The purpose of the present study was to investigate by using positron emission tomography (PET) whether the cortical pathways that are involved in visual perception of spatial location and object identity are also differentially implicated in retrieval of these types of information from episodic long-term memory. Subjects studied a set of displays consisting of three unique representational line drawings arranged in different spatial configurations. Later, while undergoing PET scanning, subjects' memory for spatial location and identity of the objects in the displays was tested and compared to a perceptual baseline task involving the same displays. In comparison to the baseline task, each of the memory tasks activated both the dorsal and the ventral pathways in the right hemisphere but not to an equal extent. There was also activation of the right prefrontal cortex. When PET scans of the memory tasks were compared to each other, areas of activation were very circumscribed and restricted to the right hemisphere: For retrieval of object identity, the area was in the inferior temporal cortex in the region ofthe fusiform gyrus (area 37), whereas for retrieval of spatial location, it was in the inferior parietal lobule in the region of the supramarginal gyrus (area 40). Thus, our study shows that distinct neural pathways are activated during retrieval of information about spatial location and object identity from long-term memory.A primary question in research on the neuroanatomical basis of memory is whether long-term memory (LTM) for object identity and spatial location is mediated by different neural systems (1-5). With regard to perception, studies in humans and other species have indicated that the dorsal visual pathway that includes regions of parietal cortex is involved in perception of spatial location, whereas the ventral visual pathway that includes structures in inferotemporal cortex is involved in processing information about object identity § (6,(8)(9)(10)(11)(12). Models of recognition memory have posited that the very pathways involved in perceptual processing of stimuli also participate in their storage and recovery (13)(14)(15). Recovery of information about spatial location and object identity from LTM should, therefore, activate the dorsal and ventral pathways differentially. Partial support for this hypothesis comes from positron emission tomography (PET) studies in humans in which it has been reported that retrieval from LTM for words and faces activates areas in the posterior and inferior convexity of the temporal lobes, structures that are also involved in perception of these materials (16,17). There are no PET studies, however, on LTM for spatial location nor any studies designed to determine whether memory for the location and identity of the The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact. 3721 very same stimuli is mediated b...
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.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.