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Biomedical subjects

D R Cherek

Publications and source records attributed to D R Cherek.

At least 55 records · Page 3Linked to original sources
PubMed1991

Human aggressive responding during acute tobacco abstinence: effects of nicotine and placebo gum.

Aggressive and point maintained operant responding of heavy nicotine dependent male tobacco smokers were measured during five 25-min sessions conducted over an 8-h period. Responding under three tobacco abstinence conditions was compared to responding during a baseline condition of ad libitum smoking of the subject's preferred brand of cigarettes. The three tobacco abstinence conditions were: (1) placebo gum, (2) nicotine gum or (3) no gum. Under placebo and nicotine gum conditions, subjects were given two pieces of placebo or 2 mg nicotine gum to chew for 30 min prior to each session. Expired air carbon monoxide (CO) levels were measured at the end of each session to monitor smoking under baseline conditions and compliance with nonsmoking requirements under abstinence conditions. Aggressive responding was increased in no gum and placebo gum conditions, with the highest frequency of aggressive responding occurring under no-gum conditions. Aggressive responding during nicotine gum conditions did not differ from baseline ad libitum tobacco smoking. Point maintained responding was either not affected or decreased under placebo and no-gum conditions. These results provided objective data consistent with clinical reports of increased irritability among dependent tobacco smokers during acute tobacco abstinence.

Adult↗
PubMed1991

Effects of triazolam on human aggressive, escape and point-maintained responding.

Placebo and triazolam (0.125, 0.25 and 0.5 mg/70 kg of body weight) were administered to male subjects under double-blind conditions prior to experimental sessions which provided three operant response options. These options were: 1) responding maintained by the presentation of points exchangeable for money, 2) responding which ostensibly resulted in the subtraction of points from a fictitious person was termed aggressive since this responding resulted in the delivery of an aversive stimulus to another person, and 3) responding which ostensibly protected the subject's point counter from subtractions initiated by the other person and was termed escape. Aggressive and escape responding were initiated by subtracting points from the subject. Point subtractions were attributed to the other person. Aggressive and escape responding were maintained by initiation of provocation-free intervals (PFI), during which no further point subtractions were presented. Triazolam produced dose-dependent decreases in point-maintained and escape responding. The effects of triazolam on aggressive responding varied across subjects.

Adult↗
PubMed1990

Effects of acute administration of diazepam and d-amphetamine on aggressive and escape responding of normal male subjects.

Normal males participated in sessions providing two operant response options and were administered either diazepam (study I and II) or d-amphetamine (study II). The acute effects of diazepam on human aggressive responding, which ostensibly subtracted points from another person, were determined in study I. Study II was conducted to determine the extent to which social context and response consequence influenced diazepam (study I) and d-amphetamine (previous research) effects on aggressive responding. In study II, the other response option was escape responding which protected the subject's counter from point losses. Aggressive and escape responding were engendered by subtracting points from the subject's counter, and maintained by initiation of intervals free of point loss. Point subtractions were attributed to the other person (study I) or to a machine (study II). Responding to accumulate points exchangeable for money was available in both studies. Acute diazepam administration decreased aggressive responding in most subjects (study I), slightly increased escape responding (study II), and decreased responding to accumulate points. In study II, d-amphetamine increased both escape responding and responding to accumulate points. The effects of d-amphetamine and diazepam were altered by the instructed source of point loss.

Aggression↗
PubMed1990

Benzodiazepine-induced impairment of matching-to-sample performance in humans.

The effects of benzodiazepines on a visual pattern matching-to-sample (MTS) task were examined in nine healthy male volunteers. The MTS task employed randomly generated checkerboard-like stimuli presented on a video display. The sample and two comparison stimuli were simultaneously presented. Nonmatching comparison stimuli were randomly generated to be 3.125, 6.25, 12.5, 25.0, 37.5, or 50.0 percent different from the sample. Subjects responded on left or right button manipulanda to identify the matching comparison stimulus. The nonmatching stimulus condition was maintained constant for a 60-sec component and the percentage difference of the nonmatching stimuli was systematically varied across multiple components. The effects of triazolam (2.25-9.0 micrograms/kg) and lorazepam (7.5-45 micrograms/kg) were examined in a within-subjects, double-blind, placebo-controlled study. Under placebo conditions, response rates and accuracy were a positive function of the nonmatching stimulus discriminability. Triazolam produced dose-related decreases in response rate at nonmatching stimulus conditions greater than or equal to 25%. Only the 9.0 micrograms/kg dose of triazolam decreased accuracy and this occurred across all nonmatching stimulus conditions. Lorazepam effects were qualitatively similar but less robust than those of triazolam.

Adult↗
PubMed1990

The effects of codeine on human aggressive responding.

Ten healthy male research subjects received placebo, 25, 50 and 75 mg/70 kg of codeine in a controlled laboratory setting. During each session subjects had two response options. The non-aggressive response option was maintained by points exchangeable for ten cents. The aggressive response option ostensibly subtracted a point from the subject's fictitious partner. Aggressive responding was engendered by point subtractions attributed to a fictitious partner. Codeine did not significantly alter the frequency of monetarily reinforced, nonaggressive, responding. Aggressive responding was significantly increased at the 50 mg/70 kg dose of codeine. The frequency of aggressive responses during the placebo sessions preceding administration of the first codeine dose were significantly and positively correlated with scores on the Buss-Durkee Hostility Scale. Aggressive responding increased for four of five subjects scoring below the median on the Buss-Durkee Hostility Scale at the 50 mg/70 kg dose; while administration of 50 mg/70 kg increased aggressive responding of one subject who scored above the median. Aggressive responding for both groups of subjects was unaffected by the 75 mg/70 kg dose.

