scholarly journals Maintained goal-directed control with overtraining on ratio schedules

2021 ◽  
Vol 28 (12) ◽  
pp. 435-439
Author(s):  
Eric Garr ◽  
Yasmin Padovan-Hernandez ◽  
Patricia H. Janak ◽  
Andrew R. Delamater

It is thought that goal-directed control of actions weakens or becomes masked by habits over time. We tested the opposing hypothesis that goal-directed control becomes stronger over time, and that this growth is modulated by the overall action–outcome contiguity. Despite group differences in action–outcome contiguity early in training, rats trained under random and fixed ratio schedules showed equivalent goal-directed control of lever pressing that appeared to grow over time. We confirmed that goal-directed control was maintained after extended training under another type of ratio schedule—continuous reinforcement—using specific satiety and taste aversion devaluation methods. These results add to the growing literature showing that extensive training does not reliably weaken goal-directed control and that it may strengthen it, or at least maintain it.

2021 ◽  
Author(s):  
Eric Garr ◽  
Yasmin Padovan-Hernandez ◽  
Patricia Janak ◽  
Andrew R. Delamater

It is thought that goal-directed control of actions weakens or becomes masked by habits over time. We tested the opposing hypothesis that goal-directed control becomes stronger over time, and that this growth is modulated by the overall action-outcome contiguity. Despite group differences in action-outcome contiguity early in training, rats trained under random and fixed ratio schedules showed equivalent goal-directed control of lever pressing that grew over time. We confirmed that goal-directed control was maintained over time under another type of ratio schedule—continuous reinforcement—using both specific satiety and taste aversion devaluation methods. These results add to the growing literature showing that extensive training does not always weaken goal-directed control, and can strengthen its expression.


1987 ◽  
Vol 65 (3) ◽  
pp. 787-795 ◽  
Author(s):  
William F. Vitulli ◽  
J. Ken Lambert ◽  
Stella W. Brown ◽  
Joseph M. Quinn

The objective of this exploratory investigation was to determine the interactive effects of fixed-ratio scheduling of microwave reinforcement in tandem with changes in microwave intensity. Nine albino rats were conditioned to regulate their thermal environment with microwave radiation while living in a Skinner (operant conditioning) Box in which the ambient temperature was about 27.13°F at the beginning of the session. Each rat obtained a 6-sec. exposure of microwave radiation on a fixed-ratio schedule of MW reinforcement, the values of which varied from FR-1 to FR-30. Intensities of MW radiation were 62.5 W, 125 W, 250 W, and 437.5 W. Sessions lasted for 8 to 9 hr. over an approximate 13-mo. period. The effects of the intensity of microwave reinforcement varied as a function of the ratio value of the schedule used. Continuous reinforcement (FR-1) produced the lowest over-all rates, whereas FR-15, and FR-25 produced the highest over-all rates. Relatively higher thermal-behavior rates occurred under 62.5 W than under any of the other MW intensities for FR-1, FR-15, and FR-25, whereas FR-10 and FR-30 ratios produced intermediate rates of thermal responding which were constant for all values of MW intensity. These data are explained in terms of interactive effects between the “local” satiation or deprivation properties of the MW intensity and the ratio requirements of the schedule of MW reinforcement.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vladimir L. Tsibulsky ◽  
Andrew B. Norman

AbstractTransition from the highest rate of lever-pressing activity during the unloading (extinction) phase of a cocaine self-administration session to an extremely low activity rate during the remission phase is in many cases gradual. This makes it difficult to assess the duration of the unloading phase after a fixed ratio 1 (FR1) or breakpoint after a progressive-ratio (PR) self-administration session. In addition, 3–5 days of training under the PR schedule results in a dramatic and persistent increase in the rate of presses during PR sessions and in the unloading phase following FR1 self-administration sessions. The goals of this study were to find the definition of the last press demarcating the border between the unloading and remission phases of the session and to determine if this border was also affected by PR training. Rats were trained to self-administer cocaine under the FR1 schedule and then under the PR schedule of drug delivery. Distributions of inter-press intervals (IPIs) during the unloading phase in sessions before and after PR training were compared. It was found that the distribution of cocaine-induced IPIs during the unloading phase was lognormal, bimodal, and independent of previously injected cocaine unit doses. The first mode represented intervals within the short bouts of stereotypic presses and the second mode represented intervals between bouts. The two modes were approximately 0.7 s and 21 s during unloading prior to and 0.6 s and 1.5 s after PR self-administration training. The total number of presses per unloading phase increased eightfold. When the FR1 schedule was restored, the intervals between bouts remained very short for at least 7–10 days and only then started a gradual increase towards baseline levels. The last unloading press was defined as the press followed by the IPI longer than the defined criterion. PR training resulted in a substantial and long-lasting increase in lever-pressing activity during unloading. The duration of the unloading phase did not depend on the rate of lever-pressing activity.


1967 ◽  
Vol 25 (2) ◽  
pp. 561-565 ◽  
Author(s):  
Joseph N. Hingtgen ◽  
Susan K. Coulter

To determine whether auditory stimuli can control operant responding in mute autistic children, 4 Ss were presented with 5 pairs of auditory stimuli. During the presentation of 1 stimulus the child was able to obtain food on a previously established fixed-ratio schedule of lever pressing, while during the presentation of the second stimulus an extinction schedule was in effect. A new set of stimuli was introduced when the preceding set was learned. 3 of the 4 children learned to discriminate four pairs of auditory stimuli within an average of 36 daily 40-min. sessions. The data indicate that some mute autistic children are capable of learning simple auditory-motor associations.


2021 ◽  
Vol 22 (5) ◽  
pp. 2397
Author(s):  
Chrysostomos Charalambous ◽  
Tereza Havlickova ◽  
Marek Lapka ◽  
Nina Puskina ◽  
Romana Šlamberová ◽  
...  

Cannabis/cannabinoids are widely used for recreational and therapy purposes, but their risks are largely disregarded. However, cannabinoid-associated use disorders and dependence are alarmingly increasing and an effective treatment is lacking. Recently, the growth hormone secretagogue receptor (GHSR1A) antagonism was proposed as a promising mechanism for drug addiction therapy. However, the role of GHS-R1A and its endogenous ligand ghrelin in cannabinoid abuse remains unclear. Therefore, the aim of our study was to investigate whether the GHS-R1A antagonist JMV2959 could reduce the tetrahydrocannabinol (THC)-induced conditioned place preference (CPP) and behavioral stimulation, the WIN55,212-2 intravenous self-administration (IVSA), and the tendency to relapse. Following an ongoing WIN55,212-2 self-administration, JMV2959 3 mg/kg was administered intraperitoneally 20 min before three consequent daily 120-min IVSA sessions under a fixed ratio FR1, which significantly reduced the number of the active lever-pressing, the number of infusions, and the cannabinoid intake. Pretreatment with JMV2959 suggested reduction of the WIN55,212-2-seeking/relapse-like behavior tested in rats on the twelfth day of the forced abstinence period. On the contrary, pretreatment with ghrelin significantly increased the cannabinoid IVSA as well as enhanced the relapse-like behavior. Co-administration of ghrelin with JMV2959 abolished/reduced the significant efficacy of the GHS-R1A antagonist in the cannabinoid IVSA. Pretreatment with JMV2959 significantly and dose-dependently reduced the manifestation of THC-induced CPP. The THC-CPP development was reduced after the simultaneous administration of JMV2959 with THC during conditioning. JMV2959 also significantly reduced the THC-induced behavioral stimulation in the LABORAS cage. Our findings suggest that GHS-R1A importantly participates in the rewarding/reinforcing effects of cannabinoids.


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