PSYCHOPHYSICAL RELATIONS IN VISUAL PERCEPTION OF LENGTH, AREA AND VOLUME

E kman , G., and J unge , K. Psychophysical relations in visual perception of length, area and volume. Scand. J. Psychol ., 1961, 2 , 1–10. — Subjective length, area and volume as functions of the corresponding stimulus variables were studied in three experiments. The exponents of the psychophysical power functions scattered around 1 for perception of 'real' space. For perspective drawings of cubes and spheres, however, the exponents were about 0.75. From a further analysis of the data it was tentatively concluded that perspective and shadow are insufficient cues to visual volume, and that the subjective scale reflects perception of area rather than volume, especially in the case of small stimuli.     

A COMPARISON BETWEEN CHILDREN AND ADULTS IN A PRISONERS' DILEMMA GAME

S jöberg , L., B okander , I., D encik , L. & L indbom , K. A comparison between children and adults in a prisoner's dilemma game. Scand. J. Psychol ., 1969, 10 , 158–166.— A comparative study using three different stooge strategies. The game was played for a total of 67 trials. Children (4–6 years old) exhibited more cooperation than adults, and a stronger tendency to make a cooperative move after own defection, regardless of outcome. Both the frequency of cooperative moves and the state-conditioned propensities showed some stability over time and similar intercorrelations for adults and children.     

GEOGRAPHICAL DATA AS PSYCHOPHYSICAL STIMULI

L undberg U. & E kman G. Geographical data as psychophysical stimuli. Scand. J. Psychol . 1972, 13 , 81–88.—Thirty-three students reported their subjective estimates of the area, the number of people, and the average population density of 44 different countries. Subjective scales were constructed for each variable and it was found that these scales could be roughly described by simple power functions of the corresponding physical scales. The subjective scales were positively related to each other, and the correlations they showed exceeded the corresponding correlations between the physical variables. Empirical estimates of population density may be described by a simple power function of the expected subjective population density with the exponent of o.63.     

TRANSITION FROM ROD TO CONE VISION: II. Successive contrast

S tabell , B. & S tabell , U. Transition from rod to cone vision. II. Successive contrast. Scad J. Psychol., 1969, 10 137–139—Transition from chromatic rod to chromatic cone activity during dark adaptation is interpreted as a kind of color mixing.     

THE STABILITY OF PATHOLOGIC SIGNS IN THE PERCEPTUAL PROCESS AS REVEALED BY A SERIAL TACHISTOSCOPIC EXPERIMENT

S mith , G. J. W., and J ohnson , G. The stability of pathologic signs in the perceptual process as revealed by a serial tachistoscopic experiment. Scand. J. Psychol ., 1961, 2, 142–148.—The study demonstrates high inter-rater and inter-set consistency in a serial tachistoscopic experiment utilizing pairwise presentations of stimuli A and B, B being presented at constant time levels, A at gradually increasing ones. Two parallel sets contain two series each. In one series A is incongruent with B, in another a threat directed against B. Fifty psychiatric patients are given the two sets with a one-day interval. Reports of change in A and B during the micro-genesis of A are scored in the dimensions of repression, isolation, projection, and depression.     

THE INFLUENCE OF AUDITORY STIMULUS INTENSITY ON APPARENT DURATION

B erglund , B., B erglund , U., E kman , G. & F rankenhaeuser , M. The influence of auditory stimulus intensity on apparent duration. Scand J. Psychol ., 1969, 10 21–26.— apparent duration of an auditory signal of 1000 C/S was measured by the method of magnitude estimation. Ten different stimulus intensities ranging from 57 to 104 dB were used in combination with three different durations: 50, 250, and 500 msec. The results showed that the apparent duration of the signal grew as a logarithmic function of stimulus intensity. These results are consistent with the hypothesis relating apparent duration to activation level as well as with results of similar experiments involving electrical and vibrotactile stimulation.     

VISUAL AFTER-IMAGES: CENTRAL AND PERIPHERAL EFFECTS: A comment upon Kolehmainen and Tuomisaari

P iggins , D. J. Visual after-images: central and peripheral effects. A comment upon Kolehmainen and Tuomisaari. Scand. J. Psychol ., 1969, 10 , 287–288.— Evidence is presented to support the view that visual after-images are influenced by central loci in the human visual system. The evidence for the involvement of a central site comes from studies on the 'fragmentation' of geometrical figures viewing as prolonged after-images. (Completely stabilized retinal images.)     

