Limits...
Efficient search for a face by chimpanzees (Pan troglodytes).

Tomonaga M, Imura T - Sci Rep (2015)

Bottom Line: Both species exhibit the face-inversion effect in which the inverted presentation of a face deteriorates their perception and recognition.They also found human adult and baby faces--but not monkey faces--efficiently.This conclusion was supported by a simple simulation experiment using the saliency model.

View Article: PubMed Central - PubMed

Affiliation: Primate Research Institute, Kyoto University, 41-2 Kanrin, Inuyama, Aichi 484-8506, JAPAN.

ABSTRACT
The face is quite an important stimulus category for human and nonhuman primates in their social lives. Recent advances in comparative-cognitive research clearly indicate that chimpanzees and humans process faces in a special manner; that is, using holistic or configural processing. Both species exhibit the face-inversion effect in which the inverted presentation of a face deteriorates their perception and recognition. Furthermore, recent studies have shown that humans detect human faces among non-facial objects rapidly. We report that chimpanzees detected chimpanzee faces among non-facial objects quite efficiently. This efficient search was not limited to own-species faces. They also found human adult and baby faces--but not monkey faces--efficiently. Additional testing showed that a front-view face was more readily detected than a profile, suggesting the important role of eye-to-eye contact. Chimpanzees also detected a photograph of a banana as efficiently as a face, but a further examination clearly indicated that the banana was detected mainly due to a low-level feature (i.e., color). Efficient face detection was hampered by an inverted presentation, suggesting that configural processing of faces is a critical element of efficient face detection in both species. This conclusion was supported by a simple simulation experiment using the saliency model.

No MeSH data available.


Results of Experiment 4.Response times for correct trials of each target. Error bars show standard errors across chimpanzees. ***p < 0.001.
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f6: Results of Experiment 4.Response times for correct trials of each target. Error bars show standard errors across chimpanzees. ***p < 0.001.

Mentions: In the next two experiments, we examined the generality and limits of efficient searching for a face. In previous experiments, we used the chimpanzee face as the target. In this experiment, we presented the faces of human females (Caucasian), as well as those of babies, Japanese macaques, and chimpanzees. The participant chimpanzees were very familiar with Caucasian females (as experimenters) and macaques (living in adjacent enclosures) but had almost no experience with human babies. Thus, we expected that the chimpanzees would detect the human female and macaque faces more efficiently than the human baby faces if familiarity had some effect on searching efficiently for a face. However, as shown in Fig. 6, the chimpanzees rapidly detected the human face, regardless of age, and showed significantly slower response times for the macaque facial target (F(3,33) = 35.70, P = 1.80 × 10−10; multiple comparison, macaque face vs. others, Ps < 0.001). The accuracy results were similar to those for the response times and are described in Supplementary Materials.


Efficient search for a face by chimpanzees (Pan troglodytes).

Tomonaga M, Imura T - Sci Rep (2015)

Results of Experiment 4.Response times for correct trials of each target. Error bars show standard errors across chimpanzees. ***p < 0.001.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4504146&req=5

f6: Results of Experiment 4.Response times for correct trials of each target. Error bars show standard errors across chimpanzees. ***p < 0.001.
Mentions: In the next two experiments, we examined the generality and limits of efficient searching for a face. In previous experiments, we used the chimpanzee face as the target. In this experiment, we presented the faces of human females (Caucasian), as well as those of babies, Japanese macaques, and chimpanzees. The participant chimpanzees were very familiar with Caucasian females (as experimenters) and macaques (living in adjacent enclosures) but had almost no experience with human babies. Thus, we expected that the chimpanzees would detect the human female and macaque faces more efficiently than the human baby faces if familiarity had some effect on searching efficiently for a face. However, as shown in Fig. 6, the chimpanzees rapidly detected the human face, regardless of age, and showed significantly slower response times for the macaque facial target (F(3,33) = 35.70, P = 1.80 × 10−10; multiple comparison, macaque face vs. others, Ps < 0.001). The accuracy results were similar to those for the response times and are described in Supplementary Materials.

Bottom Line: Both species exhibit the face-inversion effect in which the inverted presentation of a face deteriorates their perception and recognition.They also found human adult and baby faces--but not monkey faces--efficiently.This conclusion was supported by a simple simulation experiment using the saliency model.

View Article: PubMed Central - PubMed

Affiliation: Primate Research Institute, Kyoto University, 41-2 Kanrin, Inuyama, Aichi 484-8506, JAPAN.

ABSTRACT
The face is quite an important stimulus category for human and nonhuman primates in their social lives. Recent advances in comparative-cognitive research clearly indicate that chimpanzees and humans process faces in a special manner; that is, using holistic or configural processing. Both species exhibit the face-inversion effect in which the inverted presentation of a face deteriorates their perception and recognition. Furthermore, recent studies have shown that humans detect human faces among non-facial objects rapidly. We report that chimpanzees detected chimpanzee faces among non-facial objects quite efficiently. This efficient search was not limited to own-species faces. They also found human adult and baby faces--but not monkey faces--efficiently. Additional testing showed that a front-view face was more readily detected than a profile, suggesting the important role of eye-to-eye contact. Chimpanzees also detected a photograph of a banana as efficiently as a face, but a further examination clearly indicated that the banana was detected mainly due to a low-level feature (i.e., color). Efficient face detection was hampered by an inverted presentation, suggesting that configural processing of faces is a critical element of efficient face detection in both species. This conclusion was supported by a simple simulation experiment using the saliency model.

No MeSH data available.