Processing of novelty and familiarity in the aging brain

When we see or hear something, we can quickly decide whether it is familiar or new. Our brain is particularly good at distinguishing new information from what we already know. Although the ability to discriminate between old and new information is quite relevant, we still do not entirely understand how it works, especially if old/new decisions involve never-before-seen items, such as abstract images or non-words. This thesis aimed to understand how the brain processes and discriminates such items and how aging affects this. Moreover, it aimed to see whether acetylcholine, a neurotransmitter in our brains known to be crucial for memory processing, was involved in age-related recognition impairments. The studies have shown that old/new recognition depends on how strongly an old memory is embedded. Compared to younger people, older people had difficulties recognizing new items correctly, and the lack of acetylcholine did not lead to an age-related recognition deficit.