Multiple Shifts in Magnitude of Reward

1981 ◽  
Vol 49 (1) ◽  
pp. 335-338 ◽  
Author(s):  
David T. Goomas
Keyword(s):  
Contrast Effect ◽  
Large Reward ◽  
Small Reward ◽  
Negative Contrast Effect ◽  
Negative Contrast ◽  
Positive Contrast ◽  
Positive Contrast Effect ◽  
Shift Group

Three groups of 5 rats were administered either large reward (10 pellets), small reward (2 pellets), or multiple shifts (Iarge-small-large-etc.) in an alleyway. The multiple-shift group received a total of 7 large and 6 small phases of reinforcement. Early in training the shifted group exhibited positive contrast effect to a shift to large reward and negative contrast effect to a shift to small reward. Later in training, the same group showed neither effect perhaps because experience with the shift provided a smaller discrepancy between the upshifts and downshifts in magnitude of reward.

Runway Performance as a Function of Magnitude of Runway Reward and Intertrial Reinforcement

1973 ◽  
Vol 32 (1) ◽  
pp. 331-335 ◽  
Author(s):  
Roger W. Black ◽  
William House ◽  
Jon Moss
Keyword(s):  
Contrast Effect ◽  
Negative Contrast Effect ◽  
Negative Contrast ◽  
Positive Contrast ◽  
Straight Alley ◽  
Positive Contrast Effect ◽  
Runway Performance ◽  
Extended Training ◽  
Runway Trial ◽  
Intertrial Reinforcement

Rats were trained to traverse a straight alley for either 1 or 10 food pellets as reward. Each runway trial was preceded by an intertrial reinforcement of 1 or 10 pellets. A negative contrast effect obtained and persisted throughout the 72 trials conducted. Although there was a strong suggestion of a positive contrast effect throughout training, the effect did not prove reliable. The contrast effect results were interpreted as challenging the view that with extended training ITRs become “irrelevant” to runway reward.

Effects of Preshift Small Magnitude of Reward Received during Goalbox Placements on the Negative Contrast Effect

2004 ◽  
Vol 94 (2) ◽  
pp. 683-686 ◽  
Author(s):  
Richard S. Calef ◽  
Michael C. Choban ◽  
Katherine R. Glenney ◽  
Ruth A. Calef ◽  
Errika M. Mace ◽  
...  
Keyword(s):  
Contrast Effect ◽  
Large Reward ◽  
Food Reward ◽  
Small Reward ◽  
Negative Contrast Effect ◽  
Negative Contrast ◽  
Straight Alley ◽  
Control Group ◽  
Small Magnitude ◽  
Experimental Group

During preshift, one experimental group of rats was given a large magnitude of food reward following a traversal of a straight alley and during a goalbox placement, while the other experimental group was given a small reward during goalbox placement and a large reward following a run. During postshift, all experimental groups were given a small reward of food following a traversal down the runway and during a goalbox placement. A control group was maintained on small reward during placements and following a traversal throughout the study. Only the group who received preshift large reward during placement and following a runway response ran slower to small reward during postshift than the control group maintained on small reward (negative contrast effect).

Effects of Shifts in Delayed Food Reward: Repeated Shifts

1979 ◽  
Vol 45 (1) ◽  
pp. 219-222
Author(s):  
David T. Goomas
Keyword(s):  
Contrast Effect ◽  
Food Reward ◽  
Negative Contrast Effect ◽  
Negative Contrast ◽  
Positive Contrast ◽  
Positive Contrast Effect ◽  
Second Shift

In a repeated-shifts study, a negative contrast effect was obtained when a group of rats was shifted from 0- to 20-sec. delayed food reward only in the first, but not the second, shift. No positive contrast effect was obtained in either shift when a group of rats was shifted from 20- to 0-sec. delayed food reward. Shifts in delay are not repeatedly effective in inducing negative contrast and not effective at all in inducing positive contrast.

