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A computer-aided training program was developed in SuperCard and piloted with professional painters. Taking a modern programmed-instruction/behavioral-education approach, cTRAIN is structured as a series of information sets. Each information set consists of a series of information screens (three to five recommended) followed by quiz screens (one to three recommended) structured as four-response multiple choice questions. Correct quiz responses produce positive feedback and continuation in the series, whereas incorrect responses result in "error" feedback and return the student to the beginning of the information set to repeat the same information screens and the same quiz question. This report demonstrates a specific implementation, respiratory protection requirements, using the flexible cTRAIN system for developing training modules. Fifteen adults completed the respiratory protection program, demonstrating substantial and significant (p < .0001 by paired t test) gains from baseline pretest (19.4 out of 30 questions) to the immediate posttest (28.1). Performance remained elevated (26.4) on a retest taken 1 week later.

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We demonstrate the In Situ testbed, a system that aids in evaluating computational models of learning, including artificial neural networks. The testbed models contingencies of reinforcement rising an extension of Mechner's (1959) notational system for the description of behavioral procedures. These contingencies are input to the model under test. The model's output is displayed as cumulative records. The cumulative record can then be compared to one produced by a pigeon exposed to the same contingencies. The testbed is tried with three published models of learning. Each model is exposed to up to three reinforcement schedules (testing ends when the model does not produce acceptable cumulative records): continuous reinforcement and extinction, fixed ratio, and fixed interval. The In Sitt testbed appears to be a reliable and valid testing procedure for comparing models of learning.

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A pigeon earned its daily food by pecking a key according to reinforcement schedules that produced food about once per day. Fixed-interval (FI), Fixed-time (FT), and various complex schedules were arranged to demonstrate the degree to which a scalloped pattern of responding remained. Pausing continued until about an hour before the reinforcer could be earned for FIs of 12, 24, and 48 h. Pausing was not as long for FIs of 18, 19, and 23 h. Pausing of about 24 h was seen for FI 36 h. FT 24 h produced continued responding but at a diminished frequency. The pattern of responding was strongly controlled by the schedule of reinforcement and seemed relatively independent of the cycle of human activity in the surrounding laboratory. Effects of added ratio contingencies and of signaling the availability of reinforcement in FT were also examined. Signaled FTs of 5 min-3 h produced more responding during the signal (autoshaping) than did FTs of 19 or 24 h.

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The Agency for Toxic Substances and Disease Registry convened a workshop in Atlanta, GA, that evaluated approaches and methods to ascertain whether there are neurobehavioral sequelae to children and adults exposed to hazardous substances in the environment. This article, developed from that workshop, addresses the feasibility of employing extant neurobehavioral tests to screen pediatric populations. A matrix lists basic functions to be assessed during eight developmental periods ranging from birth to high school. The best of these neurobehavioral tests for pediatric populations and the types of assessment tools that are still needed are discussed. We make 10 specific recommendations to establish a hazardous substances neurobehavioral screen for pediatric populations, including appointing a review panel, developing a structured questionnaire, convening a conference on design and analysis, addressing minority and socially disadvantaged populations, coordinating adult and child assessment methods, information sharing among Federal agencies, baseline data, methodology research, research associated with hazardous worksites, and establishment of a pediatric databank.

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The effects of neonatal dopamine depletion on activity levels and locomotor patterns were tested in rats at 4 months of age. Measurements were taken using an activity pattern monitor. The lesioned group was significantly hypoactive in comparison to the control animals during the initial exposures to the monitor. Examination of locomotor paths indicated that the lesioned animals failed to develop the increasingly organized spatial behavior observed in control animals. In a second study, changes in motility and locomotor patterns before, during, and after the repeated administration of a D1-dopamine agonist, SKF-38393 (3.0 mg/kg) were investigated. A priming effect, leading to increases in ambulations and fine movements, was observed only in the lesioned animals after repeated administration of SKF-38393. The D1-dopamine agonist did not change the activity of the unlesioned animals and did not lead to persistent effects in lesioned animals tested 2 and 4 days following the final drug administration. Across the duration of the second study, the lesioned group did not demonstrate hypoactivity. Overall, the experiments showed that neonatal dopamine depletion disrupts the normal patterns of behavior associated with habituation to a novel environment, and repeated administration of SKF-38393 can further alter these abnormal activity patterns.

