Involvement of the anterior cingulate cortex in time-based prospective memory task monitoring: An EEG analysis of brain sources using Independent Component and Measure Projection Analysis

The Processing Mechanism of Repetitive Practice Affecting Time-Based Prospective Memory

Time-based prospective memory (TBPM) refers to performing intended actions at a specific time in the future. The TBPM task is very common in daily life, and whether it can be successfully completed can affect our quality of life. Repeated behavior training can usually improve social cognitive performance, and this study focused on exploring whether TBPM performance could improve with repeated behavior training. Meanwhile, we also focused on whether behavior training could reduce attention consumption, both internal and external, attention on TBPM tasks. In this study, a single-factor between-subject design was adopted. Seventy-three undergraduates were assigned to three groups: the control group, the baseline group, and the experimental group. The baseline group only needs to perform ongoing tasks, so the ongoing task performance of the control group will not be affected by TBPM tasks. The control group needs to perform both ongoing and TBPM tasks without practice. The experimental group needs to perform both ongoing and TBPM tasks after 30 exercises. The ongoing task is a typical working memory task. The TBPM task was to press a "1" button every 1 min. The results showed that the performance of ongoing tasks in the baseline group, experimental group, and control group decreased sequentially, and the experimental group had less time monitoring than the control group. The results indicated that behavior training could reduce attention consumption in both internal attention and external attention, but it could not reach the level of automatic processing.

The Role of Stimuli-Driven and Goal-Driven Attention in Shopping Decision-Making Behaviors-An EEG and VR Study

The human attention system, similar to other networks in the brain, is of a complex nature. At any moment, our attention can shift between external and internal stimuli. In this study, we aimed to assess three EEG-based measures of attention (Power Spectral Density, Connectivity, and Spectral Entropy) in decision-making situations involving goal-directed and stimulus-driven attention using a Virtual Reality supermarket. We collected the EEG data of 29 participants in 2 shopping phases, planned and unplanned purchases. The three mentioned features were extracted and a statistical analysis was conducted. We evaluated the discriminatory power of these features using an SVM classifier. The results showed a significant (p-value < 0.001) increase in theta power over frontal, central, and temporal lobes for the planned purchase phase. There was also a significant decrease in alpha power over frontal and parietal lobes in the unplanned purchase phase. A significant increase in the frontoparietal connectivity during the planned purchase was observed. Additionally, an increase in spectral entropy was observed in the frontoparietal region for the unplanned purchase phase. The classification results showed that spectral entropy has the highest discriminatory power. This study can provide further insights into the attentional behaviors of consumers and how their type of attentional control can affect their decision-making processes.

Aging and time-based prospective memory in the laboratory: a meta-analysis on age-related differences and possible explanatory factors

In older adults' everyday life, time-based prospective memory (TBPM) is relevant as health-related intentions are often part of daily activities. Nonetheless, it is still unclear which task-related factors can potentially moderate the magnitude of age-related differences, such as duration of the PM target time (the time-window within which an individual must complete a given TBPM task), the frequency of the TBPM tasks, and the criterion chosen to compute PM accuracy. The present meta-analysis aimed to quantify age-related differences in laboratory TBPM tasks, and to investigate how specific task-related factors potentially moderate the magnitude of age effects. The results showed that age effects consistently emerged among the studies, with older adults showing lower TBPM performance and checking the clock less often than younger adults, especially for shorter intervals (e.g., ≤ 4 min). Furthermore, the results indicated that the duration of the PM target time interacted with the frequency of the PM task, suggesting that learning effects may attenuate the magnitude of age differences in TBPM performance. The results are discussed in terms of potential implications about the possible cognitive processes involved in TBPM and aging, as well as in terms of robustness of the TBPM laboratory paradigm in aging research.

Effective external reminders impair the practice effect of time-based prospective memory

The practice effect of time-based prospective memory (TBPM) refers to the phenomenon that TBPM task performance can be significantly improved by repetitive behavioural training. However, reminders are a common strategy for people to perform TBPM tasks in daily life. A large amount of evidence shows that reminders can improve TBPM performance when individuals pay less attention to time information. However, the present study was the first to explore whether external reminders might simultaneously impede the practice effect of TBPM. In this study, 81 undergraduate students were randomly assigned to control group (N = 27, M_age  = 20.00, SD_age  = 1.04), reminder group (N = 26, M_age  = 20.35, SD_age  = 1.70) and non-reminder group (N = 28, M_age  = 20.25, SD_age  = 1.17). In the training stage, the reminder group could receive effective external reminders, while the non-reminder group could not. The results of the training stage revealed that compared with the non-reminder group, the reminder group had fewer time monitoring times and better TBPM performance. In the testing stage, when reminders were removed from the reminder group, we found that compared with the control group without TBPM training, the TBPM performance of the reminder group failed to improve, while that of the non-reminder group improved significantly. Meanwhile, the time estimation ability of the reminder group was not as improved as that of the non-reminder group.

