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Publication Abstract Display
Type: Published Abstract
Title: HIV-associated prospective memory impairment is associated with strategic monitoring.
Authors: Doyle KL, Woods SP, Weber E, Cameron MV, Grant I, and the HNRC Group
Year: 2012
Publication: 120th Annual Convention of the American Psychological Association (Division 40), Orlando, FL
Volume: Issue: Pages:
Abstract:HIV-associated Prospective Memory Impairment is Associated with Strategic Monitoring INTRODUCTION: HIV is associated with deficits in both time- and event-based prospective memory (PM), which is an aspect of episodic memory that describes the complex cognitive process of executing a future intention (i.e., remembering to remember). Of direct clinical relevance, HIV-associated PM impairment is a strong predictor of declines in everyday functioning, including medication non-adherence (Woods et al., 2009), poorer health-related quality of life (Doyle et al., in press), dependence in instrumental activities of daily living (Woods et al., 2008), and unemployment (Woods et al., 2011). As such, it is important to understand the cognitive mechanisms of HIV-associated PM impairment, which prior inferential work suggests may at least partly reflect deficiencies in the strategic monitoring of time- and event-based cues (Zogg et a., 2011). Nevertheless, no prior studies have prospectively or directly evaluated this hypothesis in HIV using a theory-driven approach. According to McDaniel & Einsteinís multi-process theory (2000), the cognitive architecture of PM may include strategic cue monitoring that is voluntary and reliant on higher-level attentional and executive function resources or more involuntary and relatively automatic monitoring processes. Given this theory along with the prominent frontostriatal neuropathophysiology HIV infection (Ellis et al., 2009), one might expect HIV+ individuals to exhibit less strategic cue monitoring during a PM task, and that voluntary monitoring frequency would be associated with performance on tests of PM, time perception, and executive functions. METHODS: Thirty-seven individuals with HIV-associated neurocognitive disorders (HAND) and 82 seronegative volunteers were included in the study. HAND was diagnosed based on a comprehensive neurocognitive, psychiatric, and medical evaluation in accordance with Frascati criteria. Exclusion criteria included a diagnosis of severe psychiatric illness or neurological disease, a verbal IQ estimate of <70 based on the Wechsler Test of Adult Reading (WTAR), diagnosis of substance dependence within the 6 months of evaluation based on the Composite International Diagnostic Interview (CIDI version 2.1), urine toxicology screen positive for elicit drugs on the day of evaluation (excluding marijuana), or a Breathalyzer test positive for alcohol. The HAND sample was 86% male, 57% Caucasian and averaged 46 (± 14) years of age and 13 (± 3) years of education. Fifty-seven percent of the sample had AIDS diagnoses and 19% had detectable plasma HIV RNA values, but the rates of current immunosuppression (CD4 counts < 200) were low (8%). Participants were administered the Memory for Intentions Screening Test (MIST; Raskin et al., 2010; Woods et al., 2008) as part of a broader neuropsychological, medical, and psychiatric evaluation. The MIST is a standardized measure of PM, consisting of eight PM trials completed in the context of an ongoing distracter task. Primary indices of the MIST include summary, time- and event-based scores, and also codes for various error types (e.g., omission errors). Cue monitoring during the MIST was measured using a computer program that required participants to press any key to display a digital clock, which would appear for 6 seconds per press. Participants were instructed that they could check the clock at any point during the test in order to keep track of time, but that they were not required to do so (i.e., monitoring was voluntary). Monitoring was operationalized as the raw number of times that a participant accessed the clock over the last 5 minutes of the MIST, which prior research suggests is the most likely period of impaired monitoring in clinical sample (range = 0 to 8). RESULTS: An independent-samples t-test indicated that the HAND group had significantly fewer clock checks (M = 3.1, SD = 2.2) as compared to seronegatives (M = 4.1, SD = 2.3, p = .04, Cohenís d = -.42). Subsequent correlation analyses in the HAND group alone showed that monitoring behavior was associated with PM performance on the MIST, including the summary score (r = .36, p = .03), time-based score (r = .34, p = .04), and omission errors (Received 12/1/2011 12:02 AM) Page 2 of 3 Proposal ID: ind121980 (i.e., no response was given) (r = -.33, p = .05). Monitoring was not associated with performance on event-based trials, the ongoing word search task, post-test recognition scores, or other error types (i.e., loss of time, loss of content, or task substitution errors) (all ps > .10). Monitoring in HAND was also associated with rule violations on the Tower of LondonDX (r = -.33, p = .05) and Time Production (r = -.36, p = .03), but not with Trailmaking Test Part B, digit span backward, or Time Estimation (ps > .10). DISCUSSION: Taken together, these findings are consistent with the multi-process theory in that individuals with HAND exhibited less strategic, voluntary time monitoring during a complex clinical PM task as compared to a seronegative comparison group. Monitoring performance was strongly associated with several aspects of PM performance in the HAND cohort, most notably time-based PM and errors of omission. Monitoring also correlated with 2 neurocognitive tests that required strategic monitoring and time perception. These results suggest that more frequent voluntary monitoring of oneís environment for cues is associated with better PM outcomes in HIV. Future research is needed to determine the temporal dynamics of monitoring during the delay between intention encoding and cue detection, as well as to develop rehabilitation techniques to enhance PM cue monitoring in naturalistic environments (e.g., content-free cueing via text messaging) that may prove helpful in improving everyday functioning outcomes (e.g., medication adherence) in HIV-infected persons with PM deficits.

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