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Headsprout Early Reading is a computer-based program designed on behavioral principles to enhance the basic skills that underpin the initial development of reading. In a within and between groups design, and using primary schools within Northern Ireland that had a currently high proportion of disadvantaged pupils, children who were behind their peers in progress with reading were randomly allocated to an intervention group (n = 79), where the target was to work through 80 reading training episodes within a school year, or a teaching as usual group (n = 44). Reading skills were assessed in all children before, at the midpoint, and after the intervention using a flashcard-based phonics identification test with three levels of difficulty, and before and after intervention using a standardized reading assessment, which generated a sentence reading age and a phonics reading age. Both groups showed increased scores on all measures over the 6 months of the study, but the intervention group showed markedly greater improvement. Importantly, the mean scores on sentence reading age and phonics reading age for the intervention group increased by over 17 months and 12.1 months, respectively, as opposed to 7.6 months and 7.8 months with the control group. These findings also validated the use of the flashcard-based phonics identification test with this population. This study indicates that widespread use of Headsprout Early Reading in mainstream education could be highly effective.

Behavior analysis takes a natural science approach to human and animal behavior. Some basic tenets are widely agreed in the field but it can be argued that some other assumptions are implicit in our approach and, if unexamined, may impair progress. Since the time of David Hume, there has been a strong Western philosophical tradition of naturalism and realism. Although behavior analysis has from the outset embraced pragmatism, features of naturalism are embedded in the metaphysics of science and thus have been imported into behavior analysis. Many versions of naturalism imply dualism, but this can be avoided without abandoning a naturalist–realist position either by adopting the historicist approach of Rorty, which suggests that apparently a priori truths are often merely conventions of a philosophical tradition, or by accepting Wittgenstein’s view that there are hinge statements that are fundamental to our thinking but are not propositional beliefs and do not entail dualism. As an alternative, we can adopt the metaphysical assumptions of monism, possibly starting from William James’s approach of neutral monism. Revising our metaphysical assumptions while retaining the pragmatism that is central to behavior analysis may enable us to engage more effectively with cognitive psychology, to develop stronger links with ecological psychology and other approaches that reject representationalism, and to move beyond the debate about the status of private events.

Variations in prompt delay procedures are used in discrete-trial training to reduce the occurrence of errors before task mastery. However, the variations are seldom compared systematically. Using an adapted alternating treatments design, the present study compared progressive prompt delay with 2-s or 5-s constant prompt delay, on the acquisition of an expressive labeling task in four participants with autism spectrum disorder and intellectual disability. While all three prompt delay methods led to mastery of the tasks, albeit only when the tasks were simplified for one participant, progressive prompt delay generally proved the most efficient method on several measures, including lower error rates. This is consistent with the nature of the progressive prompt delay procedure which allows less time for errors to occur early in training. It is provisionally concluded that selection of progressive prompt delay is supported as a wise first choice option for clinicians, as a history of high error rates may impair later learning.

Linalool is an enanitomer monoterpene compound identified as the pharmacologically active constituent in a number of essential oils and has been reported to display anxiolytic properties in humans and in animal models and to exert both GABAergic and glutamatergic effects. In Experiment 1 linalool (100, 200, and 300, i.p.) had no significant effects compared with saline in an activity tracker with C57BL/6j mice. Experiment 2 assessed the effects on operant extinction with mice of chlordiazepoxide at a dose (15 mg/kg, i.p.) previously shown to facilitate extinction, and the same doses of linalool, compared with saline. Linalool had a dose-related facilitatory effect on extinction. While the effects of the highest dose of linalool most closely resembled the effects of chlordiazepoxide, the pattern of results suggested that linalool may affect both the acquisition of extinction learning, which is influenced by glutamatergic processes, and the expression of extinction, known to be affected by GABAergic agents such as chlordiazepoxide.

