A general lesson illustrated by this simple series of experiments is that the effect of a given dose of a drug in a given subject in a single session can be strongly modified by the pattern of responding engendered by the schedule in effect. Specifically, in this example, after an appropriate dose of phenobarbital the rate of responding under FR was slightly increased, while rate of responding under FI was decreased. Responding in a FR component persisted following a dose that abolished responding under FI. As noted, researchers have often approached behavioral research with preconceptions as to what influences on behavior are important (e.g., motivations, emotions, phenomena of learning, and "cognition"). The preconceptions extended to the study of drugs and much ingenuity and effort have been expended in seeking experimental situations that had plausibility as reflecting the influence of interest. For example, if a drug has a different effect on responding in the presence and absence of an influence (e.g., the influence of a putative "emotion" such as "fear"), there was a tendency to immediately attribute the effect to an attenuation (or enhancement) of the influence (e.g., attenuation of fear). The conclusion was not warranted. It relied on two assumptions: That the change in rate of responding was the effect of fear and that the change due to the drug was due to a selective effect on fear. Either or both assumptions may be incorrect. In any case, it is a basic finding of behavioral pharmacology, illustrated already, that different rates of responding can be differently affected by a dose of drug. If the putative effect of fear was to slow the rate of responding and the drug increased the slowed rate of responding more than the rate in the absence of fear, the parsimonious explanation is that the difference in the rates of responding produces the difference in the effects of the drug. It is not surprising that different rates of responding should be differently affected by a dose of drug. It is commonplace in pharmacology for the effect of drug to be influenced by the physiological state of the system that is affected by the drug. The effect of epinephrine on the smooth muscle of the gastrointestinal tract is to cause relaxation if the tone is already high but contraction if the tone is low. The relationship between effect on drug and the control rate of responding has been extensively investigated. It is surprising, however, that there are many instances in which the effect of the drug, expressed as a ratio to control, is related to the control rate by a simple relationship: Namely, the log of the effect is a descending linear function of the log of the control rate. High control rates may be lowered by a dose of a drug, whereas low control rates are increased. The slopes and intercepts of the relationship vary widely with different drugs and different doses, and the direction of the slope can even be reversed as in the example of phenobarbital.

Conquering Fear In The 21th Century

Conquering Fear In The 21th Century

The Ultimate Guide To Overcoming Fear And Getting Breakthroughs. Fear is without doubt among the strongest and most influential emotional responses we have, and it may act as both a protective and destructive force depending upon the situation.

Get My Free Ebook

Post a comment