Comparing the effects of light alcohol consumption on human response to auditory and visual stimuli

The purpose of this study is to examine the effects of various levels of alcohol consumption on human response to auditory and visual stimuli in terms of reaction time, movement time, total reaction time, and error rate. Placebo level and three low-level alcohol doses were randomly assigned to 20 male university student volunteers. 30 min. after consuming the alcohol or placebo, participants responded to either auditory or visual stimuli. Total reaction time increased significantly at the mid-low dose of alcohol (0.3 g/kg). For alcohol doses less than .5 g/kg, the change in total reaction time was confined to reaction time, i.e., the processing time between onset of stimulus and onset of movement. Effects of alcohol were significantly more pronounced in the choice-type tests. Notably, the effects of alcohol on total reaction time and error rate were significant for auditory but not visual stimuli.     

Acute and chronic effects of cocaine on the spontaneous behavior of pigeons

The present experiment examined the effects of acute and daily cocaine on spontaneous behavior patterns of pigeons. After determining the acute effects of a range of doses, 9 pigeons were divided into three groups that received one of three doses of cocaine daily, either 1.0, 3.0, or 10.0 mg/kg cocaine. Measures were taken of spontaneous locomotion, pecking, preening, and emesis. Under daily administration, cocaine induced consistent and substantial enhancements of its locomotor effects in all 9 pigeons, consistent with the phenomenon of locomotor sensitization. The maximum locomotor output did not differ according to the size of the daily dose. Locomotion was not elevated following tests of the saline vehicle, suggesting the effect was due to cocaine, not to a change in baseline or reactivity to the injection procedure. Cocaine dose‐dependently decreased preening when given acutely, and those effects were not altered by repeated cocaine administration. Pecking occurred at very low rates and was unresponsive to cocaine treatment. Cocaine‐induced emesis showed a dose‐dependent increase under initial tests with cocaine, and those effects were attenuated following daily exposure. In a final condition, cocaine was replaced with daily saline for 30 days to assess the persistence cocaine‐related increases in locomotion. Approximately half of the pigeons continued to show enhanced effects even after 30 days without cocaine, so although persistence was obtained, it showed marked intersubject variability. The data indicate that the effects of repeated cocaine administration on the behavior of pigeons shows parallels with many effects commonly reported with rodents (i.e., increased locomotion following repeated treatment, decrease in preening or grooming, persistence following drug withdrawal).     

Antiaggressive and motor effects of the DA release inhibitor CGS 10746B

In the present study the effects of a wide range of doses of the dopamine release inhibitor CGS 10746B were evaluated in spontaneous activity and in aggressive behaviour using the paradigm of isolation‐induced aggression. The two higher doses (8 and 16 mg/kg) produced a decrease in spontaneous motor activity. Antiaggressive effects were observed after administration of doses from 4 mg/kg upwards. At this dose, CGS 10746B diminished threat and attack, and although an increase in immobility was observed, no impairment of other motor behaviours was presented. With higher doses, aggression was practically abolished but with a concomitant effect on many other behaviours. When animals were separated depending on their latency of attack, those that showed a long attack latency (LAL) presented a stronger response to 4 mg/kg than those that had a short attack latency (SAL), which were not affected in their aggression by this dose. We can conclude that presynaptic dopamine function is necessary for the normal expression of aggressive behaviours, since CGS 10746B reduces aggression at doses that do not affect spontaneous motor activity. Aggr. Behav. 27:382–390, 2001. © 2001 Wiley‐Liss, Inc.     

Alcohol and vigilance performance: effect of small doses of alcohol on simple auditory reaction time

This study explored whether a small dose of alcohol (0.67 ml/kg) would affect simple auditory RT as developed with time on task in a vigilance setting. Analysis indicated that absolute levels were not affected and no interaction with time on task was evident. Alcohol did, however, increase both number and mean duration of the extreme long reactions but this effect was not related to time on task. It was concluded that in many applied situations this effect of small alcohol doses may be critical.     

Alcohol and motion perception

Three motion perception skills were measured under different levels of alcohol ingestion. Our method for detecting decrements in visual information processing proved sensitive to blood alcohol levels as low as .02%. Alcohol in small doses increased reaction times to the onset of motion, particularly to slow speeds, but did not reduce the ability to allocate attention effectively. In view of these findings, certain motion perception tests may be valuable assays for detecting impaired performance with low blood alcohol levels.     