TRANSITION FROM ROD TO CONE VISION:III. Successive contrast anew

S tabell , U. & S tabell , B. Transition from rod to cone vision. III. Successive contrast anew. Scand. J. Psychol ., 1969, 10 , 140–144—The relation between the specific threshold level and the upper limit of the scotopic contrast color was investigated. The achromatic interval between the scotopic and the photopic component increased when time in darkness increased, and when pre-stimulation was reduced as regards intensity, duration, or cone/rod ratio. The results are interpreted on the basis of the opponent theory of color vision.     

THE VALUE OF EXTERNAL DIRECTION AND INDIVIDUAL DISCOVERY IN LEARNING SITUATIONS: The learning of a mathematical principle

W erdelin , I. The value of external direction and individual discovery in learning situations. I. The learning of a mathematical principle. Scand. J. Psychol ., 1968, 9, 241–247.—Three samples (A, B, C), selected at random from seven sixth grade classes, were instructed differently how to use a mathematical principle. A was told the principle and applied it on examples; B was given most examples first, then told the principle, and given additional examples; C was given examples only. A learned the principle better, as measured by a test given immediately after the experiment. C was comparatively better as to retention and transfer. B was between A and C.     

ON THE DETERMINATION OF VARIANCE ATTRIBUTABLE TO PREVIOUSLY ISOLATED FACTORS

H olley , J. W. & E lmgren , J. On the determination of variance attributable to previously isolated factors. Scand.J. Psychol ., 1969, 10 , 74–80.—The paper describes a method for extracting variance which can be attributed to factors which have been isolated previously. An illustration is given, using hypothetical data.     

MEASUREMENT OF AESTHETIC VALUE BY 'DIRECT' AND 'INDIRECT' METHODS

E kman , G. & K ünnapas , T. Measurement of aesthetic value by 'direct' and 'indirect' methods. Scand. J. Psychol ., 1962, 3 , 33–39.—The main features of 'direct' and 'indirect' methods for psychophysical measurement are briefly reviewed. An experiment is described, where the aesthetic value of 18 specimens of handwriting was measured by the direct method of ratio estimation and the indirect method of pair comparisons on the assumption of Thurstone's Case V. The scale constructed by the indirect method was a theoretically expected logarithmic function of the ratio scale obtained by the direct method. If the ratio scale is accepted as a criterion, the results show that a true interval scale may be constructed by the indirect method, in this experiment, provided that the assumption of constant variability is replaced by an assumption of proportional variability.     

CHROMATIC ROD AND CONE ACTIVITIES AS A FUNCTION OF THE PHOTOCHROMATIC INTERVAL

S tabbll , B. & S tabell , U. Chromatic rod and cone activities as a function of the photochromatic interval. Scand. J. Psychol ., 1969, 10,215– 219.—The Sco topic contrast color dominated for longer periods and at higher intensities the larger the magnitude of the photochromatic interval, indicating that the relative responsiveness of the chromatic rod to the chromatic cone activity increases as a function of the photochromatic interval.     

CHROMATIC ROD VISION

S tabell B. & S tabell U. Chromatic rod vision. IV. Time between pre-and test-stimulation varied. Scand. J. Psychol ., 1972, 13 , 141–144.—The scotopic contrast hue was determined as a function of time between pre-and test-stimulation. As the interval increased, the scotopic hue was found to change from orange toward yellow in the 440–475 nm region of pre-stimulation and from violet-blue toward violet in the 550–595 nm region. It is concluded that (1) depending on wavelength of pre-stimulation, the processes in the red-green substance may revert to the mid-valued state faster or slower than the processes in the yellow-blue substance, and (2) the red/blue ratio of the violet hue which has to be added to the additive opponent hue to produce the scotopic contrast hue, may change as a function of time between pre- and test-stimulation.     

CHROMATIC ROD VISION III. Duration of pre-stimulation varied

S tabell B. & S tabell U. Chromatic rod vision. III. Duration of pre-stimulation varied. Scand. J. Psychol ., 1972, 13 , 136–140.—The scotopic contrast hue was determined as a function of duration of pre-stimulation, together with the additive opponent hue. It is concluded that the red/blue ratio which has to be added to the additive opponent hue to produce the scotopic contrast hue, may change as a function of both wavelength and duration of pre-stimulation.     

