Aging alters visual processing of objects and shapes in inferotemporal cortex in monkeys

• Aging in monkeys has an effect on the visual system.
• Neuronal baseline activity does not change with aging in the inferotemporal cortex (IT).
• Neuronal latency values in the IT increase with age.
• Variables reflecting stimulus preference in IT change in a way which indicates decreased stimulus selectivity for visual neurons.

Visual perception declines with age. Perceptual deficits may originate not only in the optical system serving vision but also in the neural machinery processing visual information. Since homologies between monkey and human vision permit extrapolation from monkeys to humans, data from young, middle aged and old monkeys were analyzed to show age-related changes in the neuronal activity in the inferotemporal cortex, which is critical for object and shape vision. We found an increased neuronal response latency, and a decrease in the stimulus selectivity in the older animals and suggest that these changes may underlie the perceptual uncertainties found frequently in the elderly.