Estimation of height for persons in pictures

We report three experiments in which subjects estimated the height of persons seen in pictures. In Experiment 1, 50 realistic photographs were used as targets. The correlation between mean estimated height and actual height was .92, and target’s sex and the ratios of head to trunk, which included horizontal ratio (i.e., a ratio of head width to shoulder width) and vertical ratio (i.e., a ratio of head height to stature), were found to be effective on height estimates, although target’s sex was more effective than ratios of head to trunk. In Experiments 2 and 3, the recognizability of target persons was reduced, respectively, by inverting the person photographs and by degrading the various features of the photographs. The main results were that (1) the correlation between mean estimated height and actual height was .88 for the inverted photographs and was .80, on average, for the degraded drawings; (2) target’s sex was consistently influential in both experiments; (3) vertical ratio was effective for the inverted photographs and the mildly degraded drawings but not for the extremely degraded drawings in which only outlines of target persons were depicted; and (4) the estimation for the outlined pictures was likely to be influenced by fit of clothes to targets’ bodies. From these findings, person stimuli were considered to provide a stable metric stick of visual space under naturalistic circumstances.     

Pigeons (Columba livia) integrate visual motion using the vector average rule: effect of viewing distance

Animal Cognition - Integrating local motion signals detected by the primary motion detector is crucial for representing a rigid, two-dimensional motion. The nature of motion integration has been...     

Visual behaviors of soccer players while kicking with the inside of the foot

This study analyzed the visual behaviors of soccer players while they kicked with the inside of the foot, which involved near and far aiming skills. Participants (N = 8) were required to step forward and kick a ball to hit a target. The top three scorers were defined as the High-score group, and the three low scorers were defined as the Low-score group. Analysis indicated that the High-score group was characterized by longer quiet eye durations, which were defined as the final fixation durations on the target prior to the initiation of a kicking movement, than the Low-score group in the preparation phase. The High-score group also set their visual pivot on the frontal space between the target and the ball in the kicking phase. These two visual behaviors of the High-score group are important for soccer players to kick a ball successfully with the inside of the foot.     

Understanding of the relationship between seeing and knowing by tufted capuchin monkeys (Cebus apella)

The ability of four tufted capuchin monkeys (Cebus apella) to recognize the causal connection between seeing and knowing was investigated. The subjects were trained to follow a suggestion about the location of hidden food provided by a trainer who knew where the food was (the knower) in preference to a trainer who did not (the guesser). The experimenter baited one of three opaque containers behind a cardboard screen so that the subjects could not see which of the containers hid the reward. In experiment 1, the knower appeared first in front of the apparatus and looked into each container; next, the guesser appeared but did not look into any containers. Then the knower touched the correct cup while the guesser touched one of the three randomly. The capuchin monkeys gradually learned to reach toward the cup that the knower suggested. In experiment 2, the subjects adapted to a novel variant of the task, in which the guesser touched but did not look into any of the containers. In experiment 3, the monkeys adapted again when the knower and the guesser appeared in a random order. These results suggest that capuchin monkeys can learn to recognize the relationship between seeing and knowing. Accepted after revision: 10 September 2001 Electronic Publication     

Observing emotion in infants: facial expression,body behavior,and rater judgments of responses to an expectancy-violating event

Eleven-month-old European-American, Japanese, and Chinese infants (ns = 23, 21, and 15, respectively) were videotaped during baseline and stimulus episodes of a covert toy-switch procedure. Infants looked longer at the object during the expectancy-violating event (stimulus episode) but did not produce more surprise-related facial expressions. American and Japanese infants produced more bodily stilling during stimulus than baseline, and American infants also produced more facial sobering. Naive raters viewing both episodes could correctly identify the expectancy-violating event. Rater judgments of surprise were significantly related to infants' bodily stilling and facial sobering. Judgments of interest were related to cessation of fussing. Thus, observer judgments of infant emotions can be systematically related to behaviors other than prototypic emotional facial expressions.     

An experimental consideration of fixation properties.

