To compare temporal order memory in older adults with and without human immunodeficiency virus (HIV) infection.
The frontal and temporal lobes play a key role in temporal order memory for items in a sequence. HIV-associated episodic memory deficits correlate with damage to neocortical interneurons in the fronto-striato-thalamo-cortical pathway and with atypical activation of the medial temporal lobes. Therefore, temporal order memory may be sensitive to neuropathological changes in individuals with HIV.
In this study, 50 HIV-seropositive individuals aged ≥50 years and 50 seronegative controls performed a computerized visuospatial temporal order memory task. During the sample phase of each trial, participants were shown circles presented 1 at a time in a random sequence at the end of each of the 8 arms of a radial maze. During the choice phase, they were shown the maze with a circle at the ends of 2 of the arms and asked which circle had appeared earlier than the other in the original sequence.
Performance in both groups improved as a function of greater temporal separation between circle presentations. However, the HIV group had significantly worse memory impairment across all temporal separations, and the impairment was independently associated with clinical deficits in executive function and delayed retrospective memory.
Our results extend prior findings that HIV is associated with deficits in strategic aspects of memory encoding and retrieval. The neural mechanisms warrant further research, as do potential impacts on everyday function, eg, adherence to antiretroviral drug regimens.
*Department of Psychiatry, University of California San Diego, La Jolla, CA
†San Diego State University/University of California San Diego Joint Doctoral Program in Clinical Psychology, San Diego, CA
‡Department of Psychology, San Diego State University, San Diego, CA
Supported by National Institute of Mental Health grants R01-AG034202 (P.E.G.), R01-MH73419 (S.P.W.), and P30-MH62512 (I.G.). The views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the Navy, Department of Defense, or the US Government.
The San Diego HIV Neurobehavioral Research Program group is affiliated with the University of California San Diego, the Naval Hospital San Diego, and the Veterans Affairs San Diego Healthcare System, and includes: Director: Igor Grant, MD; Co-Directors: J. Hampton Atkinson, MD, Ronald J. Ellis, MD, PhD, and J. Allen McCutchan, MD; Center Manager: Thomas D. Marcotte, PhD; Jennifer Marquie-Beck, MPH; Melanie Sherman; Neuromedical Component: Ronald J. Ellis, MD, PhD (Principal Investigator), J. Allen McCutchan, MD, Scott Letendre, MD, Edmund Capparelli, PharmD, Rachel Schrier, PhD, Terry Alexander, RN, Debra Rosario, MPH, Shannon LeBlanc; Neurobehavioral Component: Robert K. Heaton, PhD (Principal Investigator), Steven Paul Woods, PsyD, Mariana Cherner, PhD, David J. Moore, PhD, Matthew Dawson; Neuroimaging Component: Terry Jernigan, PhD (Principal Investigator), Christine Fennema-Notestine, PhD, Sarah L. Archibald, MA, John Hesselink, MD, Jacopo Annese, PhD, Michael J. Taylor, PhD; Neurobiology Component: Eliezer Masliah, MD (Principal Investigator), Cristian Achim, MD, PhD, Ian Everall, FRCPsych, FRCPath, PhD (Consultant); Neurovirology Component: Douglas Richman, MD (Principal Investigator), David M. Smith, MD; International Component: J. Allen McCutchan, MD (Principal Investigator); Developmental Component: Cristian Achim, MD, PhD (Principal Investigator), Stuart Lipton, MD, PhD; Participant Accrual and Retention Unit: J. Hampton Atkinson, MD (Principal Investigator); Data Management Unit: Anthony C. Gamst, PhD (Principal Investigator), Clint Cushman (Data Systems Manager); Statistics Unit: Ian Abramson, PhD (Principal Investigator), Florin Vaida, PhD, Reena Deutsch, PhD, Anya Umlauf, MS.
The authors declare no conflicts of interest.
Reprints: Paul E. Gilbert, PhD, San Diego State University/University of California San Diego Joint Doctoral Program, 6363 Alvarado Court, Suite 103, San Diego, CA 92120-4913 (e-mail: firstname.lastname@example.org).
Received November 6, 2012
Accepted November 12, 2013