A case of cortical deafness: Clinical and electrophysiological data

A patient suffering from a primary myocardiopathy is suddenly no longer able to recognize speech and environmental sounds, in spite of good peripheral hearing; he remains able to speak, read, and write. The C.T. scan shows lesions involving both supratemporal planes. The cortical sensory deficit documented by the absence of late acoustic evoked potentials leads to a diagnosis of cortical deafness rather than of auditory agnosia.     

Sensory stores and high-speed scanning

A model of scanning based on separate sensory and short-term stores was suggested and tested. The experiment used a probe recognition method, with set size varied from 1 to 8 and a fast presentation rate. A masking procedure was used to vary the number of items available in a possible sensory store. Although conditions were such as to maximize the chances of detecting an effect, none was found: the possible size of the sensory store had no effect on reaction time whatsoever. Other aspects of the data lent little support to a serial exhaustive scanning model, but a previously proposed parallel processing model fared better. Finally, not only was the function for positive probes steeper than that for negative probes but also there was a crossover effect as well. This crossover is not without precedent and may indicate the need for consideration of both accuracy and latency in high-speed scanning studies.     

Influence of accommodation on the viewing of an optical illusion

This study demonstrates the role of microfluctuations of accommodation in the viewing of the concentric ring illusion. Four experiments were carried out. Experiment I consisted of changing the distance between the illusion and the eyes but retaining visual angle, luminance and pupil size constant. In Experiment II, the accommodation of the eyes is paralysed by a cycloplegic. In Experiment III, the illusion is shown to a monocular aphakic and in Experiment IV, the exposure time is varied between 1/100 and 5 sec. Furthermore, a series of observations compared the concentric ring illusion seen with both eyes simultaneously. The evidence provided by the results of these experiments plus others discussed provide evidence that the concentric ring illusion is caused by the microfluctuations of accommodation.     

Sensory scaling and the psychophysical law

Sensory scaling is analysed as a sensori-motor task for which two relations must be determined, the first, S = f(I), being the relation between I, the stimulus intensity, and S, a measure of the neural effect of the stimulus, and the second being the relation between the subject's response, R, and S. It is shown that for any scaling procedure the relation between R and S can be arbitrarily specified, and according to the choice made S = f(I) will be found to be either a power function or a logarithmic function; these two “psycho- physical laws” do not reflect empirical differences between scaling procedures but conventional differences in the assumptions made when interpreting these procedures. A model is then elaborated in which S = f(I) is fixed and the relation between R and S depends on the demands of the psychophysical task and the effects of previous learning. With this more complex model the empirical implications of the power function and log function differ; it is shown that if the latter is accepted explanations can be given for two major problems in scaling theory, the disparity between the functions given by category scaling and the direct methods, and the difference between prothetic and metathetic continua.     

Health and legal issues in undercover narcotics investigations: Misrepresented evidence

This paper outlines some types of psychological disturbances found to occur in narcotics agents who use undercover investigative methods. Research results and other clinical findings dismiss popular notions of multiple personalities as a mental injury caused by prolonged role played pseudoidentities. Coping strategies for dealing with certain paranoid reactions are seen as potential sources of contamination in the gathering of evidence of criminal activity. Issues related to questions of health versus operative talents in selecting for personal suitability for undercover work are presented.     

School attainment,self-esteem,and identity: France and England

The Tajfel-Turner Theory of Social Identity was used as a framework from which it was predicted that pupils of low attainment in secondary school should come to define themselves as indifferent to or opposed to the values of their schools. This hypothesis was examined in France and England, on self-report measures covering values, aspirations, perceptions, evaluations, beliefs and motivations. While results show numerous differences between low and high attainers common to both countries, the differences are more pronounced in England. National differences are such that the French pupils are more like high attainers. Results are interpreted as being more consistent with low attaining pupils being victims of boredom rather than failure, with the French school culture providing greater insulation against such reactions.