Ageing and memory-based orienting of attention
Although most attention studies utilize perceptual cues to orient our spatial focus, in real life it is our experience coded in long-term memory that provides the expectations about the locations and contexts in which relevant events appear. Nobre’s lab have recently developed a task for investigating the behavioural consequences and neural mechanisms for memory-based attention (Summerfield, Rao, Garside & Nobre, 2011). They have shown significant behavioural gains for detecting targets in previously learned locations within complex scenes, and have used neural imaging methods to reveal the brain areas involved and the modulatory mechanisms influencing visual processing. Overall, the results show a substantial and proactive role for memories to anticipate relevant events and tune the perceptual systems through the coordination of perceptual areas by top-down signals from brain areas in mnemonic and attentional circuits.
The purpose of this project is to explore how memory-based oriented is affected through normal aging. Associative memories are particularly vulnerable in aging, especially in individuals who develop mild cognitive impairment and dementia. This raises the possibility that as we age, not only do our memories falter, they may also fail to guide our perceptual mechanisms, leading to cognitive deficits from our earliest interactions with the incoming sensory stream of data. The study is using behavioral and MEG measures to test the presence and strength of memory-based orienting in young (20-40), middle (40-60) and older (60-80) aged adults.
Summerfield JJ, Rao A, Garside N, Nobre AC. Biasing perception by spatial long-term memory. J Neurosci. 2011 Oct 19;31(42):14952-60