Administration, Oral↗
PubMed1990

Human aggressive responses maintained by avoidance or escape from point loss.

During 50-min sessions, 6 male human subjects could press either Button A or Button B available as nonreversible options. Button A presses were nonaggressive responses and earned points according to a fixed-ratio 100 schedule. Prior to the experiment subjects were instructed that every 10 (fixed-ratio 10) Button B presses (aggressive responses) subtracted a point from a fictitious 2nd subject. A random-time schedule of point loss was used to engender aggressive responding. The instructions attributed these point losses to the Button B presses of the subject's fictitious partner. Aggressive responding either escaped or avoided point loss by initiating an interval free of point loss. The duration of the interval was varied systematically across sessions. Avoidance contingencies maintained a high rate of aggressive responding over 30 sessions in the absence of point loss. Escape contingencies also maintained aggressive responding across sessions, with rates of aggressive responding corresponding to rates of point loss.

Adult↗
PubMed1989

Effects of nicotine gum and tobacco smoking on human avoidance responding.

Three male smokers were exposed to a free-operant avoidance schedule in which a lever press postponed a point subtraction on a counter for twenty seconds. Subtractions were scheduled to occur every 5 seconds in the absence of lever presses. Prior to each experimental session the subject was administered varying amounts of nicotine via either chewing nicotine gum or smoking low or high nicotine yield cigarettes. Smoking cigarettes resulted in increased avoidance responding relative to baseline nonsmoking rates. Chewing nicotine gum did not produce changes in avoidance responding, however, nicotine blood levels produced by chewing nicotine gum were similar to levels produced by smoking cigarettes. The differential responding determined by route of nicotine administration is discussed and the implications for use of nicotine gum as an adjunct for smoking cessation is addressed.

Avoidance Learning↗
PubMed1989

Effects of d-amphetamine on human aggressive responding maintained by avoidance of provocation.

Male subjects were administered placebo and three doses of d-amphetamine (5, 10 and 20 mg per 70 kg of body weight) under double-blind conditions in a laboratory setting which provided both aggressive and nonaggressive response options. the nonaggressive response was button pressing maintained by the presentation of points which were exchanged for money. The aggressive response was pressing another button which ostensibly resulted in the subtraction of points from a fictitious person. Aggressive responding was initiated by subtracting points from the subject. Point subtractions were attributed to the other person. Aggressive responding was maintained by an avoidance contingency between aggressive responses and scheduled provoking point subtraction presentations. d-Amphetamine increased nonaggressive responding, while aggressive responding was increased at the 10 mg dose and 20 mg resulted in significant decreases in aggressive responding relative to the 10 mg dose. Comparisons with previous research indicate that the contingency relationship between aggressive responses and presentation of provoking point subtractions can alter the effects of d-amphetamine on aggressive responding.

Adolescent↗
PubMed1989

Menstrual cycle and cigarette smoking behavior.

Female cigarette smokers participated in daily two-hour sessions over at least two consecutive menstrual cycles. Automated measurements of each cigarette puff and its duration were recorded. Comparisons in these measurements were between premenstrual and menstrual portions and the rest of the cycle. Most of the subjects increased the mean number of cigarette puffs per session and/or the total puff duration per session during the menstrual phase of the cycles.

Adolescent↗
PubMed1989

Effects of secobarbital on human aggressive and non-aggressive responding.

This study examined the effects of secobarbital on human aggressive responding in a controlled laboratory setting. Sixty minutes prior to experimental sessions, male subjects were administered either placebo or 50, 100 or 200 mg per 70 kg of body weight doses of secobarbital double-blind. During these sessions, subjects could press a button to accumulate points exchangeable for money (non-aggressive response) or press another button ostensibly to subtract points from a fictitious person (aggressive response). Aggressive responding was occasioned by subtracting points from the subject. Subjects were instructed that points were subtracted by another person. Aggressive responding was maintained by contingent presentation of periods free of point subtractions, i.e., provocations. Acute secobarbital administration produced dose-dependent decreases in non-aggressive responding, and increases in aggressive responding.

Aggression↗
PubMed1989

Concurrent reinforcement and alcohol: interactive effects on human aggressive behavior.

The relationship between alcohol and human aggressive behavior was studied under conditions in which nonaggressive response requirements maintained by point presentation were manipulated. Six normal adult male recreational alcohol users pressed buttons that produced points (redeemable for money) on their own counters or ostensibly subtracted points (money) from another fictitious subject described as participating in the same study at another location. During random components of each session, subjects were required to press a button 50, 200 or 500 times in order to produce point increments on their own counters. Ten responses on a second button were required to subtract a point from the other subject during all components. Aggressive responding was engendered by occasional point subtractions which were attributed to the fictitious subject. Alcohol (0, 0.125, 0.25 and 0.5 g/kg of 95% ethanol) produced dose-related increases in aggressive responding. Aggressive responding was also significantly related to the concurrent schedule of point presentation. Finally, a significant interaction between alcohol and concurrent point presentation contingencies was observed. These results indicate that aggressive responding is affected by ongoing reinforcement contingencies not directly related to aggressive behavior and that reinforcement schedule interaction may be one factor mediating the situation-dependent nature of alcohol's effects on aggressive behavior.

Adolescent↗