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operant conditioning [keywords]
- Signaling added response-independent reinforcement to assess pavlovian processes in resistance to change and relapse. [JOURNAL ARTICLE]
- J Exp Anal Behav 2014 Jul 8.
Behavioral momentum theory asserts Pavlovian stimulus-reinforcer relations govern the persistence of operant behavior. Specifically, resistance to conditions of disruption (e.g., extinction, satiation) reflects the relation between discriminative stimuli and the prevailing reinforcement conditions. The present study assessed whether Pavlovian stimulus-reinforcer relations govern resistance to disruption in pigeons by arranging both response-dependent and -independent food reinforcers in two components of a multiple schedule. In one component, discrete-stimulus changes preceded response-independent reinforcers, paralleling methods that reduce Pavlovian conditioned responding to contextual stimuli. Compared to the control component with no added stimuli preceding response-independent reinforcement, response rates increased as discrete-stimulus duration increased (0, 5, 10, and 15 s) across conditions. Although resistance to extinction decreased as stimulus duration increased in the component with the added discrete stimulus, further tests revealed no effect of discrete stimuli, including other disrupters (presession food, intercomponent food, modified extinction) and reinstatement designed to control for generalization decrement. These findings call into question a straightforward conception that the stimulus-reinforcer relations governing resistance to disruption reflect the same processes as Pavlovian conditioning, as asserted by behavioral momentum theory.
- Ethical issues in using deception to facilitate rehabilitation for a patient with severe traumatic brain injury. [Journal Article]
- J Trauma Nurs 2014 Jul-Aug; 21(4):186-90.
To explore ethical issues in using deception to improve participation in a patient with severe traumatic brain injury who had not responded to traditional behavioral and pharmacologic approaches.Case study.A male in inpatient neurorehabilitation with history of severe traumatic brain injury and significant behavioral disruption that limited his therapy participation.Behavior modification program using principles of operant conditioning that required deception.Participation in therapies significantly improved and disruptive behaviors decreased.When used cautiously and with careful consideration of the ethical implications, deception may be permissible as part of an intervention strategy with this population but only as a last resort.
- Selective Cognitive Deficits in Adult Rats after Prenatal Exposure to Inhaled Ethanol. [JOURNAL ARTICLE]
- Neurotoxicol Teratol 2014 Jul 11.
Increased use of ethanol blends in gasoline suggests a need to assess the potential public health risks of exposure to these fuels. Ethanol consumed during pregnancy is a teratogen. However, little is known about the potential developmental neurotoxicity of ethanol delivered by inhalation, the most likely route of exposure from gasoline-ethanol fuel blends. We evaluated the potential cognitive consequences of ethanol inhalation by exposing pregnant Long Evans rats to clean air or ethanol vapor from gestational day 9-20, a critical period of neuronal development. Concentrations of inhaled ethanol (5,000, 10,000, or 21,000ppm for 6.5h/day) produced modeled peak blood ethanol concentrations (BECs) in exposed dams of 2.3, 6.8, and 192mg/dL, respectively. In offspring, no dose-related impairments were observed on spatial learning or working memory in the Morris water maze or in operant delayed match-to-position tests. Two measures showed significant effects in female offspring at all ethanol doses: 1) impaired cue learning after trace fear conditioning, and 2) an absence of bias for the correct quadrant after place training during a reference memory probe in the Morris water maze. In choice reaction time tests, male offspring (females were not tested) from the 5,000 and 10,000ppm groups showed a transient increase in decision times. Also, male offspring from the 21,000ppm group made more anticipatory responses during a preparatory hold period, suggesting a deficit in response inhibition. The increase in anticipatory responding during the choice reaction time test shows that inhaled ethanol yielding a peak BEC of ~200mg/dL can produce lasting effects in the offspring. The lack of a dose-related decrement in the effects observed in females on cue learning and a reference memory probe may reflect confounding influences in the exposed offspring possibly related to maternal care or altered anxiety levels in females. The surprising lack of more pervasive cognitive deficits, as reported by others at BECs in the 200mg/dL range, may reflect route-dependent differences in the kinetics of ethanol. Overall, these data suggest that ethanol inhalation selectively impairs cognitive function at relatively high concentrations. However, there is low likelihood of cognitive deficits in children of mothers who inhale ethanol vapors at the levels predicted at the gasoline pump.
- Error signals as powerful stimuli for the operant conditioning-like process of the fictive respiratory output in a brainstem-spinal cord preparation from rats. [JOURNAL ARTICLE]
- Behav Brain Res 2014 Jun 27.
