Activity of individual brain cells predicts cognitive flexibility

March 25, 2009

A new study provides intriguing insights into mechanisms of cognitive flexibility at the single cell level. The research, published by Cell Press in the March 26th issue of the journal Neuron, may help to explain how we can change our point of view when faced with conflict.

We rely on an appropriate configuration of , known as a , to help facilitate our behavior. However, relies on an ability to quickly shift to a new cognitive set (i.e. change our point of view) in response to changing external demands.

Brain imaging in human subjects while they engaged in trials that induced cognitive set shifts (known as shift trials) identified the (PPC) as a brain region that appears to be involved in set shifting. However, due to imaging limitations, it was not possible to determine whether the PPC neurons were responding to the stimulus presentation or behavioral response or any other during the shift trials.

Single cell recording studies in monkeys engaging in set-shifting paradigms have been unsuccessful because animals often have difficulty promptly shifting their cognitive sets under experimental conditions. "As a result, dynamic processes of cognitive set shifting have not been explored at the single-unit level in the primate brain," explains the first author Dr. Tsukasa Kamigaki from the Department of Physiology at The University of Tokyo School of Medicine.

Dr. Kamigaki and colleagues trained two monkeys to promptly shift their cognitive sets and compared neuronal activity during shift and non-shift trials to detect shift-related activity in the PPC. The experimental paradigm, originally devised for humans but modified to test in monkeys, required monkeys to match a sample stimulus to one of three choice stimuli based on one "dimension", shape or color. "Whenever the relevant dimension changed, the monkeys had to shift their cognitive set in order to respond based on the new dimension," explains Dr. Kamigaki.

The researchers discovered that PPC neurons were transiently activated when the monkeys shifted from one cognitive set to another (e.g., color to shape), but not when they shifted in the opposite direction (e.g., shape to color). Importantly, the shift-related activity preceded the corresponding behavioral responses by about four seconds and accurately predicted whether or not the cognitive set would be successfully shifted.

"Beyond the previous views that the PPC is involved mostly in cognitive processes directed to external visual objects or space, the results in the present study provide unprecedented evidence that PPC neurons contribute to flexible shifting of internal cognitive sets in primates," concludes Dr. Kamigaki.

Source: Cell Press (news : web)

Explore further: How Red Apples Mark a Cognitive Leap Forward

Related Stories

How Red Apples Mark a Cognitive Leap Forward

July 18, 2006

Children aged about four suddenly become capable of recognising that an object can be described differently depending on how it is viewed. This apparently simple skill requires cognitive changes that are not far enough advanced ...

Researchers reverse effects of sleep deprivation

January 2, 2008

Researchers at Wake Forest University School of Medicine have shown that the effects of sleep deprivation on cognitive performance can be reversed when the naturally occurring brain peptide, orexin-A, is administered in monkeys.

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

( -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.