Age and novelty: Event-related potentials to visual stimuli within an auditory oddball—visual detection task

Age-related change of event-related potentials to novel visual stimuli was investigated while participants attended to both auditory and visual stimulation. Meaningful but irrelevant pictures (novel stimuli) were presented to younger (mean = 21.8, range = 18–26 years) and older (mean = 70.0, range = 60–78) participants (10 in each group). The participants were performing an auditory oddball task and counting silently the changes of a visually presented letter. In the younger group novel stimuli elicited a posterior positivity in the 220–255 ms range. This component habituated to the repetition of the same picture. In the older group this component had longer latency, and did not habituate. A later positivity had shorter latency and larger amplitude in the younger group, but this positivity was preceded by a negative component (N2b) only in the elderly. Results show decreased sensitivity to the content of the visual stimuli in an earlier stage of novelty processing in the elderly, and the age-related slowing of both orientation-related and task-related processes.