title: Executive Dyscontrol of Learning and Memory: Findings from a Clade C HIV-positive South African Sample.
abstract: OBJECTIVE
  Although pre-clinical work suggests there might be differences in neurovirulence across HIV-1 clades, few studies investigate neuropsychological deficits in the globally predominant clade C infection. The purpose of this study was to investigate verbal learning and memory performance in HIV-positive individuals in Cape Town, South Africa, where clade C is the most prevalent subtype of the virus.
  
  
  METHODS
  Using a case-control design, we recruited 53 isiXhosa-speaking, cART-naïve HIV-positive adults and 53 demographically matched HIV-negative controls. Participants were administered a comprehensive neuropsychological test battery. The test of interest was the Hopkins Verbal Learning Test-Revised (HVLT-R); previous studies have used that instrument to identify executive dyscontrol of verbal learning and memory processes in clade B HIV-positive participants.
  
  
  RESULTS
  HIV-positive participants showed only partial impairment on the HVLT-R's learning/memory components (e.g., they recalled significantly fewer words across learning trials, but displayed relatively intact performance on delayed recall trials). They also displayed little executive dyscontrol over encoding and retrieval processes (e.g., there were no significant between-group differences on measures of semantic or serial clustering).
  
  
  CONCLUSIONS
  Post-cART era studies suggest that verbal learning and memory performance is impaired in clade B samples, at least partially due to executive dyscontrol over encoding and retrieval processes. We found few such impairments in the current clade C sample. These preliminary findings suggest different CNS vulnerability across clades that would have implications for delineating clade-specific neuropathological and neurocognitive clinical features.
authors.affiliation: a ACSENT Laboratory, Department of Psychology , University of Cape Town , Cape Town , South Africa.
authors.forename: Jade A
authors.initials: JA
authors.lastname: Witten
authors.affiliation: a ACSENT Laboratory, Department of Psychology , University of Cape Town , Cape Town , South Africa.
authors.forename: Kevin G F
authors.initials: KG
authors.lastname: Thomas
authors.affiliation: b Department of Psychiatry and Mental Health , University of Cape Town , Cape Town , South Africa.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Westgarth-Taylor
authors.affiliation: b Department of Psychiatry and Mental Health , University of Cape Town , Cape Town , South Africa.
authors.forename: John A
authors.initials: JA
authors.lastname: Joska
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D056344:Executive Function; D005260:Female; D015658:HIV Infections / Q000523:psychology*; D006801:Humans; D007858:Learning; D008297:Male; D008568:Memory; D011939:Mental Recall; D008875:Middle Aged; D012660:Semantics; D013019:South Africa; D014706:Verbal Learning
keywords: Clade C; Executive dyscontrol; HIV; Prefrontostratial circuitry; Verbal learning and memory.