Poisson signal-detection theory: Link between threshold models and the Gaussian assumption

The Gaussian model of signal detection cannot fit asymmetric data as long as the variances of the distributions are kept equal. It is therefore common practice to assume unequal variances in order to fit these data. But this assumption leads to the well-known crossover problem. The present paper provides new arguments for the abandonment of the Gaussian model with unequal variances. In its stead, this paper reevaluates multiple-parallel-threshold models. In particular, the Poisson model turns out to be very useful: it can handle data with any degree of asymmetry, giving a reasonable interpretation of the two parameters of the receiver-operating characteristic. The three-state-threshold model (Krantz, 1969) is given a new interpretation in light of the Poisson model. The slope of Poisson double-probability plots turns out to be much closer to unity than is predicted by the Gaussian approximation.     

Organization by modality,language, and category compared

Summary An experiment was presented to test a functionalistic interpretation of the modality effect. This shows a superior recall performance for auditorily as opposed to visually presented verbal information. A total of 60 subjects were presented with mixed-mode (auditory-visual words), mixed-language (Swedish-English words), or mixed-category (category-unrelated words) lists, and were asked to recall the words of each list in any preferred order. The degree of organization according to modality, language, or category and the recall performance were measured. Organization by modality was significantly higher than organization by language or category as predicted by the functionalistic view proposed. The recall performance obtained for auditory and visual words differed in a way predicted by the functionalistic view.     

Perception of autonomic reactions and actual heart rate in phobic patients

The relationship between perceived physiological arousal and actual heart-rate reactions was studied in two behavioral test situations. The subjects were 70 phobic patients (34 social phobics and 36 claustrophobics) who were given the general form of the Autonomic Perception Questionnaire about 1 month before the respective behavioral test and the specific form immediately after the test. The results showed significant correlations between APQ and actual heart rate for the social phobics, while the picture was more complicated for the claustrophobics. The implications of these results are discussed.This research was supported by Grant 05452 from the Swedish Medical Research Council.     

The role of imagery in the representation of linear orderings

Two experiments were carried out to investigate whether visual imagery was used in representing transitive linear ordering relationships. Subjects were presented with passages describing either a linear ordering or a set inclusion relationship, while being subjected to either visual or verbal interference. Performance was tested by asking subjects to judge the truth or falsity of statements concerning both the information presented in the passages and inferences that could be drawn from this information. In neither experiment was there any evidence for the linear ordering material being selectively disrupted by the visual interference task, as would have been predicted by the imagery theory. Thus it is concluded that linear orderings are probably not represented as visual images.     

Prophylactic psychiatry

The great contributions of Gantt to the problems of prophylactic psychiatry are pointed out. The author reviews his experiences with a 30-year follow-up of a population of 1800 persons. Over the 30 years, there appeared to be a 50% increase of neuroses, which raises great problems for mental health services. The Berlevåg population was offered optimal psychiatric services. Behavior therapy of neuroses and drug treatment of depression may possibly have lowered the prevalence of mental disorders. Psychophysiologic tests were used in the project. It is hoped that such tests may be utilized for early detection and treatment of mental disorders.     

The general psychophysical differential equation: A comparison of three specifications

The general psychophysical differential equation, dy/dx = W₂(y)/W₁(x), with the solution y = f(x), where x and y are subjective variables and W₁ and W₂ their subjective Weber functions, is (a) compared with a corresponding functional equation, and (b) studied from a stochastic point of view by error calculus, Methods for evaluating and handling divergences are proposed and illustrated for a number of combinations of Weber functions. It is shown that either the differential: and the functional equations have the same solution or the difference between the solutions is negligible compared to empirical scatter. The error calculus gives the same result: either no error at all or a negligible one.     

“Motority” in three functional domains of word meaning

This article deals with relations between mental motor evoking capacity (motority, Putnoky, 1975a, b) and the sensory and affective connotations, as well as certain denotations, of words. Sensory connotation is indexed by degree of visual auditory, and tactual imagery, as assessed on a 7-point scale, while affective connotation is indexed by the usual three factors tapped by the semantic differential. The aspect of denotation used here is the abstractness value of words, also based on rating by scales. The general conclusions about motority are as follows: (1) the finding that its sensory connotations are mainly via theauditory modality of imagery, and especially in correlation with abstract words, suggests that it has a specific function that may have originated in the processing of heard language; (2) it correlates with thepotency andactivity factors of affective connotation, which suggests the existence of a nonspecific function or component in it; (3) correlations with abstractness reflect that motority must have a denotative function or component, especially in case of abstract verbal stimuli. On the basis of the results, motority is supposed to play a regulative role at higher levels of the organization of word meaning in particular.Computation of SD data was carried out under the direction and according to the programming of Professor William H. May in the Center for Comparative Psycholinguistics (Director: Charles E. Osgood), University of Illinois, Urbana-Champaign, with support provided by the National Institute of Mental Health (NIMH 07705) and National Science Foundation (NSF GS 360 and 2012-X).     

Differential effects of person in the dog and in the human

People have marked effects on dog’s heart rate, with great individual variations for different persons. Apparently people to which the dog is attached have the greatest effect upon heart rate. Replications of the animal experiments using the psychotherapist and two other people revealed no effects upon the heart rate of a schizophrenic human. In the human the effects of people are probably best demonstrated in connection with verbal communication.