Ronald N. Ehrman

Bio: Ronald N. Ehrman is an academic researcher from University of Pennsylvania. The author has contributed to research in topics: Craving & Cue reactivity. The author has an hindex of 32, co-authored 54 publications receiving 5540 citations. Previous affiliations of Ronald N. Ehrman include United States Department of Veterans Affairs & Veterans Health Administration.

Conditioning factors in drug abuse: can they explain compulsion?:

Abstract: There is a good deal of clinical evidence suggesting that compulsion to resume drug taking is an important part of the addiction syndrome. The symptoms comprising motivation to resume drug use, namely craving and compulsion, have been studied experimentally in human subjects. While much work remains to be done, there is evidence showing that these symptoms are influenced by learning. The research has been guided by animal studies demonstrating that drug effects can be conditioned. Much attention has been directed toward demonstrating the existence of drug conditioning in human addicts and exploring the neurological structures that may underlie such learned responses. We do not yet know the relative importance of learning in the overall phenomenon of relapse, and treatments based on conditioning principles are still under investigation.

Classical conditioning in drug-dependent humans.

Abstract: Repetitive use of psychoactive drugs produces a variety of learned behaviors. These can be classified in the laboratory according to an operant/classical paradigm, but in vivo the two types of learning overlap. The classically conditioned responses produced by drugs are complex and bi-directional. There has been progress in classifying and predicting the types of conditioned responses, but little is known of mechanisms. New techniques for understanding brain function such as micro-dialysis probes in animals and advanced imaging techniques (PET and SPECT) in human subjects may be utilized in conditioning paradigms to "open the black box." Because the existence of conditioned responses in drug users is now well established, clinical studies have been instituted to determine whether modification of conditioned responses can influence clinical outcome. A recently completed study in cocaine addicts has produced evidence that outcome can be improved by a passive extinction technique over an 8-week outpatient treatment program.

Conditioned responses to cocaine-related stimuli in cocaine abuse patients.

Abstract: Subjects with a history of free-basing and smoking cocaine but no history of opiate injections were exposed to three sets of stimuli. They received cocaine-related stimuli in one session, opiate-related stimuli in a second session, and non-drug stimuli on a third occasion. Compared to the opiate and non-drug cues, the cocaine-related events caused reliable decreases in skin temperature and skin resistance, and reliable increases in heart rate, self-reported cocaine craving, and self-reported cocaine withdrawal. Furthermore, control subjects lacking a history of cocaine or opiate use failed to show such differential responding. These results suggest that cocaine-related stimuli evoke Pavlovian conditioned responses in cocaine abuse patients. Such findings encourage continuing efforts to develop drug treatment strategies based on conditioning principles.

Cue reactivity and cue reactivity interventions in drug dependence

Abstract: Despite a venerable history dating back to Pavlov and countless testimonials from patients such as those in the opening paragraphs of this chapter, there is much that remains to be learned about drug signals and, particularly, about ways of reducing their adverse effects on human drug users. There is a substantial amount of data showing increased craving and signs of physiological arousal to drug-related versus neutral cues in drug users for both drug classes reviewed here. Additional controlled studies will be useful in refining which responses among those studied are, in fact, conditioned in origin and therefore can be subjected reasonably to learning-based interventions. Most attempts to modify cue responsivity for clinical benefit have met with only modest success, and there is ample room for creative, but controlled, treatment-outcome studies. In recent years, several other groups have joined in the effort to understand drug-related cue reactivity, extending the research area to alcohol and nicotine (Monti et al. 1987; Niaura et al. 1988, 1989; Cooney et al. 1984; Hodgson and Rankin 1982; Drummond 1990; Laberg 1990). The interested reader is referred to several additional reviews of cue reactivity and cue exposure research related to alcohol and nicotine (Niaura 1988; Drummond 1990; Laberg 1990), opiates (Powell 1990), opiates and cocaine (Childress et al. 1988b; O'Brien et al. 1990), and all the preceding areas (Rohsenow et al. 1991).

Prelude to Passion: Limbic Activation by “Unseen” Drug and Sexual Cues

Abstract: Background The human brain responds to recognizable signals for sex and for rewarding drugs of abuse by activation of limbic reward circuitry Does the brain respond in similar way to such reward signals even when they are “unseen”, ie, presented in a way that prevents their conscious recognition? Can the brain response to “unseen” reward cues predict the future affective response to recognizable versions of such cues, revealing a link between affective/motivational processes inside and outside awareness?

Cognitive Reflection and Decision Making

Abstract: This paper introduces a three-item "Cognitive Reflection Test" (CRT) as a simple measure of one type of cognitive ability—the ability or disposition to reflect on a question and resist reporting the first response that comes to mind. The author will show that CRT scores are predictive of the types of choices that feature prominently in tests of decision-making theories, like expected utility theory and prospect theory. Indeed, the relation is sometimes so strong that the preferences themselves effectively function as expressions of cognitive ability—an empirical fact begging for a theoretical explanation. The author examines the relation between CRT scores and two important decision-making characteristics: time preference and risk preference. The CRT scores are then compared with other measures of cognitive ability or cognitive "style." The CRT scores exhibit considerable difference between men and women and the article explores how this relates to sex differences in time and risk preferences. The final section addresses the interpretation of correlations between cognitive abilities and decision-making characteristics.

NEURAL MECHANISMS OF ADDICTION: The Role of Reward-Related Learning and Memory

Abstract: Addiction is a state of compulsive drug use; despite treatment and other attempts to control drug taking, addiction tends to persist. Clinical and laboratory observations have converged on the hypothesis that addiction represents the pathological usurpation of neural processes that normally serve reward-related learning. The major substrates of persistent compulsive drug use are hypothesized to be molecular and cellular mechanisms that underlie long-term associative memories in several forebrain circuits (involving the ventral and dorsal striatum and prefrontal cortex) that receive input from midbrain dopamine neurons. Here we review progress in identifying candidate mechanisms of addiction.