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The Adaptive Visual Analog Scales is a freely available computer software package designed to be a flexible tool for the creation, administration, and automated scoring of both continuous and discrete visual analog scale formats. The continuous format is a series of individual items that are rated along a solid line and scored as a percentage of distance from one of the two anchors of the rating line. The discrete format is a series of individual items that use a specific number of ordinal choices for rating each item. This software offers separate options for the creation and use of standardized instructions, practice sessions, and rating administration, all of which can be customized by the investigator. A unique participant/patient ID is used to store scores for each item, and individual data from each administration are automatically appended to that scale's data storage file. This software provides flexible, time-saving access for data management and/or importing data into statistical packages. This tool can be adapted so as to gather ratings for a wide range of clinical and research uses and is freely available at www.nrlc-group.net. [ABSTRACT FROM AUTHOR]

Brain imaging studies find evidence of prefrontal cortical dysfunction in cocaine-dependent subjects. Similarly, cocaine-dependent subjects have problems with behaviors related to executive function and impulsivity. Since prefrontal cortical axonal tracts cross between hemispheres in the corpus callosum, it is possible that white matter integrity in the corpus callosum could also be diminished in cocainedependent subjects. The purpose of this study was to compare corpus callosum white matter integrity as measured by the fractional anisotropy (FA) on diffusion tensor imaging (DTI) between 18 cocaine-dependent subjects and 18 healthy controls. The Barratt Impulsiveness Scale (BIS-11) and a continuous performance test: the Immediate and Delayed Memory Task (IMT/DMT) were also collected. Results of the DTI showed significantly reduced FA in the genu and rostral body of the anterior corpus callosum in cocainedependent subjects compared to controls. Cocaine-dependent subjects also had significantly higher BIS-11 scores, greater impulsive (commission) errors, and reduced ability to discriminate target from catch stimuli (discriminability) on the IMT/DMT. Within cocaine dependent subjects there was a significant negative correlation between FA in the anterior corpus callosum and behavioral laboratory measured impulsivity, and there was a positive correlation between FA and discriminability. The finding that reduced integrity of anterior corpus callosum white matter in cocaine users is related to impaired impulse control and reduced ability to discriminate between target and catch stimuli is consistent with prior theories regarding frontal cortical involvement in impaired inhibitory control in cocainedependent subjects. [ABSTRACT FROM AUTHOR]

Previous research and theory have conceptualized impulsivity as a multifaceted construct that requires multiple modes of measurement for accurate assessment. This article describes a software package that includes four paradigms for measuring multiple and unique aspects of impulsivity. Specifically, four tasks are described: (1) the two choice impulsivity paradigm, (2) the single key impulsivity paradigm, (3) the GoStop impulsivity paradigm, and (4) the time paradigm. These tasks measure processes related to the capacity to tolerate delay for reward, to inhibit an already initiated response, and to estimate the passage of time. These processes have been found to be important to the understanding of impulsive behaviors. The programs are flexible and allow the experimenter to manipulate a number of parameters related to delay--reward contingencies, timing, performance feedback/payment, and data output variables. Manipulation of these parameters makes the paradigms scalable to a wide range of ability levels and appropriate for samples ranging from children to adults. The four paradigms in this software package are available at no cost and can be obtained by contacting the corresponding author. [ABSTRACT FROM AUTHOR]

Rationale: Methylene-dioxymethamphetamine (MDMA) is known to cause degeneration of serotonin nerve terminals after acute doses in animals. Similarly, behavioral studies in human MDMA users regularly find abnormalities in memory, mood, and impulse control. However, studies of brain function using brain imaging in MDMA users have been less consistent. Objectives: The purpose of this study was to determine, using functional magnetic resonance imaging (fMRI), whether individuals with a self-reported history of MDMA use would differ from non-MDMA using controls on activation while performing a working memory task. Methods: Fifteen MDMA using subjects and 19 non-MDMA using controls underwent fMRI scanning while performing the immediate and delayed memory task (IMT/DMT). The study was based on a block design in which the delayed memory task (DMT) alternated with the immediate memory task (IMT), which served as a control condition. FMRI scans were acquired on a 1.5 T scanner, using a gradient echo echoplanar pulse sequence. Results: Random effects SPM99 analysis showed significantly greater activation (whole volume corrected cluster P<0.05) during the DMT relative to the IMT in the MDMA subjects compared with the control subjects in the medial superior frontal gyrus, in the thalamus extending into putamen, and in the hippo-campus. Conclusions: Although these effects could be due to other drugs used by MDMA users, these results are consistent with behavioral problems that are associated with MDMA use, and with animal studies on the effects of MDMA on brain function. [ABSTRACT FROM AUTHOR]

