Developmental phases of sleep and motor behaviour in a cat mother-infant system: a time-lapse video approach

The evolution of sleep patterns in developing kittens was studied using time-lapse video technology and direct observation. The duration, frequency, and onset of the behavioural states and interactions of the cats were analyzed and then organized into phases that represent major changes in developmental structure during the first 6 weeks of kitten life. We have demonstrated that the kittens began exhibiting adult bi-cyclic sleep patterns on approximately Day 30 of development. During the 10-day period that preceded this consolidation of sleep pattern, REM sleep decreased by half, with a reciprocal increase in NREM sleep. These changes were coincident with an increase in kitten patterned motor behaviour and an increase in stimulation of the kittens by the mother during her bi-cyclic active periods.     

Sleep in Alzheimer's disease and other dementing disorders

It is estimated that up to 10% of the elderly population have clinically significant cognitive deficits. The neuronal pathologies that underlie the dementing disorders cause both cognitive dysfunction and disturbances in normal sleep/wake patterns. Here we report the changes in sleep/wake patterns seen with increasing severity of Alzheimer's disease, probably the most common dementing disorder. In addition, studies examining sleep/wake patterns in a number of other dementing disorders are reviewed.     

Spatial representation of a two-dimensional pattern

The purpose of this study was (a) to determine if vision and kinesthesis contribute differentially to the coding of a specific two-dimensional pattern and (b) to identify the effect of repetition on the spatial representation of this pattern. The reproductions of a specific pattern presented visually were compared with those of a pattern presented kinesthetically. The results showed that vision and kinesthesis had contributed equally to the coding of the directional components of the pattern. However, there was dominance of visual information over kinesthetic information when coding the distance between the intersecting points of the pattern, especially at the beginning of the process. Generally speaking, the visual or kinesthetic repetition, or both, have increased favourably the precision with which a specific pattern was reproduced in distance and direction.     

Newborns' preferential tracking of face-like stimuli and its subsequent decline.

Goren, Sarty, and Wu (1975) claimed that newborn infants will follow a slowly moving schematic face stimulus with their head and eyes further than they will follow scrambled faces or blank stimuli. Despite the far-reaching theoretical importance of this finding, it has remained controversial and been largely ignored. In Experiment 1 we replicate the basic findings of the study. In Experiment 2 we attempt a second replication in a different maternity hospital, and extend the original findings with evidence suggesting that both the particular configuration of features, and some aspects of the features themselves, are important for preferential tracking in the first hour of life. In Experiment 3 we use a different technique to trace the preferential tracking of faces over the first five months of life. The preferential tracking of faces declines during the second month. The possible causes and consequences of this observation are discussed.     

Assertiveness, social support, and psychological adjustment following spinal cord injury.

Tested predictions that assertiveness and social support would be significantly predictive of psychological adjustment. Furthermore, it was anticipated that assertiveness and certain types of social relationships would differentially interact to predict adjustment, since positive and negative effects of both variables have been noted in prior research. Trained raters interviewed 156 persons receiving either in-patient or out-patient care for cord injuries and administered measures of assertiveness, social support, depression and psychosocial impairment. Persons who reported a keen sense of responsibility for the welfare of another reported more depression and impairment. Persons reporting higher levels of support facilitating social integration and reassuring personal worth were less depressed. Several significant interactions between assertiveness and different social support relationships revealed beneficial and deleterious effects on depressive behavior and impairment secondary to the disability. Results are discussed as they advance theoretical understanding of the effects of assertiveness and social support. Implications for discriminate cue learning in assertion training for persons with physical disability are proposed.     

Visual palatability of food in patients with eating disorders and dieting women

The effects of 19 meals of different caloric content on slides on palatability and hypothetical duration of consumption were investigated in 7 patients with anorexia nervosa, 17 patients with bulimia nervosa at the beginning and after 8 weeks of hospital treatment. Nine healthy females served as controls. At the beginning of treatment, palatability of low caloric food was significantly higher and hypothetical duration of consumption of high caloric food was significantly longer in patients when compared to controls. After 8 weeks, in the patients palatability of low caloric food had decreased. Dislike for high caloric food remained stable in anorexics.     

Multiple role juggling and daily mood states in working mothers: an experience sampling study

The effects of multiple role juggling (i.e., simultaneously attending to demands of different roles) on daily mood states of employed mothers were examined. Ss completed activity and mood questionnaires 8 times a day for 8 days. Multiple role juggling had immediate negative effects on task enjoyment and mood. However, contrast effects and habituation to role juggling occurred when mood and satisfaction were examined over time. Furthermore, mood states tended to spill over from one episode to the next within a day, but contrast effects were found across days. These results reflect the complex nature of psychological adjustment to multiple role occupancy.     

Siblings in dyads: relationships among perceptions and behavior

The ways in which middle-childhood siblings perceive themselves as similar or different was assessed with a sample of 40 pairs of 9- to 11-year-old (younger) and 12- to 14-year-old (older) siblings. Each child was interviewed and completed a card sort procedure and a measure of self-competence. Sibling pairs participated in three behavioral tasks coded for cooperation and conflict. Self-ratings, self-perceptions, and sibling behavior were analyzed for their association with the perceived similarity construct. Siblings perceived themselves as being more like one another than did their mothers. Forty-one percent of the variance in their perceived similarity was accounted for by paired self-cooperation ratings, social competence, and behavioral task scores.     

Is object texture a constraint on human prehension?: kinematic evidence

The present experiment determined whether object texture influenced the transport and grasp components of human prehension. Infrared markers placed on the index finger, thumb, and wrist were recorded using a WATSMART system. The test objects were cylindrical dowels (103 mm high, 25 mm diameter, and 150 g in weight) of various surface materials (plain metal, coated with Vaseline, and covered with coarse sandpaper). Only temporal kinematic measures were affected by texture: Movement time (ms), time after peak deceleration (ms), percentages of movement time following maximum aperture, velocity, and deceleration were all significantly greater for the slippery dowel than the normal and rough dowels. Results indicated that the increased time associated with the slippery dowel could be explained entirely by increased time between contact with the dowel and dowel lift. Thus, these results are like those of Weir, MacKenzie, Marteniuk, Cargoe, and Frazer (1991), in which object weight was shown not to affect the free-motion phase, which includes the transport and grasp components of prehension. It appears that intrinsic object properties like weight and texture affect only the finger-object interaction phase of prehension; subsequent research is needed to dissociate inertial and surface friction effects while in contact with objects