Contiguity and contingency in the acquisition and maintenance of an operant

Three experiments compared the effects of nondifferential and differential reinforcement of response location on a circular dimension. Rats were required to operate a vertical joystick to produce food. When food was delivered immediately after responses, but independent of response location, the spatial concentration of responding was low and no progressive changes were observed. Traditional and percentile schedules of differential reinforcement for response location produced highly reliable acquisition of spatially concentrated responding. Once concentrated responding had been established, nondifferential reinforcement was sufficient to maintain it in some subjects. Since only the differential reinforcement schedules established a contingency with respect to response location, it was concluded that this relationship was necessary for acquisition, but that response-reinforcer contiguity may be sufficient for maintenance. This conclusion is consistent with the view that operant conditioning is a contiguity-based process, but that contingencies are required to produce reliable contiguity between reinforcers and particular responses.     

The effects of dispositional empathy on emotional reactions and helping: A multidimensional approach

Recent research indicates that an affective state termed empathic emotion, and characterized by feelings of sympathy and compassion for another, is associated with altruistic responding. That is, persons experiencing high levels of empathic emotion offer help to another even when escape from the situation is easy. Persons experiencing high levels of another emotional state—personal distress—help much less when escape from the situation is easy. A study was conducted to test two related hypotheses. The first was that individual differences in empathy can influence empathic emotion and personal distress, above and beyond the influence of situational factors. The second hypothesis was that this effect of individual differences is due to variation in emotional and not cognitive empathy. The results provide support for both hypotheses. Regarding hypothesis 1, a significantly greater proportion of the variance in emotional reactions was accounted for when individual difference factors were included as predictors. Hypothesis 2 was also supported: It was found that a dispositional measure of emotional empathy was clearly related, and a dispositional measure of cognitive empathy was clearly unrelated, to these emotional reactions. The results provide support for a multidimensional view of empathy.     

Cortical spreading depression and conditioned taste aversion: an attempt to resolve a controversy

The claim (Winn, Todd, & Elias, Behav. Biol. 19, 55-63 (1977) ) that cortical spreading depression (CSD) can serve as US in the conditioned taste-aversion (CTA) paradigm was experimentally examined. Rats given 15-min access to novel 0.1% sodium saccharin (CS) followed by ip NaCl and bilateral or unilateral CSD (US) displayed similar saccharin preference (54%) as the sham-CSD-treated controls in a multiple-bottle retention test. Rats receiving ip LiCl (0.15 M, 2% body weight) and sham CSD as the US showed marked saccharin aversion. It is concluded that CSD does not elicit CTA and that some claims to the contrary can perhaps be ascribed to CSD-induced disruption of attenuation of neophobia.     

Strength of the nervous system and augmenting-reducing: Paradox lost

Two conflicting viewpoints were identified regarding the relationship between sensation seeking and subjective response to stimulation: (a) that sensory augmenters are high sensation seekers compared with sensory reducers (the view of Zuckerman and Buchsbaum); and (b) that it is the reducer rather than the augmenter who is the high sensation seeker (the view of Petrie and Vando). Proponents of the first approach measure Augmenting-Reducing through the use of the average cortical-evoked response, while advocates of the second position use Petrie's version of the Kinaesthetic Figural Aftereffects Test or Vando's Reducer-Augmenter Scale. It is argued that the disagreement is semantic and results from the differences in method of measurement. It is further argued that most, if not all, of the research findings may be accommodated within the framework of strength-of-the-nervous-system theory which distinguishes between two dimensions,sensitivity andfunctional endurance. The implications for future research are pointed out.     

Raising standards of practice in school psychology through the use of field-based training

A model is presented for upgrading school psychology practice in an entire state by raising the level of entry for school psychology certification. A central feature of the plan is that it permits those who currently do not meet the revised standards to participate in a field-based program. This allows them to increase their knowledge and skills so that they may continue to hold positions, but at a higher level of competence. The development of the program, its implementation, and an evaluation of its efforts over a five-year period are presented.     

Multidimensional scaling of individual differences for an individual person with a hand-held calculator

An extension to the INDSCAL method of individual differences scaling was developed. The method derives measures of deviation from a “standard” observer, who is defined in terms of the INDSCAL subject weights. These weights are calculated for one individual person at a time. The method is implemented in a small hand-held calculator. The calculator is used for data acquisition, and it interacts with the user in a conversational manner through an alpha-numeric display. The present implementation of the method scales 84 judgments of pair similarity among seven objects and derives subject weights on two dimensions. The method can be extended to sets of up to 16 objects and up to six dimensions. The method is a feasible, cost-effective approach to classification of individuals on complex perceptual attributes within a single 1-h session.     

Allocation of attention: Uncertainty effects when monitoring one or two visual gratings of noncontiguous spatial frequencies

When an observer is visually presented with a sinusoidal grating, he will often do worse in detecting a given grating when he is uncertain about its spatial frequency than when he is certain. Theoretical explanations of such uncertainty effects assume that the observer has attentional control over multiple spatial-frequency channels. This attentional control can be selectively allocated. If one grating is presented on most of the trials, randomly intermixed with trials of gratings of other spatial frequencies, an experienced observer will use a stationary single-band attention strategy. If two gratings, separated in spatial frequency by four octaves, are randomly presented on most of the intermixed trials, an experienced observer will use a more complex attention strategy; he can monitor the spatial frequencies of the two extreme stimuli with little or no monitoring of intermediate spatial frequencies.     

The measurement of response force during a lever-press shock-escape procedure in rats

Three albino rats were given extensive exposure to an escape procedure in which shocks were scheduled to occur 30 sec apart. The amount of downward force exerted on the lever was continuously recorded and compared with traditional discrete measurement in which only responses above an arbitrary force threshold were recorded. Subjects typically remained in contact with the lever throughout the shock-free intertrial interval. Shock onset reliably occasioned a brief lurch from and return to the lever, which resulted in a lever-press escape response being recorded. Lever contact, which occupied an average of 90% of session time, showed great stability in force after a brief (e.g., 5-sec) period of instability after each shock terminated. In general, continuous measurement revealed considerably different results than discrete measurements of on-lever behavior. For example, continuous lever contact fluctuating near response threshold was often recorded as discrete responding, and sustained lever contact occurring below response threshold was omitted from discrete measurement.