Thesis (Ph.D.)--Brown University, 2005. / Vita. Thesis advisor: Russell M. Church. Includes bibliographical references (leaves 101-107). Also available online.

Thesis (M.A.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (June 27, 2007) Includes bibliographical references.

No description available.

Thesis (Ph. D.)--State University of New York at Binghamton, Psychology Department, 2008. / Includes bibliographical references.

The present study was concerned with the development and maintenance of (precurrent) behavior that increases the probability of reinforcement for another (current) behavior. A single-subject methodology was employed. Nine human subjects responded on a computer mouse that contained two buttons. One (current) button was reinforced according to a probability schedule (p = .02 or a minor deviation thereof), Depending on the condition, the other button either had no scheduled consequence (i.e., the precurrent contingency was absent) or increased the probability of reinforcement (p = .08) for current responding for 15 s (i.e., the standard precurrent contingency was present). Generally, with the precurrent contingency absent, precurrent responding quickly dropped to near zero levels ; with the precurrent contingency present, precurrent responding maintained at enhanced levels. Between- and within-subject replications suggest that the precurrent contingency was responsible for the maintenance of precurrent responding. Initial exposure to the precurrent contingency resulted in the acquisition of precurrent responding for four of eight subjects. For the four other subjects, a special conditioning procedure was enployed. which included either: (1) increasing the degree to which a precurrent response raised the probability of reinforcement for current responding; or (2) decreasing the probability of reinforcement for current responding to zero unless a precurrent response had occurred within the previous 15 s. Both of these procedures produced enhanced levels of precurrent responding which eventually maintained when the standard precurrent contingency was reintroduced. For four subjects, a OOD was later imposed onto the precurrent contingency. Specifically, a precurrent response produced a brief timeout followed by the period of enhanced reinforcement probability for current responding. In two cases, the CDD reduced precurrent responding to near zero levels, suggesting that reinforcement for current responses immediately following a precurrent response can play an important role in maintenance. In another experiment, the acquisition of precurrent responding was observed when the OOD was part of the precurrent contingency from the beginning, suggesting reinforcement for current responses immediately following a precurrent response is not necessary for acquisition. Current responding generally occurred at a high stable rate within sessions, between sessions, and between conditions. Efficiency (defined as the proportion of current responses in a session emitted under the enhanced probability state) rarely approached maximal levels and generally did not Improve with extended exposure to the precurrent contingency. Post-session verbal reports were recorded for six subjects. The conditioning and extinction of precurrent responding was demonstrated in the absence of "awareness" of the precurrent contingency. The accuracy of the reports varied both between- and within-subjects, and like efficiency, did not Improve with extended exposure to the precurrent contingency. Some issues considered in the discussion include (1) the role of frequency of contact with the precurrent contingency in acquisition and (2) discriminative control by the reinforcement schedules. Directions for future research are also discussed. / Graduate

M.A. (Psychology) / Minimal brain dysfunction as a diagnostic category with specific manifestations in terms of decreased scholastic ability, deficits in perseptual-motor and attentional functioning, has received a great deal of attention over the past ten years. However, the precise nature of this condition is still unclear, especially with regards to children diagnosed as having minimal brain dysfunction's response to remedial treatment and medication. From a literature survey it was concluded that there are two groups of children with minimal brain dysfunction. These groups comply with the definitions made by Kenny, (1980) of a hiperkinotaxic group and a pseudohiperkinotaxic group where the former appear to be a group of children who do not respond to any form of training or treatment without the addition of stimulant medication. The pseudohiperkinotaxic group respond to educational remedial and psychological treatment without stimulant medication, where stimulant medication may even decrease their functional ability. It was hypothesized that because of certain neuro-chemical factors hiperkinotaxic children are less conditionable without stimulant medication, than the pseudohiperkintoxic chirdren. In order to investigate this hypothesis three groups of children were isolated, a control group with no sign of minimal. brain dysfunction, an experimental group with minimal brain dysfunction who responded psychological and educational treatment only with the addition of stimulant medication...

