Another cognitive capacity that shows more severe limitations in Alzheimer’s Disease (AD) is the ability to shift strategies. One task used extensively is the dimensional change card sort task (DCCS) originally designed by Zelazo (see link above) to test children. In the game, children must sort cards into two categories based on a single dimension — it could be that all the red ones go in one pile and all the blue ones go in a different pile. Later, that dimension, color, is supposed to be ignored in favor of a different dimension, shape. Now all the bunnies, both the red and the blue ones, go in one box and all the boats, regardless of their color, go in another box. Sorting in this way, typically 3-year old children can learn either sorting rule when presented first, but fail to switch to a second sorting rule (color to shape, or shape to color). By 5 years of age, most children can do this switching. This is considered a problem of executive function, or your ability to meta-think and select rules that guide your behavior within individual instances. Elderly people and AD patients show more rigidity in switching from one rule to another, and AD patients are typically appreciably worse at switching and show more errors and perseverate longer using older rules in tasks that demand switching (like in various Stroop tasks tested with AD patients).
Here is Haagen Dasz again, now sorting on the basis of size, with the smaller ones being the ones to select to get a treat. The first dimension, size, is trained using virtual cheerios and then tested without any clues for which one of two items is correct. Later, after monkeys show 80% correct choice, the dimension is changed. In this case, sometimes the diamonds are orange, but the color (orange/black) is irrelevant in the “size” game. The poster below shows our first presentation of these data, both from children whom we tested in the same task as monkeys. We find that 3-year olds in our choice task do not switch rules readily. Our 5-year olds did switch almost instantly. The monkeys also were able to switch quite well. We are re-testing them every 6 months to see if age causes a more rigid switching system.
Read the published article on rule switching (2022, online).
CITATION: Neiworth, J. J., Balaban, M. T., Wagner, K., Carlsen, A., Min, S., Kwon, Y. I. C., & Rieth, I. (2022). A modified version of the dimensional change card sort task tests cognitive flexibility in children (Homo sapiens) and cotton-top tamarins (Saguinus oedipus). Journal of Comparative Psychology, 136(3), 155–171. https://doi.org/10.1037/com0000312
Please review our poster of rule switching in 3-5 year old children, college students, and adult tamarin monkeys, presented at the Association for Psychological Science (APS) in 2017.