Alterations in shock-induced fighting and locomotor activity following intracerebroventricular injection of hydrocortisone in the rat

Three experiments were conducted in an attempt to clarify the facilitatory influence of hydrocortisone on shock-induced fighting in rats. Results of the first experiment indicated a biphasic, dose-dependent action of intraventricularly-administered hydrocortisone. Low (25 μg) and intermediate (50 μg) doses both facilitated fighting whilst the high (100 μg) dose exerted a potent suppressant effect. Two control tests were performed to determine whether alterations in pain reactivity or locomotor activity could have accounted for the observed changes in fighting behaviour. None of the treatments altered shock thresholds (Experiment 2) but whilst neither low nor intermediate doses affected activity measures, the high dose preferentially reduced vertical activity (Experiment 3).     

The spontaneously hypertensive rat as an animal model of attention-deficit hyperactivity disorder: effects of methylphenidate on exploratory behavior

Spontaneously hypertensive rats (SHR) show a pervasive hyperactivity in several paradigms. Thus, these rats may be used as an animal model of childhood hyperactivity also called Attention-Deficit Hyperactivity Disorder. This disorder is frequently treated with psychomotor stimulant drugs, but little is known about the effects of such drugs on behavior. The present study investigated the behavioral effects of 1-24 mg/kg methylphenidate (Ritalin) on the exploratory behavior of male SHR and Wistar-Kyoto control rats (WKY) in a two-compartment free-exploration open field. Except following very high doses. SHR spent most of the session time in the field while WKY stayed in the home cage. Low and medium doses were followed by increased activity in the field for SHR and increased activity in the cage for WKY. The response-stimulatory effects of low to medium doses of methylphenidate are less in SHR than in WKY. Starting at medium doses, activity decreased and stereotyped behavior increased progressively by increasing dose. Locomotor activity in the field decreased following lower doses than locomotor activity in the cage, and vertical activity (rearing) was reduced by lower doses than horizontal activity (crossing). The following conclusions were drawn. (i) There is no "paradoxical" inhibition of SHR hyperactivity following methylphenidate. On the contrary, SHR activity is in fact stimulated, albeit to a lesser degree than that of WKY. (ii) The stimulatory effects of low to medium doses are, in general, most pronounced for the kind of exploratory behavior most frequently used by the rat during baseline conditions. (iii) Rearing might be more susceptible to adverse effects of methylphenidate than ambulation.     

Alcohol and previous acquaintance: Mood and social interactions in small groups

The effects of alcohol (0.75 g/kg) on qualitative and quantitative aspects of verbal interaction and self-reported mood were studied in small groups of either strangers or acquaintances. Four groups consisting of two male and two female subjects were observed during discussion of a film topic. Significantly more verbal activity was observed as a function of alcohol ( p <0.01), consistent with self-reported euphoria, affiliative moods, and reduced social anxiety. Bales IPA data indicated that more negative emotions were expressed ( p <0.05) and more assertive communications were delivered as part of the generally increased verbal activity under alcohol conditions. Although alcohol and previous acquaintance tended to alter mood ratings in similar ways, alcohol was clearly the more powerful agent. Alcohol increased both total verbal activity and the output of more self-disclosing or provoking verbal responses. Although acquaintance alone had neither of these effects, it tended to promote the increase in verbal activity produced by alcohol.     

Repeated diazepam administration reversed working memory impairments and glucocorticoid alterations in the prefrontal cortex after short but not long alcohol-withdrawal periods

The study was designed to assess whether repeated administration of diazepam (Valium®, Roche)—a benzodiazepine exerting an agonist action on GABA_A receptors—may alleviate both the short (1 week, 1W) and long-term (6 weeks, 6W) deleterious effects of alcohol withdrawal occurring after chronic alcohol consumption (6 months; 12% v/v) in C57/BL6 male mice. More pointedly, we first evidenced that 1W and 6W alcohol-withdrawn mice exhibited working memory deficits in a sequential alternation task, associated with sustained exaggerated corticosterone rise and decreased pCREB levels in the prefrontal cortex (PFC). In a subsequent experiment, diazepam was administered i.p. for 9 consecutive days (1 injection/day) during the alcohol withdrawal period at decreasing doses ranging from 1.0 mg/kg to 0.25 mg/kg. Diazepam was not detected in the blood of withdrawn mice at the time of memory testing, occurring 24 hours after the last diazepam injection. Repeated diazepam administration significantly improved alternation rates and normalized levels of glucocorticoids and pCREB activity in the PFC in 1W but not in 6W withdrawn mice. Thus, repeated diazepam administration during the alcohol-withdrawal period only transitorily canceled out the working memory impairments and glucocorticoid alterations in the PFC of alcohol-withdrawn animals.     