This study compared the efficacy of the Headsprout© Early Reading (HER) program with SENCO-delivered supplementary literacy instruction. Participants were primary school children (aged 6–9) in receipt of free school meals and supplementary literacy instruction. Data were collected within their school setting. The treatment group received HER intervention, while the treatment as usual (TAU) group received SENCO-delivered intervention, inclusive of guided reading, paper-based phonics training and word recognition tasks. It was hypothesized that children in the HER intervention group would significantly outperform those in the TAU group on measures of word/non-word recognition and sentence reading over a 7-month period. Thirty-two pupils with specific literacy difficulty were randomized to either HER (n = 17) or TAU (n = 15). Literacy skills were assessed using the Phonics and Early Reading Assessment pre- and post-intervention. ANOVA and t test analysis found that HER made significantly greater gains on measures of word/non-word recognition [t(30) = 7.55, p

Background: People with intellectual disabilities are more at risk of obesity than the general population. Emerging literature indicates that multicomponent interventions are most effective, however, individual results are variable and little research exists as to why this is the case. Methods: Focus groups were conducted to explore lived experiences between two groups of adults with intellectual disabilities; an overweight group (n= 6) and a group identified as successful in losing weight (n= 6). Similarities and differences were explored across four domains. Transcripts were produced and analysed using Theoretical Thematic Analysis. Results: Similarities included service centre supports, basic food knowledge and issues restricting independence. The successful weight loss group had also internalised health messages, engaged with external reinforcement programmes, responded to positive feedback and demonstrated healthier dietary habits. Conclusion: Weight management interventions would benefit from understanding the influence that internalisation of health messages, effective reinforcement systems and positive feedback can have on supporting the adoption of healthier habits. The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This research was supported by funding from the charity RESPECT and the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement no. PCOFUND-GA-2013-608728. Additional funding for PhD research was provided by Department of Education and Learning (DEL). peer-reviewed

Many prompting procedures exist for teaching skills to individuals with autism spectrum disorder and intellectual disability; however, direct comparisons between variations of prompt delay are rarely made. Here, we compared three variations of prompt delay (2-s or 5-s constant delay and 5-s progressive delay) alongside trial-and-error instruction. Four learners were taught a conditional discrimination task using a match-to-sample arrangement. Performances were compared using effectiveness and efficiency measures in an adapted alternating treatments design. A procedural modification, in the form of differential reinforcement, was applied to the prompt delay procedure for two of the four participants. With or without this procedural modification, results suggest progressive prompt delay may be effective and the most efficient in reducing learner errors during instruction.

Although researchers have evaluated the application of equivalence-based instruction (EBI) to naturalistic teaching settings, few have examined individualized educational programs of application. The current study therefore employed an EBI procedure to teach individual categorization lessons to pre-school age children (n = 5). A category sort test was used to identify stimuli for each child which were incorrectly categorized pre-intervention. These stimuli consisted of real-world stimuli from non-overlapping categories (e.g., toys, clothing, and fruit). Participants were trained in six conditional discriminations tested for the emergence of three three-member classes (A1, B1, C1; A2, B2, C2; A3, B3, C3) using a computerized touchscreen matching to sample (MTS) procedure. Participants subsequently were trained to identify receptively the category label for the C stimulus in each class. Following training and testing, the category sort test was re-administered. All participants demonstrated categorization of the directly trained class members and further generalization to addition unknown stimuli. The results show that little training was required in the use of touchscreen responding indicating that the use of such devices may provide a simple means of computerized teaching in young populations.

Motivation for food reinforcers in mouse models of type 2 diabetes was examined in three experiments. In all experiments, physiological measures indicated the presence of type 2 diabetes. In Experiment 1, high-fat fed Swiss TO mice and lean controls showed a preference for high-fat corn oil reinforcers over high-sugar syrup reinforcers in a T-Maze task, but there were no differences between the two groups. In Experiment 2, high-fat fed Swiss TO mice and lean controls responded for corn oil or food pellet reinforcers on progressive ratio schedules. While break point numbers were higher for corn oil than food pellets, and satiation or extinction reduced break points, there were no differences between the groups. In Experiment 3, streptozotocin treatment was used to induce type 2 diabetes in C57Bl/6 j mice that were compared with controls while responding for corn oil or food pellet reinforcers on progressive ratio schedules. While break point numbers were higher for corn oil than food pellets before and after streptozotocin treatment, and satiation or extinction reduced break points, there were no differences between the groups. Parameters for a more complex method of assessment of progressive ratio behaviour derived from Killeen’s Mathematical Principles of Reinforcement were also computed. While the parameter associated with incentive value was higher for corn oil than for food pellets, parameters were not significantly affected by streptozotocin treatment. Overall, a range of behavioural measures of food motivation failed to reveal effects of changes relative to controls in mice that showed physiological evidence of type 2 diabetes.

