Scitech  Rats, monkeys, and the human brain

Despite rapid advancements in the field of neurocognitive science, many complexities of the human brain, the “last frontier” of the human body, remain elusive. Executing even a single function, such as vision, requires simultaneous cooperation of dozens of regions of the brain. Isolating and studying specific regions in the human brains is often costly, impractical, and sometimes impossible.

If the processes behind human behaviours are too complex to understand, can we study the processes behind the behaviour of animals to shed light on that of humans?
At the September Cutting Edge science lecture titled “Dissecting the Components of Animal Behaviour as a Window into the Human Mind,” Yogita Chudasama, associate professor of psychology at McGill, discussed compelling evidence to support the viability of researching animal behaviour to shed light on that of humans.

Chudasama, whose main area of research is behavioural neuroscience, explained that the belief that animals are incapable of exhibiting complex behaviour akin to humans is quickly losing ground. Proof that rats are capable of performing intricate behavioural tasks suggests that we can in fact use animal models to “decompose” the causes of compromised brain function.

A region of the brain that controls a specific behavior in rats is likely to control the same behavior in humans. For example, the OFC region of the frontal cortex in both humans and rats is responsible for higher cognitive functions such as decision making. Chudasama’s research has found that damage to this region impairs a rat’s propensity for “reversal leaning.” If a rat with OFC damage were to learn to associate choosing a door with a triangle on it with a reward, it would be nearly impossible for the rat to forget the correlation. Even when choosing the door with the triangle no longer yields the reward, the rat will compulsively continue to choose that door.

Chudasama explained that humans with OFC damage also exhibit difficulty in reversal learning, as was shown in the Wisconsin card sorting experiment. The experiment tested the speed at which an individual can catch on to a change in rules in sorting a special set of cards. When the experimenter changes the rules, a subject with OFC damage will not alter their method of sorting even if they are repeatedly informed they are sorting the cards incorrectly. This behavioural correlation between animals and humans with OFC damage supports the idea that animal models can be used to accurately gauge human behaviour.

Further experiments in Chaudasuma’s lab use primate models, and have drawn parallels between damage in the pre-limbic system with memory impairment, as well as the connection between emotional reactions and the ability to adapt to an environment.

Chaudasuma thinks that information about the correlation between brain function in various mammals and humans will be invaluable in the ongoing quest to decode the enigmatic mystery of the human mind.