OBJECTIVE INDICATORS OF PERCEPTION

B okander , I. Objective indicators of perception. I. Simple reaction-time. Scand. J. Psychol ., 1962, 3, 192–195.—This paper demonstrates that simple reaction-time, viz. the time interval between the onset of a meaningful picture stimulus and a simple motor response, is dependent upon the nature of the picture in such a way that stimuli selected to produce more involvement give longer reaction-times. Two experiments were performed. In the first, involving and neutral stimuli were centered around the middle of the pictures, while the second pair of pictures differed with respect to peripheral qualities.     

AVOIDANCE BEHAVIOUR TO LIGHT IN THE PROTOZOA TETRAHYMENA: The effect of a gradual versus an abrupt boundary between dark and light

B ergström , S. R. Avoidance behaviour to light in the Protozoa Tetrahymena. The effect of a gradual versus an abrupt boundary between dark and light. Scand. J. Psychol ., 1969, 10 , 81–88.—Samples of Tetrahymena, trained to avoid light, were placed in the dark part of a partially lighted chamber. The frequency of animals entering the lighted part through a gradual and through an abrupt boundary between dark and light was observed. It was found that a gradual boundary was a much more effective obstacle to the animals than an abrupt one.     

ON LEARNING TO PREDICT EVENTS

B jörkman , M. On learning to predict events. Scand. J. Psychol ., 1962, 3 , 233–240.—A rather large group of 'real life situations' requires a subject to predict events which are causally related to variables of the situation. Some operational characteristics of such situations are described. A primary question concerns the learning of the connection between situation and event ( S → E learning).—In an illustrative experiment frequency of 'reinforcement by observation' is varied. It is found that this factor can vary considerably without affecting rate of learning. As a preliminary conclusion it is suggested that reinforcement by observation as a differentiating factor is dependent on other factors, e.g. the dispersion of states of the situation.     

THE ACQUISITION OF CONSERVATION OF SUBSTANCE AND WEIGHT IN CHILDREN: II.External reinforcement of conservation of weight and of the operations of addition and subtraction

S medslund , J. The acquisition of conservation of substance and weight in children. II. External reinforcement of conservation of weight and of the operations of addition and subtraction. Scand. J. Psychol ., 1961, 2 , 71–84. —The subjects were 5–7 years old. Group I was allowed to observe empirical conservation of weight on a balance. Group II practised on additions and subtractions of material with controls on the scales. Group III took only the pre- and posttests. The data show no appreciable differences in frequency of acquisition of conservation between the three groups. It is concluded that none of the experimental conditions were necessary or sufficient for the acquisition of principles of conservation. The hypothesis is advanced that cognitive conflict may be the crucial factor involved.     

GENERATION OF WORDS FROM STEREOSCOPICALLY PRESENTED NON-WORD STRINGS OF LETTERS

R ommetveit , R., B erkley , M. & B røgger , J. Generation of words from stereoscopically presented non-word strings of letters. Scand. J. Psychol. , 1968, 9, 150–156.—Subjects were exposed to stereoscopically presented pairs of non-word strings of letters (e.g. shar/shap). Instead of responding with either left- or right-eye image, they frequently reported seeing a word generated by combining the two images (e.g., 'sharp'). The way a particular pair of superimposed letters (such as r and p) will be processed, seemed to depend upon semantic and morphological aspects. As rivals for the same serial position in two different words, only one of them will be 'seen'. When appropriate as neighbors in the same word, both tend to be seen, and in the appropriate spatial arrangement.     

TRANSITION FROM ROD TO CONE VISION I. Simultaneous contrast

S tabell , B. Transition from rod to cone vision. I. Simultaneous contrast. Scand. J. Psychol ., 1969, 10 , 61–64.—Above the specific threshold, color quality depended on the test filter, while at lower intensities the same color was observed irrespectively of the test filter used, confirming the assumption that colors within the photochromatic interval are triggered by rod activity. The lawful relation between rise of specific threshold and increase of rod sensitivity was not found under the condition of simultaneous contrast.