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Biomedical subjects

F G Moeller

Publications and source records attributed to F G Moeller.

At least 37 records · Page 2Linked to original sources
PubMed1999

Symptomatology of depression and anxiety in female "social drinkers".

Self-reported alcohol use, Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI) scores were obtained during on-site interviews of 172 female applicants for paid participation in behavioral research. Mood symptomatology as reflected in BDI and BAI scores was analyzed as a function of alcohol use and other demographic variables. Women reporting even light alcohol use (up to three drinks per week) were significantly more symptomatic than abstinent women. In contrast, no significant differences in symptomatology were observed due to race or education level. This analysis extends previous findings of depressed mood in women (while sober) whose lifestyle includes moderate alcohol consumption and suggests that even light alcohol use is related to depressed and/or anxious mood.

Adult↗
PubMed1999

The effects of a cumulative alcohol dosing procedure on laboratory aggression in women and men.

OBJECTIVE: This study directly compared the effects of cumulative alcohol dosing procedure on aggression in both women and men. METHOD: Thirteen women and 13 men consumed three beverages 1 hour apart. There were two experimental conditions: (1) a placebo day, when subjects consumed three 240 ml beverages, each containing only 1 ml of alcohol; and (2) an alcohol day, when subjects consumed three 240 ml beverages, each containing 0.35 g/kg of 95% alcohol. Alcohol doses for women were reduced by 8%. Prior to beverage consumption, and periodically after consumption, subjects participated in 25-minute laboratory testing sessions designed to measure aggression. In this paradigm, subjects could earn points by responding on a button, or aggress toward a fictitious opponent who ostensibly subtracted earnings from them. RESULTS: Both women and men showed an increase in aggressive responding after drinking alcohol but not placebo. As a group the greatest increases were observed after consuming the second alcohol drink (BAC = 0.08%). Aggressive responding, however, remained elevated for several hours after alcohol consumption. A post hoc analysis of the data indicated that subjects with high aggression levels under placebo conditions showed the greatest increases in aggression under alcohol conditions. CONCLUSIONS: These results indicate that at least under these conditions, alcohol does increase aggression in both women and men. The aggression-increasing effects of alcohol appear to be long-lasting and specific to individuals with the higher aggressive tendencies while sober.

Adult↗
PubMed1999

Alcohol increases commission error rates for a continuous performance test.

BACKGROUND: Studying the effects of alcohol on Continuous Performance Test (CPT) performance was of interest for two reasons, i.e., (1) perhaps because of the ease of the task used in previous experiments, alcohol has not been found to impair performance, and (2) CPT commission errors (described below) have been related to impulsive behavior. METHODS: In this study, the CPT featured both an Immediate Memory Task (IMT) and a more difficult Delayed Memory Task (DMT). We compared the performance of 18 subjects under both alcohol and placebo conditions, using a within-subject design. Both the IMT (0.5-sec delay) and the DMT (3.5-sec delay, with distracter stimuli at 0.5-sec intervals) required the subject to respond if a briefly displayed number was identical to the one presented before it. Stimuli included target (identical match), catch (4 of 5 digits matched), and novel (random number) stimuli. On 2 separate days, subjects performed between administrations of three hourly placebo drinks or three hourly drinks containing 0.20 g/kg of alcohol (producing peak breath alcohol concentrations of approximately 0.035%). RESULTS: The main finding was that alcohol consumption increased responses to catch stimuli (i.e., commission errors) in the DMT. In contrast, performance in the IMT (the easier task) was unaffected by alcohol. Commission errors measured during peak breath alcohol concentrations were significantly correlated with scores on the Barratt Impulsivity Scale for both the IMT and DMT. Discriminability (A') between target and catch stimuli was reduced by alcohol for the DMT only. CONCLUSIONS: These data indicate that even small amounts of alcohol can produce measurable changes in CPT performance parameters if the task is of sufficient difficulty and that commission errors can be increased by alcohol consumption.

Adult↗
PubMed1998

Ipsapirone neuroendocrine challenge: relationship to aggression as measured in the human laboratory.

