STUDIES IN THE PSYCHOLOGICAL EFFECTS OF A NEW DRUG (DIETHYLPROPION): Subjective effects in the natural environment

Two doses diethylpropion, one dose pipradrol, one dose amobarbital and placebo were administered to 116 subjects, who rated their state on twenty variables. The variables were intercorrelated under pipradrol and pentymal. The correlation matrices were subjected to factor analysis. Four factors were found in both studies: Happiness, Alertness, Relaxation, and Flight of thoughts. There is some agreement between the two factor analyses. There were few significant effects of the drugs on factor scores, but the structure is quite unambiguous: pipradrol and diethylpropion are stimulating, and amobarbital tranquilizing.     

Meinungsänderung durch eigenes Handeln Die Rückwirkung einstellungskonträrer Agitation

Zusammenfassung Zur Klärung der Frage, ob und unter welchen Umständen einstellungskonträre Agitation auf den Agitator zurückwirkt, wurden Gruppen- und Einzelversuche durchgeführt. Als Versuchspersonen dienten insgesamt 409 männliche und weibliche Oberschüler und Studenten. In allen Versuchen mußten die Versuchspersonen Reden erfinden und halten. Die Messung der Meinungsänderung und einiger hypothetischer Variablen wurde mit Fragebogen vorgenommen, zum Teil wurden nach den Versuchen Interviews durchgeführt.Wir erhielten folgende Hauptergebnisse: Erfinden und Vortragen von Argumenten für einen zudiktierten Standpunkt führen, unabhängig voneinander und von der im Vortrag enthaltenen Argumentation, zu einer Meinungsänderung. Ihre Richtung und ihr Ausmaß sind außerdem abhängig vom Verhältnis der zudiktierten Stellungnahme zu anderen, bereits vorhandenen psychischen Inhalten — starke Verankerung der ursprünglichen Meinung führt zur Meinungsänderung im Gegensinne der Agitation (Bumerang-Effekt) — sowie vom Grad der Willentlichkeit der Handlung: bereits die Entscheidung, einen einstellungskonträren Standpunkt nach außen zu vertreten, kann zu einer Meinungsänderung führen. Das Lernen der Argumente, die Bewertung der eigenen Leistung, des Versuchs und Versuchsleiters sowie Eigenschaften eines Themas für sich erweisen sich nicht als alleinige Bedingungen der Meinungsänderung.Diese und andere, weniger wichtige Ergebnisse werden diskutiert. Die Theorie der kognitiven Dissonanz wird als beste einheitliche Erklärungsgrundlage der empirischen Befunde angesehen.

---

Summary Experiments with groups and single persons were conducted to test the effect of persuasive behaviour on the communicator. 409 male and female high-school and university students served as subjects. In all experiments the subjects had to invent and verbalize speeches contradicting their own opinion. Opinion change and some hypothetical variables were measured by questionnaires, the sessions were partially followed by interviews.Main results: Inventing or speaking of arguments in favour of an appointed opinion lead, independently of each other and of the informational content of the arguments, to opinion change the direction and magnitude of which are, in addition, dependent on the relation of the argument to previously existent mental contents (if the original opinion is strongly anchored, the persuasive behaviour results in a boomerang effect), as well as the degree of volition of the subject's persuasive behaviour. (Already the decision to defend a point of view contrary to one's own may lead to opinion change). Learning of arguments and evaluation of own achievement, of the experiment and the experimenter as well as the qualities of a topic in itself cannot be shown to be the only conditions of opinion change.These and other, less important results are discussed; the theory of cognitive dissonance is considered the best uniform explanation of these empirical results.

---

---

Diese Arbeit wurde von der philosophischen Fakultät der Ludwig Maximilians-Universität in München als Dissertation angenommen.Die referierten Versuche wurden durch das Yale Communication and Attitude Change Programme und die Gesellschaftder Freunde der Wirtschaftshochschule Mannheim e.V. finanziell gefördert. Der Verfasser dankt den genannten Institutionen für ihre Unterstützung.     

A note on further experiments on the effects of meprobamate on discrimination performance in the monkey

A previous experiment (Gross and Weiskrantz, 1961) has shown that performance on a successive auditory discrimination task is impaired by injections of meprobamate. The present two brief experiments indicate that the drug also impairs simultaneous visual discrimination performance, although not to the same degree as found earlier for auditory discrimination. The original finding, therefore, cannot be attributed simply to unique features of the auditory discrimination situation, such as the “go—no-go” response contingency. Since neither overtraining nor drug habituation appears to be of great importance, it is suggested that the lesser effect of the drug in these experiments reflects the greater stability of visual than auditory habits in the monkey.

Earlier work has shown that meprobamate and reserpine can cause a severe deterioration in auditory discrimination performance of monkeys (Gross and Weiskrantz, 1961). This result was taken as supporting a hypothesis, growing out of still earlier research, that tranquillizers decrease the utilization of sensory information (Weiskrantz and Wilson, 1956; Weiskrantz, 1957).

The auditory task, as is almost always the case with monkeys as subjects, involved a “go—no-go” type of response contingency—i.e. the animal had to respond to the positive stimulus and had not to respond to the negative stimulus in order to achieve reward. It might be objected, therefore, that the deterioration in performance was associated not with discrimination as such but with the animals' willingness to perform at all. In fact, it was found that the animals tended to make most of their errors under the drugs by responding when they should not rather than not responding when they should.

The purpose of the present experiments, therefore, was to test the animals with a visual discrimination task in which both the positive and negative stimuli were presented simultaneously. An effect of the drug could not, in this situation, be characterized simply as altering the responsiveness of the animal. A further purpose in using visual stimuli was to test the generality of the earlier finding in a sense modality other than audition.