Respiratory neuromuscular activity needs to adapt to physiologic and pathologic conditions. We studied the conditioning effects of sensory fiber (putative Ia and II type from neuromuscular spindles) stimulation on the fictive respiratory output to the diaphragm, recorded from C4 phrenic ventral root, of in-vitro brainstem-spinal cord preparations from rats. The respiratory burst frequency in these preparations decreased gradually (from 0.26±0.02 to 0.09±0.003 bursts(-1)±SEM) as the age of the donor rats increased from zero to 4 days. The frequency greatly increased when the pH of the bath was lowered, and was significantly reduced by amiloride. C4 low threshold, sensory fiber stimulation, mimicking a stretched muscle, induced a short-term facilitation of the phrenic output increasing burst amplitude and frequency. When the same stimulus was applied contingently on the motor bursts, in an operant conditioning paradigm (A 500ms pulse train with a delay of 700ms from the beginning of the burst) a strong and persistent (> than 1 hour) increase in burst frequency was observed (from 0.10±0.007 to 0.20±0.018 bursts(-1)). Conversely, with random stimulation burst frequency increased only slightly and declined again within minutes to control levels after stopping stimulation. A forward model is assumed to interpret the data, and the notion of error signal, i.e. the sensory fiber activation indicating an unexpected stretched muscle, is re-considered in terms of the reward/punishment value. The signal, gaining hedonic value, is reviewed as a powerful unconditioned stimulus suitable in establishing a long-term operant conditioning-like process.
- OPERANT PSYCHOLOGY MAKES A SPLASH-IN MARINE MAMMAL TRAINING (1955-1965). [JOURNAL ARTICLE]
- J Hist Behav Sci 2014 Jun 24.
Despite the wide spread use of operant conditioning within marine animal training, relatively little is known about this unique application of behavioral technology. This article explores the expansion of operant psychology to commercial marine animal training from 1955 to 1965, specifically at marine parks such as Marine Studios Florida, Marineland of the Pacific, Sea Life Park, and SeaWorld. The contributions of Keller and Marian Breland and their business Animal Behavior Enterprises (ABE) as well as other early practitioners of behavioral technology are reviewed. We also describe how operant technology was introduced and formalized into procedures that have become the cornerstone of marine animal training and entertainment. The rapid growth of the marine park industry during this time was closely linked to the spread of behavioral technology. The expansion of operant training methods within marine animal training is a unique success story of behavioral technology.
- Efficacy of interventions to improve feeding difficulties in children with autism spectrum disorders: a systematic review and meta-analysis. [JOURNAL ARTICLE]
- Child Care Health Dev 2014 Jun 25.
Feeding difficulties are relatively common in children with autism spectrum disorders (ASD), but current evidence for their treatment is limited. This review systematically identifies, reviews and analyses the evidence for intervention in young children with ASD and feeding difficulties.A comprehensive search strategy was used to identify studies from January 2000 to October 2013. Studies were included if they described interventions where the goal was to increase desirable eating behaviours or decrease undesirable eating behaviours using an experimental design, including single-subject research methodology. Studies were reviewed for descriptive information, and research quality was appraised using a formal checklist. Individual study findings were compared using Improvement Rate Difference (IRD), a method for calculating effect size in single-subject research.Overall, 23 papers were included. All studies reviewed had five or fewer participants, and reported on operant conditioning style intervention approaches, where the child is prompted to perform an action, and receives a contingent response. Where quality measures were not met, it was primarily due to lack of detail provided for the purposes of replication, or failure to meet social validity criteria. Meta-analysis indicated a medium-large effect size [mean = 0.69, 95% confidence interval (CI) 0.60 to 0.79] when the outcome measured was an increase in desirable behaviours (e.g. consuming food), but a small-negligible effect size (mean = 0.39, 95% CI 0.18 to 0.60) when the outcome measured was a decrease in undesirable mealtime behaviours (e.g. tantrums). Only a small proportion of studies reported outcomes in terms of increased dietary variety rather than volume of food consumed.The reviewed literature consisted primarily of low-level evidence. Favourable intervention outcomes were observed in terms of increasing volume, but not necessarily variety of foods consumed in young children with ASD and feeding difficulties. Further research in the form of prospective randomized trials to further demonstrate experimental effect in this area is required.
- Contextual control of operant behavior: evidence for hierarchical associations in instrumental learning. [JOURNAL ARTICLE]
- Learn Behav 2014 Jun 25.
Recent research has suggested that operant responses can be weakened when they are tested in new contexts. The present experiment was therefore designed to test whether animals can learn a context-(R-O) relation. Rats were given training sessions in context A, in which one response (R1; lever pressing or chain pulling) produced one outcome (O1) and another response (R2; chain pulling or lever pressing) produced another outcome (O2) on variable interval reinforcement schedules. These sessions were intermixed with training in context B, where R1 now produced O2 and R2 produced O1. Given the arrangement, it was possible for the animal to learn two distinct R-O associations in each specific context. To test for them, rats were then given aversion conditioning with O2 by pairing its presentation with lithium-chloride-induced illness. Following the aversion conditioning, the rats were given an extinction test with both R1 and R2 available in each context. During testing, rats showed a selective suppression in each context of the response that had been paired with the reinforcer subsequently associated with illness. Rats could not have performed this way without knowledge of the R-O associations in effect in each specific context, lending support to the hypothesis that rats learn context-(R-O) associations. However, despite a complete aversion to O2, responding was not completely suppressed, leaving the possibility open that rats form context-R associations in addition to context-(R-O) associations.
- Dual role of serotonin in the acquisition and extinction of reward-driven learning: involvement of 5-HT1A, 5-HT2A and 5-HT3 receptors. [JOURNAL ARTICLE]
- Behav Brain Res 2014 Jun 17.
