Masaki Tomonaga

• University of Human Environments

Dolphins are known to recognize their environment through echolocation. Previous studies have reported that they can discriminate the shape, size, thickness, and even material of objects through echolocation. However, little is known about the discrimination of quantities other than size and thickness (e.g., the number of objects). It is also uncle...

Based on the invention and development of photography and movie in the 19th century, schools of contemporary art, such as Futurism, have emerged that express the dynamism of motion in painting. Painting techniques such as multiple stroboscopic images, motion blur, and motion lines are culturally based, but the biological basis of their perception h...

Dolphins are known to recognize their environment through echolocation. Previous studies have reported that they can discriminate the shape, size, thickness, and even material of objects through echolocation. However, little is known about the discrimination of quantities other than size and thickness (e.g., the number of objects). It is also uncle...

Quantity discrimination, is thought to be highly adaptive as it allows an organism to select greater amounts of food or larger social groups. In contrast to mammals, the processes underlying this ability are not as well understood in reptiles. This study examined the effects of ratio and number size on relative quantity discrimination in African sp...

How do bottlenose dolphins visually perceive the space around them? In particular, what cues do they use as a frame of reference for left–right perception? To address this question, we examined the dolphin's responses to various manipulations of the spatial relationship between the dolphin and the trainer by using gestural signs for actions given b...

Numerical discrimination is thought to be highly adaptive as it allows an organism to select greater amounts of food or larger social groups. The processes underlying this ability are well understood in mammals with two systems being posited to control behavior, the approximate number system, which uses the ratios between numbers and the object fil...

Based on the invention and development of photography and movie in the 19th century, schools of contemporary art, such as Futurism, have emerged that express the dynamism of motion in painting. Painting techniques such as multiple stroboscopic images, motion blur, and motion lines are culturally-based, but the biological basis of their perception h...

In the present study, we examined the effects of the other's triadic attention to objects on visual search performances in chimpanzees. We found the search-asymmetry-like effect of the other's attentional state; the chimpanzees searched a target object not attended by the other individual more efficiently than that attended (Experiment 1). Addition...

How do bottlenose dolphins visually perceive the space around them? In particular, what coordinates do they use as a frame of reference for left-right perception? To address this question, we examined the dolphin's responses to various manipulations of the spatial relationship between the dolphin and the trainer by using gestural signs for actions...

We sometimes perceive meaningful patterns or images in random arrangements of colors and shapes. This phenomenon is called pareidolia and has recently been studied intensively, especially face pareidolia. In contrast, there are few comparative-cognitive studies on face pareidolia with nonhuman primates. This study explored behavioral evidence for f...

When the row of objects occluded by the window frame suddenly shifts a certain distance, we perceive “ambiguous” apparent motion to move either leftward or rightward. However, if the objects have “directionality,” we perceive these objects as moving forward, called forward-facing motion bias. In the present study, five experiments were conducted to...

We sometimes perceive meaningful patterns or images in random arrangements of colors and shapes. This phenomenon is called pareidolia and has recently been studied intensively, especially face pareidolia. In contrast, there are few comparative cognitive studies on face pareidolia with nonhuman primates. This study explored behavioral evidence for f...

When a row of objects surrounded by a frame suddenly shifts a certain distance so that part of the row is occluded by the frame, humans perceive ambiguous apparent motion either to the left or the right. However, when the objects have “directionality,” humans perceive them as moving forward in the direction in which they are pointing, which is term...

One chimpanzee, who had a long training history of conditional discrimanation tasks, was trained on a new conditional-discrimination procedure in which a visual stimulus (conditional differential outcome) corresponding to each stimulus class followed the responses to the comparison stimulus. She was also trained on identity matching with new "Kanji...