On alcoholism

Pastoral Psychology -     

A further investigation of apparent size and retinal size as determinants of the figural after-effect

A figure which is more distant from the eye than another but subtends the same visual angle is usually seen as the larger. This phenomenon is called perceptual size constancy. Experiments have been reported which show that sometimes the apparent and sometimes the retinal sizes of the stimulus figures determine the direction of the figural after-effect. These experiments are reviewed and two further experiments are reported. In the first experiment two types of stimulus figure (discs and annuli) which subtended a visual angle of 1° 36' resulted in figural after-effects, the direction of which would have been predicted by the retinal sizes of the figures. In the second experiment larger figures were used which subtended a visual angle of about 4° and which were the same as those used by Sutherland (1954). In this experiment the after-effects were generally in a direction which would have been expected if apparent size determined the direction of the after-effect. In the interpretation of the results attention is drawn to the “Central Tendency Effect” which has been observed in size judgements of stimulus figures of varying size. Two hypotheses are suggested; one is that the true figural aftereffect has been obscured by the “Central Tendency Effect” in successive judgements, and the other is that time error in successive judgements of size is essentially a figural aftereffect. Some supportive evidence for the latter hypothesis is reported. It is concluded that apparent size is not a critical determinant of the figural after-effect.     

Attention and automaticity: Toward a theoretical integration

We sketch an initial version of a theory intended to account for the role of attention in the acquisition and expression of automaticity, and we test some initial predictions. The theory combines Logan's instance theory of automaticity and Bundesen's theory of visual attention, with Bundesen's theory determining what Logan's theory learns. We report four experiments that test the assumption that subjects learn what they report explicitly do not learn what they do not report explicitly. The experiments provide partial support for the predictions and encourage further development of the combined theory. Received: 4 September 1997 / Accepted: 12 January 1998     

The altered rationale for the choice of a standard animal in experimental psychology: Henry H. Donaldson, Adolf Meyer, and "the" albino rat

The mid 20th-century dominance of albino rats in nonhuman experimental psychology research often presumed that the animal embodied fundamental psychological processes that could generalize to a wide range of vertebrates. The author describes the conceptual basis for the original choice of white rats by the 2 individuals most responsible for establishing rats as a prominent animal model in the life sciences at the turn of the century: Henry H. Donaldson and Adolf Meyer. The author stresses the comparative rationale that justified their choice and argues that they sought generality through attention to diversity and species differences. Their approach contrasts sharply with the later view of the rat as a generic animal model that could represent similarities shared by all vertebrates. It is suggested that the change resulted from an emphasis on standardization produced by the growing industrialization of the life sciences in America.     

Judgments of perceptual groups: Reliability and sensitivity to stimulus transformation

The reliability of subjects’ judgments of the groups present in dot patterns and the sensitivity of those judgments to stimulus transformation were assessed. The subjects indicated the groups that they saw within random dot patterns, and each judgment was compared with those of other subjects and with their own judgments for related presentations. Within subjects, each pattern appeared in an initial presentation, an identical repetition, and a transformed state (a rotation or a change in scale). Witfiin-subjects judgments were more reliable than between-subjects judgments. An interpretation of within-subjects results was made in relation to predictions made by a formal algorithm of grouping by proximity (the CODE algorithm), which assumes that grouping by proximity is invariant over transformations such as rotations or changes in scale. A slight cost to transforming the patterns was found. The implications for CODE and for using grouping judgments as data are discussed.     

Desired control,felt control,and dental pain: Recent findings and remaining issues

This paper reviews a series of studies examining how desire for control among dental patients affects their reaction to dental treatment. This research (across eight samples) indicates that low perceived control is associated with heightened stressful responding before and during dental treatment only among patients reporting high desire for control Thus, the impact of low perceived control appears to be moderated by desire for control. An additional finding is that manipulations of control (e.g., providing information, stress inoculation training) primarily impact patients reporting both a high desire for control (during treatment) and low initial perceived control. These data suggest that consideration of patients' desire for control in addition to their perceived control increases our ability to predict their level of dental stress. Additionally, these data provide initial support for the view that the discrepancy between high desire for control and low perceived control play a causal role in patient's perceptions of dental pain and fear.This research was supported by grant USPHS-NIH 5 RO1 DEO 9419-02 (H. L. and R. B. coprincipal investigators) and by BRSG/College of Dentistry seed money.     

In search of the point of no return: the control of response processes

Control processes underlying response inhibition were examined. Six Ss performed a visual choice reaction task and were occasionally presented with a tone that told them to withhold the response. Reaction time results were in agreement with a model that assumes a race between response activation and response inhibition processes. Event-related brain potentials, electromyogram, and continuous response measures showed that responses could be interrupted at any time. Evidence was obtained for two inhibitory mechanisms: inhibition of central activation processes and inhibition of transmission of motor commands from central to peripheral structures. Results have implications for the distinction between controlled and ballistic processes.     

Distraction,Control, and Dental Stress1

This study examined the efficacy of external distraction as a coping strategy. Thirty-eight dental patients were randomly assigned to one of three groups: incidental music during the dental procedure, music coupled with suggestions that music would help reduce stress, or a no-treatment control group. Patients in both music groups reported experiencing less stress (i.e., less pain. less discomfort, more control) than patients in the no-treatment group. Patient ratings made by dentists, blind to condition, provided converging evidence for the therapeutic effect of distraction. Thus, distracting music was found to be effective in reducing stress and increasing perceptions of control. The relative ease and simplicity of implementing external distraction compared to manipulating actual control in a medical setting may make this manipulation attractive to professionals involved with individuals experiencing stress.