The effect of spatial cues on infants’ responses in the AB task,with and without a hidden object

The errors made by infants in the AB task were taken by Piaget as an indication of an inability to update their representations of the spatial location of a hidden object. This paper presents an experiment designed to further investigate the role of spatial representations in the production of the error. The introduction of strong visual cues to spatial location was found to reduce the traditional A‐not‐B search error. However, it also increased perseveration when a ‘lids‐only’ analogue of the AB task was used, in which infants are simply cued to pick up lids rather than encouraged to search for a hidden object. These results present a challenge to the dynamic systems account of the error given by Smith, Thelen, Titzer and McLin (Psychological Review, 106 (1999), 235–260), and indicate that the traditional A‐not‐B search error arises from a difficulty in updating representations of the spatial location of hidden objects. The relation of these results to Munakata’s PDP model (Developmental Science, 1 (1998), 161–211) and Thelen, Schöner, Scheier and Smith’s (Behavioural and Brain Sciences, 24 (2001), 1‐‐86) most recent dynamic systems model of the A‐not‐B error is also discussed.     

Stress and smoking in adolescence: a test of directional hypotheses.

The authors conducted a comparative test of the hypotheses that (a) stress is an etiological factor for smoking and (b) cigarette smoking causes increases in stress (A. C. Parrott, 1999). Participants were a sample of 1,364 adolescents, initially surveyed at mean age 12.4 years and followed at 3 yearly intervals. Measures of negative affect, negative life events, and cigarette smoking were obtained at all 4 assessments. Latent growth modeling showed negative affect was related to increase in smoking over time; there was no path from initial smoking to change in negative affect. Comparable results were found for negative life events, with no evidence for reverse causation. Results are discussed with respect to theoretical models of nicotine effects and implications for prevention.     

CHILD LABOUR: AN UNDERDEVELOPED TOPIC IN PSYCHOLOGY

Certain issues concerning child labour are raised: Why do psychologists do so little research on children working, despite the fact that it is widespread? Does work harm the child's development or deprive the child of necessary opportunities for play? How should research on child labour be conducted?     

Incorporating the size principle into an ensemble of back-propagating neurons

As researchers try to move from cybernetics to neural reality, it is time to look at the match between the back propagation strategy and the functional parameters of neurons. Traditionally, the “bias value” in the back propagation activation function has served a mathematical rather than a biological function. By incorporating a production system into the activation logic at the hidden layer, we are able to arrive at a conditional bias value that approximates the function of thresholds in biological neurons.     

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.     

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.     

Health Beliefs and Intentions: Predictors of Return Compliance in a Tuberculosis Detection Drive1

A prospective design was employed to study the ability of various factors to predict return compliance in a tuberculosis detection drive. Five hundred fiftythree participants in the drive were asked to complete a questionnaire tapping their views of TB (based on the Health Belief Model) and their intentions to return for the recommended skin test reading. Behavioral intention was found to be an important predictor of return rates, and the inclusion of the HBM variables aided in the classification noncompliers. Practical and theoretical implications of these findings are discussed.     

Relationships between locus of control,health value,and preventive health behaviors among women

This study examines the relationships between locus of control expectancies, rated health value, and reported participation in preventive health behaviors among a healthy sample of undergraduate women. The prediction that participation in preventive health behaviors would be a joint function of an internal health-related locus of control belief and holding health in high value was not supported. Instead, individuals who valued their health reported participating in a greater number of health-enhancing behaviors compared to those who valued their health less. Respondents' scores on a health value scale in combination with their rated health status proved to be better predictors of health behaviors than their locus of control beliefs. Limitations of locus of control research with young, healthy individuals are discussed and further investigation into the utility and validity of health value scales is recommended.