Brain and Cognition 59 (2005) 103–113 www.elsevier.com/locate/b&c 0278-2626/$ - see front matter  2005 Elsevier Inc. All rights reserved. doi:10.1016/j.bandc.2005.05.013 Neural correlates of temporal-order judgments versus those of spatial-location: Deactivation of hippocampus may facilitate spatial performance P.V. Rekkas a,¤ , M. Westerveld b,c,d , P. Skudlarski a , J. Zumer a , K. Pugh c , D.D. Spencer b , R.T. Constable a,b,d a Department of Diagnostic Radiology, Yale University, New Haven, CT 06520, USA b Department of Neurosurgery, Yale University, New Haven, CT 06520, USA c Department of Pediatrics, Haskin’s Laboratories, New Haven, CT 06510, USA d Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA Accepted 12 May 2005 Available online 15 September 2005 Abstract The retrieval of temporal-order versus spatial-location information was investigated using fMRI. The primary Wnding in the hip- pocampus proper, seen in region of interest analyses, was an increase in BOLD signal intensity for temporal retrieval, and a decrease in signal intensity for spatial retrieval, relative to baseline. The negative BOLD signal change with spatial memory processing, while unexpected, is consistent with the recent fMRI literature indicating decreased BOLD can be associated with neuronal activation, and it is argued that the deactivation observed here may facilitate spatial performance. Spatial-location judgments also yielded a stronger (positive) response in the right midfrontal gyrus, while temporal-order judgments (autobiographic condition only) showed greater activity in the left superior temporal gyrus, suggesting greater working memory demands and greater semantization for each judg- ment type, respectively. Finally, all conditions activated the left midfrontal gyrus, although autobiographic memories showed addi- tional activity in the medial frontal gyrus.  2005 Elsevier Inc. All rights reserved. Keywords: Memory recall; Episodic memory; Autobiographic; Semantic; Hippocampus; Deactivation; Functional neuroimaging; fMRI; Spatial- location; Temporal-order 1. Introduction There is strong evidence to implicate the hippocampal formation in spatial processing. This hypothesis has been supported in the rodent literature (Morris, Garrud, Rawlins, & O’Keefe, 1982; Morris, Anderson, Lynch, & Baudry, 1986; Silva, Paylor, Wehner, & Tonegawa, 1992; Tsien, Huerta, & Tonegawa, 1996), work with non- human primates (GaVan, 1998; GaVan & Harrison, 1989a, 1989b; Murray, Baxter, & GaVan, 1998; Murray, Davidson, GaVan, Olton, & Suomi, 1989), and within the human population (Ghaem et al., 1997; Maguire, Frac- kowiak, & Frith, 1997; Maguire et al., 1998; Rosenbaum et al., 2000). In fact, it has been argued that lesions to the hippocampus produce a speciWc disruption to the pro- cessing of spatial information, and that subsequent problems with general memory are secondary to, or an indirect result of, compromised spatial function (for dis- cussion see GaVan, 2001). In contrast, the role of the hippocampus in temporal- order discriminations is less clear. Judgements of tempo- ral-order are usually thought to rely on the frontal lobe * Corresponding author. Fax: +1 203 785 6534. E-mail address: vivien.rekkas@yale.edu (P.V. Rekkas).