Implementation of a common testing platform for two groups of macaques at the German Primate Center
The goal of our project was to introduce a touchscreen-based testing device (eXperimental Behavioral Instrument, XBI) developed by one of the project partners, as a new setup for cognitive tests in a group of socially housed captive long-tailed macaques at the DPZ. The XBI has been used successfully as an automated learning tool with another macaque species and we want to use it as a common platform to facilitate comparative studies between different groups of captive monkeys.
Touchscreen based studies offer a unique flexibility regarding standardized and automated presentation of stimuli and can make training and testing more efficient and less prone to human-induced errors or biases. For example, in a training session the timing of reward given is essential for the individuals’ learning process. If the reward for a correct response is provided manually by the human experimenter, s/he unconsciously might signal a preferred choice (“Clever Hans effect”) or, when many different trials in a row have to be presented, make errors due to fatigue or being temporarily inattentive. Automatic reward systems delimit such potential error and enhance learning performance in this respect. Another advantage of such automated systems is the number of trials a subject potentially can perform in a given time period, i.e. automatic reward is delivered faster than manual reward. If not used for training or experimental sessions, the XBI can be used as enrichment devices offering distraction and stimulation for the monkeys.
Our long-term goal is to develop a common test battery investigating individual and species differences in the motivation to participate in cognitive testing. The touchscreen studies will be complemented by personality assessments via questionnaire ratings and behavioral tests. Factors under investigation will include, but are not limited to, assessment of temperament, sociality, and testing environment (e.g., single vs. group testing).