Thirty-one human subjects were administered a neuroendocrine challenge with the 5-HT1a agonist ipsapirone after completing six sessions of a laboratory measure of aggression, the Point Subtraction Aggression Paradigm (PSAP), in order to determine if a laboratory measure of aggression was related to serotonin function. Subjects who showed more aggressive responding on the PSAP (n = 11) had a significantly blunted temperature response to ipsapirone compared to those with less aggressive responding (n = 20). There was no difference between the two groups on the cortisol response to ipsapirone. This study supports a relationship between serotonin function and aggression as measured in the human laboratory, similar to the well-documented association between self-reported aggression and serotonin.

Adult↗
PubMed1998

Laboratory measurement of adaptive behavior change in humans with a history of substance dependence.

Individuals vary in their ability to adapt to changes in environmental conditions. In the present study, two laboratory experiments investigated components of adaptation in subjects with and without a history of substance dependence. In each of two experiments, the subjects were exposed to conditions that required changing response patterns between experimental days. On day 1, subjects earned monetary rewards under conditions that produced high rate responding, but on day 2 were required to wait 10 s between each response. Collectively, the two experiments demonstrated that the subjects meeting criteria for past substance dependence, and having extensive histories of substance use (> 10 years), adjusted poorly to the transition. In both studies, these subjects tended to persevere on the previously established high-rate response pattern. These data suggest a deficiency in adaptive behavior change, particularly when that change requires an abrupt slowing of response rates following a brief history of high-rate responding.

Adaptation, Psychological↗
PubMed1998

Immediate versus delayed visual memory task performance among schizophrenic patients and normal control subjects.

In an exploratory study, 10 schizophrenic patients and 10 normal control subjects performed immediate and delayed memory tasks, which were variants of previously developed continuous performance tests. Both tasks required participants to identify five-digit numbers which were repeated. Numbers were presented in series for 500 ms each and separated by a 500-ms time-out period. In the immediate memory task, subjects were to respond if a number was identical to the one that had immediately preceded it. The delayed memory task differed from the first task in that a longer delay (3.5 s) between stimuli was introduced, and during this delay distracter stimuli appeared. While normal control subjects performed accurately on both tasks (exceeding 80% correct detections), schizophrenic patients performed poorly, performing worse on the delayed memory task than on the immediate memory task. Rates of commission errors (responses made to similar, but not identical numbers) were nearly equal between groups on the immediate memory task, but on the delayed memory task normal control subjects made relatively more commission errors while schizophrenic patients made fewer commission errors. No differences in response latencies were observed between subject groups or tasks. This paradigm may prove useful in discriminating subtle differences in immediate and delayed memory capability among psychiatric populations and normal control subjects.

Adult↗
PubMed1998

Impulsivity and history of drug dependence.

Impulsivity was contrasted between 32 subjects with a history of drug-dependence (DRUG+) and 26 subjects with no drug use history (DRUG-) using both behavioral and self-report measures. The hypothesis was that the DRUG+ group would be more impulsive than the DRUG- group. Subjects in the DRUG+ group self-reported more of a tendency toward impulsivity than the DRUG- group in the situations posed in questionnaires. In the behavioural paradigm involving a choice between a smaller intermediate reward and a larger but delayed reward, DRUG+ subjects selected the impulsive option more often, but these differences were not significant. The DRUG+ and DRUG- groups did differ on the mean delay interval for the larger reward, indicating less ability to tolerate longer delays for the larger reward. A frequency distribution of delay intervals for the larger reward indicated that DRUG+ subjects were more likely to maintain very short intervals and less likely to maintain longer intervals.

Adult↗
PubMed1998

Antisocial personality disorder and alcohol-induced aggression.

This study compared the effects of alcohol on aggressive responding between subjects with antisocial personality disorder (ASPD) and subjects without ASPD. Eighteen alcohol drinking subjects (10 subjects without ASPD and 8 subjects with ASPD) underwent testing on a laboratory measure of aggression, the Point Subtraction Aggression Paradigm, after consumption of placebo and three doses of alcohol (0.25 g/kg, 0.5 g/kg, and 1.0 g/kg). There was a significant difference in the effect of alcohol on aggressive responding on the Point Subtraction Aggression Paradigm between subjects with ASPD and subjects without ASPD. Subjects with ASPD had a greater increase in aggressive responding after alcohol, compared with non-ASPD subjects. There was no difference between the two groups in the effect of alcohol on monetary-reinforced responding.