Serotonin (5-HT) has been proposed as a possible encoder of reward. Nevertheless, the role of this neurotransmitter in reward-based tasks is not well understood. Given that the major serotonergic circuit in the rat brain comprises the dorsal raphe nuclei and the medial prefrontal cortex (mPFC), and because the latter structure is involved in the control of complex behaviors and expresses 1A (5-HT1A), 2A (5-HT2A), and 3 (5-HT3) receptors, the aim was to study the role of 5-HT and of these receptors in the acquisition and extinction of a reward-dependent operant conditioning task. Long Evans rats were trained in an operant conditioning task while receiving fluoxetine (serotonin reuptake inhibitor, 10mg/kg), tianeptine (serotonin reuptake enhancer, 10mg/kg), buspirone (5-HT1A partial agonist, 10mg/kg), risperidone (5-HT2A antagonist, 1mg/kg), ondansetron (5-HT3 antagonist, 2mg/kg) or vehicle. Then, animals that acquired the operant conditioning without any treatment were trained to extinct the task in the presence of the pharmacological agents. Fluoxetine impaired acquisition but improved extinction. Tianeptine administration induced the opposite effects. Buspirone induced a mild deficit in acquisition and had no effects during the extinction phase. Risperidone administration resulted in learning deficits during the acquisition phase, although it promoted improved extinction. Ondansetron treatment showed a deleterious effect in the acquisition phase and an overall improvement in the extinction phase. These data showed a differential role of 5-HT in the acquisition and extinction of an operant conditioning task, suggesting that it may have a dual function in reward encoding.
- Operant conditioning of the soleus H-reflex does not induce long-term changes in the gastrocnemius H-reflexes and does not disturb normal locomotion in humans. [JOURNAL ARTICLE]
- J Neurophysiol 2014 Jun 18.
In normal animals, operant conditioning of the spinal stretch reflex or the H-reflex has lesser effects on synergist muscle reflexes. In rats and people with incomplete spinal cord injury (SCI), soleus H-reflex operant conditioning can improve locomotion. We studied in normal humans the impact of soleus H-reflex down-conditioning on medial (MG) and lateral gastrocnemius (LG) H-reflexes and on locomotion. Subjects completed six baseline and 30 conditioning sessions. During conditioning trials, the subject was encouraged to decrease soleus H-reflex size with the aid of visual feedback. Every sixth session, MG and LG H-reflexes were measured. Locomotion was assessed before and after conditioning. In successfully conditioned subjects, the soleus H-reflex decreased 27.2%. This was the sum of within-session (task-dependent) adaptation (13.2%) and across-session (long-term) change (14%). The MG H-reflex decreased 14.5%, due mainly to task-dependent adaptation (13.4%). The LG H-reflex showed no task-dependent adaptation or long-term change. No consistent changes were detected across subjects in locomotor H-reflexes, EMG activity, joint angles, or step symmetry. Thus, in normal humans, soleus H-reflex down-conditioning does not induce long-term changes in MG/LG H-reflexes and does not change locomotion. In these subjects, task-dependent adaptation of the soleus H-reflex is greater than it is in people with SCI, while long-term change is less. This difference from results in people with SCI is consistent with the fact that long-term change is beneficial in people with SCI, since it improves locomotion. In contrast, in normal subjects, long-term change is not beneficial and may necessitate compensatory plasticity to preserve satisfactory locomotion.
- Differential regulation of MeCP2 and PP1 in passive or voluntary administration of cocaine or food. [JOURNAL ARTICLE]
- Int J Neuropsychopharmacol 2014 Jun 17.:1-14.
Cocaine exposure induces changes in the expression of numerous genes, in part through epigenetic modifications. We have initially shown that cocaine increases the expression of the chromatin remodeling protein methyl-CpG binding protein 2 (MeCP2) and characterized the protein phosphatase-1Cβ (PP1Cβ) gene, as repressed by passive i.p. cocaine injections through a Mecp2-mediated mechanism involving de novo DNA methylation. Both proteins being involved in learning and memory processes, we investigated whether voluntary cocaine administration would similarly affect their expression using an operant self-administration paradigm. Passive and voluntary i.v. cocaine intake was found to induce Mecp2 and to repress PP1Cβ in the prefrontal cortex and the caudate putamen. This observation is consistent with the role of Mecp2 acting as a transcriptional repressor of PP1Cβ and shows that passive intake was sufficient to alter their expression. Surprisingly, striking differences were observed under the same conditions in food-restricted rats tested for food pellet delivery. In the prefrontal cortex and throughout the striatum, both proteins were induced by food operant conditioning, but remained unaffected by passive food delivery. Although cocaine and food activate a common reward circuit, changes observed in the expression of other genes such as reelin and GAD67 provide new insights into molecular mechanisms differentiating neuroadaptations triggered by each reinforcer. The identification of hitherto unknown genes differentially regulated by drugs of abuse and a natural reinforcer should improve our understanding of how two rewarding stimuli differ in their ability to drive behavior.