How chimpanzees (Pan troglodytes) perform in a modified emotional Stroop task

Area of Science:

• Cognitive psychology
• Primate behavior
• Comparative cognition

Background:

• The emotional Stroop task reveals how emotion influences human cognition.
• Humans show slower responses to negative emotional words compared to neutral words.
• Investigating emotional Stroop effect in chimpanzees can offer insights into primate cognition.

Purpose of the Study:

• To determine if chimpanzees exhibit an emotional Stroop effect.
• To adapt the emotional Stroop task for use with non-human primates.
• To explore the impact of emotional stimuli on chimpanzee cognitive performance.

Main Methods:

• Eight chimpanzees (Pan troglodytes) participated using a touchscreen interface.
• Experiment 1: Assessed color-based stimulus selection with congruent vs. incongruent image-frame colors.
• Experiment 2: Employed a modified emotional Stroop task with images of humans (veterinarian, caretaker, stranger) and a control (white square).

Main Results:

• Chimpanzees demonstrated faster and more accurate responses when image and frame colors matched in Experiment 1.
• In Experiment 2, chimpanzees responded slower to veterinarian images, particularly after recent anesthesia.
• Performance impairment correlated with the recency of stressful experiences, indicating emotional valence influence.

Conclusions:

• Chimpanzees exhibit a modified emotional Stroop effect, influenced by emotional valence.
• The modified emotional Stroop task is a viable method for studying cognitive-emotional interactions in non-human primates.
• Findings suggest that emotional stimuli can modulate cognitive performance in chimpanzees, similar to humans.