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Operant Conditioning of Rats |
Saturday, May 23, 2020 |
10:00 AM–11:50 AM |
Marriott Marquis, Level M2, Marquis Ballroom 1/2 |
Area: EAB |
Instruction Level: Basic |
Chair: Fabio Leyser Goncalves (Universidade Estadual Paulista) |
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Evaluation of Conditioned Reinforcement on Spontaneously Hypertensive Rats |
Domain: Basic Research |
FABIO LEYSER GONCALVES (Universidade Estadual Paulista), Beatriz Guimarães (Paradigma), Guilherme Popowicz (Universidade de São Paulo), Juliana Brasileiro (Universidade Federal de São João Del Rey) |
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Abstract: Spontaneously Hypertensive Rats (SHR)has been considered as a valid animal model of attention deficit hyperactivity disorder (ADHD). Several theories propose that ADHD would be less responsive to positive reinforcement, especially delayed and conditioned reinforcement. The aim of this paper is to compare conditioned reinforcement on SHR, Wistar Kyoto (WKY) and Wistar rats. For that 16 SHR, 15 WKY and 12 Wistar were submitted to a Multiple FI2min-Ext5min schedule where a feedback light was manipulated (Experiment 1) or to a conditioned reinforcement procedure where a 3s lights-off stimulus (LO) was associated to food with or without delay, and then tested as reinforcer under extinction for the primary reinforcer (Experiment 2). On Experiment 1, ANOVA Type Nonparametric Statistics indicated differences between strains [F (1,644, 16) = 12.097; p<0.001], but not feedback light as conditioned reinforcement [F (1, 14.61985) = 2.688; NS]. Experiment 2 Indicated a main effect of strain [F(1.9, 4.3) = 3.199; p<0.05], lever [F(1, 8)=64.862; p<0.001], and phase [F(4.3, 3.6) = 4.977; p<0.001] and all interactions (between p<0.001 and p<0.05). Relative treatment effects indicated that SHR responded more under extinction than WKY and WIS. Together, experiments suggests that SHR would have a greater deficit on extinction than on reinforcement process. |
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Affordances Influence Lever-Pressing Acquisition Speed and Lever Choice in Rats |
Domain: Basic Research |
ANGEL JIMENEZ (Universidad de Guadalajara) |
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Abstract: Behavior analysis has focused on examining the effects of the consequences of behavior. However, evidence suggests that rats’ operant performance is attuned to the affordances that the operant setting provides, such as lever height. This presentation will cover two studies on rats’ progression from lever pressing acquisition to situations where lever pressing has been instrumentally conditioned. In experiment 1 lever pressing acquisition was examined in three groups of naïve rats, in each group lever height was set at 1, 11, or 18 cm-height. Response acquisition was faster at the 11-cm height lever group, and lever pressing latency was shorter with the 18-cm lever group. In experiment 2 lever pressing was reinforced in two concurrent equal variable-ratio schedules of reinforcement, and in successive conditions lever height was varied asymmetrically. That is, one lever was higher than the other. Across conditions, preference between both levers changed showing a linear trend with increasing lever heights. Collectively, the research suggests that preorganized properties of behavior (i.e., the animal’s abilities) interact with the environment before operant learning emerges. |
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Why Study Duration? A Summary of Recent Investigations |
Domain: Basic Research |
THOMAS P. BYRNE (Massachusetts College of Liberal Arts), Nicole Nadeau (Massachusetts College of Liberal Arts), Kabas Essameldin Elmeligy (Massachusetts college of liberal arts), Brianna Sarno (Massachusetts College of Liberal Arts) |
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Abstract: Compared to rate of discrete responding, response duration has received scant attention as a dependent measure in behavior analysis. We will present results from a series of recent experiments in which we studied the duration of lever-pressing in laboratory rats. In all of the investigations, we arranged the delivery of edible reinforcers if depressing a response lever fell under or exceeded a programmed interval. We will discuss three general findings in detail. First, response duration may present some advantages over response rate for studying the effects of delayed reinforcement. Second, response duration increases significantly during extinction. This occurs whether or not there has been a history of differential reinforcement for depressing the response lever. This has implications for the interpretation of resurgence when behavior has a salient duration dimension. And finally, arranging reinforcement for response duration results in chains of idiosyncratic responses that rats emit concurrently with lever pressing. Whether these responses should be operationally defined as lever pressing presents a conceptual challenge. |
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Effects of the Temporal Separation of Multiple-Schedule Components on Differential Resistance to Change |
Domain: Basic Research |
RAQUEL ALO (Universidade de Brasília, Brazil), Sara Neves (Universidade de Brasília), Felipe Rodrigues (Universidade de Brasília) |
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Abstract: To examine the effects of the temporal separation of multiple VI VI schedule components on differential resistance to change (DRTC), two experiments were conducted with rats. Reinforcement rates and magnitudes (reinforcers per cycle) were manipulated in Experiments 1 and 2, respectively, to produce rich and lean components. In both experiments, the separation of the components was manipulated by using different component durations, during one condition, and different intercomponent intervals (ICI), during another condition. Total exposure to the components was constant across sessions of each condition. Resistance to satiation was evaluated by delivering increasing amounts of the reinforcer before each test session. In Experiment 1, different component duration either increased (F2 and F4), decreased (F1 and F02), or had no consistent effects (F3) on DRTC. Increasing ICIs produced either an increase (F02) or an increase followed by a decrease (i.e., an inverted U function) in DRTC. In Experiment 2, increases in component duration produced either an increase (F6 and F8) or no consistent effects on DRTC. Increasing ICIs produced an increase (F7) or an inverted U effect on DRTC. Results are discussed in terms of the discrimininability of contingencies that are too close or too separate in time. |
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