This study investigated whether Headsprout©, an internet-based phonics program designed on behavioral principles, is an effective supplementary tool to improve literacy skills of children who have spent time in care and are at risk of reading failure. Participants were 8 children (aged 5 to 10) who had spent over 3 years in care and were fully adopted at the time of the study. Participants' literacy skills were assessed prior to intervention using 2 standardized reading attainment tests. Participants were then randomly assigned to either treatment or a waiting list comparison group. There were 2 Headsprout© treatments, but all participants in the treatment group completed 1 HeadsproutStartCopTextStartCopText© lesson 4 times per week, under the supervision of the first author, while participants in the comparison group interacted with the first author 4 times per week engaging in nonliteracy-based computer activities. Results from 2 standardized reading attainment tests showed an improvement in word recognition age and oral reading fluency for the HeadsproutStartCopTextStartCopText© learners but scores either remained the same or decreased over a 4-month period for participants in the comparison group. The findings support the wider use of HeadsproutStartCopTextStartCopText© with at-risk children though more research is clearly warranted at this time.

A field experiment explored the effect of feedback and goal-setting interventions on residential electricity use in households in Northern Ireland. Alternating orders of presentation of feedback and no feedback conditions were used to explore the longer-term effect of feedback on conservation performance. Group 1 received 5 months of feedback followed by 5 months of no feedback, Group 2 underwent 5 months of no feedback followed by 5 months of feedback, and Group 3 experienced alternating 2-month periods of feedback and no feedback over 10 months, using a reversal design. Group 1 saved a mean 9.54% of electricity during the feedback condition, but Group 2 increased their use by a mean 14.24%. Group 3 showed a pattern of cumulative reductions over successive feedback periods, with a mean reduction in electricity use of 33%. Participants in Group 3 did not show a return to baseline levels of electricity use during the no feedback condition. The importance of exploring different reactions to feedback is discussed.

Order judgements are slower and less accurate when reversed. That is, when participants see two events in a sequence (e.g., circle …square), they are quicker to report ‘Before’ statements (e.g., “Circle before Square”) than ‘After’ statements (“Square after Circle”). The current study sought to determine whether a reversal effect will also occur when participants are instructed to produce a sequence of responses. Twenty participants were trained to criterion on simple ‘Before’ and ‘After’ instructions that specified sequences of two responses (e.g., “Circle before Square”). In a subsequent test, participants produced instructed sequences (e.g., circle … square) more quickly and more reliably when instructed to choose one stimulus before another than when they were requested to choose one stimulus after another. The implications of these findings for current theories of relational responding are considered.

The current study investigated the relative effects of Before and After relational cues on temporal order judgments. In Experiment 1, participants (n= 20) were exposed to a 5-phase temporal relational responding task. Participants observed a sequence of 2 familiar shapes and then completed either a Before or an After statement to describe the sequence. Response speeds were significantly faster for Before statements than for After statements. Experiment 2 (N = 24) extended Experiment 1, using abstract rather than familiar stimuli, and replicated the findings. The current data extend previous research, which employed temporal relational responding tasks as a measure of cognitive abilities such as intelligence, by focusing on differences in speed between responding in the presence of relational cues used in such tasks. The differences in response speeds observed between Before and After cues suggest that more work is needed to understand the specific processes that underpin such responding.

