Local and global factors of similarity in visual search

Effects of the similarity between target and distractors in a visual search task were investigated in several experiments. Both familiar (numerals and letters) and unfamiliar (connected figures in a 5 × 5 matrix) stimuli were used. The observer had to report on the presence or absence of a target among a variable number of homogeneous distractors as fast and as accurately as possible. It was found that physical difference had the same clear effect on processing time far familiar and for unfamiliar stimuli: processing time decreased monotonically with increasing physical difference. Distractors unrelated to the target and those related to the target by a simple transformation (180° rotation, horizontal or vertical reflection) were also compared, while the physical difference was kept constant. For familiar stimuli, transformational relatedness increased processing time in comparison with that fort unrelated stimulus pairs. It was further shown in a scaling experiment that this effect could be accounted for by the amount of perceived similarity of the target-distractor pairs. For unfamiliar stimuli, transformational relatedness did have a smaller and less pronounced effect. Various comparable unrelated distractors resulted in a full range of processing times. Results from a similarity scaling experiment correlated well with the outcome of the experiments with unfamiliar stimuli. These results are interpreted in terms of an underlying continuum of perceived similarity as the basis of the speed of visual search, rather than a dichotomy of parallel versus serial processing.     

The effect of social support on prenatal care.

This article examines the effects of social support on the receipt of adequate prenatal care. A study was conducted to test the hypotheses that social support helps women overcome obstacles to obtaining such care, and that social support has greater effects on women facing the most obstacles. Survey data were gathered for more than 90% of the women who gave birth in Oklahoma hospitals during specific periods in the summer of 1986. The authors found only weak support for the first hypothesis, and for the second hypothesis found only support that must be qualified according to the measure of social support. Strong evidence indicates, however, that difficulty in paying for prenatal care, personal inconveniences, and unwanted pregnancies are obstacles to obtaining such care. The findings account for some of the frequently observed demographic differences associated with receipt of adequate prenatal care, although such differences persisted even after the obstacles were considered. The authors present implications for policy makers seeking to improve women's receipt of adequate prenatal care.     

Developing the matrix representation grid (MRG): A method for observing group processes. Findings from time-limited group psychotherapy for alcohol-dependent patients

The MRG was published 1988 in order to support developments in group psychotherapy methods as one of the all too few process observation research methods for studying group-as-a-whole. After 9 years of what pilot studies have labeled successful clinical trials, this study aims at validating the MRG against the established SAVI: Structural Analysis of Verbal Interaction (Agazarian & Simon 1989). Videotaped group sessions from short-term groups for alcohol dependent patients conducted along two therapy methods, one behaviorally oriented and the other group analytic, are used as material. The MRG is validated in the study, confirmed to be clinically valuable, and some interesting comparisons between the two treatment modalities are also made.     

An injection olfactometer for humans and a new method for the measurement of the shape of the olfactory pulse

An injection olfactometer for human psychophysical experiments is described. The olfactometer is capable of presenting, either mono- or birhinally, single odorants and binary mixtures. The pulse form of the olfactory stimulus at the exit of the olfactometer approaches a rectangular form, which makes the olfactometer well suited for olfactory reaction time measurements. Since stimulation periods are independent of the subject’s inhalation, time-intensity measurements over prolonged periods of time are possible as well. In the second part of this paper, a new technique is described for the measurement of the stimulus pulse form at the exit of the olfactometer.     

Pharmacological dissociation of memory: anisomycin, a protein synthesis inhibitor, and leupeptin, a protease inhibitor, block different learning tasks

Inhibition of protein synthesis by anisomycin for a short duration impairs memory of a one-trial inhibitory avoidance task in rats. Memory of escape conditioning involving eight trials is disrupted only if the duration of protein synthesis is prolonged by repeated injections. In marked contrast, olfactory memory of rats trained on two odor discriminations is not affected by anisomycin even if the duration of inhibition is prolonged and the number of trials is reduced to a minimum. In previous work, leupeptin, a thiol proteinase inhibitor, was shown to impair olfactory discrimination learning, but left inhibitory and avoidance conditioning intact. Together, these results provide a pharmacological double dissociation of memory, and suggest that the same chemistries, or mixtures of chemistries, may not be involved in all types of memory.     

