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Biomedical subjects

A Wikler

Publications and source records attributed to A Wikler.

At least 19 recordsLinked to original sources
PubMed1979

"Mental set" in controls, postalcoholics, chronic schizophrenics, and "organics".

Subjects consisted of (normal) controls, postalcoholics, chronic schizophrenics, and "organics" (a miscellaneous group of patients with acquired organic brain disorders including posttraumatic encephalopathy, Alzheimer's disease, Behçet's disease, Huntington's chorea and poststroke encephalopathy). "Mental set" was measured by comparisons of simple auditory-manual reaction times (RTs) at preparatory intervals (PIs) of 2, 5, and 10 sec following "warning" light flashes. First, the PIs were varied randomly over 48 trials (irregular procedure); then, each of the three PIs was held constant for 16 successive trials (regular procedure). Overall RTs increased significantly and progressively from controls to postalcoholics to chronic schizophrenics to organics. Mean differences between irregular and regular RTs at each PI were either significantly less for postalcoholics, chronic schizophrenics, as well as chronic schizophrenics and organics show distinct impairment of "mental set," which may be a sign of organic brain dysfunction, if other factors such as severe cultural deprivation can be excluded.

Adult↗
PubMed1978

'Loss of control' in alcoholics.

This study evaluates the ability of alcoholics to regulate their blood alcohol levels (BAL) within a designated range by relying primarily on interoceptive cues. Forty male alcoholics and 20 control subjects were exposed to an initial training session in which they received sufficient ethanol to maintain them within a designated BAL range over a 2 1/2-hour period. They were then exposed to two experimental sessions, one providing "overfeedback" and one "underfeedback." During each session, subjects had ten drinking decisions to make with respect to regulation of their BAL. The results indicated that alcoholics displayed greater "loss-of-control" than control subjects. This finding supported the hypothesis that alcoholics may possess a neurophysiologic feedback dysfunction that contributes to their relative inability to regulate ethanol intake.

Adult↗
PubMed1977

Marijuana: effects on free recall and subjective organization of pictures and words.

The free recall of pictures and words was compared following the administration of marijuana or placebo in a multitrial free recall task. Since pictures are thought to be registered in both visual and verbal memory stores with this encoding being mediated by some form of mental imagery, it was predicted that marijuana would produce a greater deficit in word recall in comparison to picture recall because the drug has been reported to facilitate imagery. A trend in the opposite direction followed intoxication; picture recall was inferior to word recall in the later stages of acquisition. Although overall recall was inferior under marijuana, no differences were found between the treatment conditions in subjective organization as determined by a variety of clustering measures. Recall performance following marijuana intoxication was positively related to level of recall performance in the placebo condition.

Adult↗
PubMed1977

Marijuana: effects on storage and retrieval of prose material.

In a two phase design, an attempt was made to differentiate the effect of marijuana on the storage and retrieval of prose material. In the first phase, 40 male subjects were administered a single 500 mg marijuana cigarette containing 2.1%delta9-THC or a placebo cigarette. Fifteen minutes after smoking, they listened to and at the same time read a narrative passage of approximately 200 words in length. Subsequently, an immediate free recall test was given in which subjects were required to write down as much of the story as they could remember. The second phase was conducted 24h later. Marijuana and placebo subjects were randomly subdivided into four groups with half of the subjects participating in the same drug condition as occurred on day one while the others switched drug state. Fifteen minutes after smoking, all subjects recalled the passage presented on day one and then were given 24 questions concerning facts and events in the story which could be answered in a few words. These questions served as retrieval cues. Following this, a new passage was presented in the same manner as occurred on day one. After an immediate free recall test, another cued recall test was administered. Results indicated that marijuana reduced immediate recall under both cued and uncued conditions incomparison to placebo. No relative cued recall advantage was found in the marijuana groups for the old or new story and marijuana produced only a moderate decrement in recall of the old story on day two. However, marijuana given in the second phase significantly reduced memory for items recalled in the initial phase irrespective of drug or cueing condition in phase one, suggesting that retrieval was also affected. Some decrement in recall of the new story did occur as a function of drug state change in group M-P. This effect was related to the serial position of input items. Serial position did not interact with drug state under any other recall condition.

Cannabis↗
PubMed1977

Marijuana: dose-response effects on pulse rate, subjective estimates of potency, pleasantness, and recognition memory.

34 experienced marijuana users were divided into four equated groups of eight subjects each based on recognition memory test performance. One week later each group was retested following administration of marijuana containing 0, 5, 10 or 15 mg delta9-tetrahydrocannabinol. A dose-related effect of marijuana on pulse rate and subjective measures of potency and pleasantness occurred. Ratings of potency and changes in pulse rate were highly correlated, but this relationship did not hold within a given dosage group as determined by partial correlations. No effect of marijuana on the distribution of hit and false alarm rates or confidence ratings during the recognition memory test was noted.

