Alexandra Hering

A process-model based approach to prospective memory impairment in Parkinson's disease

The present review discusses the current state of research on the clinical neuropsychology of prospective memory in Parkinsons disease. To do so the paper is divided in two sections. In the first section, we briefly outline key features of the (partly implicit) rationale underlying the available literature on the clinical neuropsychology of prospective memory. Here, we present a conceptual model that guides our approach to the clinical neuropsychology of prospective memory in general and to the effects of Parkinsons disease on prospective memory in particular. In the second section, we use this model to guide our review of the available literature and suggest some open issues and future directions motivated by previous findings and the proposed conceptual model. The review suggests that certain phases of the prospective memory process (intention formation und initiation) are particularly impaired by Parkinsons disease. In addition, it is argued that prospective memory may be preserved when tasks involve specific features (e.g., focal cues) that reduce the need for strategic monitoring processes. In terms of suggestions for future directions, it is noted that intervention studies are needed which target the specific phases of the prospective memory process that are impaired in Parkinsons disease, such as planning interventions. Moreover, it is proposed that prospective memory deficits in Parkinsons disease should be explored in the context of a general impairment in the ability to form an intention and plan or coordinate an appropriate series of actions.

Adult Age Differences, Response Management, and Cue Focality in Event-Based Prospective Memory: A Meta-Analysis on the Role of Task Order Specificity

The present meta-analysis investigated whether event-based prospective memory (PM) age effects differ by task order specificity. In specified PM tasks, the order of the ongoing and the PM task response is predetermined, which imposes demands on cognitive control to navigate the possible response options. In contrast, unspecified PM tasks do not require responding in a particular order. Based on 57 studies and more than 5,500 younger and older adults, results showed larger PM age effects in specified compared with unspecified PM tasks. Additionally, the effect of task focality on age differences was replicated. Results suggest that both pre- and postretrieval processes independently affect PM age effects.

Prospective memory training in older adults and its relevance for successful aging

In research on cognitive plasticity, two training approaches have been established: (1) training of strategies to improve performance in a given task (e.g., encoding strategies to improve episodic memory performance) and (2) training of basic cognitive processes (e.g., working memory, inhibition) that underlie a range of more complex cognitive tasks (e.g., planning) to improve both the training target and the complex transfer tasks. Strategy training aims to compensate or circumvent limitations in underlying processes, while process training attempts to augment or to restore these processes. Although research on both approaches has produced some promising findings, results are still heterogeneous and the impact of most training regimes for everyday life is unknown. We, therefore, discuss recent proposals of training regimes aiming to improve prospective memory (i.e., forming and realizing delayed intentions) as this type of complex cognition is highly relevant for independent living. Furthermore, prospective memory is associated with working memory and executive functions and age-related decline is widely reported. We review initial evidence suggesting that both training regimes (i.e., strategy and/or process training) can successfully be applied to improve prospective memory. Conceptual and methodological implications of the findings for research on age-related prospective memory and for training research in general are discussed.

Cognitive and neural plasticity in older adults' prospective memory following training with the Virtual Week computer game.

Prospective memory (PM) – the ability to remember and successfully execute our intentions and planned activities – is critical for functional independence and declines with age, yet few studies have attempted to train PM in older adults. We developed a PM training program using the Virtual Week computer game. Trained participants played the game in 12, 1-h sessions over 1 month. Measures of neuropsychological functions, lab-based PM, event-related potentials (ERPs) during performance on a lab-based PM task, instrumental activities of daily living, and real-world PM were assessed before and after training. Performance was compared to both no-contact and active (music training) control groups. PM on the Virtual Week game dramatically improved following training relative to controls, suggesting PM plasticity is preserved in older adults. Relative to control participants, training did not produce reliable transfer to laboratory-based tasks, but was associated with a reduction of an ERP component (sustained negativity over occipito-parietal cortex) associated with processing PM cues, indicative of more automatic PM retrieval. Most importantly, training produced far transfer to real-world outcomes including improvements in performance on real-world PM and activities of daily living. Real-world gains were not observed in either control group. Our findings demonstrate that short-term training with the Virtual Week game produces cognitive and neural plasticity that may result in real-world benefits to supporting functional independence in older adulthood.

Older Adults Have Difficulty in Decoding Sarcasm.

