Nicola Ballhausen

A virtual week study of prospective memory function in autism spectrum disorders

Prospective memory (PM) refers to the implementation of delayed intentions, a cognitive ability that plays a critical role in daily life because of its involvement in goal-directed behavior and consequently the development and maintenance of independence. Emerging evidence indicates that PM may be disrupted in autism spectrum disorders (ASDs), potentially contributing to the functional difficulties that characterize this group. However, the degree, nature, and specificity of ASD-related impairment remains poorly understood. In the current study, children between 8 and 12 years of age who were diagnosed with ASDs (n=30) were compared with typically developing children (n=30) on a child-appropriate version of the Virtual Week board game. This measure provides an opportunity to investigate the different sorts of PM failures that occur. The ASD group showed significant PM impairment on measures of time-based (but not event-based) prospective remembering. However, only a subtle difference emerged between regular and irregular PM tasks, and group differences were consistent across these tasks. Because regular and irregular tasks differentially load retrospective memory, these data imply that the PM difficulties seen in ASDs may primarily reflect a monitoring deficit and not an encoding and memory storage deficit. PM performance was poorer under conditions of high ongoing task absorption, but the magnitude of this effect did not vary as a function of group. In both groups, time-based (but not event-based) PM difficulties were associated with functional outcomes in daily life, but only an inconsistent association with executive control emerged.

The impact of cognitive control on children’s goal monitoring in a time-based prospective memory task

The present study investigated whether developmental changes in cognitive control may underlie improvements of time-based prospective memory. Five-, 7-, 9-, and 11-year-olds (N = 166) completed a driving simulation task (ongoing task) in which they had to refuel their vehicle at specific points in time (PM task). The availability of cognitive control resources was experimentally manipulated by imposing a secondary task that required divided attention. Children completed the driving simulation task both in a full-attention condition and a divided-attention condition where they had to carry out a secondary task. Results revealed that older children performed better than younger children on the ongoing task and PM task. Children performed worse on the ongoing and PM tasks in the divided-attention condition compared to the full-attention condition. With respect to time monitoring in the final interval prior to the PM target, divided attention interacted with age such that older children’s time monitoring was more negatively affected by the secondary task compared to younger children. Results are discussed in terms of developmental shifts from reactive to proactive monitoring strategies.

Adult age differences in prospective memory in the laboratory: are they related to higher stress levels in the elderly?

To explain age deficits found in laboratory-based prospective memory (PM) tasks, it has recently been suggested that the testing situation per se may be more stressful for older adults, thereby impairing their performance. To test this assumption, subjective and physiological stress levels were assessed at several times during the experiment in 33 younger and 29 older adults. In addition, half of participants were randomized in a condition where they completed a relaxation intervention before performing a time-based PM task. Results confirmed the age deficit in laboratory PM. Subjective and physiological stress levels showed no age difference and no detrimental association with PM. The intervention successfully reduced stress levels in both age groups but had no effect on PM or the age deficit. In conclusion, data suggest that age deficits usually observed in laboratory PM may not be due to higher stress levels in the older adults.

Prospective memory function in late adulthood: affect at encoding and resource allocation costs.

Some studies have found that prospective memory (PM) cues which are emotionally valenced influence age effects in prospective remembering, but it remains unclear whether this effect reflects the operation of processes implemented at encoding or retrieval. In addition, none of the prior ageing studies of valence on PM function have examined potential costs of engaging in different valence conditions, or resource allocation trade-offs between the PM and the ongoing task. In the present study, younger, young-old and old-old adults completed a PM task in which the valence of the cues varied systematically (positive, negative or neutral) at encoding, but was kept constant (neutral) at retrieval. The results indicated that PM accuracy did not vary as a function of affect at encoding, and that this effect did not interact with age group. There was also no main or interaction effect of valence on PM reaction time in PM cue trials, indicating that valence costs across the three encoding conditions were equivalent. Old-old adults’ PM accuracy was reduced relative to both young-old and younger adults. Prospective remembering incurred dual-task costs for all three groups. Analyses of reaction time data suggested that for both young-old and old-old, these costs were greater, implying differential resource allocation cost trade-offs. However, when reaction time data were expressed as a proportional change that adjusted for the general slowing of the older adults, costs did not differ as a function of group.

Emotional valence differentially affects encoding and retrieval of prospective memory in older adults

Studies manipulating emotional valence in prospective memory (PM) have so far revealed inconsistent results. In the present study, two experiments were conducted to systematically disentangle the effects of varying emotional valence in the encoding versus retrieval phase of PM in older adults. Results showed that, while cue valence at retrieval had no influence on PM performance, at encoding both positive and negative valence resulted in reduced PM performance. Findings suggest that emotional valence may have an influence on mnemonic processes at encoding rather than modifying cue detection in aging.

Time-based prospective memory in children and adolescents with 22q11.2 deletion syndrome

Abstract Objective: 22q11.2 deletion syndrome, also known as velo-cardio-facial syndrome (VCFS) is a genetic disorder caused by a microdeletion on chromosome 22q11.2 and characterized by marked impairment in visual attention and executive function. The present study examined if this cognitive deficit extends to prospective memory (the type of memory involved in remembering to perform actions in the future). Method: 20 participants with 22q11.2DS aged between 6 and 14 were included in the study as well as 22 typically developing individuals (TDC) aged 6–12. To measure prospective memory, participants were asked to play a driving game (the Dresden Cruiser). This time-based prospective memory task required children to remember to refuel their car when the fuel level was low by pressing a refuel button while driving. Results and discussion: Participants with 22q11.2DS remembered less often to refuel the car. Furthermore, participants with 22q11.2DS checked the fuel gage significantly less often than the controls. Conclusions: Participants with 22q11.2DS therefore demonstrate difficulties completing a time-based prospective memory task. This can be explained by a generally less frequent time checking behavior in comparison to TDC.