Adult↗
PubMed1997

Subjects with a history of drug dependence are more aggressive than subjects with no drug use history.

Aggressive responding was compared between 29 subjects with a history of substance dependence and 24 subjects with no drug use history, using the Point Subtraction Aggression Paradigm. The hypothesis was that subjects from the substance dependence history group would emit more aggressive responses than subjects with no drug use history. The substance dependence history group emitted more aggressive responses per session than the non drug using group (F(1,49) = 14.867, P = 0.032). These results are consistent with previous studies that have reported an association between aggression and drug abuse or dependence.

Adult↗
PubMed1997

Antisocial personality disorder and aggression in recently abstinent cocaine dependent subjects.

To study the relationship between cocaine abstinence symptoms, personality, and aggression, we used the Point Subtraction Aggression Paradigm (PSAP) to measure aggression in 18 subjects admitted for the treatment of cocaine dependence. Eight subjects met criteria for antisocial personality disorder (ASPD). There was a significant correlation between presence of ASPD and frequency of aggressive responding by stepwise multiple regression. When presence of ASPD was factored out of the correlations, there was no significant relationship between aggressive responding and cocaine craving, withdrawal symptoms, amount of cocaine used, or length of time since use. These preliminary results suggest that in cocaine dependent individuals seeking treatment, current aggression is most dependent on the individual's previous aggressive behavior.

Adult↗
PubMed1997

A positive correlation between self-ratings of depression and laboratory-measured aggression.

Aggression and depressive symptoms have been linked using self-rating scales as measures of aggression. In order to study this relationship using an objective measure of aggression, we studied normal controls (42 women and 23 men) with the Point Subtraction Aggression Paradigm (PSAP) and the Beck Depression Inventory (BDI). There was a significant positive correlation (r = 0.442, P = 0.003) between the level of aggressive responding on the PSAP and the level of depressive symptoms on the BDI in women but not in men (r = 0.064, P = 0.773). This study provides some evidence of a link between aggressive behavior and depressive symptoms in a non-clinical population, possibly due to a common neurochemical etiology.

Adolescent↗
PubMed1997

Studies of violent and nonviolent male parolees: I. Laboratory and psychometric measurements of aggression.

Male parolees were recruited into a laboratory study to determine the relationship between their previous aggression history, psychometric measures of aggression, and behavioral measures of aggressive responding using a laboratory methodology: the Point Subtraction Aggression Paradigm. Subjects were assigned to a violent or nonviolent group based upon their criminal history. Subjects participated in sessions in which they were given three response options defined as: (1) nonaggressive responding which earned money, (2) aggressive responding which ostensibly subtracted money from another fictitious person, (This responding was defined as aggressive since it resulted in the ostensible delivery of an aversive stimulus (subtraction of money) to another person), and (3) escape which protected the subject's earnings from subtractions initiated by the other person. Results indicated that the violent subjects emitted significantly more aggressive responses than subjects in the nonviolent group. The number of aggressive responses parolees emitted was significantly correlated with most psychometric measures of aggression. This study provides external validity for our laboratory measurement of human aggressive responding, since aggressive responding was directly related to violent criminal histories.

Adult↗
PubMed1997

Studies of violent and nonviolent male parolees: II. Laboratory and psychometric measurements of impulsivity.

Males parolees were recruited into a laboratory study to determine the relationship between their previous criminal history (violent versus nonviolent), and behavioral and psychometric measures of impulsivity. During sessions, subjects were given two response options defined as: 1) an impulsive choice--small monetary reward after a short fixed delay; and 2) a self-control choice--a larger monetary reward after a variable longer delay. Based upon an extensive experimental literature in animals and humans related to delay of gratification, the degree of impulsivity was defined as the proportion of trials on which the subject selected the impulsive option. Our results indicated that the violent subjects selected the impulsive option significantly more often than the nonviolent parolees. The number of impulsive responses parolees emitted was significantly correlated with the number of aggressive responses reported in an earlier paper. This study provides support for the relationship between impulsivity and aggression among male parolees.

Adult↗
PubMed1997

The influence of menstrual-cycle phase on the relationship between testosterone and aggression.

