Age-Related Differences in Cue-Guided Preparation and Target Processing in Crossmodal Response Precueing

This study investigated age-related differences in the influence of spatial and modality-specific precues on preparation and target processing in crossmodal action. Younger and older adults (n = 36 and 33) performed a crossmodal response-precueing task requiring speeded choice responses, either manually or vocally, to unimodal visual or auditory targets, while event-related potentials were recorded. Three precue types were used: modality precues, which indicated the response effector without spatial information; spatial precues, which indicated abstract left-right response information without specifying the effector; and uninformative precues. Behaviorally, informative precues were associated with better performance in both age groups, but older adults showed faster and less accurate responses following spatial precues, suggesting that advance left-right response information facilitated rapid responding but increased response-selection errors when it had to be mapped onto the appropriate manual or vocal response after target onset. At the neural level, cue-locked contingent negative variation results indicated cue-related modulation of sustained preparation and overall reduced preparatory engagement in older adults. Target-locked early negativity, analyzed across manual and vocal response conditions, showed the clearest age-dependent cue modulation, whereas P3 measures indicated broader age-related differences in target-related processing. Cue-locked lateralized readiness potentials (LRPs), analyzed for manual-response trials, showed lateralized activity within the cue-target interval only following spatial precues, providing evidence of lateralized response preparation when response-side information was available before target onset, whereas target-locked LRP onset analyses in manual-response trials provided limited evidence for reliable cue- or age-dependent differences in LRP timing. Together, these findings suggest that aging alters how precues are used to configure preparation under unresolved response uncertainty. Spatial precues can support rapid responding in older adults, but this preparation may become error-prone when the appropriate response effector must still be selected after target onset.