Studies



Using a large-scale motion-capture system, we reconstructed pigeons' "gaze" and examined how they selectively use different regions of visual fields when viewing attention-getting stimuli. This technique can be used to study attention during the collective behavior of birds. 



Using image analysis techniques, we showed that the appearance of the human eye is distinguished from that of the nonhuman ape eye. Experiments showed that the uniformly white sclera facilitates the visibility of eye-gaze in both humans and chimpanzees. Our results supported the gaze signaling hypothesis (also known as the cooperative-eye hypothesis).

eLife digestUniversity of Konstanz, Discover Magazine


We administered nebulized oxytocin (and control placebo saline) to humans' two closest relatives, bonobos and chimpanzees, and found that these two species differed in the observed effect of oxytocin on their social attention. 



In this outreach project, we asked professional contemporary artists to make movies 'for chimpanzees' and compared chimpanzees' and humans' responses to the movies in eye-tracking. 


We showed that great apes can use their self experiences to infer whether the actor can see through the barrier in a false belief task.  Featured in The AtlanticSmithonian, An introductory article by Alia Martin (Martin A (2019) Belief Representation in Great Apes. Trends Cogn. Sci. 23(12):985-986.)



Kano F., Walker J., Sasaki T., Dora B. (2018) Head-mounted sensors reveal visual attention of free-flying homing pigeons. Journal of Experimental Biology, 221(17), jeb183475.
We developed and tested 'pSensor', that can record free-flying pigeons' head movement (as a proxy for gaze) with IMU (Inertial Measurement Unit) and flight trajectories with GPS. 
Featured in JEBCosmos





Kano F., Moore R., Krupenye C., Hirata S., Tomonaga M., Call J. (2018) Human ostensive signals do not enhance gaze following in chimpanzees, but do enhance object-oriented attention. Animal Cognition, 21(5), 715-728. 
We showed that encultured chimpanzees (but not zoo-reared chimpanzees) respond to the human experimenter's 'ostensive' cues; the cues that a human adult often uses to indicate her/his intention of informing something useful to others. However, their responses to the ostensive cues are somewhat different from human infants' and dogs' in the previous reports. 



Kano F., Shepherd S.V., Hirata S., Call J. 2018 Primate social attention: Species differences and effects of individual experience in humans, great apes, and macaques. PLOS ONE 13(2), e0193283. 
We found that bonobos, chimpanzees, orangutans, monkeys, and humans differ in their eye movement patterns when they are watching videos of these species. We also found that individual experiences such as rearing history (institute-reared, zoo-reared, bio lab-reared) affected social attention in chimpanzees.





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
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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. 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 eye-tracking 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.
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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

We showed that bonobos look at the eyes of conspecific and allospecific facial images for a longer duration than chimpanzees. 


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


We showed that great apes (chimpanzees, bonobos, and orangutans), like human adults and infants, predict a human actor's reaching by eye movement. 



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 bonobos, chimpanzees, orangutans, and human infants and adults. 

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.