AN EXPERIENTIALLY DERIVED BASE-RATE ERROR IN HUMANS

Abstract— Two experiments tested college students in a delayed matching-to-sample procedure designed to explore how multiple competitive sources of control interact in determining choice behavior. The primary sources of potential control were the frequency with which each of two colors was correct (base rates) and the accuracy of a sample in predicting the correct choice (accuracy rate). In one experiment, subjects ignored the base rates, and therefore made nonoptimal choices. These results mimicked the well-known base-rate error found in verbal responses to questions. In a second experiment, manipulations to increase subjects' motivation did not alleviate the error significantly. Together, these results suggest that the base-rate error may represent a broad behavioral pattern not restricted to verbal arenas. The results are compared with previous attempts to reconcile behavioral and cognitive lines of experimentation.     

Book reviews

Integrative Psychological and Behavioral Science -     

A pointing technique for rapidly collecting localization responses in auditory research

A technique is described for rapidly collecting responses in auditory-localization experiments. Subjects indicate the perceived direction of the sound by pointing at a 20-cm-diam spherical model. In Experiment 1, the subjects judged the direction of a broadband signal, which could originate from any of 239 directions ranging through 360° of azimuth and between ?45° and +90° of elevation. Using this technique, the subjects responded 2–8 times more rapidly than previous subjects who used either a verbal-reporting technique or a head-pointing technique. Localization judgments were as accurate as they had been with verbal reports, but were not as accurate as judgments collected using the head-pointing technique. In Experiment 2, the signal was turned off and the experimenter read the spherical coordinates of the signal location to the subjects. The subjects pointed to these coordinates more accurately than they had judged the direction of the sounds in Experiment 1, suggesting that the response technique had not been the limiting factor in that experiment. Circumstances relevant to the choice of response techniques for auditory-localization experiments are discussed.     

Work-Relationship Values and Gender Role Differences in Relation to Career-Marriage Aspirations

This study of female and male undergraduate business majors explored the relationship of their preferred future career-marriage arrangement to their relationship and work values, work motivation, and gender role orientation Results indicate that the dual-career, career-job, and career-home groups showed significant differences on these dimensions. Additionally, sex and gender role differences reflected cultural stereotypes of achievement orientation in men and barriers to career pursuits of women. The results are discussed in terms of interpersonal, intrapersonal, and societal factors underlying career-marriage aspirations. Implications for practitioners and suggestions for future research are given.     

The other side of the coin: Cognitive properties of nonreward

In this comment, I examine Amsel’s theory in the light of rats’ reaction not to frustrative non-reward per se, but to the more complicated case in which frustrative nonreward is part of a rule-based sequence of reward quantities. The discussion goes beyond Amsel’s emphasis on dispositional memory to consider cognitive and representational memory—the signaling properties of reinforcement and nonreinforcement. The strengths and weaknesses of Amsel’s theory are discussed with the fresh perspective that this viewpoint provides, and some issues emerge that may be fruitful for further study.     

Diaphragmatic spasm: A neglected cause of dyspnoea and chest pain

The study included 17 patients, 12 women and 5 men, with a recurrent symptom complex involving chest pain and dyspnoea characterized by inability to get a full breath. Some attacks had subsided spontaneously. Others had lasted hours or days. When examined by fluoroscopy during an attack, each subject was found to have a nearly maximally contracted (flat) diaphragm. In some of them the attack was promptly interrupted by a small intravenous injection of sodium amytal. In others it could be aborted by a conscious effort at full expiration. The syndrome associated with diaphragmatic spasm is discussed in comparison with other noncardiac sources of chest pain and dyspnoea.     

Spatial compatibility of signal-response position in pointing

Two experiments are reported in which, by means of a pointing task, we studied the stimulus-position effect, i.e. the inverted U-shape form of the reaction-time function in relation to stimulus position in tasks in which stimuli and/or responses are arranged in a horizontal array. The response consisted of aiming the index finger from a central starting point at a target area on a screen. Reaction time was the main dependent variable. The spatial relation between the position of the imperative signal and the position of the response was manipulated by varying the spatial S-R compatibility and physical distance that separated the positions of stimulus and response. The stimulus-position effect was shown to depend on the compatibility of the S-R relation (Exp. 1). In Exp. 2 it was found that the modulation of the stimulus-position effect by spatial compatibility disappeared completely when the distance between the positions of stimulus and response was reduced. None of the experiments revealed that the stimulus position effect depended on signal discriminability, which renders an interpretation of this effect in terms of perceptual processes unlikely. We argue that the attentional model of spatial coding provides the most reasonable explanation of the obtained reaction-time patterns.     

Laterally induced impedance effects in vision

A linear integral equation for a system of mutually impeding points is developed and solved explicitly. Particular solutions are shown to be subharmonic functions for a large class of stimuli. Specialized forms of the general equation presented in this paper occur within a number of mathematical models of Mach bands. In addition to these known spatial properties, our results also show that the time course of this basic equation may be useful in developing models of transient neural activity as well as of temporal psychophysical phenomena, such as the Broca-Sulzer effect. Further, a spatial transfer function much like the low-frequency cutoff of empirically derived modulation transfer functions follows directly from our basic integral equation if the additional assumption of spatial homogeneity is imposed.