Plasma testosterone levels and aggressive behavior were measured in 12 women with and without perimenstrual affective symptomatology (e.g., depression, irritability) during the menstrual, midfollicular, ovulatory, and premenstrual phases of the menstrual cycle. The Point Subtraction Aggression Paradigm was used to quantify aggressive response to provocation. Subjects had two response options: a point-maintained option (100 presses earned a point worth 10 cents) and an aggressive response option (10 presses ostensibly subtracted a point from a fictitious partner's counter). Subjects were provoked by the periodic subtraction of a point that was attributed to the responding of a fictitious opponent. Although plasma testosterone levels (determined by radioimmunoassay) increased significantly during the ovulatory phase, aggressive response to provocation remained unchanged across the menstrual cycle. Plasma testosterone did not differ between the 2 groups during any phase. A relationship between plasma testosterone levels and use of the aggressive response option was seen only during the midfollicular phase (Spearman r = .673, p = .017). These preliminary data suggest that: 1. The relationship in female subjects between endogenous testosterone and aggressive behavior is inconsistent; 2. self-report of perimenstrual symptomatology is a more consistent predictor of aggressive behavior across the menstrual cycle than plasma testosterone; and 3. perimenstrual emotional symptomatology is not related to testosterone levels.

Adolescent↗
PubMed1996

Tryptophan depletion and aggressive responding in healthy males.

In order to study the effect of decreasing plasma tryptophan levels on aggressive responding in a controlled laboratory setting, we administered two doses (25 g and 100 g) of a tryptophan-free amino acid mixture to ten healthy male subjects after 24 h of a low tryptophan diet. Subjects were screened for current or past psychiatric, or non-psychiatric medical illness. Aggressive responding on a free-operant laboratory measure of aggression (the Point Subtraction Aggression Paradigm) and plasma tryptophan levels were measured before and after drinking the amino acid mixture. There was a significant increase in aggressive responding 5 h after the 100 g mixture and a significant increase in aggressive responding 6 h after the 25 g mixture compared to a baseline day when no drink was administered. There was also a significant decrease in plasma tryptophan at 5 hours after ingestion compared to baseline for both doses of amino acid mixture. This study supports the hypothesis that tryptophan depletion increases aggressive responding in healthy males in a laboratory setting, probably by decreasing brain serotonin.

Adult↗
PubMed1995

Cerebellar blood flow in schizophrenic patients and normal control subjects.

We used 133Xe dynamic single-photon emission computed tomography (DSPECT) to measure the resting cerebellar blood flow in 17 neuroleptic-free schizophrenic and schizophreniform patients and 13 normal control subjects. A subset of these subjects (11 patients and 7 control subjects) additionally underwent activation studies during the Wisconsin Card Sorting (WCS) and Number Matching (NM) tests. Baseline relative cerebellar blood flow was significantly lower in older patients than in age-matched control subjects. For absolute cerebellar flow, there was a significant difference between patients and control subjects in the overall activation response (patients: NM 13.4% increase, WCS 15.7% increase; control subjects: NM 3.1% decrease, WCS 0.0% change). This difference was more pronounced in older subjects. Cerebral blood flow significantly increased during NM (patients: 21.3% increase, control subjects: 6.5% increase) and WCS (patients: 16.5% increase, control subjects: 9.7% increase). The difference in the magnitude of cerebral NM activation between schizophrenic patients and control subjects, although not statistically significant, may call into question the appropriateness of using NM as a control task in schizophrenic patients. Finally, we found no differences between the effects of WCS and NM on cerebellar or cerebral blood flow. Because of the small number of subjects in each group, the results of this study should be interpreted cautiously.

Adult↗
PubMed1995

Low plasma homovanillic acid levels in recently abstinent alcoholic men.

OBJECTIVE: To explore dopaminergic mechanisms in alcohol dependence, the authors measured plasma homovanillic acid (HVA) in recently detoxified alcohol-dependent men. METHOD: Plasma HVA was measured in 83 male patients with a diagnosis of alcohol dependence who had maintained documented abstinence for at least 3 weeks and in 69 healthy male comparison subjects. RESULTS: The alcoholic patients as a group had significantly lower levels of plasma HVA than the comparison subjects. This difference was not influenced by any other measured covariate, including a family history of alcohol dependence. CONCLUSIONS: These results imply that factors such as alcohol dependence should be taken into account in future studies of plasma HVA.

Alcohol Drinking↗