The Memory for Intentions Screening Test (MIST) is a clinical measure of prospective memory (PM). There is emerging support for the sensitivity and ecological relevance of the MIST in clinical populations. In the present study, the construct validity of the MIST was evaluated in 40 younger (18–30 years), 24 young-old (60–69 years), and 37 old-old (70+ years) healthy adults. Consistent with expectations derived from the PM and aging literature, older adults demonstrated lower scores on the MIST’s primary scale scores (particularly on the time-based scale), but slightly better performance on the semi-naturalistic 24-hour trial. Among the healthy older adults, the MIST showed evidence of both convergent (e.g., verbal fluency) and divergent (e.g., visuoperception) correlations with standard clinical tests, although the magnitude of those correlations were comparable across the time- and event-based scales. Together, these results support the discriminant and convergent validity of the MIST as a measure of PM in healthy older adults.

To navigate, we must continuously estimate the direction we are headed in, and we must use this information to guide our path toward our goal1. Direction estimation is accomplished by ring attractor networks in the head direction system2,3. However, we do not understand how the sense of direction is used to guide action. Drosophila connectome analyses4,5 recently revealed two cell types (PFL2 and PFL3) that connect the head direction system to the locomotor system. Here we show how both cell types combine an allocentric head direction signal with an internal goal signal to produce an egocentric motor drive. We recorded their activity as flies navigated in a virtual reality environment toward a goal stored in memory. Strikingly, PFL2 and PFL3 populations are both modulated by deviation from the goal direction, but with opposite signs. The amplitude of PFL2 activity is highest when the fly is oriented away from its goal; activating these cells destabilizes the current orientation and drives turning. By contrast, total PFL3 activity is highest around the goal; these cells generate directional turning to correct small deviations from the goal. Our data support a model where the goal is stored as a sinusoidal pattern whose phase represents direction, and whose amplitude represents salience. Variations in goal amplitude can explain transitions between goal-oriented navigation and exploration. Together, these results show how the sense of direction is used for feedback control of locomotion.

Individuals with substance use disorders (SUDs) commonly report lapses in prospective memory (PM) in their daily lives; however, our understanding of the profile and predictors of laboratory-based PM deficits in SUDs and their associations with everyday PM failures is still very preliminary. The current study examined these important questions using well-validated measures of self-report and laboratory-based PM in a mixed cohort of 53 SUD individuals at treatment entry and 44 healthy adults. Consistent with prior research, the SUD group endorsed significantly more self-cued and environmentally based PM failures in their daily lives. Moreover, the SUD group demonstrated significantly lower time-based PM performance, driven largely by cue detection errors. The effect of SUDs on PM was particularly strong among participants with fewer years of education. Within the SUD cohort, time-based PM was correlated with clinical measures assessing executive functions, retrospective memory, and psychomotor speed. Importantly, time-based PM was uniquely associated with elevated PM failures in daily lives of the SUD participants, independent of current affective distress and other neurocognitive deficits. Findings suggest that individuals with SUD are vulnerable to deficits in PM, which may in turn increase their risk for poorer everyday functioning outcomes (e.g., treatment non-compliance).

Despite the prevalence of HIV-associated episodic memory impairment and its adverse functional impact, there are no empirically-validated cognitive rehabilitation options for HIV-infected persons. The present study examined the self-generation approach, which is theorized to enhance new learning by elaborating and deepening encoding. Participants included 54 HIV-infected and 46 seronegative individuals, who learned paired word associates in both self-generated and didactic encoding experimental conditions. Results revealed main effects of HIV serostatus and encoding condition, but no interaction. Planned comparisons showed that both groups recalled significantly more words learned in the self-generation condition, and that HIV+ individuals recalled fewer words overall compared to their seronegative counterparts at delayed recall. Importantly, HIV+ participants with clinical memory impairment evidenced comparable benefits of self-generation compared to unimpaired HIV+ subjects. Self-generation strategies may improve verbal recall in individuals with HIV infection and may therefore be an appropriate and potentially effective cognitive rehabilitation tool in this population.

HIV-associated neurocognitive disorders (HAND) remain highly prevalent in the era of cART, but there are no validated psychological interventions aimed at improving cognitive outcomes. This study sought to determine the potential benefit of semantic cueing on category fluency deficits, which are prevalent in HIV and impact daily functioning. Eighty-six HIV-infected individuals and 87 demographically matched seronegative participants were administered a standard (i.e., uncued) and a cued category fluency task. Results revealed significant improvements in cued versus uncued performance in HIV, particularly for persons with lower levels of education. The cueing benefit observed may inform rehabilitation efforts aimed at ameliorating HAND.