Why does memory span increase with age?

Ordered recall of auditory digits was obtained from children of 4, 7, 9, and 11 years of age. Lists had one of three types of sound pattern: melody, prosody, or monotone. For each sound pattern condition, half the lists were temporally grouped. Effects of sound pattern were minor, and not obviously age-specific. Profound effects of temporal grouping and clear-cut primacy effects appeared for all age groups and all conditions. These results render less plausible the popular hypothesis that the increase of memory span with age is due to the emergence of active strategies. It is suggested that the development of span may be due to an increase in the ease with which children can identify the individual items and encode information about their order.     

Transformations. I. The effect of DAF on sentence generation

A hypothesis based on the psycholinguistic derivation of sentences was tested. The task required that sentences temporarily stored in memory be transformed and spoken with delayed auditory feedback. An instruction to repeat the stimulus sentence verbatim or grammatically transform it was placed either immediately before or immediately after the sentence. Two measures of interference were obtained based on the syllable rates for the response times. The different grammatical forms showed significant variation in the amount of interference, but the amount of interference appeared to relate primarily to the length of the transformed sentence rather than to its derivational complexity. Interaction between the position of the instruction and the sentence generation task is discussed in terms of the underlying memory functions involved. A further test was proposed.     

The legalization of the school psychologists’ world

Discusses the increasing tendency of legal rules to shape school psychologist's conduct. Court cases, legislation, and empirical studies treating with this issue are analyzed. The article suggests that “the legalization of the school psychologist's world” may afford an opportunity to reshape, in more “non-formal” and collegial ways, relationships with other school professions, students, and parents.     

Cardiovascular responses to avoidance conditioning in the dog: Effects of alpha adrenergic blockade

Laboratory dogs were trained to press a response panel to postpone shocks during daily one-hour avoidance conditioning periods. Each dog was also confined in the experimental environment for 5 hours prior to the avoidance periods. Blood pressure and heart rate were monitored continuously during these experiments from chronically indwelling arterial catheters. Extended training resulted in the emergence of a cardiovascular response pattern during the pre-avoidance interval characterized by gradual increases in blood pressure together with decreases in heart rate. Elevations in both blood pressure and heart rate were sustained during the avoidance periods. During sessions in which alpha adrenergic activity was suppressed by phenoxybenzamine, absolute levels of blond pressure were found to be lower than during control (non-drug) sessions, but a progressive rise in blood pressure continued to be observed during pre-avoidance. These results suggest that sustained cardiovascular responses during avoidance periods are associated with activation of the sympathetic nervous system, but that the gradual rise in blood pressure during pre-avoidance is due to other factors.     

Periodicity pitch perception and its upper frequency limit in cats

We have established a procedure for behavioral assessment of periodicity pitch perception in the cat. This procedure requires the training of cats to make a differential response to two different pure tones, and then testing for the transfer of learning when complex stimuli known to produce periodicity pitch sensations in humans are substituted for the pure tones. Complex stimuli consisted of three to five harmonically related frequencies of the same amplitude and phase. Eight cats were the subjects of these experiments. Two of them were controls. It is demonstrated here that cats do perceive periodicity pitch. We also used this procedure to measure the upper frequency limit of periodicity pitch perception for two cats. The frequencies tested were 100, 200, 300, 400, 600, 800, 900, and 1,200 Hz. The data indicate that the upper frequency limit of periodicity pitch perception in the cat is on the order of 600 to 800 Hz. There is a trend of decreasing prominence of the perception of periodicity pitch as the component frequencies are increased. These results are parallel to the human psychophysical data.     

Hardware and software evolution of an adaptive ability measurement system

A software system for the administration of six different strategies of adaptive ability tests in a variety of formats was developed both on a large-scale time-sharing system and on a real-time minicomputer system. Factors influencing both hardware selection and software design are discussed.