The results provide preliminary support for our predictions about the association between sensation seeking and visual selective attention in HIV positive adults. When selective attention demands were at their greatest in the perceptual span task (array size 12), sensation seeking accounted for 22.9% of the variance in target identification performance. Furthermore, as can be seen in , this effect appears to be genuine in that this association was not due to a small subset of participants or to a few outliers in the sample. Indeed, the range in target identification accuracy was large, with low sensation seekers performing quite poorly while high sensation seekers performed considerably better.
When selective attention demands were diminished (array sizes 1 and 4 conditions), sensation seeking was completely unrelated to perceptual span performance. Although the selective attention demands in the array size 4 condition were greater than in the array size one condition (there was a significant difference), this level of challenge was apparently not sufficient to elicit performance differences associated with sensation seeking. This lack of association was not likely due to a restricted range in performance in the array size 4 condition considering the evident variability in accuracy scores. These results are important because, at least in the present task situation, it shows that sensation seeking was not associated with perceptual or cognitive performance in general but only when selective attention demands were sufficiently high. Careful consideration should be addressed to this distinction between low and high attention demands in future studies that examine the relationship between sensation seeking and attention processing in HIV positive adults.
When examining specific components of sensation seeking, as per the subscales of the SSS-V, all but TAS was associated with span task performance in array size 12. Although the correlations for ES, Dis, and BS were all relatively modest in size compared to the relationship between sensation seeking in general (SSS-V total score) and performance in array size 12, this is to be expected because of the more restricted range in possible scores for the subscales (0–9) versus that of the total score (0–36). One possibility for why TAS (Thrill and Adventure Seeking) in particular would fail to be associated with perceptual span performance is that the desire to engage in physical risk-related behaviors is antithetical to performing a physically monotonous computer task. On the other hand, the same sort of reasoning would not necessarily apply to a subscale like BS or ES because of the challenge imposed in the array size 12 condition (the task feels quite difficult in this condition). In addition, it appears that the subscales were related to each other (as they are supposed to be), based on the finding that once Dis (the subscale with the largest correlation) is inserted as a predictor of array size 12 performance, none of the other subscales significantly add to the predictive function. Because the subscales of the SSS-V are interrelated, it might make more sense to remain at the more general conceptual level of sensation seeking, unless there are a priori hypotheses about specific subscales.
A mediating mechanism for the superior selective attention in the high sensation seeking HIV positive adults could be a relatively heightened level of arousal. Arousal is an admittedly elusive concept. However, if sensation seeking is indeed indicative of arousal differences in HIV positive adults, it may be useful to examine arousal in HIV positive adults in relation not only to processes of attention and other domains of cognition but also to risk-related behaviors, coping strategies, psychopathology, treatment, and other domains of behavior that could be influenced by individual differences in arousal. For example, although there is data showing that methylphenidate reduces cognitive slowing in HIV positive adults (Hinkin, et al. 2001
), the effectiveness of such a stimulant might clearly be modulated by individual differences in levels of arousal. This same issue also pertains to our recent finding of impaired sustained attention in stimulant (cocaine and/or methamphetamine) using HIV positive adults (Levine et al. 2006
). Individual differences in sensation seeking and/or arousal might also explain the inconsistency in research results on drug abuse and HIV infection. Although some studies report greater cognitive impairment in drug abusing HIV positive adults relative to control subject groups (seronegative drug abusers and clean seronegatives) (e.g., Starace et al. 1998
), other studies report no interactive effect between drug abuse and HIV infection (e.g., Selnes et al. 1997
). Perhaps the greater sensation seeking (on average) in HIV positive drug abusers facilitates their selective attention and related cognitive abilities, offsetting any expected exacerbated cognitive deficits due to drug abuse.
Another factor that could influence the high sensation seekers superior selective attention performance is coping style. With an average response accuracy of 57.5% in the array size 12 condition, it is clear that the selective attention demands were quite high and exceeded the capacity of the lowest sensation seekers. If a unique and difficult computer task can be construed as a novel experience, then while the low sensation seekers apparently were overwhelmed (or perhaps gave up), the high sensation seekers appeared to have vigorously engaged this difficult novel situation, thus “rising to the occasion”. Although coping with a difficult computer task is not the same as coping with a difficult life situation, the present results are compatible with research showing an association between high sensation seeking and more active efficacious coping strategies in such disparate populations such as ex-prisoners of war (Solomon et al. 1995
) and injured high school athletes (Smith et al. 1992
Ultimately, the role of individual differences (gender, education, age, etc.) is important to more precisely characterize the cognitive sequela of neuropsychologically important disorders. The finding that sensation seeking accounted for 22.9% of the variance in perceptual span performance is a large effect, not only in HIV research but in psychological research in general. One question for future studies is, how does sensation seeking modify other aspects of attention and cognition in HIV positive adults? Because sensation seeking is not strongly associated with general intelligence (Zuckerman 1979
), it would be expected that sensation seeking is associated with only certain aspects of cognition in HIV positive adults. In fact, because perceptual span performance is considered an index of early selective visual processing and iconic capacity limitations, it seems likely that individual differences in sensation seeking would be associated with subsequent cognitive processes or domains that are linked to perceptual span. Another related question, from a more neuropsychological perspective, is how does sensation seeking modify the neuropsychological profile of HIV positive adults?
The present results with sensation seeking and selective attention show that personality factors may be an important source of individual differences in the neuropsychological outcome of HIV positive adults. This is a preliminary report, and a replication of such a finding is needed with a larger sample of participants. In addition, although the perceptual span task has been a useful tool, shown to be sensitive both to HIV infection and to sensation seeking, the relationship between sensation seeking and other measures or aspects of attention should be examined. For instance, although greater sensation seeking seems to be related to improved selective attention on a task like the perceptual span task, this may not be the case where attention must be sustained over time such as on a vigilance task. The role of substance abuse should also be considered. Although a previous report (Hardy et al. 2004
) showed no association with past alcohol and substance abuse with perceptual span performance, current abusers were excluded from those analyses as they were in the present report as well. Considering that sensation seeking differences may be mediated by differences in arousal, active substance abuse (especially stimulant abuse) might modify the association between sensation seeking and selective attention in HIV. And finally, because age and disease progression has been shown to affect neurocognitive functioning (especially attention) in HIV positive adults (Hardy et al. 1999
), such factors are commendable of examination in the relationship between sensation seeking and attention in HIV.