Cutting-edge cognitive science blog Developing Intelligence has a fantastic article on pupil dilation and its likely link to mental processing and arousal.
The eyes are fascinating for neuroscientists as they show the only part of the central nervous system visible from outside the body – namely, the retina.
Areas of the frontal lobes, called the frontal eye fields are specifically involved in eye movements (often called ‘saccades’) and eye movements are known to reflect a range of cognitive abilities.
Hence, eye movements are studied as a way of trying to understand what might be going on in the brain, particularly in people experiencing mental illness.
According to the new research, however, pupil dilation may also be an important measure of brain function.
One study has shown that it could be directly related to the amount of information held in memory:
In the most compelling finding from this literature, pupil diameter has been observed to increase with each successive item maintained in memory, up until each subject’s working memory capacity – and then to contract incrementally as each item is reported back to the experimenter.
As always, there’s a wonderfully thorough analysis over at Developing Intelligence so head over there if you want some more startling details of this developing field.
Link to article ‘Eyes, Window to the Soul – and to Dopamine Levels?’