Brain Health Blog

Several years ago, researchers were testing the cognitive abilities of a group of college students and senior citizens. During their initial data collection, most of which was done at night, they found that the college students significantly out-performed the seniors.

Then they started testing the groups at 8am. Suddenly the college students were doing worse, and the seniors much better. It became clear that cognitive prowess is related to time of day. One explanation is that the sleep cycle of the two groups is very different. At 8am, most college students are barely awake or responsive. Robert West et al suggested the groups have a different alertness cycle, and found that time of day affects working memory and executive function differently in the young and old.

Our Poll
I recently did an informal poll to see if our readers have personally observed differences in their performance across the day. In response to “During what part of the day does your brain function best?”:

44% Morning
33% Late night
22% Afternoon
0% said Same All Day or After Dinner
18 people responded (this is not a very popular blog yet!)

An immediate take-away is that everyone who responded felt that they perform best at a certain time of day. I would need more respondents to interpret if there is an overall favorite time, but “After Dinner” is emerging as the least favorite period for cognitive crunching. This may be due to the body’s need to start digesting that food, which involves the autonomic nervous system moving more blood to the digestive system, and a resulting reduction in alertness.

Since time of day has a significant impact on cognition, it would be prudent to schedule important or demanding tasks for times when we’re sharpest. Professional acquaintances may now have a better understanding of why I never want to meet in the morning…