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.     

Ratio size and cocaine concentration effects on oral cocaine-reinforced behavior.

Monkeys were given a choice between cocaine solutions and water under concurrent fixed-ratio reinforcement schedules. The operant response was spout contact. Six rhesus monkeys served as subjects. The cocaine concentration was varied from 0.0125 to 0.8 mg/ml, and the fixed-ratio value was varied from 8 to 128. Cocaine maintained higher response rates than did water over a wide range of conditions. Response rate and number of cocaine deliveries per session were inverted U-shaped functions of concentration. These functions were shifted to the right as the fixed ratio was increased. The number of cocaine deliveries was more persistent as fixed-ratio value was increased when the unit dose was larger rather than smaller. Cocaine consumption was analyzed as a function of unit price (fixed-ratio value divided by cocaine concentration), and unit price accounted for between 77% and 92% of the variance in cocaine consumption for individual monkeys. The current data support the claim that a drug's reinforcing effects increase directly with dose and underscore the need to gather parametric data when examining the effects of experimental manipulations on a drug-reinforced baseline.     

Food and cocaine self-administration by baboons: effects of alternatives.

The effects of the availability of an alternative reinforcer on responding maintained by food pellets or drug solutions were examined in 8 adult male baboons (Papio hamadrayas anubis). During daily 23-hr experimental sessions, baboons had access to both food pellets and fluid under a two-choice procedure, in which the response requirement, under a fixed-ratio schedule, differed for the two commodities. There were no restrictions on access to water, which was continuously available from a spout at the rear of each cage. In Experiment 1, the fixed-ratio requirement, or cost, for fluid delivery remained constant while the fixed-ratio requirement for pellets was changed every 2 or 3 days when (a) no fluid, (b) a dilute dextrose vehicle, (c) 0.008 mg/kg per delivery cocaine, (d) 0.016 mg/kg per delivery cocaine, or (e) 0.032 mg/kg per delivery cocaine was available concurrently. In Experiment 1, progressively increasing the response requirement for pellets decreased pellet intake, but for 4 baboons pellet intake at maximum pellet cost was lower when cocaine, compared to the vehicle, was available. Increasing the response requirement for pellets had variable effects on vehicle intake. However, increasing the response requirement for pellets increased intake of at least one dose of cocaine to a greater extent than vehicle in all 8 baboons. Thus, cocaine could be considered a more effective economic substitute than vehicle for pellets. Experiment 2 systematically varied the order in which the response requirements for a pellet delivery were presented and added a control condition in which cocaine doses, yoked to the amount self-administered, were given three times during the session by the experimenter. Again, pellet intake at maximal pellet cost was lower when cocaine, compared to the vehicle, was available. In contrast, experimenter-given cocaine doses did not alter responding maintained by pellets. Thus, the effects of self-administered cocaine on responding maintained by food pellets differed from the effects of experimenter-given cocaine on responding maintained by food pellets.     

Synergistic effects of ethanol and cocaine on brain stimulation reward.

The effects of two widely abused drugs, ethanol and cocaine, were examined alone and in combination on intracranial reward processes. In agreement with previous research, higher doses of both cocaine and ethanol alone produced facilitation of behavior maintained by brain stimulation reward. Low intraperitoneal doses of ethanol and cocaine, which alone did not affect performance, were found to reduce stimulation reward threshold and modestly increase response rate. The enhancement of brain stimulation reward by the combination of ethanol and cocaine suggests that both drugs may produce their rewarding effects through common neuronal substrates and that they may potentiate the abuse of each other.     

Emotion dysregulation and threat-related attention bias variability

Although theory suggests that a bias for attending to threat information (ABT) may be a biobehavioral process underlying the transdiagnostic vulnerability factor of emotion dysregulation, there is a paucity of empirical evidence showing direct associations between emotion dysregulation and ABT. The purpose of the present study was to examine the relation between ABT and emotion dysregulation. Participants (N?=?200) completed a battery of self-report questionnaires and a modified dot-probe task with both neutral and threat stimuli and four stimulus presentation durations. Task response times were used to examine traditionally calculated ABT scores, as well as attention bias variability (ABV). As predicted, those with greater emotion dysregulation exhibited greater ABV. Importantly, emotion dysregulation was not associated with response time variability on trials for which only neutral stimuli were presented, thus increasing confidence that emotion dysregulation-related ABV is specific to the presence of threat stimuli and not merely a function of general variability in response times. Results suggest that those with greater emotion dysregulation exhibit attentional dyscontrol in the presence of perceived threat that is characterized by dynamic shifts between vigilance and avoidance.     

