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Biomedical subjects

R I Herning

Publications and source records attributed to R I Herning.

At least 19 recordsLinked to original sources
PubMed1990

Changes in mood, craving, and sleep during short-term abstinence reported by male cocaine addicts. A controlled, residential study.

We examined changes over 28 days in mood states, craving for cocaine, and sleep during short-term abstinence reported by 12 male, predominantly intravenous-using, cocaine-addicted subjects residing in a research facility. For comparison, we examined 10 nonaddicted control subjects. There were no significant differences between cocaine addicts and controls regarding demographics and selected DSM-III-R diagnoses other than psychoactive substance use disorder and antisocial personality disorder. There were significantly higher scores of psychiatric symptoms reported by cocaine addicts 1 week before admission. Mood-distress and depression scores recorded at admission and during short-term abstinence were significantly greater than those reported by controls. Addicts' mood-distress scores and craving for cocaine were greatest at admission and decreased gradually and steadily during the 28-day study. There were no significant differences between groups regarding reports of sleep other than difficulty falling asleep and clearheadedness on arising. Although there were significant differences in resting heart rate at admission and over time, there were no significant differences in weight gain or blood pressure. Given the absence of a classic "withdrawal" pattern, "short-term abstinence" may be a more appropriate classification of psychological and physical phenomena experienced by cocaine addicts who initiate abstinence in a controlled environment.

Adult↗
PubMed1990

Dose-dependent atropine-induced changes in spontaneous electroencephalogram in human volunteers.

Atropine is an anticholinergic drug used in military medicine as an antidote following exposure to cholinesterase-inhibiting nerve agents. However, atropine causes neuropsychologic effects that impair performance. In the present study, we examined electrophysiologic indices that may accompany performance deficits. Quantitative electroencephalographic (EEG) analyses of changes induced by atropine (1.5, 3.0, and 6.0 mg/70 kg, intramuscularly) were assessed in seven male volunteers in a placebo-controlled, double-blind, cross-over experiment. Spontaneous EEG recordings were obtained from relaxed subjects before, 2 hours after, and 8 hours after atropine. Atropine significantly increased delta power, decreased alpha power, and tended to increase theta power and reduce beta and theta frequency. EEG indices of vigilance were reduced by the drug. Dose-related increases in sedation and dysphoria were obtained; some subjects liked these effects. Together, these findings confirmed that atropine causes dose- and time-related electrophysiologic and subjective effects that predict impaired performance.

Adult↗
PubMed1989

Auditory event-related potentials in adolescents at risk for drug abuse.

We evaluated sensory and cognitive information processing in noninstitutionalized delinquent male adolescents and in age-matched low delinquency controls. Detailed psychometric testing documented the nature of the aggressive behavior of these young men. Deficits in information processing, as assessed by event-related potential (ERP) techniques, were observed at several levels of the auditory system in the delinquent group. The delinquent group showed delays in wave V of the brainstem auditory evoked potential, shorter N100 latency, and decreased slow wave amplitude of cognitive event-related potentials when subjects were asked to perform a mental task in a noisy environment. It remains to be determined whether or not such information-processing deficiencies are common among delinquent populations and how they might influence the development of delinquent behavior and drug abuse.

Adolescent↗
PubMed1989

EEG and brainstem auditory evoked response potentials in adult male drug abusers with self-reported histories of aggressive behavior.

Auditory brainstem evoked response (BAER) and spontaneous electroencephalogram (EEG) were measured in 124 adult male drug abusers. We examined the relationships among psychiatric diagnoses, paper and pencil measures of aggression and hostility, and electrophysiological features. Subjects meeting criteria for antisocial personality disorder (ASP), as defined by DSM-III, were not significantly different from non-ASP subjects for either BAER or spontaneous EEG measures. The more overtly aggressive subjects had significant delays in BAER latency. Aggressive subjects also had more delta activity and less alpha activity in the spontaneous EEG, as have been observed in "psychopaths" and "criminals." Although ASP and aggression are related, these data indicate that aggressiveness may be a separate, albeit overlapping, trait. As both early aggression and a diagnosis of ASP are predictors of later drug use, the findings that only aggression was associated with EEG slowing and brainstem delays may indicate that ASP and aggression make independent contributions to vulnerability to the development of drug abuse.

Adult↗
PubMed1989

Spontaneous EEG changes during tobacco abstinence and nicotine substitution in human volunteers.

