Development of Memory for Spatial Locations and Object/Place Associations in Infant Rhesus Macaques with and without Neonatal Hippocampal Lesions

• Type of Material: Article
• Authors: Shala N. Blue, Emory University; Andrew M. Kazama, Emory University; Jocelyne Bachevalier, Emory University
• Language: English
• Date: 2013-11
• Publisher: Cambridge University Press (CUP)
• Publication Version: Final Published Version
• Copyright Statement: © The International Neuropsychological Society 2013
• Final Published Version (URL): http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=9065692&fileId=S1355617713000799
• Title of Journal or Parent Work: Journal of the International Neuropsychological Society
• ISSN: 1355-6177
• Volume: 19
• Issue: 10
• Start Page: 1053
• End Page: 1064
• Grant/Funding Information: This work was supported by the National Institute of Mental Health (MH-58846), National Center for Research Resources P51RR165, currently supported by the Office of Research Infrastructure Programs/OD P51OD11132, and by Center for Behavioral Neuroscience grant NSF IBN-9876754.
• Keywords: Allocentric space; Macaca mulatta; Visual-paired comparison task; Parahippocampal cortex; Developmental amnesia; Egocentric space
• Research Categories: Psychology, General; Biology, Neuroscience; Health Sciences, Human Development

Abstract

This study traces the development of spatial memory abilities in monkeys and reports the effects of selective neonatal hippocampal lesions on performance across development. Two different versions of the visual paired-comparison (VPC) task were used. The VPC-Spatial-Location task tested memory for object-locations that could be solved using an egocentric spatial frame of reference and the VPC-Object-In-Place task taxed memory for spatial relations using an allocentric reference frame. Eleven rhesus macaques (6 neonatal sham-operated controls and 5 with neonatal neurotoxic hippocampal lesions) were tested on both tasks as infants (8 months), juveniles (18 months), and adults (5–6 years). Memory for spatial locations was present by 18 months of age, whereas memory for object-place relations was present only in adulthood. Also, neonatal hippocampal lesions delayed the emergence of memory for spatial locations and abolished memory for object-place associations, particularly in animals that had sustained extensive and bilateral hippocampal lesions. The differential developmental time course of spatial memory functions and of the effects of neonatal hippocampal lesions on these functions are discussed in relation to morphological maturation of the medial temporal lobe structures in monkeys. Implications of the findings for the neural basis of spatial memory development in humans are also considered.