Differential antagonism of cocaine self-administration and cocaine-induced disruptions of learning by haloperidol in rhesus monkeys

Six rhesus monkeys responding under a three-component multiple schedule were administered haloperidol to determine its effects on cocaine self-administration and on cocaine's disruptive effects on the repeated acquisition and performance of response chains. In the absence of haloperidol, 0.0032-0.032 mg/kg/infusion of cocaine increased response rate and the number of infusions in the self-administration component when compared to saline administration, whereas 0.1-0.32 mg/kg/infusion decreased response rate and the number of infusions. When compared to saline administration, the two lowest infusion doses of cocaine had little or no effect on responding in the acquisition and performance components; however, higher infusion doses of cocaine dose-dependently decreased response rate in these components. In addition, the higher doses of cocaine also increased the percentage of errors in the acquisition and performance components. Pretreatment with haloperidol (0.0032 or 0.01 mg/kg, i.m.) antagonized the effects of low doses of cocaine on the number of infusions in the self-administration component, whereas only the 0.01-mg/kg dose antagonized the effects of high doses of cocaine on the number of infusions. Neither dose of haloperidol antagonized the rate-decreasing effects of cocaine on responding in the acquisition and performance components significantly; the highest dose of haloperidol alone decreased rates of responding in each component. Antagonism of cocaine's error-increasing effects by haloperidol was only evident at one dose of cocaine (0.032 mg/kg/infusion), and was more complete in the performance components than in the acquisition components. Together, these data show the limited suitability of haloperidol for selectively antagonizing cocaine self-administration in the context of a multiple schedule involving transition behavior, and show the lack of uniform antagonism across operant behaviors.     

Tolerance to the effects of cocaine on performance under behavior-correlated reinforcement magnitude

Four pigeons responded under a fixed-interval 8-min schedule of food delivery in which the amount of food delivered at the end of each interval depended on performance during the interval (i.e., a correlated schedule). Specifically, duration of access to grain was contingent upon the number of responses made during the first 4 min of the interval. This differential outcome did not affect response rates or patterning relative to performance under a simple fixed-interval 8-min schedule. Behavior under the correlated schedule was then investigated under doses of cocaine ranging from 0.3 to 10.0 mg/kg. A bitonic dose-response function was obtained for response rates and the time with head in the food hopper, whereas dose-dependent decreases were observed in the mathematical index of curvature (Fry, Kelleher, & Cook, 1960). The dose that produced the greatest increase in the head-in-hopper time was then administered prior to each session. Following repeated administration of cocaine, disruptions in response patterning were attenuated for all 4 pigeons; tolerance was also observed to the rate-increasing effects and increased head-in-hopper time for 2 pigeons after chronic cocaine administration. Tolerance therefore developed despite the fact that the initial effect of cocaine was to increase the amount of food obtained.     

Cocaine and food as reinforcers: effects of reinforcer magnitude and response requirement under second-order fixed-ratio and progressive-ratio schedules.

Reinforcer magnitude and fixed-ratio requirement were varied under two second-order schedules. Under one, the first sequence of a fixed number of responses completed after the lapse of a 10-min fixed interval produced reinforcement. Under the second, a second-order progressive-ratio schedule, the fixed number of responses increased after each reinforcement. Either cocaine (0 to 300 micrograms/kg/inj) or food (0 to 5,700 mg/delivery) reinforcers were delivered. Under some conditions, a 2-s illumination of stimulus lights occurred on completion of each ratio sequence. Under the second-order schedule, as cocaine dose or amount of food increased, rates of responding increased; at the highest values, rates of responding decreased. Increases in the ratio requirement from 10 to 170 responses minimally decreased overall response rates. Under the second-order progressive-ratio schedule, increases in dose of cocaine or amount of food increased rates of responding; at the highest amounts of food, rates of responding decreased but response rates at the highest dose of cocaine remained relatively high. The highest ratio requirement that was completed (breaking point) depended on the dose of cocaine but was less dependent on the amount of food. Removing brief-stimulus presentations had a greater effect on completion of ratio requirements with cocaine compared to food.     

