and Jacobsen 1991; Kapadia et al. 1995; Ferber et al. 2003). Numerous studies have focused on the ability of a coherent representation of objects and shapes, especially in the context of integration mechanisms along the ventral visual pathway (e.g., Malach et al. 1995; Gilbert et al....