This study explores concurrent and criterion validity of a Continuous Performance Test, the Immediate and Delayed Memory Tasks (IMT/DMT). Concurrent validity was examined through comparison with collateral measures of impulsivity, while criterion validity was assessed by comparison of groups with differing levels of impulsive behavior, those with and without disruptive behavior disorders (DBD). DBDs in the DSM-IV include conduct disorder and oppositional defiant disorder, which are both largely characterized by impulsive behaviors, We compared group performance on the IMTIDMT and several collateral measures of impulsivity between adolescent controls (n = 22) and psychiatric inpatients with a DBD diagnosis (n= 22). Data collected indicated thaI (1) DBD patients emitted more commission errors; (2) commission errors, but not correct detections. were significantly correlated with collateral measures of impulsivity, and (3) in post-hoc comparisons, those D8D patients with histories of physical fighting emitted the greatest number of commission errors, followed by DBD nonfighters. and then controls. Similar group performance differences were observed for collateral impulsivity measures. This study supports the use of commission error rates on the Immediate and Delayed Memory Tasks as a behavioral measure of impulsivity. With further development, objective measures like these may prove useful in clinical assessment procedures and in monitoring treatment outcome. [ABSTRACT FROM AUTHOR]

Investigates the use of Immediate and Delayed Memory Task software package to study attention, memory and impulsivity. Design of the package; Manipulation of parameter numbers to suit a particular research questions; Components of the computer program.

Compares laboratory models of impulsive behavior in women ages 18 to 40. Groups of women recruited for the study; Types of impulsive paradigms compared.

Plasma l-tryptophan (Trp) reductions have been related to aggression increases in men. Impairment of serotonin synthesis and neurotransmission is one explanation. Using repeated-measures, this Trp manipulation study measured laboratory-induced aggression in 12 women after Trp augmentation (T+), depletion (T−), and food-restricted (fasting control) conditions. Participants were provoked with periodic subtraction of money from their task earnings by a (fictitious) partner. Aggression was defined as the number of point subtractions participants made from their fictitious partner. Participants completed five testing sessions under each condition. T+ decreased aggressive responses and T− increased aggressive responses. Post-hoc analyses showed changes in aggressive behavior were specific to women with higher fasting control plasma Trp, which is consistent with research demonstrating that men with higher levels of baseline Trp are more aggressive. These findings indicate that both T+ and T− can influence aggressive behavior and that certain subgroups of women may be more susceptible to serotonin manipulation. [Copyright &y& Elsevier]

Continuous Performance Test (CPT) responding was compared between 15 adults with a history (childhood/adolescent) of Conduct Disorder (CD) and 15 normal controls. Of particular interest was whether response latencies and commission errors, which have been suggested to be measures of impulsivity, would differ between the groups. The CPT procedure used included two conditions: Immediate Memory Task and Delayed Memory Task (IMT/DMT; Dougherty et al., 1998). Both the IMT (0.5-s delay) and DMT (3.5-s delay with distracter stimuli at 0.5-s 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 (four of five digits matched), and novel (no match). Participants completed six 22-min testing sessions scheduled across a single day. The most significant findings were that the CD group (compared to the control group) had (a) elevated commission errors (responses to catch stimuli); (b) lower stimulus discriminability (between target and catch stimuli); and (c) shorter response latencies. These results are consistent with the few previous studies indicating that these parameters are related to impulsive behaviors. [ABSTRACT FROM AUTHOR]