Younger and older adults differ in performance on a range of social-cognitive skills, with older adults having difficulties in decoding nonverbal cues to emotion and intentions. Such skills are likely to be important when deciding whether someone is being sarcastic. In the current study we investigated in a life span sample whether there are age-related differences in the interpretation of sarcastic statements. Using both video and verbal materials, 116 participants aged between 18 and 86 completed judgments about whether statements should be interpreted literally or sarcastically. For the verbal stories task, older adults were poorer at understanding sarcastic intent compared with younger and middle-aged participants, but there was no age difference in interpreting control stories. For the video task, older adults showed poorer understanding of sarcastic exchanges compared with younger and middle-aged counterparts, but there was no age difference in understanding the meaning of sincere interactions. For the videos task, the age differences were mediated by the ability to perceive facial expressions of emotion. Age effects could not be explained in terms of variance in working memory. These results indicate that increased age is associated with specific difficulties in using nonverbal and contextual cues to understand sarcastic intent. (PsycINFO Database Record

Importance Effects on Age Differences in Performance in Event-Based Prospective Memory

Background: Most laboratory-based studies on prospective memory show a decline with increasing age. Theoretical explanations for age differences focus on the allocation of attentional resources to support prospective remembering. The recruitment of prospective memory target monitoring seems to be influenced by perceived task importance. Objective: In the present study, we investigated the influence of task importance on the magnitude of age differences in event-based prospective memory. Methods: Healthy younger (n = 25) and older (n = 25) adults were instructed a priori to prioritize either the ongoing or the prospective memory task before performing an event-based prospective memory task. Results: We found an interaction between age and task importance: instructed higher importance of the ongoing task compared to the prospective memory task component produced significant age-related declines in prospective remembering. By contrast, if older adults treated the prospective memory task component as more important than the ongoing task, they achieved equivalent levels of prospective memory performance as their younger counterparts, but did so at a cost to ongoing task performance. Conclusions: The present data indicate that task importance is one of the factors determining the presence or absence of age deficits in prospective remembering. Findings are discussed in the context of limited processing resources in old age and theoretical frameworks of event-based prospective memory.

Cognitive processes in the Breakfast Task: Planning and monitoring.

The Breakfast Task (Craik & Bialystok, 2006) is a computerized task that simulates the planning and monitoring requirements involved in cooking breakfast, an everyday activity important for functional independence. In Experiment 1, 28 adults performed the Breakfast Task, and outcome measures were examined with principal component analysis to elucidate the structure of cognitive processes underlying performance. Analyses revealed a 2-component structure which putatively captured global planning and local monitoring abilities. In Experiment 2, the structure of Breakfast Task performance was cross-validated on a new sample of 59 healthy older adults who also performed tests assessing working memory, processing speed, inhibition, reasoning and prospective memory. Factor analyses showed that the global planning component from the Breakfast Task was significantly correlated with individual differences in executive functions but the local monitoring component was independent of such functions. The Breakfast Task provides a fast, enjoyable, and lifelike assessment of complex everyday planning and monitoring, and their underlying processes such as working memory and executive functions.

Revisiting the age-prospective memory-paradox: the role of planning and task experience

The present study aimed at investigating age-related differences in prospective memory performance using a paradigm with high ecological validity and experimental control. Thirty old and 30 young adults completed the Dresden Breakfast task; a meal preparation task in the lab that comprises several subtasks including event- and time-based prospective memory tasks. Participants were required to plan how to perform the task. Results showed that young adults outperformed old adults: they completed more subtasks, showed better event- and time-based prospective memory performance and planning quality. In contrast, old adults adhered to their plans more closely than young adults. Further exploratory gender-specific analyses indicated that old women did not differ from young men in time-based prospective memory performance, general task performance and time monitoring in contrast to old men. Possibly, differences in experience in breakfast preparation might account for these differential findings.

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.

The role of cue detection for prospective memory development across the lifespan

Behavioral findings suggest an inverted U-shaped pattern of prospective memory development across the lifespan. A key mechanism underlying this development is the ability to detect cues. We examined the influence of cue detection on prospective memory, combining behavioral and electrophysiological measures, in three age groups: adolescents (12-14 years), young (19-28 years), and old adults (66-77 years). Cue detection was manipulated by varying the distinctiveness (i.e., how easy it was to detect the cue based on color) of the prospective memory cue in a semantic judgment ongoing task. Behavioral results supported the pattern of an inverted U-shape with a pronounced prospective memory decrease in old adults. Adolescents and young adults showed a prospective memory specific modulation (larger amplitudes for the cues compared to other trials) already for the N1 component. No such specific modulation was evident in old adults for the early N1 component but only at the later P3b component. Adolescents showed differential modulations of the amplitude also for irrelevant information at the P3b, suggesting less efficient processing. In terms of conceptual implications, present findings underline the importance of cue detection for prospective remembering and reveal different developmental trajectories for cue detection. Our findings suggest that cue detection is not a unitary process but consists of multiple stages corresponding to several ERP components that differentially contribute to prospective memory performance across the lifespan. In adolescents resource allocation for detecting cues seemed successful initially but less efficient at later stages; whereas we found the opposite pattern for old adults.