Memory updating through aging: different patterns for socially meaningful (and not) stimuli

Updating is a crucial function responsible of working memory integrity, allowing relevant information to be active and inhibiting irrelevant one; updating has been studied mainly with verbal stimuli, less with faces, stimuli with high adaptive value and social meaning.

Our aim was to test age-related differences in updating for different stimuli in three different age groups: young adults (range 20-30 years), young-old (range 60-75 years) and older-old participants (range 77-87 years).

To this end, we administered control measures (i.e., vocabulary and visuospatial tasks), span tasks (forward, backward) and two updating tasks: one with no socially relevant material (i.e., letters) and another one with socially relevant material (i.e., human faces, where, in particular, the combination between facial expression and gaze direction was manipulated). In both tasks we collected response times (RTs) at different steps of an updating task (i.e., encoding, maintaining, and updating goal-relevant information).

We found that age linearly produces an increase in processing speed regardless the stimulus considered, either letter or human face. However, with face stimuli, the magnitude of the difference is greater for the letter updating task, than for the face updating task. In turn, the results claim for a stimulus-specific updating process as the age-related decline is less pronounced when socially meaningful stimuli are involved than when no socially meaningful ones are.