Over the 30 years of conflict, Northern Ireland escaped the worst excesses of illegal drug trafficking and usage. This was in large part due to the 'policing' of local community crime by paramilitaries. However, since the first 'cease-fire' in 1994 the province has witnessed a dramatic and unprecedented rise in the availability of illicit drugs. This increased availability reflects rising consumption of these drugs in the province. The aim of this study was to explore the perceptions that a sample of health and social care professionals' hold of illicit drug users in Northern Ireland. A survey methodology was used. Community settings across Northern Ireland were accessed. Focus groups and face-to-face interviews were used as data collection methods. Thirty-five health and social care professionals took part in this study. Thirty-two took part in six focus groups; three respondents underwent one-to-one interview. The participating professionals reported to have little or no education or training in the care and treatment of illicit drug users. Some stated that they would reject the offer of education and training in this area to prevent contact with illicit drug users. Many displayed strongly negative views of this client group, often expressing a preference not to care for or treat these people, preferring all their care to be given by specialists in illicit drug treatment. These findings indicate that most of the health and social care professionals who took part in this study appear unprepared and unwilling to meet the challenge of caring for illicit drug users. The findings will be of interest to service providers within and outside the UK.

Learning and memory are central topics in behavioral neuroscience, and inbred mice strains are widely investigated. However, operant conditioning techniques are not as extensively used in this field as they should be, given the effectiveness of the methodology of the experimental analysis of behavior. In the present study, male C57Bl/6 mice, widely used as background for transgenic studies, were trained to lever press on discrete-trial fixed-ratio 5 or fixed-interval (11 s or 31 s) schedules of food reinforcement and then exposed to 15 extinction sessions following vehicle or chlordiazepoxide injections (15 mg/kg i.p., administered either prior to all extinction sessions, or prior to the final 10 extinction sessions). Extinction of operant behavior was facilitated by drug administration following training on either schedule, but this facilitation only occurred once a number of extinction sessions had taken place. The extinction process proceeded more rapidly following fixed-interval training. Resistance to extinction was equally high following training with either schedule type, and was reduced by drug administration in both cases. These phenomena were evident in individual cumulative records and in analyses of group data. Results are interpreted in terms of phenomena of operant extinction identified in Skinner's (1938) Behavior of Organisms, and by behavioral momentum theory. These procedures could be used to extend the contribution of operant conditioning to contemporary behavioral neuroscience.

Extinction following positively reinforced operant conditioning reduces response frequency, at least in part through the aversive or frustrative effects of non-reinforcement. According to J.A. Gray's theory, non-reinforcement activates the behavioural inhibition system which in turn causes anxiety. As predicted, anxiolytic drugs including benzodiazepines affect the operant extinction process. Recent studies have shown that reducing GABA-mediated neurotransmission retards extinction of aversive conditioning. We have shown in a series of studies that anxiolytic compounds that potentiate GABA facilitate extinction of positively reinforced fixed-ratio operant behaviour in C57B1/6 male mice. This effect does not occur in the early stages of extinction, nor is it dependent on cumulative effects of the compound administered. Potentiation of GABA at later stages has the effect of increasing sensitivity to the extinction contingency and facilitates the inhibition of the behaviour that is no longer required. The GABAergic hypnotic, zolpidem, has the same selective effects on operant extinction in this procedure. The effects of zolpidem are not due to sedative action. There is evidence across our series of experiments that different GABA-A subtype receptors are involved in extinction facilitation and anxiolysis. Consequently, this procedure may not be an appropriate model for anxiolytic drug action, but it may be a useful technique for analysing the neural bases of extinction and designing therapeutic interventions in humans where failure to extinguish inappropriate behaviours can lead to pathological conditions such as post-traumatic stress disorder.

