Seven open-field measures (defecation, urination, ambulation, washing, rearing, latency, and inner circle activity) were obtained using a number of different scoring methods for albino and hooded rats.The albino Ss were tested on 3 different occasions. The first test session was conducted when Ss were 90 days old, the second test session was held 63 days later and a third test session was conducted 154 days after the second. The hooded rats were subjected to 1 test session when Ss were 90 days old. The reliability of these measures was examined using test-retest and odd-even day correlations. The obtained results suggested that defecation, ambulation and rearing can be considered as providing reliable measures of behaviour in the open-field.

Cardiac and visual orienting responses were measured as indexes of attention in 4-month old infants. Two stimulus situations were used In the first situation the presentation of a peripheral stimulus followed the offset of a central fixation stimulus. In the second situation the peripheral stimulus came on while the central fixation stimulus was on. The visual-response measure confirmed other findings that with simultaneous presentation the probability of orienting to the peripheral stimulus is decreased. The cardiac data indicated that on the trials in which the peripheral stimulus did not elicit lateral eye/head movements the stimulus was still being detected.

Seven open-field measures (defecation, ambulation, urination, washing, rearing, latency and inner circle activity) were obtained using a number of different scoring methods for albino and hooded rats. The validity of these measures was examined using (a) day by day decrease of open-field behaviour, (6) effects of retesting over a period of time, [c) variation of stimulus intensity (light and noise). It was found that methods a and b did not provide satisfactory validity estimates. Method c indicated that defecation and latency can be accepted as valid indices of emotionality in rats. Two independent behavioural dimensions in open-field performance. 504.

PROBLEM Wechsler ( 6 ) introduced the Wechsler Memory Scale (WMS), which was designed t o detect special memory defects in individuals with specific brain injuries. Since the publication of the scale, relatively little research has been done using the WMS, and the few studies that have been conducted have produced rather disappointing results. Cohen('), Howard(*, 3 , and Parker(5) found in most cases that the scale did not discriminate between various clinical groups. In fact, Parker(5) suggested that memory quotients derived from WhIS n-ere not valid indices of memory ability. *A full report of this study may be obtairted gratis from the authors.

Two experiments investigated the importance of visual sensory modality in mediating enriched environmental effects during the preweaning period, and the importance of onset and duration of the enriched experience during the same period. Rat mothers and pups were exposed together in an enriched environment for either 7 or 11 days at different periods from Day 1 to Day 21. Also included was a group of rats which received only handling from Day 11 to Day 21 postpartum and another group in which the mothers were exposed to the enriched environment during the last trimester of pregnancy. Some rats were tested at 27 days of age, and others were tested at 64 days of age in the Hebb-Williams maze test. It was found that exposure in the enriched environment for a period of 7 days before the eyes opened improved rats' problem-solving behavior above that of control rats and to the level of rats which received such experience after the eyes had opened. Handling of rats did not improve problem-solving behavior, nor did exposure during the gestation period. It was concluded that vision is not the most important factor in mediating effects during the preweaning period, since improvement in problem-solving behavior can occur before the visual system is fully developed. It was suggested that the beneficial enrichment effects might be mediated by the mother, who, in some way, transmits additional stimulation to the infant rat during this early stage of development.