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Two groups of rats (N = 4 each) were trained to discriminate either triadimefon (40 mg/kg) or methylphenidate (4 mg/kg) from saline in a two-lever, milk-reinforced drug discrimination paradigm. Dose-response functions were determined during 5-min extinction sessions. Both agents produced a dose-related increase in the percentage of responses that occurred on the drug lever. In the substitution phase of the study, rats trained to discriminate triadimefon were tested with methylphenidate and rats trained to discriminate methylphenidate were tested with triadimefon. Triadimefon substituted completely for methylphenidate and methylphenidate substituted completely for triadimefon. These results indicate that triadimefon can function as a discriminative stimulus and that it shares discriminative stimulus properties with methylphenidate.

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The relative potency of d- and l-threo-methylphenidate (d-MPH and l-MPH) was evaluated using three behavioral paradigms for rats: Responding maintained by a fixed-interval schedule of reinforcement (FI), responding maintained by a concurrent variable-interval schedule of reinforcement (Conc VI VI), and consumption of sweetened condensed milk during a 15-min free-access period. In each case the potency of the d-MPH enantiomer greatly exceeded that of the l-MPH enantiomer. Temporal control of responding was reduced (FI) choice responding was equalized for most rats (Conc VI VI), and milk consumption was suppressed by d-MPH and dl-MPH.

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The time course of serum concentration and performance on a concurrent probability matching task were evaluated in normal adults receiving 0.15 or 0.3 mg/kg of methylphenidate. The behavioral task, an arcade-like problem-solving game, revealed that drug-treated subjects improved their performance upon repeated testings during pharmacokinetic evaluation at a lower rate than did non-treated controls over the same time span. However, drug-treated subjects failed to adopt the adaptive problem-solving strategies selected by controls.

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Rats were trained to press a lever for food pellets provided according to a fixed interval 60-sec schedule of reinforcement. Probe trials (peak trials) assessed responding over two-min periods with no pellet delivered. The low rates of responding found early and late in probe trials were increased by methylphenidate and 1.0 mg/kg d-amphetamine (rate-dependent effect). Further, the mean time of responding (peak time) was shortened for both drugs (timing effect).

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The onset and sequential changes of psychosexual arousal for male and female were compared. During an erotic film presentation, genital hemodynamic and groin skin temperature measures of sexual arousal recorded moderate to large increases for both sexes. A sequential analysis revealed strikingly similar male-female response patterns for both the genital and groin measures of arousal. Thus, the commonly held view that males typically show a greater sexual responsivity to visual erotic stimuli than do females was not supported.

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This manuscript reports the results of a problem-solving exercise presented to participants at a Workshop on Neurotoxicology Testing in Human Populations held in Rougemont, North Carolina in October, 1983. Response recommendations are the consensus of workshop participants. These are not comprehensive or definitive solutions and should be interpreted with caution. Each exposure scenario represents a "real world" situation previously encountered by neurologists and epidemiologists. Ideally, a toxin affects a single, easily tested modality early in the illness before producing a complex neurological syndrome. Unfortunately this rarely happens; difficult choices and compromises about testing are usually necessary. At the end of each scenario likely areas of early subtle dysfunction were discussed and possible testing methods were outlined. Working participants were instructed to comment on the approach to the scenarios and to add to or dispute the proposed tests. It is clear that there are no right or wrong answers; however, the participants were urged to try to reach some sort of consensus. In each instance participants assumed that they were being notified by the company and not by a state or federal agency, and were to determine what would be the most reasonable and effective way to offer help or obtain outside assistance in these situations.

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A description is offered for a microcomputer-based testing system which utilizes an Apple II microcomputer with the Pascal language and additional hardware resources. Tasks implemented for the system have been selected to broadly sample cognitive functioning with some sensory and motor evaluation as well. Efforts to evaluate sensitivity, task interrelations, and reliability of measurement are described.

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Long-Evans rats were intubated with 0.3 or 1.0 mg/kg of triethyltin sulfate (TET) or 0.3 mg/kg of trimethyltin hydroxide (TMT) from postnatal day 3-29. 1.0 mg/kg of TMT was given on alternate days beginning on postnatal day 3. Learning and memory were assessed in an automated radial-arm maze when the rats were 180-200 days old. With this maze accuracy and activity data can be collected simultaneously. TET or TMT treatment resulted in an increase in the number of days required to adequately perform and radial-arm maze task, and a transient deficit in accuracy. However, the most pronounced effect in both TET and TMT-treated animals was hyperactivity which became manifest on the second day of testing and persisted throughout the remainder of testing.

