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Dr. Lynn Hasher

Dr. Lynn Hasher

Senior Scientist, Rotman Research Institute

Professor of Psychology and Marketing, University of Toronto

Research Focus

 

The work in my laboratory continues to focus on inhibitory control over the contents of working memory - or over momentary consciousness. Most recently we have shown that classic measures of working memory do not measure how much information can be held onto. Rather they measure the amount of task-relevant information that is held. People with small working memory spans tend to continue to deal with no longer relevant information while people with large working memory spans focus only on the currently relevant information. Older adults' spans tend to be reduced in size, relative to that of younger adults' spans, but that reduction is because older adults continue to consider no longer relevant information, while younger adults do not. The theory that guides this work is published in a chapter in the Attention and Performance volume (2000).

Other work focuses on the degree to which performance, particularly that of older adults' is impacted by the time at which they are tested. We continue to show that on many tasks (e.g., including span tasks, attention tasks, memory tasks and some neuropsychological tests), the performance of older adults is far better at their optimal time (usually the morning) than it is at their nonoptimal time (later in the day). We attribute this to the operation of circadian arousal patterns that impact on inhibitory control, but not on excitatory control.