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The Effects Of Pre-Trial Event Stimulus Properties On Timing In The Peak Interval Procedure, Daniel A. Garces
The Effects Of Pre-Trial Event Stimulus Properties On Timing In The Peak Interval Procedure, Daniel A. Garces
Dissertations, Theses, and Capstone Projects
In the peak interval procedure, intruded conditioned stimuli produce shifts in peak/middle time towards later values, regardless of whether these stimuli are presented prior to or during the timing signal. Although the effects of during-trial stimulus properties—temporal location, duration, and salience—have been previously reported, no research exists on how before-trial stimulus properties influence the extent of shifts in middle time. In the present study, we manipulated within subjects both the temporal location and type (i.e., cue alone, response-independent reinforcer alone, or cue and response-contingent reinforcer together) of the pre-trial event. An individual-trial analysis suggested that the type of stimulus event …
Series Of Intermittent Heroin Injections Enhances Acquisition Of Operant Responding For Cues Paired With Natural Rewards, Jennifer Morrison
Series Of Intermittent Heroin Injections Enhances Acquisition Of Operant Responding For Cues Paired With Natural Rewards, Jennifer Morrison
Dissertations, Theses, and Capstone Projects
Repeated-intermittent heroin use has been implicated in altering learning processes. Ranaldi et al. (2009) and Morrison et al. (2011) demonstrated that repeated-intermittent heroin administration leads to an enhancement of conditioned reinforcement by a food-paired light stimulus; however, the mechanism governing this effect is still largely unknown. The aims of the present study were to examine modifications in Pavlovian and operant associations for cues paired with natural rewards after a series of intermittent heroin injections. The study consisted of three phases: (1) Pavlovian Conditioning Phase (4 days)- in which three groups of rats had a light stimulus paired with food, and …