Catarina Soares and Carlos Pinto, researchers from the Laboratory of Animal Learning and Behavior at CIPsi, in co-authorship with Ana Sousa, published the article entitled "Externalizing forgetting: Delay testing in a long operant chamber" in the Journal of Experimental Psychology: Animal Learning and Cognition.
The researchers explain that, like us, pigeons are able to estimate the passage of time. They demonstrate this when, for example, they respond differently depending on the duration of a stimulus: They choose (by pecking) a red stimulus if they saw a light on for 4 seconds, but they choose a green stimulus if the light was on for 12 seconds. This type of task also allows for the study of memory, simply by introducing an interval between the presentation of the light and the green and red stimuli. For the animal to choose the correct color, it must memorize the duration of the light during that waiting interval.
In the study, the researchers were interested in the estimation of time intervals and what happens to the memory of those durations during the waiting interval. To do this, they trained and tested the pigeons in a long experimental box - similar to a hallway where the animal can walk from side to side - where the "short" and "long" responses were in opposite and distant locations.
This strategy of trying to externalize an internal, inaccessible process helps us understand the processes of temporal estimation as well as forgetting.
Soares, C., Sousa, A., & Pinto, C. (2023). Externalizing forgetting: Delay testing in a long operant chamber. Journal of Experimental Psychology: Animal Learning and Cognition, 49(2), 96–110. https://doi.org/10.1037/xan0000353