Electroencephalographic correlates of tobacco abstinence and nicotine substitution were measured in adult male cigarette smokers in residence on a research ward in two experiments. After ad libitum smoking, seven subjects were deprived of nicotine for 10 days and then resumed smoking. During tobacco abstinence, there were significant decreases in alpha frequency and beta frequency and increases in theta power. These effects were observed as early as 29 hr and in some instances persisted for 7 days. In the second experiment, a group of eight heavy smokers chewed 12 pieces of either placebo or nicotine-containing polacrilex gum (2 or 4 mg) per day while deprived of cigarettes. In the placebo condition, electroencephalographic signs were similar to those accompanying tobacco deprivation in the first experiment. Administration of nicotine polacrilex prevented the appearance of these tobacco withdrawal signs. This study provides new information on the time course of certain electrophysiologic components of the tobacco withdrawal syndrome and confirms that the effects are specific to the deprivation of nicotine. The data also suggest that the 4-mg polacrilex was more effective than the 2-mg dose when the results across all measures were considered.

Adult↗
PubMed1988

Mecamylamine reduces some EEG effects of nicotine chewing gum in humans.

Spontaneous EEG was recorded in nine cigarette smokers who had been abstinent from tobacco for 12 hr. Subjects were treated with a capsule containing either centrally acting nicotine blocker, mecamylamine (10 mg), or placebo. At each of three 60-min intervals after the capsule was ingested, the subjects chewed two pieces of gum containing a total of 0, 4 or 8 mg of nicotine. Nicotine and mecamylamine dose combinations were randomized across subjects. Two three-minute periods of spontaneous EEG were recorded before the capsule and before and after gum chewing from bipolar electrode montages at the following positions: Cz-T5, Cz-T6, Cz-F7 and Cz-F8. During one period the subjects relaxed with eyes closed, in the other period they performed a math task with eyes open. When the drugs were given individually, mecamylamine decreased beta power and nicotine gum (4 and 8 mg) increased alpha frequency. Mecamylamine pretreatment prevented the increase in alpha frequency caused by the 4 mg gum dose but not the 8 mg dose. Alpha power was increased by the 8 mg gum dose and that increase was prevented by mecamylamine. Self-reported ratings of the "strength" of the gum were significantly diminished by mecamylamine pretreatment. The data are consistent with the results of earlier studies which indicate that the effects of tobacco administration and withdrawal are mediated by central actions of nicotine.

Adult↗
PubMed1987

Cocaine effects on electroencephalographic cognitive event-related potentials and performance.

The effects of cocaine on electroencephalographic indices, information processing and motor performance were measured in 12 normal volunteers. They were tested with an auditory continuous performance task before, 60 and 180 min after a 3 mg/kg oral dose of cocaine hydrochloride or placebo in a double-blind counterbalanced crossover design. EEG from Fz, Cz and Pz were averaged for the eye movement-free correct trials. N100, P200, P300 components and CNV were measured. Cocaine increased N100 amplitude for the warning stimulus and CNV amplitude. P300 amplitude and latency, reaction time and sensory sensitivity (d') were not altered by cocaine. The increase in N100 and CNV amplitude may reflect mobilization of additional attentional resources to produce optimal performance on the task when subjects were distracted by the cardiovascular, subjective and other cocaine effects.

Adult↗
PubMed1987

Speech event related potentials reflect linguistic content and processing level.

Amplitude changes in the auditory event related response reflect differences in linguistic content and the level of processing of spoken sentences. Thus, the neurophysiology of the cognitive processes underlying speech perception can be evaluated by noninvasive techniques. Semantically correct, semantically incorrect, and grammatically incorrect sentences were processed either semantically or syntactically by 25 subjects while their EEGs were recorded. The amplitude of the P250 component to each word varied with processing level. A slow positive wave appeared after semantically correct sentences regardless of the linguistic processing level. N480 and P780 components were observed following words which made the sentences incorrect.

Adult↗
PubMed1986

Tetrahydrocannabinol content and differences in marijuana smoking behavior.

Changes in smoking behavior in response to a change in marijuana potency were measured in marijuana users. A marijuana cigarette containing 1.2% or 3.9% tetrahydrocannabinol (THC) was smoked on separate days by ten experienced users. Puff volume, duration and number, interpuff interval, inhalation volume and duration were averaged for each cigarette. The high potency cigarettes were smoked with more puffs and longer interpuff intervals, but also with greater inhaled volumes of air, thereby diluting the marijuana smoke.