Abstract Some studies have shown that sharp reduction of L-tryptophan (Trp) concentration in plasma results in increases in laboratory-measured aggression. Conversely, raising plasma Trp has blunted aggression. These effects are presumably due to impaired or enhanced serotonin synthesis and neurotransmission in the brain. In this study, the laboratory-measured aggressive behavior of eight men under both Trp depletion (T-) and Trp loading (T+) conditions was compared to their aggressive behavior under food restricted control conditions (overnight fast without an amino acid beverage). Subjects were provoked by periodic subtraction of money which was attributed to a fictitious other participant, and aggression was defined as the number of retaliatory responses the subject made ostensibly to reduce the earnings of the (fictitious) other participant. Following ingestion of the T- beverage, aggressive responding was significantly elevated relative to the food-restricted control condition, and this increased aggressive behavior became more pronounced across behavioral testing sessions on a time-course which paralleled previously documented decreases in plasma Trp concentrations. In contrast, no changes were observed in aggressive responding under T+ conditions relative to food-restricted conditions. These within-subject behavioral changes under depleted plasma Trp conditions support earlier indications of a role of serotonin in regulating aggression. [ABSTRACT FROM AUTHOR]

Four adults participated in an experiment designed to study how the duration of an interval free from provocation, following aggressive responding, affected the maintenance of such responding. In testing sessions, two response options were made available on separate buttons labeled 'A' and 'B.' Pressing Button A 100 times incremented a point accumulation counter, and these points were later exchanged for money (one point = 10 cents). Pressing Button B 10 times subtracted a point from a fictitious other subject. These B button responses were defined as aggressive because they ostensibly presented an aversive stimulus (i.e., point subtraction) to another person. Subjects were provoked by subtracting points from their point counter at random intervals (ranging from 6 s to 120 s), and instructions attributed these point subtractions to the responding of the other subject. Button B responding could initiate periods free from provocation. Subjects were exposed to two provocation-free interval durations (5 s and 62.5 s) in order to determine what role the provocation-free interval had in maintaining aggressive responding. We found that brief (5 s) provocation-free intervals (a) can initially engender high rates of aggressive responding; but (b) cannot maintain aggressive responding during extended periods of exposure. These findings demonstrate the importance of the consequences of aggressive responding in determining the probability of an aggressive response following provocation. [ABSTRACT FROM AUTHOR]

Presents information on a study which suggested that there may be gender differences in the effects of repeated alcohol administration on motor performance. Brief review of related literatures; Materials and methods; Overview on the placebo effects; Breath alcohol concentration curves values between men and women; Conclusions.

Six adults participated in an experiment designed to study the effects of provocation frequency, that is, point subtractions, on free-operant aggressive responding. Subjects were given two response options on separate buttons labeled 'A' and 'B.' Pressing Button A was maintained by a fixed-ratio 100 schedule of point presentation. A counter was incremented when a point was earned, and these points were later exchanged for money (one point = 10 cents). Subjects were instructed that the completion of each fixed-ratio 10 on Button B subtracted a point from a second subject (fictitious) also responding to accumulate money. Button B responses were operationally defined as aggressive because they ostensibly presented an aversive stimulus (i.e., point subtraction) to another person. To engender Button B responding, the subjects were provoked by having points subtracted from their from their point counter at random intervals (ranging from 6 s to 120 s). Instructions attributed these point subtractions to Button B responding made by another subject (fictitious). Button B responding could initiate periods free from provocation. The duration of these provocation-free intervals was varied in two experiments. Subjects were exposed to five different levels of provocation frequency in order to determine if aggressive responding would be proportionate to the frequency of provocation. This experiment demonstrates that rates of responding on the B button generally increase as the frequency of point subtractions increases. This finding is consistent with the nonhuman research which has shown that the probability of aggressive responding is proportionate to the frequency of aversive stimulus presentation. [ABSTRACT FROM AUTHOR]

Aggressive responding was compared between 21 men and 21 women using the © Point Subtraction Aggression Paradigm which provides both the opportunity to aggress and to escape provocation. Subjects were between the ages of 18 and 23 years old and reported no drug use history. The hypothesis was that females would emit more escape, but fewer aggressive, responses than males. Results showed that men and women did not significantly differ in the number of aggressive responses emitted, F(1, 36) =.19, p <.67, or the number of escape responses emitted, F(1, 36) =.02, p <.89, although a significant gender by race interaction was found, F(2, 36) = 6.17, p <.005. These results are consistent with the notion that gender differences in aggressive behavior are not large under laboratory conditions, and they suggest that the availability of an escape option in this paradigm does not have the expected reductive effect on female aggressive responding. [ABSTRACT FROM AUTHOR]

Presents topic areas of human operant behavior (HOB) literature published since 1983. Percentage of representation of HOBs in reports; Frequency of HOB publications; Content area of research; Subject populations; Identification of authoritative HOB papers; Topical bibliography.