A study by researchers from UC Berkeley has found one explanation for how humans excel in relational reasoning, a cognitive skill that allows for problems to be solved even in unfamiliar circumstances.
Published in the journal Neuron, the study suggests that mild shifts in the brain's parietal and frontal lobes are linked to higher cognition, with the frontoparietal network specifically playing a role in retrieving memories, solving problems, analyzing, and thinking abstractly thanks to its ability to adapt fluidly depending on the task to be done.
"It's not just that we humans have language at our disposal. We also have the capacity to compare and integrate several pieces of information in a way that other primates don't," explained Silvia Bunge, a neuroscientist from UC Berkeley and principal investigator to the study, adding that the study has allowed researchers to seriously consider tweaks to the frontoparietal network due to evolution as a means of differentiating between how humans and other primates are able to solve problems.
To confirm their hypothesis, the researchers analyzed studies that tracked changes in a developing brain's anatomy and compared neural patterns in the brains of humans and other primates as well as how humans and other primates tackled different tasks involving reasoning.
According to their findings, three parts of the brain have been identified to have key roles in relational reasoning: the rostrolateral prefrontal cortex, the inferior parietal lobule and the dorsolateral prefrontal cortex. Furthermore, synaptic pruning, which happens when neuron signals speed up and white matter takes the place of gray matter during adolescence, was more obvious in the brain's inferior parietal regions.
An analysis of behavioral studies also showed that humans were likelier to rely on higher-order strategies when judging situations while non-human primates usually turned to perceptual similarities and were slower at problem solving and reasoning.
"These results do not necessarily prove that non-human primates are unable to reason using higher-order thinking, but if it is possible to train non-humans to produce human-like performance on tasks associated with higher-order relational thinking, it is certainly not something that comes naturally to them," concluded the study.
Also critical to the results of the study was research led by Matthew Rushworth, a neuroscientist from Oxford University, which compared neural patterns between humans and macaque monkeys. While the brains of both humans and macaque monkeys were similar in the parietal and frontal regions, the rostrolateral prefrontal cortex in humans significantly differed from the frontal cortex of macaque monkeys.
