Structuring of early reaching movements: a longitudinal study

Reaches, performed by 5 infants, recorded at 19 weeks of age and every third week thereafter until 31 weeks of age, were studied quantitatively. Earlier findings about action units were confirmed. At all ages studied, movements were structured into phases of acceleration and deceleration. Reaching trajectories were found to be relatively straight within these units and to change direction between them. It was also found that at all ages, there was generally one dominating transport unit in each reach. The structuring of reaching movements changed in four important ways during the period studied. First, the sequential structuring became more systematic with age, with the dominating transport unit beginning the movement. Second, the duration of the transport unit became longer and covered a larger proportion of the approach. Third, the number of action units decreased with age, approaching the two-phase structure of adult reaching. Finally, reaching trajectories became straighter with age.     

Postphenomenological Method and Technological Things Themselves

Human Studies - We live in a world where it is impossible to exist without, and beyond, technologies. Despite this omnipresence, we tend to overlook their influence on us. The vigorously developing...     

Recognizing images: The role of motivational significance,complexity, social content,age, and gender

Memory for affective events plays an important role in determining people’s behavior and well-being. Its determinants are far from being completely understood. We investigated how recognition memory for affective pictures depends on pictures’ motivational significance (valence and arousal), complexity (figure-ground compositions vs. scenes), and social content (pictures with people vs. without people) and on observers’ age and gender. Younger, middle-aged, and older adults viewed 84 pictures depicting real-life situations. After a break, the participants viewed 72 pictures, half of which had been viewed previously and half of which were novel, and were asked to endorse whether each picture was novel or had been presented previously. Hits, false alarms, and overall performance (discrimination accuracy) were our dependent variables. The main findings were that, across participants, recognition memory was better for unpleasant than pleasant pictures and for pictures depicting people than pictures without people. Low-arousal pictures were more accurately recognized than high-arousal pictures, and this effect was significantly larger among middle-aged and older adults than younger adults. Recognition memory worsened across adulthood, and this decline was steeper among men than women. Middle-aged and older women outperformed their male counterparts. This study suggests that how well we are able to successfully discriminate previously seen pictorial stimuli from novel stimuli depends on several pictures’ properties related to their motivational significance and content, and on observer’s age and gender.     

Developmental kinesics: How children acquire communicative and non-communicative nonverbal behavior

This article is a position paper concerning the major issues in the study of children's acquistion of nonverbal behavior. In linguistic theory non-verbal behavior may be considered irrelevant, it may be condsidered the precursor of verbal language, or it may be viewed as an integral part of human communication which is verbal and nonverbal. The author opts for the latter theory. Concerning the relationship between what is innate and what is learned, the paper discusses that nonverbal expression is innate, but culture determines its forms and its uses. The paper then presents a brief history of Developmental Kinesics, explaining its technical difficulties and its methodological complexities. It proceeds by documenting the function of maternal nonverbal behavior towards the neonate. Finally, the paper treats the levels of analysis. A distinction is drawn between communicative and non-communicative nonverbal behavior. Its affective, emotional function relates to ego state; its regulatory function governs face-to-face interaction; and its referential, informative function pertains to the message proper. The child also acquires the non-interactional aspects of body movements which distinguish different peoples. Expression and perception must be studied separately; and finally, nonverbal behavior has to be correlated with verbal behavior and particular attention has to be focused on the double bind.