Age-related modulation of EEG time-frequency responses in prospective memory retrieval

BACKGROUND

Prospective memory involves remembering to execute an intention at the appropriate moment (prospective component) as well as retrieving the intended action (retrospective component). Several electrophysiological studies showed that neural activity associated with the prospective and the retrospective component differed between older and younger adults. However, these studies mainly reported event-related potentials (ERP), without considering other oscillatory parameters of age-related neural modulations that might be associated with the two components.

OBJECTIVE

In the present study, we analysed electrophysiological data to describe the age-related patterns of brain oscillations associated with the prospective and the retrospective components of prospective memory.

METHODS

The prospective and the retrospective components were manipulated in two experiments. In experiment 1, the prospective component was manipulated by varying the cue distinctiveness (i.e., how easy it was to detect the cue based on colour). In experiment 2, the retrospective component was manipulated by varying the number of intentions to be remembered (i.e., one or two intentions). We used time-frequency analysis to characterise the EEG oscillatory activity in younger and older adults.

RESULTS

The prospective component was associated with age differences in alpha and beta frequency bands. Compared to younger adults, older adults showed a decrease of parietal alpha activity when they detected distinct prospective memory cues, and a decrease of parietal beta when they detected less distinct cues. Moreover, older adults showed less beta activity compared to the younger adults across experimental manipulations. No age differences emerged with respect to the retrospective component.

CONCLUSIONS

The specific pattern of oscillatory activity associated with the prospective component in older adults could underlie the dynamic deployment of different attentional resources supporting cue detection. Moreover, beta activity in both experiments might support an attempt exerted by older adults to enhance task coordination processes. Overall, cluster-based permutation analyses provided a first description of the changes of the EEG time-frequency responses related to intention retrieval in older adults.

Resting-state functional brain connectivity predicts cognitive performance: An exploratory study on a time-based prospective memory task

Resting-state functional brain connectivity (rsFC) is in wide use for the investigation of a variety of cognitive neuroscience phenomena. In the first phase of this study, we explored the changes in EEG-reconstructed rsFC in young vs. older adults, in the both the open-eyes (OE) and the closed-eyes (CE) conditions. The results showed significant differences in several rsFC network metrics in the two age groups, confirming and detailing established knowledge that aging modulates brain functional organisation. In the study's second phase we investigated the role of rsFC architecture on cognitive performance through a time-based Prospective Memory task involving participants who monitored the passage of time to perform a specific action at an appropriate time in the future. Regression models revealed that the monitoring strategy (i.e. the number of clock checks) can be predicted by rsFC graph metric, specifically, eccentricity and betweenness in the OE condition, and assortativity in the CE condition. These results show for the first time how metrics qualifying functional brain connectivity at rest can account for the differences in the way individuals strategically handle cognitive loads in the Prospective Memory domain.

The Practice Effect on Time-Based Prospective Memory: The Influences of Ongoing Task Difficulty and Delay

The practice effect on prospective memory refers to the phenomenon that prospective memory performance can improve with behavior training. Some studies have found that event-based prospective memory (EBPM) can benefit from practice. However, only a few studies have focused on the practice effect on time-based prospective memory (TBPM). In the present study, we planned to explore whether the practice effect on TBPM existed and what its processing mechanism was. In Experiment 1, we tested whether the practice effect existed at all under different background task conditions. The results showed that the practice effect existed only under an easy ongoing task condition. When a 600 ms delay was added after each difficult ongoing task in Experiment 2, we found the same effect as for the easy ongoing task condition in Experiment 1. In addition, the results also suggested that the practice effect was closely related to the improvement in the effectiveness of time monitoring. The present study confirmed the existence of practice effect of TBPM under some conditions of sufficient attention resources and further explored its causes for the first time, which made us have a deeper understanding of the plasticity of TBPM caused by behavior training.