Studies

Krupenye, C.*, Kano, F.*, Hirata, S., Call, J., Tomasello, M. (2016). Great apes anticipate that other individuals will act according to false beliefs. Science, 354(6308): 110-114. (*shared first-authors, co-correspondence). 

We examined if great apes anticipate, with their looks (so-called anticipatory looks), an agent’s action based on the agent’s false beliefs. We followed a seminal infant study (Southgate, Senju, Csibra, 2007) for the general design to test false-belief understanding and also followed Kano & Hirata (2015, Current Biology) to make optimized videos for apes. We created two videos having the same general design (after the seminal infant study) but differing in scenarios. Apes reliably anticipated that the agent would act according to false beliefs in two scenarios. 


Featured in NY TimesScienceNature,Scientific AmericanNew ScientistBBCThe GuardianWashington PostLos Angeles TimesBusiness InsiderSalonHuffington PostDiscovery NewsUS News & World ReportABCCBSThe Christian Science Monitor






Kano, F., Hirata, S., Deschner, T., Behringer, V., & Call, J. (2016). Nasal temperature drop in response to a playback of conspecific fights in chimpanzees: A thermo-imaging study. Physiology & Behavior, 155, 83-94. 

We applied an infrared thermo-imaging to examine the chimpanzee's emotional responses to a playback of conspecific fights. Chimpanzees dropped their nasal-tip temperature in response to the stimuli. A remote measurement of skin temperature is a promising technique in this field.




Kano F, Hirata S (2015) Great Apes Make Anticipatory Looks Based on Long-Term Memory of Single Events. Current Biology 25(19): 2513-2517.
We used a novel eye-tracking task to study great apes’ long-term memory shaped through single experiences. We found that, when watching the same video again with a 24-hr delay, great apes make anticipatory looks to the critical, emotional events based on where-what information.

Featured in The New York Times, New Scientists, The Gurdian, etc.





Kano F, Hirata S, Call J (2015) Social Attention in the Two Species of Pan: Bonobos Make More Eye Contact than Chimpanzees. PLoS ONE 10(6): e0129684. doi:10.1371/journal.pone.0129684

Bonobos and chimpanzees are known to differ in many interesting ways. For example, bonobos are in general more affiliative and tolerant to the conspecifics than chimpanzees. I tested if bonobos make more eye contacts than chimpanzees, because, in humans, people with more needs for affiliation tend to make more eye contacts. Indeed, bonobos focused on the eyes of conspecifics better than chimpanzees in my eye-tracking experiment.


Kano, F., & Call, J. (2014). Great apes make goal-directed action prediction by eye movements, Psychological Science, 25(9): 1691-1698.


I tested if great apes (chimps, bonobos, orangs), like human adults and infants, predict reaching actions by eye movements. Apes were familiarized to movie clips of a human hand reaching to grasp one of two objects. Then object locations were swapped, and the hand made an incomplete reach between the objects. In a control condition, a mechanical claw performed the same action. Apes predictively looked at the familiarized goal object rather than the familiarized location when viewing the hand action. However, they did make no prediction when viewing the claw action. 



Kano, F., & Call, J. (2014). Cross-species variation of gaze following and conspecific preference among great apes, human infants and adults. Animal Behaviour 91: 137-150.. 



Gaze following was compared between four hominoid species.  All species followed the gaze of own species model. The species differences were that 1) bonobos followed the gaze more sensitively than chimpanzees, and that 2) chimpanzees and human infants followed only own-species gaze but not other-species gaze, while bonobos, orangutans, and human adults did follow other-species gaze.

Kano, F., & Tomonaga, M. Head-Mounted Eye Tracking of a Chimpanzee under Naturalistic Conditions. PLoS ONE, 8(3), e59785, 2013
Media article (http://www.insidescience.org/content/chimps-point-view/978)
Pan, the chimpanzee, wearing the eye-tracker





Spontaneous scanning of faces by orangutan, gorilla, and human participants.
Gap-overlap task revealed the similarities and differences of basic eye-movement properties between great apes and humans
Chimpanzees scanned visual scenes more quickly and more widely than humans. 

Chimpanzees were similar to humans in their pattern of viewing complex and abstract scenes. 
Among many video contents, chimpanzees viewed fighting scenes most strongly.
Humans extensively viewed eyes. Chimpanzees also viewed eyes but viewed mouth relatively more often. 
Humans viewed eyes when presented with any facial expressions, while chimpanzees viewed mouth expressions more often.
Chimpanzees followed only chimpanzee gaze, while human adults followed both chimpanzee and human gaze.
A chimpanzee on the eye-tracking setting.
Typical scanpaths by chimpanzees and humans.
A chimpanzee recognized the emotional scene better in a memory task.
A chimpanzee on the touch-panel setting.