Psychological performance assessment via interactive voice response systems

Two experiments examined the feasibility of psychological assessment using interactive voice response (IVR) technology and the potential sensitivity of such assessments to alcohol and fatigue effects. In Experiment 1, 10 subjects performed a 12-min battery of six IVR-administered tasks, Monday through Friday, over 2 weeks. Minimal learning effects were evident during training. Repeated administrations indicated high test-retest reliabilities. In Experiment 2 (double-blind, alcohol/placebo crossover design), 7 subjects were tested every 2 h over a 24-h period during two experimental sessions (peak blood alcohol concentrations =80 mg/dL). Several IVR-administered tasks were sensitive to alcohol impairment, but not as sensitive as laboratory-based measures specifically designed to assess alcohol impairment. Little evidence for fatigue-related impairment was obtained. The results support optimism for the potential to assess psychomotor and cognitive functioning distally via telephony; however, further refinement and validation of the methods are needed.     

Alcohol and vigilance performance: effect of small doses of alcohol on simple visual reaction time

The effects of small doses of alcohol were tested in a vigilance setting. Subjects were repeatedly tested during three 30-min. sessions. The stimulus event was a visual light located in front of subjects. The average intersignal interval was 3.75 sec., and the dependent measure was simple reaction time. Analysis indicates that alcohol produced a skewness in the RT-distribution with time on task; the longer reactions increased more than the shorter ones. Especially the extremely long reactions (blockings) increased markedly with time on task under alcohol. Results were discussed in relation to other studies reporting divergent results in similar test situations.     

Acute alcohol intoxication paired with appetitive reinforcement: effects upon ethanol intake in infant rats

A recent study suggested that infant rats process alcohol odor and/or taste during acute ethanol intoxication probably due to ethanol elimination via respiration and salivation. The present set of experiments was meant to analyze the possibility that this orosensory processing may act as a conditioned stimulus when an appetitive reinforcer is paired with the state of intoxication. In the first experiment it was observed that intragastric administration of a mildly intoxicating ethanol dose (1.5 g/kg), paired during postabsorptive time intervals with oral infusion of sucrose, was sufficient to promote a significant preference to ethanol. In Experiment 2 different doses of ethanol were either paired or explicitly unpaired with sucrose administration. The result reported in Experiment 1 was replicated and it was observed that a higher dose (3.0 g/kg) unpaired with the reinforcer resulted in alcohol aversions in terms of alcohol consumption patterns. However, when the reinforcer was paired with this dose, the aversion was inhibited. Finally, in the third experiment results indicated that preexposure to alcohol odor eliminates sucrose-conditioned alcohol preferences. These results indicate that, in physiologically immature rats, alcohol preference can be regulated by prior associative experiences involving the state of intoxication and consequences internal and/or inherent to this state.     

Predictors of physical activity,healthy eating and being smoke-free in teens: A theory of planned behaviour approach

This paper elicited context specific underlying beliefs for physical activity, fruit and vegetable consumption and smoke-free behaviour from the Theory of Planned Behaviour (TPB), and then determined whether the TPB explained significant variation in intentions and behaviour over a 1 month period in a sample of grade 7–9 (age 12–16 years) adolescents. Eighteen individual interviews and one focus group were used to elicit student beliefs. Analyses of this data produced behavioural, normative and control beliefs which were put into a TPB questionnaire completed by 183 students at time 1 and time 2. The Path analyses from the main study showed that the attitude/intention relationship was moderately large for fruit and vegetable consumption and small to moderate for being smoke free. Perceived behavioural control had a large effect on being smoke free and a moderately large effect for fruit and vegetable consumption and physical activity. Intention had a large direct effect on all three behaviours. Common (e.g. feel better, more energy) and behaviour-specific (e.g., prevent yellow fingers, control my weight) beliefs emerged across the three health behaviours. These novel findings, to the adolescent population, support the importance of specific attention being given to each of the behaviours in future multi-behavioural interventions.     