原因调节与反应调节的情绪变化过程

采用生理心理实验法研究忽视、抑制、重视、宣泄等方式调节负情绪的情绪变化过程,发现忽视有效减弱了主观感受和表情行为,并引起R-R问期更大的增加;抑制不能减弱主观感受,并引起手指脉搏血容振幅更大的增幅;重视增强了主观感受;宣泄增强了主观感受,并相对地减弱了生理激活水平。研究表明原因调节可以更有效地调整负情绪主观感受,反应调节使负情绪成分变化出现“水压模型”式循环动力特点;情绪调节过程实现着情绪在心理适应中的促进(或阻碍)作用。     

Fixed-interval schedule of cocaine reinforcement: effect of dose and infusion duration

Rhesus monkeys were trained on a fixed-interval 9-min limited-hold 3-min schedule of intravenous cocaine reinforcement. A 15-min timeout followed each reinforcement or limited-hold expiration. An identical schedule of food reinforcement was interspersed in the session to assess rate-modifying effects of the drug infusions not specific to drug reinforcement. In one experiment, response rate for cocaine reinforcement was shown to be a positive function of reinforcement magnitude for a dose range from 0 to 800 ug/kg/inj. At these doses, there was little effect on food reinforced responding except at the highest dose, where responding decreased. Results of the second experiment indicated that increasing the duration of the cocaine infusion produced a change in response rate similar to decreasing unit dose. The response rate change for a given increase in infustion duration was less at a unit dose of 400 ug/kg than at 200 ug/kg.     

Effects of cocaine on briefly signaled versus completely signaled delays to reinforcement.

Key pecking by 4 pigeons was maintained by a multiple schedule consisting of two variable-interval 60-s schedules wherein each food presentation followed a nonresetting 27-s delay that was either briefly signaled at its outset or completely signaled. Brief-signal duration was adjusted so that response rates maintained by the briefly and completely signaled delays of reinforcement were similar. In general, acute administration of small to intermediate doses (0.3 to 3.0 mg/kg) of cocaine produced either small increases in response rates in both components or no change, and larger doses (5.6 to 13.0 mg/kg) decreased response rates. Chronic (i.e., daily) cocaine administration (10.0 mg/kg) resulted in tolerance to the rate-decreasing effects in both components. Cocaine's effects were generally similar whether delays were completely or briefly signaled. Discontinuation of cocaine administration and subsequent removal of the delay signals also had similar effects in both components of the multiple schedule. Taken together, these results are consistent with the view that the two types of delay signals were equally effective in maintaining responding during the variable-interval schedules.     

Mindful attention predicts greater recovery from negative emotions,but not reduced reactivity

This study investigated the role of dispositional mindful attention in immediate reactivity to, and subsequent recovery from, laboratory-induced negative emotion. One hundred and fourteen undergraduates viewed blocks of negative pictures followed by neutral pictures. Participants’ emotional responses to negative pictures and subsequent neutral pictures were assessed via self-reported ratings. Participants’ emotional response to negative pictures was used to index level of emotional reactivity to unpleasant stimuli; emotional response to neutral pictures presented immediately after the negative pictures was used to index level of emotional recovery from pre-induced negative emotion (residual negativity). Results indicated that mindful attention was not associated with the emotional response to negative pictures, but it was associated with reduced negative emotion in response to the neutral pictures presented immediately after the negative pictures, suggesting better recovery as opposed to reduced reactivity. This effect was especially pronounced in later experimental blocks when the accumulation of negative stimuli produced greater negative emotion from which participants had to recover. The current study extends previous findings on the relationship between dispositional mindfulness and reduced negative emotion by demonstrating that mindful attention may facilitate better recovery from negative emotion, possibly through more effective disengagement from previous stimuli.     

