Deficits in complex motor functions, despite no evidence of procedural learning deficits, among HIV+ individuals with history of substance dependence

Department of Psychiatry, University of Illinois-Chicago, USA.
Neuropsychology (Impact Factor: 3.27). 12/2008; 22(6):776-86. DOI: 10.1037/a0013404
Source: PubMed


Human immunodeficiency virus (HIV) and drugs of abuse affect common neural systems underlying procedural memory, including the striatum. The authors compared performance of 48 HIV seropositive (HIV+) and 48 HIV seronegative (HIV-) participants with history of cocaine and/or heroin dependence across multiple Trial Blocks of three procedural learning (PL) tasks: Rotary Pursuit (RP), Mirror Star Tracing (MST), and Weather Prediction (WP). Groups were well matched on demographic, psychiatric, and substance use parameters, and all participants were verified abstinent from drugs. Mixed model analyses of variance revealed that the individuals in the HIV+ group performed more poorly across all tasks, with a significant main effect of HIV serostatus observed on the Mirror Star Tracing and a trend toward significance obtained for the Rotary Pursuit task. No significant differences were observed on the Weather Prediction task. Both groups demonstrated significant improvements in performance across all three procedural learning tasks. It is important to note that no significant Serostatus x Trial Block interactions were observed on any task. Thus, the individuals in the HIV+ group tended to perform worse than those in the HIV- group across all trial blocks of procedural learning tasks with motor demands, but showed no differences in their rate of improvement across all tasks. These findings are consistent with HIV--associated deficits in complex motor skills, but not in procedural learning.

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Available from: Raul Gonzalez, Oct 01, 2015
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    • "It has been hypothesized that this shift depends primarily on implicit mechanisms (Brand et al., 2007), which are gradually superseded by executive (Brand et al., 2007) or declarative memory processes (Gupta et al., 2009). We have previously reported variable implicit learning performance among HIV+ compared with HIV– SDIs (Gonzalez et al., 2008; Martin, Gonzalez, Vassileva, & Maki, 2011). These prompted the question of whether serostatus effects on IGT performance among SDIs might be more prominent during the first three trial blocks—for example , that HIV+ SDIs' decision making might be more susceptible initially to ambiguity but eventually improved to the HIV– drug users' level of advantageous decision making. "
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    ABSTRACT: HIV+ substance-dependent individuals (SDIs) make significantly poorer decisions than HIV- SDIs, but the neurocognitive mechanisms underlying this impairment have not been identified. We administered the Iowa Gambling Task (IGT), a measure of decision making under uncertain risk, and the Cups Task, a measure of decision making under specified risk, to a group of 56 HIV+ and 23 HIV- men who have sex with men (MSMs) with a history of substance dependence enrolled in the Multicenter AIDS Cohort Study. The IGT provides no explicit information regarding the contingencies for each possible choice, and the probability of each outcome remains ambiguous at least for the early trials; in contrast, the Cups Task provides explicit information about the probability of each outcome. The HIV+ group made significantly poorer decisions on the IGT than the HIV- group. Cups Task performance did not differ significantly between HIV- and HIV+ groups. Exploratory analyses of the IGT data suggested that HIV+ subjects tended to perform more poorly during the early learning phase when uncertainty about specific outcomes was greatest. Additionally, performance on the final two trial blocks was significantly correlated with Stroop Interference scores, suggesting that IGT performance is driven increasingly by executive control during the later portion of the task. Potential cognitive mechanisms to be explored in later studies are discussed, including impairment in implicit learning processing.
    Journal of Clinical and Experimental Neuropsychology 05/2013; 35(6). DOI:10.1080/13803395.2013.799122 · 2.08 Impact Factor
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    • "In 1993, Martin and colleagues suggested that HAND may be associated with impaired motor skill learning, which Kalechstein et al. (1998) later showed may be exacerbated in individuals with comorbid depression. However, a larger and more comprehensive study of substance abusers by Gonzalez et al. (2008) revealed that, although HIV infection was associated with slowed complex motor skills (e.g., rotary pursuit), there was no evidence of impaired procedural learning per se. Although perceptual priming appears to be spared in HIV infection, HAND is nevertheless associated with deficits in semantic priming (e.g., Nielsen- Bohlman et al. 1997). "
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    ABSTRACT: Advances in the treatment of the human immunodeficiency virus (HIV) have dramatically improved survival rates over the past 10 years, but HIV-associated neurocognitive disorders (HAND) remain highly prevalent and continue to represent a significant public health problem. This review provides an update on the nature, extent, and diagnosis of HAND. Particular emphasis is placed on critically evaluating research within the realm of cognitive neuropsychology that aims to elucidate the component processes of HAND across the domains of executive functions, motor skills, speeded information processing, episodic memory, attention/working memory, language, and visuoperception. In addition to clarifying the cognitive mechanisms of HAND (e.g., impaired cognitive control), the cognitive neuropsychology approach may enhance the ecological validity of neuroAIDS research and inform the development of much needed novel, targeted cognitive and behavioral therapies.
    Neuropsychology Review 07/2009; 19(2):152-68. DOI:10.1007/s11065-009-9102-5 · 4.59 Impact Factor
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    • "Surprisingly few studies have investigated the effects of either a positive HIV serostatus or substance abuse on these functions, despite their common effects on striatum (cf. A. Martin et al. 1993; van Gorp et al. 1999). Recently we reported evidence of additive effects of HIV on SDIs' performance of two motor skill learning tasks, the Pursuit Rotor and the Star Mirror Tracing Task (Gonzalez et al. 2008). This initial investigation found no evidence of impairment of probabilistic learning measured by the Weather Prediction Task (Knowlton et al. 1996), however the study sample was primarily male; follow up analyses have indicated possible gender effects on vulnerability to impaired performance on this cognitive procedural learning task (Martin, unpublished data 2008). "
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    ABSTRACT: Substance abuse and co-infection with hepatitis C (HCV) are two highly relevant determinants of neurocognitive and neuroimaging abnormalities associated with HIV. Substance abuse and HCV are common in the HIV population and there is increasing evidence that the CNS is directly compromised by these comorbid conditions via additive or synergistic processes. In this article we review the current literature regarding mechanisms of neuronal injury as well as the neuropsychological and neuroimaging signatures associated with substance abuse and HCV status among HIV patients. We discuss specific methodological challenges and threats to validity associated with studies of HIV and comorbid substance use disorders or HCV and review potential strategies for minimizing their confounding effects. Efforts to understand the interactions between HIV, substance abuse and HCV co-infection will lead to more complete models of neuropathogenesis of HIV and a greater understanding of the variability in neuropsychological expression of HIV Associated Neurocognitive Disorder.
    Neuropsychology Review 07/2009; 19(2):215-31. DOI:10.1007/s11065-009-9101-6 · 4.59 Impact Factor
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