Differential indications for desipramine--results of a controlled multiclinical study]

The antidepressants desipramine and imipramine were compared within the framework of a multiclinical study performed under the conditions of a controlled clinical experiment. There has been found a time-different remission of affective symptoms, which was not detectable for the inhibition of drive. The tachythymoleptic action of desipramine is discussed with reference to these results. Evaluation of the possibility of controlling affects shows different ranges of activity of desipramine and imipramine, with desipramine influencing especially negative psychoenergetic symptoms in the area of drives and emotions and imipramine, restrictive symptoms in addition to differential phenomena of the psychomotor expression.     

An alternative to the methodology for analysis of covariance

A general statistical model for simultaneous analysis of data from several groups is described. The model is primarily designed to be used for the analysis of covariance. The model can handle any number of covariates and criterion variables, and any number of treatment groups. Treatment effects may be assessed when the treatment groups are not randomized. In addition, the model allows for measurement errors in the criterion variables as well as in the covariates. A wide variety of hypotheses concerning the parameters of the model can be tested by means of a large sample likelihood ratio test. In particular, the usual assumptions of ANCOVA may be tested.Research reported in this paper has been partly supported by the Swedish Council for Social Science Research under project Statistical methods for analysis of longitudinal data, project director Karl G. Jöreskog, and partly by the Bank of Sweden Tercentenary Foundation under project Structural Equation Models in the Social Sciences, project director Karl G. Jöreskog.     

The effect of punishment and reinforcement procedures on a stutterer's factor II avoidance response

The purpose of this clinical experiment was to investigate the manipulability of a Factor II avoidance response (arm movement). The substantive hypothesis under test was that its suppression would be enhanced by repeated punishment sessions. During the first of nine therapy sessions response-contingent negative stimulation was not delivered. In the next five, after a base-rate period, “wrong” was made consequent upon the target response. In each of these sessions the suppression of arm movement was apparent. However, the magnitude of the suppression decreased from session to session. Evidently, the continued use of punishment did not enhance suppression. Because of this finding procedural changes were introduced in the next three therapy sessions. Verbal praise was added as a consequence of increasingly stringent omission criteria and three consecutive units of praise led to time-out from the reportedly fatiguing task of continuous speech. A marked reduction and then complete extinction resulted. Moreover, learning was evidenced since the frequency of arm movement lessened in the base-rate period of each session.     

The subjective vertical under ‘dry’ and ‘wet’ conditions at clockwise and counterclockwise changed positions and the effect of a parallel-lined background field

Summary The dependence of the subjective vertical (SV, the angle between a subjective vertical line and body median plane) on the gravity vertical (body tilt position, angle ) and on the optical vertical (i.e., a field of parallel lines seen as background to the line to be adjusted) was investigated. The SV was measured under dry and wet conditions at different degrees of body tilt attained in either clockwise (CW) or counterclockwise (CCW) progression.The measured difference in between field-of-lines left and right of the line is smallest at the upright position (=O°) and largest at =150°/165°. All body positions show a -difference between CW and CCW attainment (hysteresis), this too being least at upright and greatest at inverted body positions.These results, and changes of with test time, are discussed relative to the hypothesis that efficiency of the statolith organs decreases with body tilt increase, favouring increase of interference of somatoreceptors and the optical reference.     

A reconstructive-processing interpretation of the recognition failure phenomenon

The generality of the recognition failure phenomenon was the primary basis for the present research. It was hypothesized that the phenomenon obtains whenever an insufficient degree of compatibility exists between the task demands at recognition and those present during study. Experiments 1 and 2 demonstrated that, despite a recognition task that was incompatible to conditions of encoding, subjects could actively reconstruct aspects of the initial situation, and hence recognition failure was minimized. It was assumed that the stimulus material — categorized word pairs — facilitated this reconstructive process. Experiment 3 was designed specifically to examine further the reconstructive process as well as recognition failure. The results indicated that (a) the nature of this process could be mathematically predicted, and (b) subjects seldom failed to recognize words they recalled. The results of the present study strongly suggest an important boundary condition of the phenomenon of recognition failure. Moreover, Tulving and Wiseman's (1975) quadratic function could not predict accurately the obtained magnitude of recognition failure.