Time of supplemental feeding alters the effects of cocaine on lever pressing of rats

The present experiment assessed the effects of cocaine on the lever pressing of 4 rats maintained during 15-min sessions by a fixed-ratio 50 schedule of food reinforcement. Across phases, supplemental food was provided either immediately or 2 hr after sessions. Two rats began the experiment in the delayed-feeding condition, and 2 began the experiment in the immediate-feeding condition. Rates of lever pressing of 2 rats sometimes decreased to low levels near the ends of sessions when supplemental feeding was provided immediately, but were consistently high throughout sessions when supplemental feeding was delayed. Cocaine (1.0 to 17.0 or 30.0 mg/kg) was administered intraperitoneally 15 min prior to test sessions. In most cases, cocaine suppressed response rates at lower doses under immediate-feeding conditions. Decreases in overall response rates were correlated with dosedependent increases in the time rats spent not responding. It is suggested that delaying the time of postsession feeding increased response strength, as indicated by greater resistance to the rate-suppressive effects of cocaine.     

Facial skin temperature decreases in infants with joyful expression

Studies of infant emotion rely on the assessment of expressive behavior and physiological response because infants cannot tell their feelings. Little is known about the physiological response of infants when they are in a joyful emotion. In this study, we examined changes in facial skin temperature as a physiological response, when infants are laughing, an expressive behavior of joyful emotion. Using thermography, skin temperatures of the nose, forehead and cheek were evaluated at 2-3 months, 4-6 months and 8-10 months. A decrease in facial skin temperature occurred when they laughed. The decrease was most dramatic in the nose dropping as much as 2.0 degrees C in 2 min. The response was evident in infants older than 4 months. These results suggest that a joyful emotion could be associated with a drop in facial skin temperature, which had been considered only as a sign of an unpleasant emotion. This response is developmentally controlled.     

Emotion Regulation of Events Central to Identity and Their Relationship With Concurrent and Prospective Depressive Symptoms

Dispositional emotion regulation is related to the severity and maintenance of depressive symptoms. However, whether emotion regulation specific to an event highly central for an individual’s identity is predictive of depressive symptoms has not been examined. Nonclinical participants (N = 220) reported the extent to which they employed a selection of emotion regulation strategies when recalling low- and high-centrality events. Dispositional emotion regulation and depressive symptoms were also assessed. A 7-week follow-up was conducted. High-centrality events were associated with more emotion regulation efforts. Greater brooding and expressive suppression in relation to high-centrality memories predicted concurrent depressive symptoms after controlling for event valence and dispostional emotion regulation. Effects were absent for low-centrality memories. Emotion regulation in response to high-centrality memories did not predict depressive symptoms at follow-up beyond baseline depressive symptoms. Overall, the findings showed that maladaptive emotion regulation in response to memories of high-centrality events is important for explaining depressive symptomatology.     

Gross情绪调节模型及对心理健康的影响

Gross的情绪调节理论指出,在情绪发生过程中的情绪调节主要有情景选择、情景修正、注意分配、认知改变和反应调整五个方面。其中情景选择、情景修正、注意分配、认知改变是在情绪反应趋势形成之前发生,属于先行关注情绪调节;反应调整是在情景反应形成之后发生,属于反应关注情绪调节。同时Gross还提出了两种最常用的情绪调节策略——认知重评和表达抑制,并分析了它们对心理健康的影响。     

