An experimentalprocedure designed to disrupt an ongoing pattern of communication, followed byan assessment of how the infant responded to the disruption. The disruption consists of an adult becomingsuddenly unresponsive, while maintaining a face-to-face position with the baby. This still face period is both precededand followed by the adult to engaging in interaction with the infant. The …
Author Archives: Brian Hopkins
Still-face procedure
A procedure in which a person, usually the caregiver, after interacting in a normal manner and on instruction, becomes unresponsive (i.e., does not use facial or vocal cues). This usually results in changes in the infant‚was state (e.g., crying), attention or affect. It is taken to indicate that the young infant (typically, 2-3 months-of-age) has …
Stigmata
minor physical anomalies, such as low-seated or soft and pliable ears, epicanthus, and Greig hypertelorism (a congenital malformation of the skull characterised by an enlarged sphenoid bone, extremely wide bridge of the nose with great width between the eyes, exophtalnos or abnormal eyeball protusion, divergent strabismus and optic atrophy) . See Down‚was syndrome. Williams syndrome
Steroids
Refer to a class of chemicals defined by their chemical structure, an important group of which is steroid hormones. Cortisol and DHEA are both members of the steroid family because of their chemical structure. They have critical and widespread functions in metabolism, including adjustment to physical and psychological stress. See Cortisol, Hormones, Hypothalamic-pituitary-adrenal (HPA) axis, …
Steroid hormones
A general class of chemically related hormones, including primarily those synthesised in the testes, ovaries and adrenal cortex, or they are produced by enzymatic conversion of steroid precursors in peripheral tissues, especially adipose tissue. Steroids are directly involved in the regulation of growth and maturation, in addition to being essential to many other body functions …
Stereoscopic depth perception
Computation or detection of an aspect of object distance by comparison of the images of the same scene in the two eyes (i.e., by means of binocular disparity resulting from slightly different viewpoints of the eyes). See Binocular disparity, Depth perception, Eye movements, Motion parallax
Stepping response
Movements of the legs that can be elicited in the human newborn. When held upright, tilted slightly forward, supported under the armpits, and the soles of the feet are brought into contact with a surface, the infant displays an alternating and plantigrade stepping pattern. It is usually observed for 2-3 months postnatally and then can …
Stem cells
Undifferentiated embryonic or adult cells that have the potential to give rise to any type of differentiated cells. There are three basic sorts of stem cells: multipotent (give rise to only specific types of cells), pluripotent (can form most kinds of tissue, but not a whole organism), and totipotent (can form a whole organism as well …
Stellate cells
Sometimes called small granule cells, they are interneurons in the cerebellar cortex with multiple processes that synapse on the dendrites of Purkinje cells who action they inhibit through the release of GABA, and which in turn are excited by granule cells. Like other cells in the cerebellum, they are also found in the cerebral cortex. …
Steady state
The time-series hypothesis that a construct may deviate over time from some initial or average level, but as time goes by will eventually return to this initial state.