Marc Sommer, from the Faculty at Duke University, said:
"The brain has to keep track of decisions and the outcomes they produce. You need that continuity of thought. We are constantly keeping decisions in mind as we move through life, thinking about other things. We guessed it was analogous to working memory, which would point toward the prefrontal cortex."
According to Sommer's prediction, neuronal correlates of metacognition are present in the same areas of the brain that are responsible for cognition. This includes the frontal cortex, which is a part of the brain associated with personality expression, decision-making, and social behavior. Sommer collaborated with Paul G. Middlebrooks, a postdoctoral fellow at Vanderbilt University in studying single neurons in vivo in three frontal cortical regions of the brain, including the frontal eye field, which is linked to visual attention and eye movements, the dorsolateral prefrontal cortex, which is responsible for motor planning, organization, and regulation, and the supplementary eye field (SEF), which plays a role in the planning and control of saccadic eye movements, i.e. extremely rapid movements of the eye that enable it to continually refocus on an object.
The team asked study participants to perform a visual decision-making task, which involved random flashing lights and a dominant light on a cardboard square in order to find the location in the brain where metacognition occurs. The participants were asked to remember and point to where the dominant light appeared, guessing whether they were correct. The team discovered that even though neural activity correlated with decisions and guesses in all three areas of the brain, the putative metacognitive activity that linked decisions to bets was only located in the SEF.
Sommer explained: "The SEF is a complex area [of the brain] linked with motivational aspects of behavior. If we think we're going to receive something good, neuronal activity tends to be high in SEF. People want good things in life, and to keep getting those good things, they have to compare what's going on now versus the decisions made in the past."
He pointed out that defining such concepts linked to metacognition, such as consciousness has been complicated for decades. Sommer believes his investigations and future work with regard to metacognition as a stepping- stone in a systematic process of trying to achieve a better understanding of consciousness. He says that by studying metacognition, the big challenge of studying a "train of thought" is reduced into a simpler component, such as investigating how one cognitive process influences another.
Sommer asks: "Why aren't our thoughts independent of each other? Why don't we just live in the moment? For a healthy person, it's impossible to live in the moment. It's a nice thing to say in terms of seizing the day and enjoying life, but our inner lives and experiences are much richer than that."
Until now, there have been no studies that tested patients with mental disorders on these tasks, and Sommer wants to find out how SEF and other brain areas might be disrupted in these disorders.
"With schizophrenia and Alzheimer's disease, there is a fracturing of the thought process. It is constantly disrupted, and despite trying to keep a thought going, one is distracted very easily. Patients with these disorders have trouble sustaining a memory of past decisions to guide later behavior, suggesting a problem with metacognition."
Written by Petra Rattue