Recency effects in HIV-associated dementia are characterized by deficient encoding.
The aim of the present study was to investigate the nature and cognitive mechanisms of serial position learning effects in HIV-associated dementia (HAD). Participants were 16 persons with HAD, 50 non-demented persons with HIV-infection, and 50 demographically comparable HIV-seronegative participants. HAD participants, relative to both comparison groups, exhibited reduced middle region (p<0.01) and elevated recency region (p<0.05) recall on the Hopkins Verbal Learning Test-Revised, but no primacy region effect (p>0.10). On recognition testing, the HAD group was impaired in discriminating targets from distractors (p<0.01) in all three serial position regions; however, they were not impaired on measures of retrieval (p>0.10) within these same regions. In sum, HAD participants relied disproportionately on recency regions of the list, indicating a passive recall style of echoing only the words within their auditory attention span. Interestingly, HAD participants did not evidence significant improvement on measures of recognition, a finding that suggests that the serial position effects are most consistent with a primary encoding deficit.
Scott
J Cobb
JC
Department of Psychiatry (0847), University of California, San Diego, School of Medicine, La Jolla, CA 92093, USA.
Woods
Steven Paul
SP
Patterson
Katherine A
KA
Morgan
Erin E
EE
Heaton
Robert K
RK
Grant
Igor
I
Marcotte
Thomas D
TD
D015526:AIDS Dementia Complex / Q000503:physiopathology*; D000328:Adult; D003710:Demography; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000503:physiopathology; D006801:Humans; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D014706:Verbal Learning / Q000502:physiology*