While varying the size and complexity of a stimulus object, we measured eye movements during fixation. Although subjects' eyes are fixated at the center of the object, the experimental results indicate that "fluctuation during fixation (FDF)" which is larger movements than "miniature eye movements" occurred. In addition, FDF varies according to the peripherals of fixation points characterized by the size and complexity of the stimulus object.     

Perceptual completion in rhesus monkeys (Macaca mulatta) and pigeons (Columba livia)

In a two-dimensional drawing, when the narrow edge of a bar appears to touch the edge of a large rectangle, humans overestimate the length of the bar (Kanizsa, 1979). Kanizsa has suggested that this illusion occurs because humans perceive the bar as continuing behind the rectangle and complete the “occluded” portion of the bar. Rhesus monkeys and pigeons were trained to classify black target bars with a variety of lengths as “long” or “short.” In training, the bar was always located at the same distance from a gray box. After learning this discrimination, the subjects were tested on novel stimuli, in which the bar was located at three new locations. Monkeys showed a consistent response bias for “long” when the bar touched the box, but pigeons did not. Monkeys appear to have completed the “occluded” part like humans, whereas pigeons failed to do so. Because this procedure does not require animals to complete the “occluded” part with any particular form, their failure suggests that pigeons do not even perceive the target bar as continuing behind the “occluding” figure. The failure of pigeons may be due to difficulty in perceiving depth from two-dimensional drawings.     

Left-side dominance for song discrimination in Bengalese finches (Lonchura striata var. domestica)

Male Bengalese finches are left-side dominant for the motor control of song in the sensorimotor nucleus (the high vocal center, or HVc) of the telencephalon. We examined whether perceptual discrimination of songs might also be lateralized in this species. Twelve male Bengalese finches were trained by operant conditioning to discriminate between a Bengalese finch song and a zebra finch song. Before training, the left HVc was lesioned in four birds and the right HVc was lesioned in four other birds. The remaining four birds were used as controls without surgery. Birds with a left HVc lesion required significantly more time to learn to discriminate between the two songs than did birds with a right HVc lesion or intact control birds. These results suggest that the left HVc is not only dominant for the motor control of song, but also for the perceptual discrimination of song. Accepted after revision: 11 September 2001 Electronic Publication     

I know you are not looking at me: capuchin monkeys’ (<Emphasis Type="Italic">Cebus apella</Emphasis>) sensitivity to human attentional states

The present study asked whether capuchin monkeys recognize human attentional states. The monkeys requested food from the experimenter by extending an arm (pointing) toward the baited one of two transparent cups. On regular trials the experimenter gave the food immediately to the monkeys upon pointing but on randomly inserted test trials she ignored the pointing for 5 s during which she displayed different attentional states. The monkeys looked at the experimenter's face longer when she looked at the monkeys than when she looked at the ceiling in Experiment 1, and longer when she oriented her head midway between the two cups with eyes open than when she did so with eyes closed in Experiment 2. However, the monkeys showed no differential pointing in these conditions. These results suggest that capuchins are sensitive to eye direction but this sensitivity does not lead to differential pointing trained in laboratory experiments. Furthermore, to our knowledge, this is the first firm behavioral evidence that non-human primates attend to the subtle states of eyes in a food requesting task.     

Projecting two words with one machine: Presenting two different visual stimuli using just one projector without viewers’ noticing the duality

A new method, named the fMORI technique, for presenting two different visual stimuli using just one video projector without the viewers' noticing the duality is introduced along with several sample applications of this presentation method. The LCD projectors available now have three color LCD panels aligned differently in terms of their polarization, polarizing differently the green and magenta (red plus blue) components of its emitting image. Therefore, two visual stimuli either in green or in magenta projected on thesame screen canbe observed separately by subjects wearing an appropriate polarizing filter. This is a variation of the MORI technique (Mori, 2003, 2007b) but it requires only one video projector rather than two. Full-color movies cannot be presented with the fMORI technique, but it may be utilized in various research areas in which only static monochrome visual stimuli, such as words or numbers, are used.