Adult↗
PubMed1977

Methadone maintenance and narcotic blocking drugs.

Drugs which specifically antagonize certain of the actions of opioids are reviewed. These antagonists include nalorphine, levallorphan, naloxone, naltrexone, and cyclazocine. Programs involving antagonist treatment are discussed.

Aftercare↗
PubMed1977

Methadone maintenance and narcotic blocking drugs. Appendix.

The research history of norcodeine as a narcotic blocking drug is presented. Because of the limitations found for norcodeine usage, naloxone, cyclazocine, and naltrexone have recently received attention, and the results of research with them are detailed.

Administration, Oral↗
PubMed1977

Deficits in the regulation of ethanol intake by alcoholics.

In an appropriate experimental paradigm, loss-of-control drinking can be demonstrated when an individual consumes sufficient ethanol over time to cause his blood alcohol level (BAL) to rise progressively above a previously established, designated range. For this study, 10 alcoholics were exposed to a training session and provided accurate feedback of their blood alcohol level at ten 15-minute intervals. On following days, they were then exposed to three exposed to three experimental sessions during which they were instructed to maintain their BAL within the established training session range by relying primarily on interoceptive cues. The experimental sessions were characterized by distorted or no feedback concerning blood alcohol levels as the basis for drinking-decision behavior. The results indicated that 60% of alcoholics displayed loss-of-control (LOC) (by our criterion) in a least one session, the greatest percentage in the "No Feedback" session. The results were interpreted to support our theory of a neurophysiologic feedback dysfunction associated with LOC drinking.

Adult↗
PubMed1977

Alcoholics and high-low sensory input: a pilot study.

It is hypothesized that alcoholics possess a perceptual-neurophysiological sensitivity which renders them vulnerable to the effects of information or stimulus overload: the resort to alcohol, therefore, may represent an adaptive attempt to restore physiologic homeostasis through the pharmacologic "dampening" properties of this drug. Twelve alcoholic subjects were assigned to three different levels of audio-visual sensory stimulation (no, medium, high) and three different doses of alcohol (placebo, low, high) according to a balanced incomplete block design. The results indicated trend level and significant interactions between alcohol and sensory level effects on craving intensity and systolic blood pressure, respectively, as well as a number of other intriguing findings. Should the findings of this pilot study be replicated, they will have important implications for the understanding of alcoholism.

Alcoholism↗
PubMed1976

Marijuana and memory impairment: the effect of retrieval cues on free recall.

In an attempt to ascertain the effect of retrieval cues on recall deficits which occur following intoxication with marijuana, 40 male volunteers were presented with word lists following the smoking of a single one gram marijuana (0.94% delta 9 -THC) or placebo cigarette and then were required to recall these words immediately after presentation. Recall occurred under a condition in which cues representative of to-be-remembered words were present or in an uncued condition. Results indicated that recall was depressed following marijuana administration under both cued and uncued conditions with cues being only mildly effective in reversing the recall deficit. There was no increase in the number of internal intrusions under marijuana, but the number of external intrusions was significantly elevated under the cued conditions.

Adult↗
PubMed1976

Aspects of tolerance to and dependence on cannabis.

Tolerance at all levels of complexity in the brain involves "learning" in the sense of the acquisition of compensatory adaptations to the consequences of the presence of a drug-produced disturbance in function. Depending on the function, species, and dose of cannabis, "tissue tolerance," behaviorally augmented (to provide the presence of the disturbed function) or not, develops at different rates or not all (e.g., to impairment of the logical sequence of thoughts, to which no tolerance has yet been demonstrated). "Dispositional tolerance" (increased rate of metabolism of delta 9-THC due to enzyme induction) may play a role in the development of tolerance or "reverse tolerance" to cannabis in man. There is evidence that for the label "high," placebo effects may account for the "reverse tolerance" seen in experienced users on smoking (but not on ingestion of delta 9-THC or placebo) along with evidence of residual tolerance to other not-so-labeled effects of the drug. Dependence on cannabis, in the sense of abstinence phenomena on abrupt withdrawal of delta 9-THC, has been demonstrated in monkeys made tolerant to delta 9-THC given four times daily for about 1 month. In man, physiologic marijuana abstinence signs have not been demonstrated, but behavioral (and some physiologic) abstinence phenomena have been reported in heavy users of hashish or ganja. The between-dose hyperirritability and dysphoria reported to occur in experimental studies on chronic marijuana intoxication may actually be early and short-lived abstinence changes. In the West, where marijuana with relatively low delta 9-THC content is widely smoked, dependence in the sense of drug-seeking behavior appears to be less a function of any pharmacologic reinforcing properties the drug may have than of secondary (conditioned) reinforcement derived from the social milieu in which the marijuana is smoked. In cultures where marijuana of higher delta 9-THC content, hashish, or ganja is used, pharmacologic reinforcement (through suppression of abstinence changes) may play a greater role in maintaining drug-seeking behavior.

Animals↗