Operant behavior maintained by schedules of intermittent reinforcement has been extensively used for the investigation of the behavioral effects of drugs that affect the central nervous system. While the primary purpose of such research has been the screening of novel compounds in the search for clinically effective drugs, much else has been discovered about drug action and behavioral processes. Current research focuses on problems of social and clinical importance, such as cocaine abuse, and involves the development of novel and modified reinforcement schedules to address problems thrown up by research involving drugs. There are also new challenges posed in studying the behavior of transgenic knock-out mice. After more than 40 years, reinforcement schedules continue to be significant research techniques in behavior pharmacology. It is important that researchers are fully trained in behavior analysis in order to contribute to this rapidly developing area of behavioral neuroscience. ********** In parallel with the development of scientific approaches to psychology, there were massive developments in our knowledge and understanding of the brain and central nervous system in the twentieth century and this progress has accelerated in recent years. Practitioners of both disciplines are aware that each discipline needs the other to provide a more complete account of human psychology and behavior. However, there is a tendency to regard brain processes as more "basic" in some sense, and to expect that psychological or behavioral processes will, in the end, be explained by brain processes. Whether or not one accepts this "reductionist" philosophical position, scientific and practical considerations show that it is necessary to investigate both behavioral processes and brain processes, and the interaction between the two. From a scientific perspective, behavioral processes are interesting in their own right, and knowledge of them and their applications can be developed without necessarily knowing about the correlated brain processes. However, scientific curiosity would lead us to investigate, where possible, the brain processes that go in parallel with behavioral or psychological phenomena. From the perspective of neuroscience the argument is even more compelling: we hardly ever investigate a process in the brain or central nervous without a parallel interest in its relationship to psychological functioning. As soon as we ask, "How does this brain process affect behavior?" we require an adequate account of behavioral processes to which we can relate our study of brain function. In broad terms, behavioral neuroscience is the interdisciplinary field of study that seeks to use behavioral techniques to understand brain function, and to use techniques of neuroscience to elucidate behavioral processes. Psychology and neuroscience come together in various areas of this interdisciplinary field, and to date behavior pharmacology has been one of the most productive of these areas. The last 50 years have seen the development of the modem pharmaceutical industry, which has the capacity to synthesize new chemical compounds that may be useful in treating human diseases and ameliorating psychological distress of one kind or another. A major section of the industry is concerned with agents that may alter the functioning of the human central nervous system. In the development of a new drug that affects the human central nervous system many practical, legal and scientific issues must be addressed. As well as safety issues (the drug may be toxic to many species, or especially to humans, or it may damage certain types of tissues or impair certain physiological functions, etc.), the drug must pass various positive tests as well. Even if it is chemically similar to a compound already in use for the treatment of anxiety, for example, it may not itself be effective. If it is effective, how should it be administered, and on what type of dosing regime? …

The metabotropic glutamate receptor subtype 8 (mGlu(8)) is presynaptically located and regulates the release of the transmitter. Dysfunctions of this mechanism are involved in the pathophysiology of different psychiatric disorders. mGlu(8) deficient mice have been previously investigated in a range of studies, but the results are contradictory and there are still many open questions. Therefore, we tested mGlu(8)-deficient animals in different behavioral tasks that are commonly used in neuropsychiatric research. Our results show a robust contextual fear deficit in mGlu(8)-deficient mice. Furthermore, novel object recognition, chlordiazepoxide-facilitated extinction of operant conditioning and the acoustic startle response were attenuated by mGlu(8) deficiency. We found no changes in sensory processing, locomotor activity, prepulse inhibition, phencyclidine-induced changes in locomotion or prepulse inhibition, operant conditioning, conditioned fear to a discrete cue or in animal models of innate fear and post-traumatic stress disorder. We conclude that mGlu(8) might be a potential target for disorders with pathophysiological changes in brain areas where mGlu(8) modulates glutamate and gamma-amino butyric acid (GABA) transmission. Our data especially point to anxiety disorders involving exaggerated contextual fear, such as generalized anxiety disorders, and to conditions with disturbed declarative memory.

To establish a valid animal model of the effects of olfactory stimuli on anxiety, a series of experiments was conducted using rats in an open-field test. Throughout, effects of lavender oil were compared with the effects of chlordiazepoxide (CDP), as a reference anxiolytic with well-known effects on open-field behaviour. Rats were exposed to lavender oil (0.1–1.0 ml) for 30 min (Experiment 1) or 1 h (Experiment 2) prior to open-field test and in the open field or injected with CDP (10 mg/kg i.p.). CDP had predicted effects on behaviour, and the higher doses of lavender oil had some effects on behaviour similar to those of CDP. In Experiment 3, various combinations of pre-exposure times and amounts of lavender oil were used. With sufficient exposure time and quantity of lavender the same effects were obtained as in Experiment 2. Experiment 4 demonstrated that these behavioural effects of lavender could be obtained following pre-exposure, even if no oil was present in the open-field test. In Experiments 2–4, lavender oil increased immobility. Together, these experiments suggest that lavender oil does have anxiolytic effects in the open field, but that a sedative effect can also occur at the highest doses.