Effects of the novel acetylcholinesterase inhibitor N-octyl-1,2,3, 4-tetrahydro-9-aminoacridine on locomotor activity and avoidance learning in mice

The acetylcholinesterase reversible inhibitor N-octyl-1,2,3, 4-tetrahydro-9-aminoacridine (THA-C8) is a new synthesized derivative of tacrine (THA) characterized by an alkyl chain in the molecular structure which ameliorates the penetrability of the compound into the central nervous system. THA-C8 (0.1-5 mg/kg) significantly reduced spontaneous locomotor activity in CD1 mice at a dose of 3 mg/kg. Moreover, THA-C8 (0.2-2 mg/kg) significantly improved shuttle-box avoidance acquisition at doses (0.25, 0.3, 1 mg/kg) not affecting locomotion and that are much lower than the doses reported to be effective for THA in animal models. From the data reported it seems that the new compound could be interesting for therapeutic purposes.     

Effects of cocaine and alcohol, alone and in combination, on human learning and performance.

The acute effects of cocaine hydrochloride (4 to 96 mg/70 kg) and alcohol (0 to 1.0 g/kg), administered alone and in combination, were assessed in two experiments with human volunteers responding under a multiple schedule of repeated acquisition and performance of response chains. Subjects were intermittent users of cocaine and regular drinkers who were not cocaine or alcohol dependent. Alcohol was mixed with orange juice and ingested in six drinks within 30 min; cocaine was administered intranasally 45 min after completion of drinking. In each component of the multiple schedule, subjects completed response sequences using three keys of a numeric keypad. In the acquisition component, a new sequence was learned each session. In the performance component, the response sequence always remained the same. Results were consistent in both experiments, despite variations in the order in which the drugs were tested alone and in combination. Alcohol administered alone increased overall percentage of errors and decreased rates of responding in the acquisition component, whereas responding in the performance component generally was unaffected. Cocaine administered alone decreased rates of responding but did not affect accuracy of responding in the acquisition component, and enhanced accuracy of responding without affecting rates of responding in the performance component. The combined doses of cocaine and alcohol attenuated the effects observed with alcohol and cocaine alone. These results suggest that, under the conditions investigated in this study, (a) alcohol produces greater behavioral disruption than cocaine or cocaine-alcohol combinations, (b) cocaine and alcohol each attenuate effects of the other, and (c) such attenuation is most pronounced for cocaine attenuating the disruptive effects of alcohol.     

Use of factor analysis in the study of alcohol-induced strategy changes in skilled performance on a soccer test

The present study was designed to examine how skilled behaviour changes under the effects of two doses of alcohol (0.5 gm/kg and 1 gm/kg). A battery of perceptual-motor reference tests, together with the criterion test of a soccer slalom were given a sample of 48 male volunteers to show how performance strategies changed across the different experimental conditions. Analysis indicated little change between effects of placebo and the lower dose but some change in the composition of performance between placebo and the 1 gm/kg dose. This finding supports further use of factor analysis in the study of skilled behaviour.     

Effects of Posttraining Administration of Glucose on Retention of a Habituation Response in Mice: Participation of a Central Cholinergic Mechanism

Male Swiss mice were allowed to explore a novel environment, provided by an open-field activity chamber, for 10 min. The procedure was repeated twice with a 24-h interval. The difference in the exploratory activity between the first (training) and the second (testing) exposures to the chamber was taken as an index of retention of this habituation task. Posttraining intraperitoneal administration of glucose (10–300 mg/kg) enhanced retention in a dose-related manner, although only the dose of 30 mg/kg of glucose produced significant effects. Thus, the dose–response curve adopted an inverted U-shaped form. Glucose (30 mg/kg) given to untrained mice did not modify their exploratory performance when recorded 24 h later. The effects of glucose on retention were time-dependent, suggesting an action on memory storage. The memory-improving actions of glucose were prevented by the simultaneous administration of both the central acting muscarinic cholinergic antagonist atropine (0.5 mg/kg) and by the central acting nicotinic cholinergic antagonist mecamylamine (5 mg/kg). In contrast, neither methylatropine (0.5 mg/kg), a peripherally acting muscarinic receptor blocker, nor hexamethonium (5 mg/kg), a peripherally acting nicotinic receptor blocker, prevented the effects of glucose on retention. Low subeffective doses of glucose (10 mg/kg) and the central anticholinesterase physostigmine (35 μg/kg), but not neostigmine (35 μg/kg), given together, act synergistically and facilitated retention. We suggest that glucose modulates memory storage of one form of learning elicited by stimuli repeatedly presented without reinforcement, probably through an enhancement of brain acetylcholine synthesis and/or its release.     

