The Fast and Flexible

The causes of individual differences of cognition in animals have remained unclear for a long time. It had been hypothesized that personality types might be linked to cognitive styles, especially via the speed-accuracy trade-off. This research aimed to investigate this association between differences in animal personality and individual cognitive traits. Previous literature from this field had proposed a framework where ‘the bolder individuals learn a particular contingency faster (i.e., with fewer trails) versus the shyer individuals that have lower decision thresholds for association formation. The study aimed to test the strategies adopted by different personality types to learn a cognitive task and to verify the trade-offs. It tested the individuals for differences in learning speed and measured their flexibility in learning through reverse learning models. Bank voles, Myodes glareolus, a common rodent species, was the model organism used in the research. Based on the previous literature, the study expected faster learners to be bolder, older learners to be slower, and males to be faster learners, and females to be more flexible.

A maze (like the one shown above) was created. In the initial learning phase, odor O was the positive cue that led to the exit of the maze. But in the reverse learning task, the positive and negative cues were switched. Voles were considered to have chosen an arm of the maze when they entered it with their entire body, after leaving the decision area completely.

The speed of learning was expressed as scores based on the number of trials they needed to reach the criterion in the two tasks. The parameters measured were; latency to leave the decision area and enter the maze, which shows an animal’s ‘motivation’ to initiate the test, latency in decision making which is the time interval between entering the decision area and leaving it, and the ‘persistence’ measured as the time between its arrival at the wrong door and getting back to the decision area.

Results
The results showed a negative correlation between learning and reverse learning scores, backing the hypothesis that fast learners were slower in reverse learning tasks and vice versa. Active females also fared better in reverse learning tasks. Persistence was higher in males than in females. Bolder individuals were also reported to be more persistent than the others.

The bolder individuals were quick to enter the maze and engage in the experiment than the shyer ones. This pattern remained stable throughout the experiment.

Bolder or active individuals learned faster because they had an established routine for decision making. These routines skip or reduce the amount of time spent in assessing and sampling the environment. This is why these individuals do not fare well in reverse learning models. The study also noted that bolder individuals needed a longer time to make a correct decision in reverse learning tests, possibly because this test challenged their established routine. Scientists presume that since active individuals store less information for a shorter period, they will need more time to retrieve the choices they made in their previous attempt.

Conversely, the shyer individuals took longer to complete a cognitive task since they sampled the environmental cues closely for accurate information. This strategy makes them flexible learners and better performers in reverse learning models. These individuals also showed a knack for finding alternative solutions in reverse learning models. Existing literature suggests that many shy animals including shy low-ranking birds are more likely to find innovative solutions to a problem.

Even though male and female voles did not differ much in their learning scores, the association between boldness and cognition was more significant in males than females. Since males generally tend to roam in large areas, they need a system that can quickly analyze a steady flow of information. On the other hand, females are restricted to smaller areas, but they depend on an accurate and extensive understanding of their environment. Hence, unlike their male counterparts, female learners are slow yet flexible learners.

Figure 1. Schematic representation of the Y-maze used in the associative learning test with olfactory cues. Reaching the home cage served as a reward. Source