The role of task-set preparation and modality compatibility in age-related effects on cognitive flexibility: Evidence from task switching.

Stimulus-response (S-R) modality compatibility refers to the mapping between the stimulus modality and the modality of the response-related sensory consequences. Previous studies found larger costs of task switching with modality-incompatible mappings (auditory-manual and visual-vocal) compared to modality-compatible mappings (auditory-vocal and visual-manual). The aim of the present study was to investigate whether older adults show increased effects of modality compatibility in task switching and whether this age-related performance difference can be reduced with sufficient preparation time. Young adults (n = 44, Mage = 20.6 years) and older adults (n = 44, Mage = 70.9 years) were presented with simultaneous auditory and visual stimuli (i.e., bimodal stimulation) both at the same side or at different sides. In each trial, the target modality was indicated by a preceding cue in the target modality (i.e., auditory or visual target), which could switch versus repeat from trial to trial. Participants responded to the position of the target either manually or vocally based on prior instructions and the cue, while the cue-target interval was varied to examine task-set preparation. Importantly, in modality-compatible blocks, visual targets were mapped to manual responses and auditory targets to vocal responses, whereas this mapping was reversed in modality-incompatible blocks. Older adults showed both larger mixing costs and larger switch costs generally, and both types of costs were also larger with modality-incompatible mappings. Longer preparation time led to generally reduced switch costs, but this was not age-specific. Together, the data suggest that shielding against modality-specific crosstalk is impaired in older adults in contexts requiring updating of multimodal modality mappings. (PsycInfo Database Record (c) 2025 APA, all rights reserved).