Effects of emotion on oxytocin,prolactin, and ACTH in women

Research on both non-human mammals and humans has raised interest in the role that oxytocin may play in human attachment and attachment-related emotions. This study examined changes in plasma oxytocin, prolactin, and ACTH concentrations in response to laboratory-induced positive and negative emotions related to close, interpersonal relationships. Participants were 32 female volunteers recruited from university communities. During positive emotion induction, oxytocin decreased over time (F(1,3) = 4.41, p < 0.007), prolactin increased (F(1,3) = 4.80, p < 0.004) and ACTH remained constant. During negative emotion induction, prolactin levels increased (F(1,3) = 2.81, p < 0.05), ACTH decreased only after the induction terminated (F(1,3) = 4.02, p < 0.01) and oxytocin remained constant. While oxytocin decreased during positive emotion, this finding contrasted previous research that showed decreases in response to negative emotion. In conclusion, plasma oxytocin levels were not reliably altered by positive or negative emotion induction. While prolactin and ACTH were expected to decrease over time due to diurnal variation, they instead either increased or remained level during emotion induction, or decreased only after the induction. Overall, the degree of change in circulating hormones in response to happy and sad emotions was very small and possibly not functionally significant.     

Cognitive modeling analysis of decision-making processes in cocaine abusers

This article examines the theoretical basis of decision-making deficits exhibited by cocaine abusers in a laboratory decision-making task first described by Bechara, Damasio, Damasio, and Anderson (1994). A total of 12 male cocaine abusers and 14 comparison subjects performed the task, and the cocaine group performed significantly worse than the comparison group. A cognitive modeling analysis (Busemeyer & Stout, 2002) was used to estimate three parameters that measure importance of the cognitive, motivational, and response processes for determining the observed performance deficit. The results of this analysis indicated, for the first time, that motivational and choice consistency factors, but not learning/ memory were mainly responsible for the decision-making deficit of the cocaine abusers in this task.     

INFLUENCES ON COCAINE TOLERANCE ASSESSED UNDER A MULTIPLE CONJUNCTIVE SCHEDULE OF REINFORCEMENT

Under multiple schedules of reinforcement, previous research has generally observed tolerance to the rate‐decreasing effects of cocaine that has been dependent on schedule‐parameter size in the context of fixed‐ratio (FR) schedules, but not under the context of fixed‐interval (FI) schedules of reinforcement. The current experiment examined the effects of cocaine on key‐pecking responses of White Carneau pigeons maintained under a three‐component multiple conjunctive FI (10 s, 30 s, & 120 s) FR (5 responses) schedule of food presentation. Dose‐effect curves representing the effects of presession cocaine on responding were assessed in the context of (1) acute administration of cocaine (2) chronic administration of cocaine and (3) daily administration of saline. Chronic administration of cocaine generally resulted in tolerance to the response‐rate decreasing effects of cocaine, and that tolerance was generally independent of relative FI value, as measured by changes in ED50 values. Daily administration of saline decreased ED50 values to those observed when cocaine was administered acutely. The results show that adding a FR requirement to FI schedules is not sufficient to produce schedule‐parameter‐specific tolerance. Tolerance to cocaine was generally independent of FI‐parameter under the present conjunctive schedules, indicating that a ratio requirement, per se, is not sufficient for tolerance to be dependent on FI parameter.     

Experiential Avoidance as an Emotion Regulatory Function: An Empirical Analysis of Experiential Avoidance in Relation to Behavioral Avoidance,Cognitive Reappraisal,and Response Suppression

The purpose of the present study was to empirically test the suggestion that experiential avoidance in an emotion regulation context is best understood as an emotion regulatory function of topographically distinct strategies. To do this we examined whether a measure of experiential avoidance could statistically account for the effects of emotion regulation strategies intervening at different points of the emotion-generative process as conceptualized by Gross' (1998) process model of emotion regulation. The strategies under examination were behavioral avoidance, cognitive reappraisal, and response suppression. The specific hypotheses to be tested were (1) that behavioral avoidance, cognitive reappraisal, and response suppression would statistically mediate the differences in measures of psychological well-being between a clinical and nonclinical sample, but that (2) these indirect effects would be reduced to nonsignificant levels when controlling for differences in experiential avoidance. The results provide clear support for the first hypothesis with regard to all the studied strategies. In contrast to the second hypothesis, the results showed the predicted outcome pattern only for the response-focused strategy “response suppression” and not for cognitive reappraisal or behavioral avoidance. The results are interpreted and discussed in relation to theories on experiential avoidance and emotion regulation.