Age differences in prospective memory for everyday life intentions: A diary approach

The age benefit found in many naturalistic prospective memory (PM) tasks has been taken as evidence that PM performance in real life may be spared from aging. However, this conclusion lacks empirical confirmation. Hence, the aim of the present study was to examine possible age differences in the content of everyday PM intentions and their performance. Everyday PM was assessed in young and older adults using a diary approach. Results confirmed a general age benefit for real-life PM tasks. Importantly, this finding was qualified by revealing that the benefit only held true for specific types of intentions such as health and social intentions. Further, moderation analyses showed that the relationships between cognitive functioning and everyday PM were different for young and older adults. While better inhibition, short-term and long-term memory were related with successful PM performance in the young, this was not the case in the older adults. The present findings suggest that the age benefit found in naturalistic experimenter-given tasks extends to real-life PM performance, but may differ depending on the type of intention. Furthermore, cognitive functioning predicts performance in the young, but not in the older adults.

Mood effects on memory and executive control in a real-life situation.

In the laboratory, studies have shown an inconsistent pattern of whether, and how, mood may affect cognitive functions indicating both mood-related enhancement as well as decline. Surprisingly, little is known about whether there are similar effects in everyday life. Hence, the present study aimed to investigate possible mood effects on memory and executive control in a real-life situation. Mood effects were examined in the context of winning in a sports competition. Sixty-one male handball players were tested with an extensive cognitive test battery (comprising memory and executive control) both after winning a match and after training as neutral baseline. Mood differed significantly between the two testing situations, while physiological arousal and motivation were comparable. Results showed lowered performance after the win compared with training in selected cognitive measures. Specifically, short-term and episodic memory performance was poorer following a win, whereas executive control performance was unaffected by condition. Differences in memory disappeared when emotional states after the match were entered as covariates into the initial analyses. Thus, findings suggest mood-related impairments in memory, but not in executive control processes after a positive real-life event.

Cross-lagged relation of leisure activity participation to trail making test performance 6 years later: Differential patterns in old age and very old age.

Objective: We investigated cross-lagged relations between leisure activity participation and Trail Making Test (TMT) performance over 6 years and whether those reciprocal associations differed between individuals. Method: We analyzed data from 232 participants tested on performance in TMT Parts A and B as well as interviewed on leisure activity participation in 2 waves 6 years apart. Mean age in the Wave 1 was 73.42 years. Participants were also tested on vocabulary (Mill Hill scale) as a proxy indicator of crystallized intelligence and reported information on early and midlife cognitive reserve markers (education and occupation). Latent cross-lagged models were applied to investigate potential reciprocal activity−TMT relationships. Results: The relation of leisure activity participation predicting TMT performance 6 years later was significantly larger than was the relation of TMT performance predicting later leisure activity participation. Statistically comparing different moderator groups revealed that this pattern was evident both in individuals with low education and in those with high education but, notably, emerged in only young-old adults (but not in old-old adults), in individuals with a low cognitive level of job in midlife (but not in those with a high cognitive level of job in midlife), and in individuals with high scores in vocabulary (but not in those with low scores in vocabulary). Conclusions: Late-life leisure activity participation may predict later cognitive status in terms of TMT performance, but individuals may markedly differ with respect to such effects. Implications for current cognitive reserve and neuropsychological aging research are discussed.

The Role of Cognitive Reserve Accumulated in Midlife for the Relation between Chronic Diseases and Cognitive Decline in Old Age: A Longitudinal Follow-Up across Six Years

Objectives: The present study set out to investigate relations of the number of chronic diseases (as a global indicator of individuals’ multimorbidity) to cognitive status and cognitive decline over six years as measured by changes in Trail Making Test (TMT) completion time in old adults and whether those relations differed by key life course markers of cognitive reserve (education, occupation, and cognitively stimulating leisure activities). Method: We analyzed data from 897 participants tested on TMT parts A and B in two waves six years apart. Mean age in the first wave was 74.33 years. Participants reported information on chronic diseases, education, occupation, and cognitively stimulating leisure activities. Results: Latent change score modeling testing for moderation effects revealed that a larger number of chronic diseases significantly predicted stronger increase in TMT completion time (i.e., steeper cognitive performance decline). Notably, the detrimental relation of the number of chronic diseases to stronger increase in TMT completion time (i.e., cognitive performance decline) was significantly stronger in individuals with less engagement in cognitively stimulating leisure activities in midlife. Discussion: Present data suggest that disease‐related cognitive decline may be steeper in individuals who have accumulated less cognitive reserve in midlife. However, greater midlife activity engagement seemed to be associated with steeper cognitive decline in any case. Implications for current cognitive reserve and neuropsychological aging research are discussed. HIGHLIGHTSA larger number of chronic diseases predicted steeper cognitive decline.This association was stronger in individuals with less cognitive reserve.Midlife leisure activities seem most important in this context.Yet, midlife activity was associated with steeper cognitive decline in any case.