‘Living in the moment’ may be impossible, according to neuroscientists who have reportedly pinpointed a brain area responsible for using past decisions and outcomes to guide future behaviour.
The study, based on research conducted at the University of Pittsburgh, analyses signals associated with metacognition, a person's ability to monitor and control cognition (a term cleverly described by researchers as ‘thinking about thinking’).
“The brain has to keep track of decisions and the outcomes they produce,” Marc Sommer, who did his research for the study as a University of Pittsburgh neuroscience faculty member, said.
“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,” he added.
Researchers predicted that neuronal correlates of metacognition resided in the same brain areas responsible for cognition, including the frontal cortex, a part of the brain linked with personality expression, decision-making, and social behaviour.
The research team studied single neurons in vivo in three frontal cortical regions of the brain: the frontal eye field (associated with visual attention and eye movements), the dorsolateral prefrontal cortex (responsible for motor planning, organisation, and regulation), and the supplementary eye field (SEF) involved in the planning and control of saccadic eye movements, which are the extremely fast movements of the eye that allow it to continually refocus on an object.
To learn where metacognition occurs in the brain, subjects performed a visual decision-making task that involved random flashing lights and a dominant light on a cardboard square. Participants were asked to remember and pinpoint where the dominant light appeared, guessing whether they were correct.
The researchers found, while neural activity correlated with decisions and guesses in all three brain areas, the putative metacognitive activity that linked decisions to bets resided exclusively in the SEF.
“The SEF is a complex area [of the brain] linked with motivational aspects of behaviour,” Mr Sommer explained. “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.
“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,” he explained.
So far, patients with mental disorders had not yet been tested on these tasks, but Mr Sommer was interested to see 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 behaviour, suggesting a problem with metacognition."