Abstract
The extent to which mechanisms are shared between visual working memory (WM) and long-term memory (LTM) for the same type of information is unclear. To date WM and LTM performance has been measured using highly distinct tasks. Therefore, we developed a novel delayed-report contextual spatial memory task which allows to probe the quality of remembered objects within scenes in an analogous way in both WM and LTM. We applied the task to healthy young, middle-aged, and older adults (n=60) in order to chart whether similar patterns of age-related changes occur for WM and LTM. In each trial participants viewed either one or three everyday objects embedded in a photographic scene followed by a memory delay. They were then either probed to report the location of one of the objects (WM trials) or asked to tap a centrally-presented fixation cross (learning trials) on a touch-screen. The LTM stage followed 20 minutes later and involved an analogous memory probe on stimuli from learning trials only, in addition to confidence ratings (LTM trials). We obtained various measures of memory performance, such as response times, memory accuracy and error, quantified as the Euclidian distance between the true location of the object and the response location, that could be compared across memory domains. We found that, as expected, memory errors were larger when three objects had to be remembered as compared to one object and that errors for LTM were larger than for WM. In addition, older adults performed significantly worse than both the young and middle-aged groups. However, a preliminary analysis showed that although young and middle-aged adults had a similar increment in error from WM to LTM, the increment in older adults was smaller, suggesting an altered relationship between these two memory functions in this group.
Acknowledgement: MRC (UK), Wellcome Trust, British Academy, NIHR BRC.