Herbert Spencer's Principles of Psychology (1855, first edition) was regarded by his contemporaries, including William James and John Dewey, as a major contribution to what was then a very new discipline. In this book he first expounded his ideas about both evolution of species and how behavior of the individual organism adapts through interaction with the environment. His formulation of the principle that behavior changes in adaptation to the environment is closely related to the version of the law of effect propounded some years later by Thorndike. He can thus be seen as the first proponent of selectionism, a key tenet of behavior analysis. He also explicitly attacked the then prevailing view of free will as being incompatible with the biologically grounded view of psychological processes that he was advocating, and thus put forward ideas that were precursors of B. F. Skinner's in this important area of debate.

Several recent studies have shown that reducing gamma-aminobutyric acid (GABA)-mediated neurotransmission retards extinction of aversive conditioning. However, relatively little is known about the effect of GABA on extinction of appetitively motivated tasks. We examined the effect of chlordiazepoxide (CDP), a classical benzodiazepine (BZ) and two novel subtype-selective BZs when administered to male C57Bl/6 mice during extinction following training on a discrete-trial fixed-ratio 5 (FR5) food reinforced lever-press procedure. Initially CDP had no effect, but after several extinction sessions CDP significantly facilitated extinction, i.e. slowed responding, compared with vehicle-treated mice. This effect was not due to drug accumulation because mice switched from vehicle treatment to CDP late in extinction showed facilitation immediately. Likewise, this effect could not be attributed to sedation because the dose of CDP used (15 mg/kg i.p.) did not suppress locomotor activity. The two novel subtype-selective BZ partial agonists, L-838417 and TP13, selectively facilitated extinction in similar fashion to CDP. The non-GABAergic anxiolytic buspirone was also tested and found to have similar effects when administered at a non-sedating dose. These studies demonstrate that GABA-mediated processes are important during extinction of an appetitively motivated task, but only after the animals have experienced several extinction sessions.

Three experiments describe the effects of manipulating the frequency of response-reinforcer contiguity in a recycling conjunctive schedule. The schedule arranged that a reinforcer was delivered after 30 s provided at least one response had occurred; otherwise the next cycle started immediately. In Experiment 1, this schedule produced the typical pause-respond-pause pattern, with most responses at mid-interval; and, when a limited number of contiguities between responses and food delivery were added, the pattern became more like the monotonic scallop seen on fixed-interval schedules. In Experiment 2, the schedule was initially presented with an additional contingency that allowed contiguity on every trial. Fixed-interval-like behavior occurred and tended to persist as contiguities were gradually eliminated. In Experiment 3, the recycling conjunctive schedule alternated with a condition in which a large number of contiguities occurred. The pause-respond-pause pattern and fixed-interval-like performance occurred with few or many contiguities, respectively. The results of all three experiments illustrate how contiguity interacts with a small number of other variables to determine performance on interval schedules and illuminate previous findings with fixed-interval and fixed-time schedules.

Rats trained to lever press for sucrose were exposed to variable-interval schedules in which (i) the probability of reinforcement in each unit of time was a constant, (ii) the probability was high in the first ten seconds after reinforcement and low thereafter, (iii) the probability was low for ten seconds and high thereafter, (iv) the probability increased with time since reinforcement, or (v) the probability was initially zero and then increased with time since reinforcement. All schedules generated similar overall reinforcement rates. A peak in local response rate occurred several seconds after reinforcement under those schedules where reinforcement rate at this time was moderate or high ([i], [ii], and [iv]). Later in the inter-reinforcement interval, local response rate was roughly constant under those schedules with a constant local reinforcement rate ([i], [ii], and [iii]), but increased steadily when local reinforcement rate increased with time since reinforcement ([iv] and [v]). Postreinforcement pauses occurred on all schedules, but were much longer when local reinforcement rate was very low in the ten seconds after reinforcement ([iii]). The interresponse time distribution was highly correlated with the distribution of reinforced interresponse times, and the distribution of postreinforcement pauses was highly correlated with the distribution of reinforced postreinforcement pauses on some schedules. However, there was no direct evidence that these correlations resulted from selective reinforcement of classes of interresponse times and pauses.