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Pigeons were trained to peck keys on fixed-ratio and fixed-interval schedules of food reinforcement. Both schedules produced a pattern of behavior characterized as pause and run, but the relation of pausing to time between reinforcers differed for the two schedules even when mean time between reinforcers was the same. Pausing in the fixed ratio occupied less of the time between reinforcers for shorter interreinforcer times. For two of three birds, the relation was reversed at longer interreinforcer times. As an interreinforcer time elapsed, there was an increasing tendency to return to responding for the fixed interval, but a roughly constant tendency to return to responding for the fixed-ratio schedule. In Experiment 1 these observations were made for both single-reinforcement schedules and multiple schedules of fixed-ratio and fixed-interval reinforcement. In Experiment 2 the observations were extended to a comparison of fixed-ratio versus variable-interval reinforcement schedules, where the distribution of interreinforcement times in the variable interval approximated that for the fixed ratio.

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For several pigeons, pecking at particular locations within a ten-inch-wide response area was reinforced by grain presentations. The reinforced locations changed systematically to "shape" response location back and forth across the area. The rate and size of these shifts in reinforced locations were varied in both between-subject and within-subject comparisons to evaluate the influence of these variables on the shaping process. Larger step sizes produced larger shifts in location for all sizes inspected, with all sizes from .5 to 3.0 inches effective in shaping behavior. More rapid steps were approximately as effective as slower steps for all rates of shift inspected from 25 reinforcers to 400 reinforcers per step. These data suggest that shaping peck location proceeds most efficiently with rapid, relatively large shifts in criterion performance.

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Rats were trained to obtain food pellets from the end of each arm of an eight-arm radial maze. Baseline performance was characterized by very few entries into arms from which the food pellet had already been obtained. In Experiment 1, neither d-amphetamine (0.1-3.0 mg/kg) nor pentobarbital (1.0-10.0 mg/kg) affected choice accuracy, although the rate of arm-entry increased after d-amphetamine and decreased after pentobarbital. Scopolamine (0.1-1.0 mg/kg), on the other hand, reduced both accuracy and the rate of arm entry. In a second experiment, the effects of scopoalmine were replicated using a between-subjects design. Methylscopolamine (0.17, 1.0 mg/kg) was found to have little effect on performance. Multiple response criteria were also compared in the second experiment. Scopolamine was found to affect runs farther out the arm differently than it affected abbreviated arm entrances. A post-trial feeding test was also included to evaluate changes in reinforcer effectiveness, and showed that food continued to be a reinforcer after both scopolamine and methylscopolamine.

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Nine pigeons in a matching-to-sample task with 5 alternative stimuli were exposed to 4 dose levels of sodium pentobarbital. Each drug session alternated with a control session, and 6 determinations were made at each dose level. Dose-response curves were obtained, and drug effects are described for position-specific and stimulus-specific behaviors. These results suggest that the drug effect is to weaken control by the sample stimulus and shift control to properties of the comparison stimuli.

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Pigeons were intermittently given grain reinforcement for key pecks. Occasional 30-sec keylight changes (warning stimulus) were followed by a brief electric shock, which suppressed responding during the warning stimuli. This suppression was reduced by diazepam and ethanol, yet combinations of the two drugs did not reduce suppression (antagonistic effect). Each drug reduced responding in the absence of the warning stimulus, and combinations of the drug produced still greater reductions in this safe-period responding (synergistic effect).

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Two pigeons were exposed to a multiple schedule of grain reinforcement where key-pecks were reinforced according to a fixed ratio schedule in the presence of one stimulus and a fixed interval schedule in another stimulus. The fixed interval was adjusted to match average interreinforcer time for the fixed ratio schedule. d-Amphetamine decreased overall rate of responding in the fixed ratio schedule -- primarily by increasing pausing, especially just after a change from the fixed interval component. Rate of responding in the fixed interval schedule was increased for one bird and little affected for the other bird by d-Amphetamine. Again, changes in pausing primarily determined rate change. Since pausing was differently affected, a schedule-dependent rather than rate-dependent effect was indicated.

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