Nonhuman primate
Nonhuman primate

Eye tracking nonhuman primates

Eye tracking in nonhuman primates provides insights about decision making, emotion recognition, attention, and social behavior.

What you can measure with eye tracking

Pupil center corneal reflection (PCCR) is one of the most accurate and non-invasive ways to measure eye movements. Eye trackers using this technique typically deliver a data stream in real-time containing raw data, such as gaze origin, gaze point, and pupil diameter.

Tobii nonhuman primate

Reliability in a range of settings

When conducting eye tracking research on nonhuman primates, it is important that your solutions ensure reliability across a variety of locations and scenarios. Whether you are conducting research in a controlled laboratory setting or in an animal enclosure like a zoo or sanctuary, Tobii has built a range of eye tracking solutions that deliver robust data without compromising freedom of movement or ease of use.

Chimpanzee in the jungle

Studying cognitive processes with eye tracking

The eye tracking solution and a dedicated application, like our software Tobii Pro Lab, can further process the data to draw valuable conclusions on a wide variety of cognitive processes in NHPs, including:

  • Attention

  • Cognitive reasoning

  • Face processing

  • Social preference

  • Motivation

Fields of research

Eye tracking offers a possibility to assess human and nonhuman primates using the same or similar conditions, which provides a translational opportunity to bridge the gap between basic and clinical investigations. Our noninvasive and restraint-free eye tracking technology allows researchers to collect data in custom laboratory and natural settings while being supportive of the primate’s welfare.
Eye tracking opens research possibilities in:

  • Cognitive neuroscience

  • System neuroscience

  • Clinical and translational neuroscience

  • Ethology

  • Behavioral psychology

  • Cognitive psychology

Research setups for nonhuman primate studies

Tobii Pro Spectrum eye tracker with a screenshot

Screen-based for the lab

The visual stimuli are displayed on a screen, in a laboratory environment, using the screen-based eye trackers
Tobii Pro Spectrum and Tobii Pro Lab.

Monkey exhibit at a zoo

Screen-based for the field

The visual stimuli are displayed on a screen in a zoo or a primate sanctuary using Tobii Pro Spectrum and
Tobii Pro Lab.

An infant in front of Tobii Pro Spectrum eye tracker looks at a researcher with poppets

Standalone for the lab

The subjects observe or interact with objects or stationary physical scenes in a laboratory environment, using Tobii Pro Spectrum and Tobii Pro Lab.

Eye tracking in nonhuman primate research

Integrating eye tracking with traditional assessments of social behavior

Ryan and colleagues (2020) used Tobii Pro TX300 to study social development in rhesus macaques in a longitudinal eye tracking study. The researchers measured the duration of eye fixations to social stimuli in macaques from one to six months old. They used Tobii Studio software to record and process eye tracking data. The study results revealed a positive relationship between time spent viewing the eyes of unfamiliar conspecifics and the number of social interactions initiated with peers.

Internal arousal levels in chimpanzees

Hepach and colleagues (2021) studied chimpanzee motivation to help others. During the behavioral paradigm, chimpanzees had an opportunity to help a conspecific to obtain food. The subject’s eye pupil diameter (a proxy for internal arousal) was measured with Tobii X120 throughout the process. The study results showed that chimpanzees are motivated to help others based on direct or indirect reciprocity.

Same-sex attentional preferences in capuchins

Lonsdorf and colleagues (2019) examined capuchin’s preference for same or opposite-sex faces. The subjects gaze behavior was measured with Tobii Pro TX300 eye tracker while viewing images of unfamiliar male or female conspecific faces. The results revealed same-sex attentional preferences, suggesting that potential competitors gather more attention than prospective mates.

Related products

More information

Enabling success

Tobii offers tailored support to address research needs throughout your journey with Tobii’s eye tracking.

Person in front of the computer with academic icons visible

Tobii Funding support services

Tobii Funding support services help you improve your grant proposals for research that includes eye tracking in its methodology

Tobii Connect

Tobii Connect

Tobii Connect delivers product documentation, how-to guides, and answers to FAQs as well as access to software updates. Our customer care services help with any technical issues concerning Tobii products.

Tobii Academy

Tobii Academy

Tobii Academy our online learning platform, helping you ensure study success at every step of the way from study design to interpreting your eye tracking data.


  1. Brooks, J., Kano, F., Sato, Y., Yeow, H., Morimura, N., Nagasawa, M., Kikusui, T., & Yamamoto, S. (2021). Divergent effects of oxytocin on eye contact in bonobos and chimpanzees. Psychoneuroendocrinology, 125, 105119.
  2. Gao, J., Adachi, I., & Tomonaga, M. (2022). Chimpanzees (Pan troglodytes) detect strange body parts: An eye-tracking study. Animal Cognition.
  3. Maylott, S. E., Paukner, A., Ahn, Y. A., & Simpson, E. A. (2020). Human and monkey infant attention to dynamic social and nonsocial stimuli. Developmental Psychobiology, 62(6), 841–857.  
  4. Sato, Y., Kitazaki, M., Itakura, S., Morita, T., Sakuraba, Y., Tomonaga, M., & Hirata, S. (2021). Great apes’ understanding of biomechanics: Eye-tracking experiments using three-dimensional computer-generated animations. Primates; Journal of Primatology, 62(5), 735–747.
  5. Zhang, B., Zhou, Z.-G., Zhou, Y., & Chen, Y.-C. (2020). Increased attention to snake images in cynomolgus monkeys: An eye-tracking study. Zoological Research, 41(1), 32–38.