Role of biological-motion information in recognition of facial expressions by young children

Data on the development of the perception of facial biological motion during preschool years are disproportionately scarce. We investigated the ability of preschoolers to recognise happy, angry, and surprised expressions, and eye-closing facial movements on the basis of facial biological motion. Children aged 4 years (n = 18) and 5-6 years (n = 19), and adults (n = 17) participated in a matching task, in which they were required to match the point-light displays of facial expressions to prototypic schematic images of facial expressions and facial movement. The results revealed that the ability to recognise facial expressions from biological motion emerges as early as the age of 4 years. This ability was evident for happy expressions at the age of 4 years; 5-6-year-olds reliably recognised surprised as well as happy expressions. The theoretical significances of these findings are discussed.     

Preference for infant-directed singing in 2-day-old hearing infants of deaf parents.

L. J. Trainor (1996) reported preferences for infant-directed versus infant-absent singing in English in 4-7-month-old hearing infants of English-speaking hearing parents. In this experiment, the author tested preferences for infant-directed singing versus adult-directed singing in 15 two-day-old hearing infants of deaf parents for a Japanese and an English play song. Using a modified visual-fixation-based auditory-preference procedure, the author found that infants looked longer at a visual stimulus when looking produced infant-directed singing as opposed to adult-directed singing. These results suggest that infants prefer infant-directed singing over adult-directed singing and that the preference is present from birth and is not dependent on any specific prenatal or postnatal experience.     

Visual onset expands subjective time

We report a distortion of subjective time perception in which the duration of a first interval is perceived to be longer than the succeeding interval of the same duration. The amount of time expansion depends on the onset type defining the first interval. When a stimulus appears abruptly, its duration is perceived to be longer than when it appears following a stationary array. The difference in the processing time for the stimulus onset and motion onset, measured as reaction times, agrees with the difference in time expansion. Our results suggest that initial transient responses for a visual onset serve as a temporal marker for time estimation, and a systematic change in the processing time for onsets affects perceived time.     

Freezing degrees of freedom under stress: kinematic evidence of constrained movement strategies

The present study investigated the effect of psychological stress imposed on movement kinematics in a computer-simulated batting task involving a backward and forward swing of the forearm. The psychological stress was imposed by a mild electric stimulus following poor performance. Fourteen participants hit a moving ball with a horizontal lever and aimed at a distant target with as much accuracy as possible. The kinematic characteristics appearing under stress were delay of movement initiation, small amplitude of movement and low variability of spatial kinematic events between trials. These features were also found in previous studies in which the experimental task required high accuracy. The characteristic kinematics evident in the present study suggested that the movement strategies adopted by the stressed participants were similar to those that appear under high accuracy demand. Moreover, a correlation analysis between the onset times of kinematic events revealed that temporally consistent movements were reproduced under stress. Taken together, the present findings demonstrated that, under psychological stress, movement strategies tend to shift toward the production of more constrained trajectories, as is seen under conditions of high accuracy demand, even though the difficulty of the task itself does not change.     

Preference for consonance over dissonance by hearing newborns of deaf parents and of hearing parents

Behavioral preferences for consonance over dissonance were tested in hearing infants of deaf parents and in hearing infants of hearing parents when they were 2 days old. Using a modified visual-fixation-based, auditory-preference procedure, I found that both 2-day-old infants of deaf parents and those of hearing parents looked longer at a visual stimulus when looking produced the original version of a Mozart minuet as opposed to a version altered to contain many dissonant intervals. The relative magnitude of such preference did not significantly differ whether their parents were deaf or hearing. Infants prefer consonance over dissonance, and the preference is present from birth and is not dependent on any specific prenatal or early postnatal experience.