Rats were trained to run up and down an alleyway for sucrose reinforcement on a variable interval schedule. Differential aversive classical conditioning with auditory CSs was then conducted in a separate apparatus ("off the baseline") prior to those CSS being presented while the subjects were responding for sucrose in the alleyway. Once the effects of the CSs had extinguished, shock was reintroduced following one CS but not the other ("on the baseline" differential aversive classical conditioning). Both "off the baseline" and "on the baseline" conditioning resulted in conditioned suppression to the CS followed by shock, but little effect of the CS followed by no shock was found. In the "on the baseline" phase, total suppression of baseline responding occurred at moderate US intensities, and this appeared to result from the subject avoiding the location at which he was last shocked. At lower values, both baseline response rate and relative suppression ratio were functions of US intensity. The results are discussed in relation to the effects found in similar experiments using avoidance baselines. Estes and Skinner (1941) found that food reinforced 1everpressing was suppressed by a conditioned stimulus (CS) that was followed by an unconditioned stimulus (US) of an electric shock. Such conditioned suppression of operant behavior by a preaversive CS has also been found using avoidance baselines (Bryant, 1972). However, Rescorla and Solomon (1967) were able to find support for their motivational account of operant classical interactions from a number of studies carried out in the Pennsylvanian laboratories (e.g., Rescorla & Lolordo, 1965; Rescorla, 1967). In general, these in­ volved training dogs to jump over a hurdle on a Sidman

Rats' lever pressing produced sucrose reinforcers on a variable-interval schedule where, in different conditions, the duration of a stimulus presented immediately after reinforcement was either correlated or uncorrelated with the duration of the current interreinforcement interval. Under the baseline schedule, in which no stimulus was presented, the minimum interreinforcement interval was 8 s and the mean postreinforcement pause of each subject approximated this value. Response rates increased slowly over the first 10 to 15 s and then remained roughly constant throughout the remainder of the interval. In both the correlated and uncorrelated conditions, the added stimulus resulted in the postreinforcement pauses lengthening to values in excess of the duration of the preceding stimulus. This resulted in a poststimulus pause which was, in most cases, roughly constant irrespective of the duration of the preceding stimulus, or of the reinforcement contingencies prevailing immediately after stimulus offset. Local response-rate patterns in the uncorrelated conditions were similar to those obtained under the baseline schedule in which no stimulus was presented. However, in the correlated condition local response rates increased across the remainder of the interreinforcer interval. Further, the rate of acceleration was inversely related to the duration of the preceding stimulus. These results show that a correlation between stimulus duration and the ensuing time to reinforcement can control behavior—a type of temporal control not previously reported.

In Experiment I, the responding of rats lever pressing on a variable-interval schedule for sucrose solution was partially suppressed by a variable duration conditioned stimulus followed by shock. When food deprivation was increased, response rates during and before the conditioned stimulus increased monotonically. Varying the concentration of sucrose across blocks of sessions or from session to session in a semi-random sequence had little effect on response rates either before or during the conditioned stimulus. With a fixed sequence of increasing concentrations across a five-session block, increased concentration produced much more rapid increases in response rates before than during the conditioned stimulus. In Experiment II, rats were presented with the same sequence of increasing concentrations across a five-session block. When tested at 80% body weight, response rates increased rapidly as concentration increased, but at 100%, body-weight rates increased only slightly. The effect of a change in body weight in Experiment II thus mimicked the effect of the conditioned stimulus in the latter part of Experiment I. These findings support the view that the effect of a pre-aversive conditioned stimulus is similar to that of a change in food deprivation, but unlike that of a change in reinforcement magnitude.

