Spatial updating of gaze position in younger and older adults - A path integration-like process in eye movements.

Path integration (PI) is a navigation process that allows an organism to update its current location in reference to a starting point. PI can involve updating self-position continuously with respect to the starting point (continuous updating) or creating a map representation of the route which is then used to compute the homing vector (configural updating). One of the brain areas involved in PI, the entorhinal cortex, is modulated similarly by whole-body and eye movements, suggesting that if PI updates self-position, an analogous process may be used to update gaze position, and may undergo age-related changes. Here, we created an eyetracking version of a PI task in which younger and older participants followed routes with their eyes as guided by visual onsets; at the end of each route, participants were cued to return to the starting point or another enroute location. When only memory for the starting location was required for successful task performance, younger and older adults were generally not influenced by the number of locations, indicative of continuous updating. However, when participants could be cued to any enroute location, thereby requiring memory for the entire route, processing times increased, accuracy decreased, and overt revisits to enroute locations increased with the number of locations in a route, indicative of configural updating. Older participants showed evidence for similar updating strategies as younger participants, but they were less accurate and made more overt revisits to mid-route locations. These findings suggest that spatial updating mechanisms are generalizable across effector systems.

Ask how they did it: untangling the relationships between task-specific strategy use, everyday strategy use, and associative memory.

OBJECTIVE: Past research has shown that self-reported everyday strategy use and task-specific strategy use are related to associative memory performance in aging. Understudied is the relationship between these types of strategy use, whether they predict associative memory performance, and how this may differ across genders. METHOD: A sample of older adults (N = 566, 53% female, ages 60-80) completed this online study. Study measures included 1. Multifactorial Memory Questionnaire (MMQ) Strategy Use subscale, a self-report measure of everyday strategy use, 2. Face-Name Task (FNT), a measure of associative memory, and 3. self-initiated number and types of strategies used on the FNT. Analyses examined the interrelationships among all study measures and their relative contributions to FNT performance while accounting for intraindividual factors. RESULTS: Participants who reported using more strategies on the FNT performed better than those who used fewer or no strategies; those who reported using at least three strategies and relating FNT to past experience performed best. Women outperformed men on the FNT but did not differ in task-specific strategy use. Participants who reported using no strategies on the FNT had lower MMQ Strategy Use scores. A multiple regression analysis indicated that female gender and using at least two task strategies were significant predictors of greater FNT performance. CONCLUSIONS: The results indicate that task-specific strategy use relates more to associative memory performance than to everyday strategy use, but neither accounts for the female advantage in FNT performance. Findings encourage querying task-specific strategy use to contextualize age-related associative memory decline.

Retrieval of temporal structure at recall can occur automatically.

Temporal-structure, namely, the order in which events unfold over time, is one of the fundamental principles of episodic memory organization. A seminal empirical demonstration of the prominence of temporal structure in memory organization is the Temporal Contiguity Effect (TCE), whereby the proximity between two items at encoding predicts the likelihood of those two items being retrieved consecutively during recall. Recent studies have found that TCE occurs under a wide variety of conditions in which strategic control processes at encoding are reduced or even eliminated. This suggests that the encoding of temporal structure occurs automatically. Extending these findings, in the current study we asked whether the retrieval of temporal structure, as reflected by indices of the TCE, is influenced by strategic control processes at retrieval. To manipulate participants' ability to rely on strategic control processes, we compared standard recall performance (Full Attention condition) to a condition in which attention was divided between recall and a concurrent task (Divided Attention condition), which has been shown to disrupt such control processes. Across two experiments-one with standard encoding conditions and one with continual distraction during encoding-we found no differences in any index of the TCE between the two conditions. These results are all the more striking considering that in both experiments, dividing attention negatively affected overall recall performance compared to the Full Attention condition. Thus, while recall performance is reduced when disrupting strategic processes, the ability to use temporal structure to drive recall is not affected.