Effects of graded doses of alcohol on speed-accuracy tradeoff in choice reaction time

The inconsistency of previous results concerning the effects of alcohol on reaction time (RT) may be related to possible tradeoffs between speed and accuracy. In the present experiment, complete speed-accuracy tradeoff functions were generated for each of five doses of alcohol (0-1.33 ml/kg) in a choice RT task. Such functions permit RT differences resulting from changes in performance efficiency to be distinguished from those due to changes in subjects’ speed accuracy criteria. Increasing doses of alcohol produced a progressive decrease in the slope parameter of linear equations fit to the speed-accuracy data, but did not significantly alter the intercept of the functions with the RT axis. Thus, alcohol reduced performance efficiency by decreasing the rate of growth of accuracy per unit time. A change in speed-accuracy criterion was combined with the decrease in efficiency at the highest alcohol dose.     

Compensatory and non‐compensatory multidimensional randomized item response models

Randomized response (RR) models are often used for analysing univariate randomized response data and measuring population prevalence of sensitive behaviours. There is much empirical support for the belief that RR methods improve the cooperation of the respondents. Recently, RR models have been extended to measure individual unidimensional behaviour. An extension of this modelling framework is proposed to measure compensatory or non‐compensatory multiple sensitive factors underlying the randomized item response process. A confirmatory multidimensional randomized item response theory model (MRIRT) is proposed for the analysis of multivariate RR data by modelling the response process and specifying structural relationships between sensitive behaviours and background information. A Markov chain Monte Carlo algorithm is developed to estimate simultaneously the parameters of the MRIRT model. The model extension enables the computation of individual true item response probabilities, estimates of individuals’ sensitive behaviour on different domains, and their relationships with background variables. An MRIRT analysis is presented of data from a college alcohol problem scale, measuring alcohol‐related socio‐emotional and community problems, and alcohol expectancy questionnaire, measuring alcohol‐related sexual enhancement expectancies. Students were interviewed via direct or RR questioning. Scores of alcohol‐related problems and expectancies are significantly higher for the group of students questioned using the RR technique. Alcohol‐related problems and sexual enhancement expectancies are positively moderately correlated and vary differently across gender and universities.     

Varenicline ameliorates ethanol-induced deficits in learning in C57BL/6 mice

Ethanol is a frequently abused drug that impairs cognitive processes such as learning. Varenicline, an α4β2 nicotinic receptor partial agonist and α7 nicotinic receptor full agonist prescribed for smoking cessation, has been shown to decrease ethanol consumption. The current study investigated whether varenicline could ameliorate ethanol-induced deficits in learning and whether varenicline alters blood alcohol concentration in C57BL/6 mice. Conditioning consisted of two auditory conditioned stimulus (CS; 30 s, 85 dB white noise)—foot shock unconditioned stimulus (US; 2 s, 0.57 mA) pairings. For all studies, saline or ethanol (1.0, 1.5, 2.0 g/kg i.p.) was administered 15 min before training, and saline or varenicline (0.05, 0.1, 0.2 mg/kg i.p.) was administered 60 min before either training or testing. For blood alcohol analysis, saline or varenicline (0.1 mg/kg) was administered 60 min before collection, and saline or ethanol (1.0, 1.5, 2.0 g/kg) was administered 15 min before collection. Varenicline dose-dependently ameliorated ethanol-induced conditioning deficits for all three doses of ethanol when administered before training but not when administered 24 h later, before testing. In addition, varenicline did not alter blood alcohol concentration. The smoking cessation aid varenicline may have therapeutic uses for treating ethanol-associated disruptions in cognitive processes.