Some effects of methylphenidate on stimulus control of ratio avoidance behavior in the rat

After exposure to an avoidance schedule which included a warning signal, a rat was placed on a multiple schedule in which the first component was the same as before, i.e., a single response reset the response-shock interval, delaying shock, and the second component differed only in that four bar-presses were required to postpone shock. A fixed ratio requirement of four responses (FR 4) generated behavior resembling a fixed ratio requirement of one response (FR 1) since responding was controlled by the warning signal but more shocks were received. At a dosage of 2 mg/kg, methylphenidate given intraperitoneally decreased shock frequency during FR 4 periods while FR 1 behavior was not affected; at 4 mg/kg, stimulus control of avoidance responding was impaired during both components. Results at 4 mg/kg were partially confirmed by two animals exposed to an FR 4 avoidance schedule which included a warning signal but with different parameters. Response distributions showed that methylphenidate increased response rates in the absence of the warning signal, i.e., stimulus control of ratio-avoidance behavior was impaired although the increased response rates reduced shock frequency. One hour later responses again occurred more frequently during the signal than in its absence but shocks were less frequent than during control (non-drug) periods.     

Effects of response pacing on conditioned suppression

In this experiment, which employed a balanced design with two rat subjects, the frequency of reinforcement remained constant while the rate of operant responding was varied by means of a response pacing technique. At each of three response rates, 1-min. periods of noise were presented, and, as these periods ended, a slight unavoidable shock was delivered to the rat. This procedure resulted in suppression of the operant responding during the periods of noise. This behavioural change was measured by a suppression ratio, essentially a comparison of the response rates in the presence and absence of the noise. The suppression ratios varied in a systematic way during the experiment, denoting most conditioned suppression when the baseline rate of responding was high, and least suppression when this was low. It is therefore concluded that response rate in one factor determining the degree of conditioned suppression in this controlled experiment. The conclusion is corroborated by absolute measures of responding during the pre-shock periods of noise.     

Book reviews

>P. P. KIRSCHENMANN. Information and Reflection. D. Reidel Publishing Company, 1970. Pp. xv, 225. Indexed. $14.00.

HUBERT L. DREYFUS, What Computers Can't Do: A Critique of Artificial Reason. New York: Harper and Row, 1972. Pp. xxxv, 259. Indexed.

DONALD M. MACKAY, Information, Mechanism and Meaning. Cambridge, Massachusetts: MIT Press, 1969. Pp. ix, 196. Indexed. $2.95 (paper).

YORICK ALEXANDER WILKS, Grammar, Meaning and the Machine Analysis of Language. London : Routledge & Kegan Paul, 1972. Pp. 1–198. Indexed. $10.00.     

A psychoanalytic view of reactions to the coronavirus pandemic in China*

The American Journal of Psychoanalysis - The coronavirus pandemic, which apparently began in Wuhan in December 2019, and has persisted to the present day, has had several psychological effects in...     

Pick up the baby (or dire consequences will ensue)!

Abstract

Decades of psychoanalytic developmental studies on children one year of age and under point to the need for maternal soothing when the infant is crying. Contrary to behavioral theorists who recommend letting the infant “cry it out,” data from analytically informed researchers of very different orientations converge on the conclusion that rocking, feeding, and/or verbal soothing by the mothering figure are requisite to set the stage for good mental health during the rest of the child’s development.     

Influencing Republicans’ and Democrats’ attitudes toward Obamacare: Effects of imagined vicarious cognitive dissonance on political attitudes

The field of experimental social psychology is appropriately interested in using novel theoretical approaches to implement change in the social world. In the current study, we extended cognitive dissonance theory by creating a new framework of social influence: imagined vicarious dissonance. We used the framework to influence attitudes on an important and controversial political attitude: U.S. citizens’ support for the Affordable Care Act (ACA). 36 Republicans and 84 Democrats were asked to imagine fellow Republicans and Democrats, respectively, making attitude discrepant statements under high and low choice conditions about support for the ACA. The data showed that vicarious dissonance, established by imagining a group member make a counterattitudinal speech under high-choice conditions (as compared to low-choice conditions), resulted in greater support for the Act by Republicans and marginally diminished support by Democrats. The results suggest a promising role for the application of vicarious dissonance theory to relevant societal issues and for further understanding the relationship of dissonance and people’s identification with their social groups.