Regularity of spectral pattern and its effects on the perceptual fusion of harmonics

A single even harmonic added to an odd-harmonic complex may be judged as perceptually more salient than the odd harmonics themselves (Roberts & Bregman, 1991). It is proposed that this effect occurs because the even harmonic is inconsistent with the regular spectral pattern formed by the odd-harmonic complex (the base). Therefore, a reduction in the regularity of the base spectrum should reduce the even—odd difference. Spectral regularity was reduced either by removing base components, or by including components in the base that were inconsistent with its original pattern. Subjects listened to (primarily) harmonic complex tones and rated the clarity of one of the harmonics, cued by a preceding pure tone. Both removing components from the base and including extraneous components in the base reduced the even—odd difference. The results suggest that it is easier to segregate a harmonic from a periodic complex tone when it does not form part of the regular pattern of spectral spacing defined by the other harmonics.     

The influence of introversion/extraversion on the skin conductance response to stress and stimulus intensity

A series of studies compared skin conductance level (SCL) for introverts and extraverts during a series of tones varying in both stimulus intensity (SI) and the amount of stress preceding the tones. When a difficult paired-associate task preceded the tones, both groups were about the same for 83 dB tones but extraverts were much higher at 103 dB, introverts failing to show an increase as a function of SI. There were no differences between the two groups following a simple paired-associate task, both groups showing a similar increase with increased SI. Finally, SCL was higher for introverts than extraverts during tones preceded by a rest period, and this was especially true for the early trials and for lower SI (75 and 83 dB compared with 100 and 103 dB). Taken together, these results suggest that SCL is higher for extraverts at higher levels of arousal but that the reverse is true for lower levels of arousal. This relationship is consistent with the theory that introverts have a “weak nervous system” which develops transmarginal or protective inhibition under stress.     

The social conditions, consequences and limitations of careers guidance

The recent influence of developmental theories of occupational choice upon guidance practice in Britain is criticised. It is suggested that people do not typically 'choose' occupations in any meaningful sense: they simply take what is available. Moreover, the career of the typical industrial worker cannot be meaningfully understood in terms of self-actualisation and implementing a self-concept: guidance work based upon these concepts is accordingly unrealistic. An adequate theory for understanding school-leavers' transition to employment in Britain needs to be based around the concept not of 'occupational choice', but of 'opportunity structure'. Guidance should concentrate not on raising unrealistic expectations, but on helping people to adjust successfully within the opportunity structures open to them.     

The SSR System 7: A general encoding system with computerized transcription

This report provides an overview of the wide variety of research problems to which the SSR System is being applied and outlines some of the changes in the system that these new challenges have brought about.     

What makes a task difficult?

Summary This study explores the relationship between different task requirements and children's task performance and ratings of task difficulty. Four hundred and sixty five children (9 to 13 years old) read texts and answered questions, involving well-defined or ill-defined goals and requiring different thought operations. It was found that rated difficulty and performance were highly related for questions involving a well-defined goal. A simple modus ponens inference was easiest, checking most difficult, and recall of the text ranked in the middle. A question, involving an ill-defined goal was rated to be most difficult, whereas performance was quite high. The results confirm the assumptions that judgment of difficulty relies on two sources of information: 1) perception of goal, and 2) perception of processing effort.     

Birth control practices and conservatism

This study examined the relationship of conservatism to reports of contraceptive usage, reasons for nonusage of a particular birth control method, and knowledge of birth control information. The never married high conservative subjects who were sexually experienced revealed that they had (a) a lower frequency of usage as well as a lower variety of contraceptive methods; (b) endorsed the beliefs that it was morally wrong and that it was unnatural to use a given birth control method significantly more often as reasons for not using contraceptive techniques; and (c) less knowledge of birth control methods than did low conservative subjects who were sexually experienced. Results were interpreted to support the notion that the fear of loss of control of one's impulses and hence the basis for conservative attitudes are determinants of contraceptive usage.     

Spatial memory in the rat on a hierarchical maze

Rats were trained and tested on a hierarchical radial maze, which consisted of eight primary alleys radiating from a central platform and three secondary alleys which branched off the end of each primary alley. In four experiments, rats in groups 1, 2, and 3 were tested on maze configurations consisting of one, two, or three secondary alleys, respectively, at the end of each primary alley. In Experiment 1, each group was trained to collect food pellets in the secondary alleys. By the end of training, rats in each group collected all pellets efficiently, with little repetition of entrances into either primary or secondary alleys. In Experiments 2 and 3, tests were carried out which required retention of entrances into secondary alleys, as well as primary alleys. Two trials were run in succession, with selected secondary alleys blocked on trial 1 but open and baited with food on trial 2. Animals in groups 2 and 3 showed very accurate retention of blocked secondary alleys, regardless of variation in pattern and number of alleys blocked. A fourth experiment controlled for the possible use of food cues in Experiments 2 and 3 by rebaiting all secondary alleys between trials 1 and 2. Subjects continued to choose previously blocked alleys on trial 2, thus demonstrating that choice of blocked alleys was based on memory and not on a tendency to approach visual or olfactory food cues. Several findings of these experiments suggest that memories for primary and secondary alley choices are encoded and stored within separate memory systems. Possible coding mechanisms for these systems are discussed with reference to a process of cognitive mapping.