A delayed, differential, classical conditioning paradigm was used to investigate defense and reward conditioning of autonomic responses in psychopaths. The CSs were tones and the UCSs were shock and pictures of nudes. The Ss were drawn from the inmate population of a maximum security penitentiary and were classified as primary psychopaths (P), secondary psychopaths (S), and nonpsychopaths (NP), according to criteria proposed by Cleckley and Karpman. The three dependent variables of chief interest, the GSR, HR, and finger vasoconstriction, were recorded simultaneously on an Offner Type R Dynograph. Differential conditioning was expressed as the amplitude of response to a reinforced CS minus the amplitude of response to the unreinforced CS. The primary hypothesis of the study was that Group P would show less defense conditioning of electrodermal, cardiac, and vasomotor responses than would Group NP. The secondary hypothesis predicted no significant differences between Groups P and NP in amount of reward conditioning on any of the autonomic measures investigated. The results showed that of the three physiological systems studied only the electrodermal differentiated between Groups P and NP with Group P; (1) showing significantly less defense conditioning; (2) giving smaller conditioned ORs, and smaller UCRs to shock; and (3) having a significantly lower level of basal skin conductance midway through the experiment. There was no significant difference between the two groups in reward conditioning although the tendency was for Group P to give ORs and ARs of smaller amplitude than those given by Group NP. No significant difference was found between groups in shock detection threshold or shock tolerance level - hence these variables were ruled out as significant contributors to the difference in defense conditioning. It was also shown that a difference in basal conductance between Groups P and NP was not significantly related to the observed difference in conditioning. Under both defense and reward stimulus conditions all groups showed evidence of conditioned HR deceleration, and an increase in the amplitude of vasomotor responses. There was no significant difference between Groups P and NP on any index of either cardiac or vasomotor activity. The GSR findings pertaining to defense conditioning were interpreted as providing additional evidence that primary psychopaths are deficient in the acquisition of conditioned fear responses. The reward conditioning results indicate that there is still no evidence that primary psychopaths differ from nonpsychopaths in the conditioning of reward responses. The difference between the amount of electrodermal and cardiovascular conditioning shown by Group P was related to structural and functional differences between the physiological systems investigated. The results of this study seem to permit the following tentative conclusions: (1) The GSR may be a more appropriate autonomic correlate of the psychopath's emotional reactivity than is either HR or finger vasoconstriction. (2) The primary psychopath's autonomic conditioning deficit may be restricted to the GSR. (3) In comparison with nonpsychopaths primary psychopaths are deficient in the acquisition of classically conditioned fear responses expressed as electrodermal measures. (4) There is no evidence that primary psychopaths and non-psychopaths differ significantly in the acquisition of classically conditioned reward responses. (5) Relative to nonpsychopaths primary psychopaths appear to be electrodermally hyporeactive. / Arts, Faculty of / Psychology, Department of / Graduate

Behavior analysts refer to a decrease in response rate following repeated, contingent presentations of a reinforcing stimulus as a product of satiation. Other evidence suggests that these decreases may often be due to habituation to the sensory properties of the reinforcing stimulus. The investigation reported here sought to determine whether decreases in operant responding by 3 adults with developmental disabilities were due to satiation or habituation. During baseline, participants placed poker chips into a container, and no reinforcement was available. Within subsequent phases, participants received diet lemon-lime soda on a fixed-ratio (FR) schedule of reinforcement. In one condition, the color of the soda was constant throughout the session, and in another condition food coloring was added several minutes into the session. Results for at least 2 participants indicated that: (a) soda functioned as a reinforcer for placing poker chips in the can; (b) response rates decreased within the session to baseline levels; and (c) response rates increased following a change in the color of the soda within the session. Results for the third participant were less clear. The results support the argument made by other researchers that the terms habituation (a weakening of a behavior following contact with the reinforcing stimulus) and stimulus specificity (a strengthening of a behavior following a change in the reinforcing stimulus) may be more appropriate descriptors of within-session changes in responding. The factors associated with habituation and satiation, as well as both basic and applied research examples, are discussed.

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No description available.