Our ability to remember the images and scenes that we have encountered is remarkable - we can correctly determine whether we have seen an image before after viewing thousands, each only for a few seconds. The neural processes that support visual familiarity memory are thought to be implemented in the same brain areas as those that support visual object recognition, but both are poorly understood. Impairments in visual familiarity memory, including those that accompany disorders such as dementia, lead to devastating inabilities to recognize one's own family or home. The experiments described in this proposal take advantage of new techniques that allow us to monitor neural population responses to study how novel images become familiar across single image exposures. First, we will determine the relative contributions of different brain regions to visual familiarity memor, including V4, IT and perirhinal cortex. Next, we will determine whether and how visual object recognition and visual familiarity memory are supported by the same neural circuits. Finally, we will test whether familiarity memory storage includes a mechanism that suppresses memories of images that elicit weak visual responses and amplifies those that are strong. These results will provide crucial insights into the neural mechanisms responsible for visual familiarity memory and they have the potential to suggest targets for the treatment of familiarity memory dysfunction.
Memories of whether we have encountered specific people, objects and scenes before are thought to be stored in the same parts of the brain responsible for processing visual information, but we don't understand much about how this happens and a better understanding could lead to new treatments for deficits in visual memory such as dementia. The goal of this proposal is to understand how visual recognition and visual familiarity memory happen in the same brain areas on a fast, behaviorally relevant timescale.
