Spontaneous attention and psycho-physiological responses to others’ injury in chimpanzees

他者の怪我に対しチンパンジーが情動的に反応することを発見 --最新技術が明かす類人猿の注意と生理的反応--. 京都大学プレスリリース. 2019-06-19.Previous studies have shown that humans experience negative emotions when seeing contextual cues of others’ pain, such as injury (i.e., empathic pain), even without observing behavioral expressions of distress. However, this phenomenon has not been examined in nonhuman primates. We tested six chimpanzees (Pan troglodytes) to experimentally examine their reactions to others’ injury. First, we measured viewing responses using eye-tracking. Chimpanzees spontaneously attended to injured conspecifics more than non-injured conspecifics, but did not do so in a control condition in which images of injuries were scrambled while maintaining color information. Chimpanzees did not avoid viewing injuries at any point during stimulus presentation. Second, we used thermal imaging to investigate chimpanzees’ physiological responses to others’ injury. Previous studies reported that reduced nasal temperature is a characteristic of arousal, particularly arousal associated with negative valence. We presented chimpanzees with a realistic injury: a familiar human experimenter with a prosthetic wound and artificial running blood. Chimpanzees exhibited a greater nasal temperature reduction in response to injury compared with the control stimulus. Finally, chimpanzees were presented with a familiar experimenter who stabbed their (fake) thumb with a needle, with no running blood, a situation that may be more challenging in terms of understanding the cause of distress. Chimpanzees did not physiologically distinguish this condition from the control condition. These results suggest that chimpanzees inspect others’ injuries and become aroused by seeing injuries even without observing behavioral cues, but have difficulty doing so without explicit (or familiar) cues (i.e., open wound and blood)

Average Token Delay: A Duration-aware Latency Metric for Simultaneous Translation

Simultaneous translation is a task in which the translation begins before the end of an input speech segment. Its evaluation should be conducted based on latency in addition to quality, and for users, the smallest possible amount of latency is preferable. Most existing metrics measure latency based on the start timings of partial translations and ignore their duration. This means such metrics do not penalize the latency caused by long translation output, which delays the comprehension of users and subsequent translations. In this work, we propose a novel latency evaluation metric for simultaneous translation called \emph{Average Token Delay} (ATD) that focuses on the duration of partial translations. We demonstrate its effectiveness through analyses simulating user-side latency based on Ear-Voice Span (EVS). In our experiment, ATD had the highest correlation with EVS among baseline latency metrics under most conditions.Comment: Extended version of the paper (doi: 10.21437/Interspeech.2023-933) which appeared in INTERSPEECH 202

Eye tracking uncovered great apes' ability to anticipate that other individuals will act according to false beliefs

Financial support came from Ministry of Education, Culture, Sports, Science and Technology (K-CONNEX to FK), Japan Society for Promotion of Science (KAKENHI 26885040, 16K21108 to FK), National Science Foundation (DGE-1106401 to CK), JSPS (KAKENHI 26245069, 24000001 to SH), and European Research Council (Synergy grant 609819 SOMICS to JC)Using a novel eye-tracking test, we recently showed that great apes anticipate that other individuals will act according to false beliefs. This finding suggests that, like humans, great apes understand others' false beliefs, at least in an implicit way. One key question raised by our study is why apes have passed our tests but not previous ones. In this article, we consider this question by detailing the development of our task. We considered three major differences in our task compared to the previous ones. First, we monitored apes' eye movements, and specifically their anticipatory looks, in order to measure their predictions about how agents will behave. Second, we adapted our design from an anticipatory-looking false belief test originally developed for human infants. Third, we developed novel test scenarios that were specifically designed to capture the attention of our ape participants. We then discuss how each difference may help explain differences in performance on our task and previous ones, and finally propose some directions for future studies.Publisher PDFPeer reviewe

Nasal temperature drop in response to a playback of conspecific fights in chimpanzees : a thermo-imaging study

This study was conducted in part under the first author's postdoc program; the Japan Society for Promotion of Science (JSPS) for study abroad. FK and SH respectively received JSPS KAKENHI Grant Number 26885040 and 26245069. This study was also in part funded by JSPS MEXT KAKENHI Grant Number 24000001, JSPS-LGP-U04, JSPS core-to-core type A CCSN, and MEXT-PRI-Human Evolution.Emotion is one of the central topics in animal studies and is likely to attract attention substantially in the coming years. Recent studies have developed a thermo-imaging technique to measure the facial skin temperature in the studies of emotion in humans and macaques. Here we established the procedures and techniques needed to apply the same technique to great apes. We conducted two experiments respectively in the two established research facilities in Germany and Japan. Total twelve chimpanzees were tested in three conditions in which they were presented respectively with the playback sounds (Exp. 1) or the videos (Exp. 2) of fighting conspecifics, control sounds/videos (allospecific display call: Exp. 1; resting conspecifics: Exp. 2), and no sound/image. Behavioral, hormonal (salivary cortisol) and heart-rate responses were simultaneously recorded. The nasal temperature of chimpanzees linearly dropped up to 1.5. °C in 2. min, and recovered to the baseline in 2. min, in the experimental but not control conditions. We found the related changes in excitement behavior and heart-rate variability, but not in salivary cortisol, indicating that overall responses were involved with the activities of sympathetic nervous system but not with the measureable activities of the hypothalamus-pituitary-adrenal (HPA) axis. The influence of general activity (walking, eating) was not negligible but controllable in experiments. We propose several techniques to control those confounding factors. Overall, thermo-imaging is a promising technique that should be added to the traditional physiological and behavioral measures in primatology and comparative psychology.PostprintPeer reviewe

Great apes anticipate that other individuals will act according to false beliefs

Financial support came from NSFGRFP DGE-1106401 (CK), MEXT K-CONNEX, JSPS KAKENHI 26885040, 16K21108 (FK), JSPS KAKENHI 26245069, 24000001 (SH), and ERC-Synergy grant 609819 (JC).Humans operate with a "theory-of-mind" with which they understand that others’ actions are driven not by reality but by beliefs about reality, even when those beliefs are false. Although great apes share with humans many social-cognitive skills, they have repeatedly failed experimental tests of such false belief understanding. Using an anticipatory looking test (originally developed for human infants), we show that three species of great apes reliably look in anticipation of an agent acting on a location where he falsely believes an object to be, even though they themselves know that it is no longer there. These results suggest that great apes also operate—at least on an implicit level—with an understanding of false beliefs.PostprintPostprintPeer reviewe

A test of the submentalizing hypothesis : apes' performance in a false belief task inanimate control

Financial support came from Ministry of Education, Culture, Sports, Science and Technology (K-CONNEX to FK), Japan Society for Promotion of Science (KAKENHI 26885040, 16K21108 to FK), JSPS (KAKENHI 26245069, 24000001 to SH), and European Research Council (Synergy grant 609819 SOMICS to JC).Much debate concerns whether any nonhuman animals share with humans the ability to infer others' mental states, such as desires and beliefs. In a recent eye-tracking false-belief task, we showed that great apes correctly anticipated that a human actor would search for a goal object where he had last seen it, even though the apes themselves knew that it was no longer there. In response, Heyes proposed that apes' looking behavior was guided not by social cognitive mechanisms but rather domain-general cueing effects, and suggested the use of inanimate controls to test this alternative submentalizing hypothesis. In the present study, we implemented the suggested inanimate control of our previous false-belief task. Apes attended well to key events but showed markedly fewer anticipatory looks and no significant tendency to look to the correct location. We thus found no evidence that submentalizing was responsible for apes' anticipatory looks in our false-belief task.Publisher PDFPeer reviewe