| 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 & Einstein’s
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, Cohen’s 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
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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 one’s 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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