Adult↗
PubMed1986

Electroencephalographic effects of nicotine chewing gum in humans.

The electroencephalographic (EEG) and subjective effects of nicotine chewing gum (0, 2 and 4 mg) were compared in three tobacco deprived (12 hr) heavy smokers. EEG responses were recorded from F7, F8, T5, and T6 positions before and after the subjects chewed nicotine gum (chew rate = 1 per 2 sec) for 10 min and subsequently analyzed by a computer-based data acquisition and analysis system. Analysis of the chewed gum indicated that the subjects extracted approximately 50 percent of the available nicotine. The nicotine gum increased EEG frequencies in the alpha (7.25-14 Hz) and beta (14.25-25 Hz) bands and decreased theta (4-7) Hz) power. The EEG effects were most evident in the resting subject; the effects of the gum were similar but weaker when the EEG was aroused by a mental arithmetic task. Nicotine gum had EEG stimulant effects like those of inhaled tobacco smoke which were most apparent in the relaxed subject. In spite of this similarity, the subjects did not identify the effects of the gum as being identical to those of cigarettes.

Adult↗
PubMed1985

Information processing components of the auditory event related potential are reduced by cocaine.

The effects of cocaine on a human electroencephalographic event related potential (ERP) were measured. Forty-eight subjects received one of three IV doses (0.2, 0.4, or 0.6 mg/kg) and placebo. Thirty-three subjects received one of three oral doses (2, 3, or 4 mg/kg). All IV and oral doses reduced amplitude of the auditory ERP P200 and P300 components during the oddball task. P200 latency decreased. N100 amplitude was reduced only after IV administration. The changes in ERPs occurred during the period of peak cardiovascular and subjective effects. The amplitude reduction in ERP components occurring before the P300 component is consistent with decrements in attention, specifically selective attention. The P300 amplitude reduction after cocaine suggests a disruption of stimulus evaluation resources. The findings are inconsistent with the notion that stimulants affect only response selection and execution. The degree to which stimulants alter cognitive processes prior to response selection may depend on the magnitude of the cardiovascular, subjective, and probably other noncognitive effects.

Administration, Oral↗
PubMed1985

Cocaine increases EEG beta: a replication and extension of Hans Berger's historic experiments.

The effects of cocaine by two routes of administration were studied on the resting, awake human EEG during a 2 min sequential subtraction task. Fifty subjects were given 1 of 3 intravenous cocaine doses (0.2, 0.4 and 0.6 mg/kg). Thirty-three subjects received 1 of 3 oral doses of cocaine (2, 3 and 4 mg/kg). The EEG was analyzed as spectral power for delta, theta, alpha and beta bands. At each dose for both routes of administration, cocaine increased beta power. The increase was observed at the 5 min post-drug test session for the subjects given intravenous cocaine and at both 45 and 75 min test sessions for subjects given oral doses. In addition, a decrease in delta power was found at the 5 min test for the intravenous group and theta power was decreased at the 45 min test session. The increase in beta power was correlated with the area under the cocaine plasma versus time curve, but not with the cardiovascular effects of cocaine. The increased beta activity observed with cocaine may be a consequence of the direct stimulation of a central noradrenergic arousal system.

Adult↗
PubMed1985

The titration hypothesis revisited: nicotine gum reduces smoking intensity.

Supplemental nicotine gum reduced the intensity of smoking in six one-and-a-half to two-pack-a-day smokers. The study involved two 4-hour self-paced smoking sessions where nicotine and placebo chewing gum were administered in a double-blind fashion. Puff volume, puff duration, inhaled volume, inhaled duration, and interpuff interval were calculated for each puff on each cigarette. Blood was drawn for nicotine levels at regular intervals as well as before and after each cigarette. Cardiovascular measures were made at regular intervals. The nicotine gum reduced smoking frequency and intensity as predicted by the titration hypothesis. Precise titration (i.e., equal nicotine blood levels on both test days) was confounded by changes in smoked nicotine delivery produced by the gum. The gum, whether placebo or active, increased smoked nicotine absorption. However, while nicotine blood levels were slightly higher on nicotine gum day, the differences may not be biologically meaningful since heart rate and blood pressure increases were similar on both days. Difficulties testing the titration hypothesis are discussed.

Adult↗