Age-Related Differences in Perceptual and Mental Imagery Abilities

Anna Maria BERARDI^1*Stephen Michael Kosslyn²Anne Riffle²

• ¹LCOMS, Université de Lorraine, Metz, France
• ²Department of Psychology, Harvard University, Cambridge, Massachusetts, United States

Previous studies have demonstrated the existence of two visual processing pathways in monkeys, healthy human participants and patients with brain lesions. The dorsal and ventral visual pathways are involved in the perception of spatial locations and object recognition, respectively. Although, recent studies have challenged the idea that these two pathways are segregated, their predominant roles in vision have not been questioned. The purpose of this study was to investigate age-related differences in perceptual and mental imagery abilities using the Imagery Processing Battery (IPB), which includes 15 tasks for assessing different aspects of dorsal (spatial properties) and ventral (object properties) processing. ANOVAs indicated that for the dorsal tasks, elderly participants generally were both slower and made more errors than young participants, particularly in the imagery condition. For the ventral tasks, older participants were slower but as accurate as young participants. These results remained unchanged when the simplest version of the generalized slowing hypothesis was tested using logarithmic response times. Mean response times for each perceptual task were correlated with each other to obtain a correlation matrix; the corresponding correlation matrix was computed for the imagery tasks. Multi-Dimensional Scaling (MDS) of these matrices indicated the presence of two clusters, reflecting the dorsal/ventral nature of the tasks. However, the clusters based on data from the elderly were not as clearly segregated as those based on data from the young.