Brain Connections Reveal How We Reflect on Memories and Sensory Experiences
The brain is capable of reflecting on perceptual experiences and memories, however, these processes are not made possible by the same region suggests a new study.
"Until now, scientists have not known if such introspection was a single skill or dependent on the object of reflection," according to the University of California. "Also unclear was whether the brain housed a single system for reflecting on experience or required multiple systems to support different types of introspection."
For the study, researchers observed 60 subjects at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, in their ability to analyze their own thinking process when reflecting about sensory experience and memories.
"The perceptual decision task consisted of visual displays with six circles of vertical alternating light and dark bars -- called Gabor gratings -- arranged around a focal point," according to the study. "Participants were asked to identify whether the first or second display featured one of the six areas with a slight tilt, not always an easy determination to make."
For the reflective memory part of the study researchers showed participants a list of 145 words. Afterwards they were shown another set of words and were asked to point out which ones they had seen before.
"After each stimulus in both the perceptual decision and the memory retrieval task, participants rated their confidence in the accuracy of their responses on a scale of 1 (low confidence) to 6 (high confidence)," said the study.
Researchers found that the power to accurately reflect on perception is linked to, "enhanced connectivity between the lateral region of the anterior prefrontal cortex and the anterior cingulate, a region involved in coding uncertainty and errors of performance."
Researchers also found that one's potential to accurately reflect on memory is associated with enhanced connectivity in a different regions of the brain called the medial anterior prefrontal cortex, the precuneus and the lateral parietal cortex.
"Our results suggest that metacognitive or introspective ability may not be a single thing," Benjamin Baird, UC Santa Barbara graduate student and lead author of the study, said in a news release. "We actually find a behavioral dissociation between the two metacognitive abilities across people, which suggests that you can be good at reflecting on your memory but poor at reflecting on your perception, or vice versa."
With these results, researchers have a better understanding of the reflecting skills in the brain.
"Part of the novelty of this study is that it is the first to examine how connections between different regions of the brain support metacognitive processes," Baird said. "Also, prior means of computing metacognitive accuracy have been shown to be confounded by all kinds of things, like how well you do the primary task or your inherent bias toward high or low confidence.
The findings are published in the Journal of Neuroscience.