The computer psychiatrist: How far have we come? Where are we heading? How far dare we go?

The use of computers in psychiatry and psychology is reviewed. It is noted that computers are already being used successfully for consultation, interviewing, and continuing education. Issues related to the usage of computers in mental health are discussed. Guidelines for future work in the area are suggested.     

The effect of thematic content on the ‘Wason selection task’

This paper concerns the differential effects of use of ‘thematic’, rather than abstract (symbolic), content on the ‘Wason selection task’. An effect of thematic content has been reported several times, originally by Wason & Shapiro (1971), but Manktelow & Evans (1979) report five experiments that failed to obtain an effect and argue against the validity of the content effect in general. However, it is pointed out that four of their experiments use a novel content and that there are previous reports of non-effective content in the literature. It is concluded that a particular type of thematic content cannot be treated as a ‘random sample’ of thematic content in general, and that their argument thus rests upon their failure to produce an effect of the specific (’towns and transport’) content used by Wason and Shapiro. This produces an essentially empirical controversy which is settled in two ways. First, Manktelow and Evans’s criticisms of two previous replications are shown to be misleading. Second, an experiment is reported that exactly copies the Wason and Shapiro design and produces a significant effect of content. It is concluded that the Manktelow and Evans result most probably was due to a Type 2 error. Finally, a hypothesis is developed to account for both the effect of certain types of content and the lack of effect of others, including that used in Manktelow and Evans’s first four experiments.     

Two subjective scales of number

The way in which the apparent magnitude of numbers grows with their absolute magnitude was measured with a modified version of the direct technique Marks and Slawson (1966) used to determine the psychophysical exponent for loudness. This modified technique required subjects to estimate how evenly and randomly a sequence of integers appeared to sample the numerical continuum. The results indicate that the apparent magnitude of numbers increases with a decelerated power function of their arithmetic magnitude when a series samples from an open-ended range. However, when an upper boundary of the range is specified, the subjective scale seems to be linear. Random productions of numbers parallel the results found with judgments of presented sequences. The two scales of number provide the basis for an interpretation of the difference between magnitude and category scales: that subjects use numbers differently when the response scale is open-ended Imagnitude estimation than when it has a fixed upper limit tcategory scale. Given the assumption that subjects use numbers in this way in the two tasks, the qualitative relation between magnitude and category scales is predicted.     

Integrality over different paradigms: Card sorting and two-stimulus matching

Orthogonal interference—indicating the cohesiveness between geometrical dimensions—was examined using two separate tasks: (1) card sorting and (2) two-stimulus matching requiring same/different responses. The card-sorting results of the present experiment were contrasted with the results of our previous research (1977, 1979) which used the two-stimulus matching task. Results were generally similar in that the orthogonal interference and, consequently, the degree of integrality/separability were the same for both tasks. Evidence was found for the emergence of a new nominal dimension. This and other results are only compatible with a weaker form of the global-to-local hypothesis of perceptual processing.     

Antagonistic effects of adjacency and apparent speed in induced movement

Two experiments concerning induced movement are reported. The hypothesis was that when outline inducing frames were used, object-relative displacement was modified by two variables, adjacency and apparent speed. Adjacency is directly related to the magnitude of induced movement. Small outline frames are high in adjacency, and so small frames should be powerful generators of induced movement. On the other hand, several investigators have found the speed of the inducing frame to be inversely related to the magnitude of induced movement. It is hypothesized here that this effect of speed was determined by apparent speed (not real speed), and if so, since small objects appeared to move faster than large ones, a small outline frame should be a relatively weak generator of induced movement. In the first experiment, this hypothesis was tested using single inducing frames. In the second experiment, this hypothesis was tested using two inducing frames presented simultaneously. The implications of these experiments were discussed with regard to other theories of induced movement.     

Postdecision evaluation of choice alternatives as a function of valence of alternatives,choice, and expected delay of choice consequences

The effects of valence of alternatives, choice, and expected delay of choice consequences on postdecision evaluations of choice alternatives were studied by either giving subjects a choice between two experimental tasks (both either pleasant or unpleasant) or assigning subjects their initially preferred task. Crosscutting valence and choice, subjects expected either no delay, 10-min delay, or 30-min delay before engaging in the task. All subjects evaluated both tasks immediately after the delay instructions but before experiencing the actual delay. Results confirmed the expected dissonance effect; that is, an upward evaluation of the chosen alternative and a downward evaluation of the rejected alternative, relative to no-choice conditions. Moreover, the relative upward evaluation of the chosen alternative increased as the expected delay decreased. Valence was not found to interact with other variables. The results are discussed in terms of differential salience of choice alternatives.