A procedure is described which disrupts response-reinforcer contiguity and response dependency and which demonstrates how the location of the response dependency in interval schedules can be regarded as a controlling variable in its own right. Rats' lever pressing produced sucrose on a recycling conjunctive fixed-time 30-second fixed-ratio 1 schedule of reinforcement. Reinforcement occurred only at the end of the fixed-time component on this schedule and only if a response had occurred during that component. This produced a pause-respond-pause pattern during the interreinforcer interval for all animals. When the location of the response dependency was then restricted to a 10-second period in the middle of the fixed-time component, the pattern was accentuated and response rates increased for all animals, while postreinforcement pauses decreased sharply for two animals. When responding was required in the first 10 seconds of the fixed-time component, responding peaked earlier in the interval for all animals. Response rates were slightly below those in the previous conditions, while postreinforcement pauses were between 2 and 6 seconds across animals.

Rats were trained to leverpress concurrently for 4% and 16% sucrose solution. This established asymmetric performance. The introduction of a CS paired with free food resulted in an increased preference for the greater reinforcement. This result is discussed in terms of the motivational consequences of Pavlovian conditioning procedures.

A series of doses (0.5 to 2.0 mg/kg) of d-amphetamine was administered to rats whose lever pressing was maintained by fixed-interval 30-s, 60-s, or 120-s schedules of reinforcement by sucrose delivery. Under both saline and d-amphetamine conditions, molecular features of responding were reliably described in terms of the distribution of postreinforcement pauses and local response rate following the onset of responding. Postreinforcement pause always varied from interval to interval but, on average, shortened under the drug. Local response rate (response rate exclusive of pause time) tended to decrease under the drug, and where acceleration occurred within runs of responses, it was reduced by the drug. All of these effects were dose-related. These findings suggest that fixed-interval behavior can be analyzed effectively at a molecular level, and that the effects of d-amphetamine are best described as disruption of temporal discrimination.

When a fixed-time schedule of shocks was presented to rats lever pressing for food on a random-interval schedule, a pattern of behavior developed with a high rate of pressing after shock declining to near zero before the next shock was delivered. Once this pattern had stabilized, one-quarter of the shocks were replaced with brief auditory stimuli (tones) in a random sequence. Tone maintained behavior similar to shock, although tone was never paired with shock. Both tone and shocks elicited responding when presented at various times as probe stimuli, and responding was usually totally suppressed if neither stimulus occurred at the beginning of the fixed-time interval. When other stimuli were paired with tone and shock, only those paired with tone gained discriminative control and elicited responding. These findings suggest that stimuli that signal a shock-free, or safe, period will maintain the pattern of behavior generated by shock on a fixed-time schedule. There is a parallel between this phenomenon and the control of behavior on second-order schedules of positive reinforcement with nonpaired brief stimuli.

Over the 30 years of conflict, Northern Ireland escaped the worst excess of illegal drug trafficking and usage. However, the recent 'peace dividend' has brought with it an unprecedented rise in the availability and use of illicit drugs. With this, new problems and pressures have been brought to bear on the health service. The literature would suggest that drug users are loathed and feared by health care staff. Staff will also admit to be lacking in the knowledge and skills necessary for the delivery of appropriate support and treatment for this client group. Further, the literature has little to offer on the experiences and aspirations of drug users in relation to their treatment and the staff who care for them. In order to understand the drug users' experiences of health care and health staff, focus group methodology was employed to obtain qualitative data. A total of 20 illicit drug users from across Northern Ireland took part. Supporting the literature, all had experienced 'care' that they felt was filled with judgement, hostility and loathing. They recognized clearly the challenge they pose to health care staff. These findings indicate that there is obvious dissonance between those tasked to care for drug users and drug users themselves, with little respect being shown on either side. Results suggest that action needs to be taken to address the deficits in the knowledge, skills and values of health care professionals in relation to illicit drug users. The findings will be of interest to service providers within and outside the United Kingdom.