Higher order encoding: Process or state?

While prior data has seemed to suggest that learning occurs as a result of encoding information into higher order memory units, rather than the formation of interitem associations, the process whereby the encoding occurs has been left relatively unspecified. Two encoding models were outlined which differed to the extent that one assumed that encoding occurred as an active process after the specific items of information were registered in memory, while the other assumed that information is initially registered in memory in the encoded state. The results from two studies seem to offer the most support for the second of these two models.     

Graded changes in evoked response (P300) amplitude as a function of cognitive activity

Using a stepwise discriminant analysis, we demonstrate that the amplitude of P300 is a graded function of the complexity of information processing required of a S following a stimulus. This relationship between cognitive complexity and P300 is apparent only when the S is not pressed to generate fast and accurate discriminant responses to the stimuli. Under a reaction-time regime, a large P300 is elicited independently of stimulus predictability or cognitive complexity. It seems that P300 is a measure of the amount of activity of a general-purpose cortical processor.     

Adolescent pregnancy: intervention into the poverty cycle

Adolescent pregnancy, irrespective of the marital status of the mother, seems to be a determining factor in the incidence of female headed households, divorce, excessive fertility, and poverty. In addition, the pregnant teenager is, obstetrically, a high risk patient, and her offspring, due to poor prenatal care and inadequate nutrition on the part of the mother, is likely to suffer in terms of physical and mental development. This in turn will lead to further poverty, which will continue the cycle. One way to interrupt the cycle may be by delaying the first birth to young adolescent girls. There are 3 stages at which prevention can take place: preventing intercourse, preventing conception, and terminating pregnancy. For the teenager, preventing conception seems the most feasible. Effforts to design family planning programs especially for teenager should be expanded. By this, 2 generation can benefit: the teenager herself and her potential offspring.     

An inexpensive activity measuring device for small animals

A satisfactory device for measuring activity of rats or other small animals has been a difficult problem. Several types of instruments have given incorrect measurements or are prohibitively expensive. Photocells give the same readout to a bobbing head as for a walk over a considerable distance requiring only the interruption of a light beam. Other devices require rotation of wheels or complex integrating circuits which must be replicated or scanned and recorded for simultaneous activity measurement of many animals. The device reported here utilizes the tilting of balanced cages to actuate a single microswitch coupled to an impulse counter for each cage. The system has functioned well for several years.     

Fragmentation and identifiability of repeatedly presented brief visual stimuli

Ss were given repeated brief presentations of geometric forms and drew what they thought they saw. The stimulus patterns were presented tachistoscopically for as many repetitions as necessary for correct identification. The nature and sequential properties of pattern fragments reported prior to correct identification were examined. The first fragments to be reported were generally straight line elements of the stimulus patterns. With repeated presentations, more features were gradually reported until the complete figure was correctly identified. The pattern of construction appeared similar to patterns of fragmentation found in research on stabilized retinal images, prolonged afterimages, and conditions of steady fixation. Implications of these findings for theories of pattern information processing were discussed.     

Attribute identification in children as a function of stimulus dimensionality

Thirty-two four-year-old and 32 six-year-old children were presented a conjunctive concept that involved either two values from within a single dimension (unidimensional condition) or two values from different dimensions (bidimensional condition). As predicted, the results showed that the uni- vs bidimensional factor had no effect upon the performance of the younger children, while the older children solved more rapidly in the unidimensional than in the bidimensional condition. The results were interpreted to suggest that the younger children's responding is not under dimensional control and that a major source of difficulty for older children solving the conjunctive concept is the necessity of responding to two dimensions, not to two values.     

Evaluation of family intervention through unobtrusive audio recordings: experiences in "bugging" children

Five children referred to a child-family intervention program wore a radio transmitter in the home during pre-intervention and termination assessments. The transmitter broadcast to a receiver-recording apparatus in the home (either activated by an interval timer at predetermined "random" times or by parents at predetermined "picked" times). "Picked" times were parent-selected situations during which problems typically occurred (e.g., bedtime). Parents activated the recorder regularly whether or not problems occurred. Child-deviant, parent-negative, and parent-commanding behaviors were significantly higher at the picked times during pretest than at random times. At posttest, behaviors in all three classes were substantially reduced at picked times, but not at random times. For individual subject data, reductions occurred in at least two of the three dependent variables for three of the five cases during random time assessments. In general, the behavioral outcome data corresponded to parent-attitude reports and parent-collected observation data.     

When psychiatric patients interact with computer terminals: Problems and solutions

A computer system for on-line psychiatric patient assessment has been developed at the Veterans Administration Hospital in Salt Lake City. Unlike the typical on-line computer system designed for skilled terminal operators, this system is designed to interact with unskilled psychiatric patients. Special design considerations necessary to support this approach are discussed.