apes

Assistant Professor of Psychology Rachel Wu’s research investigating perceptual narrowing at the neural level disproves the prevalent idea that we lose certain abilities from underuse.

Perceptual narrowing is a behavioral and neurological theory that states that our brain’s sensitivity to distinguish between foreign stimuli declines as we become more acclimated to our current environment. This is because during our early developmental stage, we are trying to learn our local language and surroundings. This “narrows” our perspective and we are believed to lose the ability to distinguish between stimuli that we are not regularly exposed to.

The theory of perceptual narrowing has been misconstrued and popularized as sayings like “use it, or lose it” and “you can’t teach an old dog new tricks.” Professor Wu explained the negative impact of such misconceptions: “(These) stereotypes seem to negatively affect adults’ confidence in their learning abilities, which may create a downward spiral in confidence in decreased future learning even by young adulthood.”

Professor Wu’s experimental design compared human ability to distinguish from visual native and non-native stimuli and explored the theory of perceptual narrowing by innovatively utilizing two kinds of measurements: behavioral and neurological with an electroencephalogram (EEG). Since it is believed that neural processes directly lead to behavior, Professor Wu felt that it was important to study them in relation to one another — a novel approach that distinguishes her study from others on the same subject.

Her study performed two experiments — one measured the ability to detect non-native or foreign stimuli, and the other measured accuracy to detect native stimuli. The first experiment required each participant to perform two tasks: detecting the presence of a specific ape face amongst other ape faces, and detecting the presence of ape faces amongst animal faces.

The second experiment had the exact procedure but required a different group of participants who were presented with a combination of male and female faces with no hair, as it is a significant gender cue. Half of the participants were assigned to detect the presence of female faces, while the other had to detect the presence of male faces. This experiment served as the control, or “baseline” condition. Behavioral performance was determined by the participant’s accuracy and response time, while scalp electrodes simultaneously recorded brain activity.

Expectedly, people in the first experiment exhibited poorer accuracy than the participants in the second experiment. Results of the first experiment indicated higher accuracy when distinguishing ape faces from other animal faces as opposed to distinguishing one particular ape face from another. While both results aligned with the theory of perceptual narrowing, the most notable aspect of Professor Wu’s research was the results from the EEG. Though behavioral results varied between the two experiments, the EEG revealed no significant differences in brain activity between both groups.

The results of Wu’s research displays the brain’s plasticity and resiliency through perceptual narrowing. Her study indicates that the brain does not lose the capacity to do certain tasks with age, and that anything can be overcome with practice.

“I hope adult learners become more optimistic about their learning in the second half of life … If society can become more accepting of adult learners, I believe we can create a larger population of happy healthy aging adults,” Wu expressed.