Delay of gratification in children: The effects of training under fixed,decreasing and increasing delay of reward

The effect of fixed, gradually decreasing, or increasing delay of reward in discimination learning on later delay of gratification was investigated. In discrimination training, employing a correction procedure, a candy reward was delivered either after 0, 10, 20, 40 or 60 sec fixed delay; or after 60 sec in the first block of trials and decreased in successive block; or reward was immediate in the first block of trials and delay was gradually increased to 60 sec. In the delay of gratification tests, subjects could press a button immediately to receive a small reward (one candy or a cheap toy) or delay pressing and receive an increasingly larger reward (more candy or a better toy).Learning was not significantly affected by either fixed or decreasing delays. Increasing delays resulted in faster learning than decreasing delays. The increasing delay group demonstrated superior delay of gratification on both tests. Fixed delay groups did not differ significantly among themselves, nor from the decreasing delay group. The effectiveness of exposure to increasing delays in facilitating delay of gratification was interpreted as due to either the acquisition of coping responses or the extinction of frustration.     

Using three-dimensional graphics in neuropsychological hypothesis testing

This paper presents the application of an overlapping sampling technique used with a fast Fourier transform on electroencephalographic data. The use of this sampling and analysis technique is demonstrated on data in which steady state, rate of change, and critical event hypotheses are tested. The benefit of applying computer-generated three-dimensional graphics to the results of using this innovative sampling and analysis technique is emphasized.     

Type A Behavior and Diabetic Control: Implications of Psychological Reactance for Health Outcomes1

According to laboratory research, Type A coronary-prone individuals are sensitive to threats to their personal control and react to such threats with active and often stressful coping responses. The present investigation tested the prediction that these features of Type A behavior would interfere with blood glucose regulation in insulin-dependent diabetes mellitus patients. Two independent hypotheses were investigated. Because elevated sympathetic arousal, a concomitant of stressful coping, is associated with elevated glucose levels, it was predicted that Type A diabetics experiencing high levels of life stress would display poorest blood glucose control (indexed by Hemoglobin A₁c). The second hypothesis was derived from the observation that Type As are more likely than Type Bs to respond to control threats with reactance in order to restore the perception of control. Given that illness or treatment can reduce personal control, it was predicted that Type A diabetics would be most reactant and, thus, most medically noncompliant. To test these hypotheses, 37 Type 1 diabetics were assessed for Type A behavior, life change, attributional style, desire for control (both within treatment and in general), and specific perceptions of and actions to their diabetes. Type As were more likely than Type Bs to show poor blood glucose control. However, for patients in general, and Type As in particular, blood glucose regulation was not related to life stress. Rather, those Type As who displayed poor glucose control made more extreme self-attributions about the cause of their diabetes, were angrier about it, and felt they should fight it. The implications of these findings for a reactance-Type A model of medical compliance are discussed.     

A parallel but not necessarily connectionist model of the auditory system

The basic processing elements (the neurons) in the brain operate in the millisecond range and are about a million times slower than a computer (Feldman, 1985). In order to make up for this lack of computational speed, the brain must use a parallel multisynaptic method to transmit information. This paper presents a parallel processing model of the auditory system; the model accounts for the frequency and the sound-localization information.     

Component analysis of ECG by computer

The present paper describes a set of interactive computer programs and methods (i.e., cardiac component analysis, CCA) that allow the collection, summation, and averaging of the time durations of the various ECG components. The programs are written in FORTRAN and run on a Texas Instruments minicomputer using an Intecolor 8001 terminal as the display device. The program’s features include analog-to-digital conversion, color display of individual heart-beats, operator interaction, and statistical summation with tabular output. Subroutines are well structured and easily transported to other machines. Although these programs may be used on-line, it has been more efficient to perform the analyses off-line, after a subject has completed the task. Various versions of the program have been used to analyze human, baboon, and dog ECGs in 2- to 30-sec epochs, at sample rates of 258 and 1,000 samples/sec. Preliminary results from an experiment of the effects of meditation and cognitive overload are discussed.     

The development of alertness

Two experiments explored variation in the alerting process across age and warning interval as well as the effects of alertness on subsequent processing. Experiment 1 obtained alertness functions for a group of 5-year-olds, 8-year-olds, and adults. Results revealed strong age differences in speed of alerting and in maintenance of alertness over a 1-sec interval. Five-year-olds alerted more slowly than older groups and sustained optimal alertness less well. Both groups of children showed more variability in alerting functions compared with adults. Experiment 2 examined the degree to which age differences in processing speed were attributable to differential speed and maintenance of alerting. Masking functions obtained across variations in the alerting interval revealed that when level of alertness was optimal in both 5-year-olds and adults, minimal age differences in processing speed were observed. During short, nonoptimal alerting intervals, speed of processing in adults was faster than in 5-year-old children. The pattern of results across studies suggested that alertness can fluctuate over time in young children, that level of alertness affects subsequent perceptual processing speed, and that developmental variation in speed and maintenance of alertness can partly explain observed age differences in processing speed. The potential role of alertness in more complex cognitive tasks is discussed.     

Developmental differences in the allocation of processing capacity

Recently psychologists have formulated a comprehensive view of attention involving allocation of processing capacity. Although developmental changes in processing capacity have been proposed as one source of age differences in certain cognitive skills, there has been little systematic investigation of this hypothesis. In the present study, second and sixth graders and adults (8, 12, and 20 years of age, respectively) performed a letter-matching task (primary task) concurrently with an auditory detection task (secondary task). Changes in reaction time in the secondary task as a function of manipulations of the primary task were used to estimate capacity allocation to the primary task. Primary task variables included stage of processing (alerting, encoding, rehearsing, responding) and matching condition (physical-identity vs name-identity matching). Age differences in secondary task performance were found to be related to stage of processing but not to matching condition. Earlier stages of the letter match task (alerting, encoding) required somewhat more capacity allocation in younger subjects. Later stages (rehearsing, responding) made substantially higher demands on capacity in children. Capacity allocation may be an important cognitive variable mediating developmental differences in basic information processing skills, and may underlie age trends found in performance of certain complex cognitive tasks.