How does aging influence object-location and name-location binding during a visual short-term memory task?

Abstract

Objective: Age-related impairments in human visual short-term memory (VSTM) may reflect a reduced ability to retain bound object representations, viz., object form, name, spatial, and temporal location (so called ‘memory sources’). Our objective is to examine how healthy aging affects VSTM in a battery of memory recognition tasks in which sequentially presented objects, locations, and names (as auditory stimuli) were learned, with one component cued at test.Methods: Thirty-six young healthy adults (18–30 years) and 36 normally aging older adults (>60 years with no underlying health and vision issues) completed five VSTM tasks: 1. Object recognition for two or four objects; 2. Spatial location recognition for two or four objects; 3. Bound object-location recognition for two or four objects; 4. Object recognition with location priming for two or four objects; 5. Bound name (auditory)-location (cross-modal) recognition for four objects.Results: Significantly lower performance for older adults was found in spatial location recognition [task 2, p = 0.03], bound object-location recognition [task 3, p = 0.001], object recognition with location priming [task 4, p = 0.02], and bound name-location recognition [task 5, p = 0.001, independent samples t-test] tasks. A significant age group-task interaction was found (p = 0.02).Conclusion: Performance for all tests except test 1 was impaired in older adults. Lower performance for older adults was most significant in VSTM tasks requiring object-location (visual only) or name-location (auditory and visual) binding. The findings are compatible with the ‘memory source’ model, demonstrating that age-related binding performance is influenced by spatial coding and location priming deficits.