Dimensions of sucrose solutions in the successive negative contrast effect

2020 ◽  
Vol 69 ◽  
pp. 101615
Author(s):  
Juan Carlos Ruiz-Salas ◽  
L. Gonzalo de la Casa ◽  
Mauricio R. Papini
Keyword(s):  
Contrast Effect ◽  
Negative Contrast Effect ◽  
Negative Contrast ◽  
Successive Negative Contrast ◽  
Sucrose Solutions

scholarly journals Psychopharmacological characterisation of the successive negative contrast effect in rats

2015 ◽  
Vol 232 (15) ◽  
pp. 2697-2709 ◽  
Author(s):  
C. E. Phelps ◽  
E. N. Mitchell ◽  
D. J. Nutt ◽  
H. M. Marston ◽  
E. S. J. Robinson
Keyword(s):  
Contrast Effect ◽  
Negative Contrast Effect ◽  
Negative Contrast ◽  
Successive Negative Contrast

Behavioral Contrast in Pigeons with Qualitatively Different Reinforcers

1979 ◽  
Vol 45 (2) ◽  
pp. 535-538 ◽  
Author(s):  
Donald L. Pingrey ◽  
Denis L. Delehanty ◽  
D. Alan Stubbs
Keyword(s):  
Multiple Schedule ◽  
Contrast Effect ◽  
Reinforcement Schedule ◽  
Behavioral Contrast ◽  
Positive Contrast ◽  
Response Rates ◽  
Positive Contrast Effect ◽  
Positive Behavioral Contrast ◽  
Extinction Component

Three white Carneaux pigeons were trained to respond on a mult VI 1-min. (milo reinforcement), VI 1-min. (pea reinforcement) schedule when each component was associated with a different key, feeder, and reinforcer. The experiment was divided into four phases. In Phases 1 and 3, baseline rates of responding were established. In experimental Phases 2 and 4, one component of the multiple schedule was changed to extinction. During the experimental phases, response rates decreased in the extinction component and increased in the unchanged component (positive behavioral contrast). The increase in responding in the unchanged component was greater when the more valued reinforcer was extinguished. These findings are very similar to those reported by Beninger and Kendall (1975) and extend the positive contrast effect to another species, pigeons.

scholarly journals Successive Positive Contrast in One-Way Avoidance Learning

2002 ◽  
Vol 55 (2b) ◽  
pp. 171-184 ◽  
Author(s):  
Antonio Cándido ◽  
Antonio Maldonado ◽  
Alicia Rodríguez ◽  
Alberto Morales
Keyword(s):  
Avoidance Response ◽  
Avoidance Learning ◽  
Contrast Effect ◽  
Positive Contrast ◽  
Warning Signal ◽  
Specific Weight ◽  
Control Group ◽  
Positive Contrast Effect ◽  
Safe Place ◽  
Improved Performance

The main finding of these experiments was a positive contrast effect in one-way avoidance learning. Experiment 1 showed that increasing safety time during one-way avoidance training led to improved performance, surpassing that of a control group that had received the high reward (safe time) from the beginning of training. Experiment 2 showed that a similar positive contrast effect occurred when the time spent in the danger compartment before the onset of the warning signal was shortened. These results suggest that time spent in a safe context acts as a reinforcer of the avoidance response; however, its incentive value depends not only on its duration, but also on the length of the time spent in the danger compartment before the onset of the signal. Overall, results also suggest that the avoidance response is a mixture of flight (motivated by fear) and approach (to a safe place) behaviour. The specific weight of the flight or approach component may be a function of the time and the amount of activation of each emotional state (fear or relief) due to opponent homeostatic compensatory processes that occur in the danger and safe compartments during one-way avoidance learning.

scholarly journals Effects of early life and current housing on sensitivity to reward loss in a successive negative contrast test in pigs

2019 ◽  
Vol 23 (1) ◽  
pp. 121-130 ◽  
Author(s):  
L. Luo ◽  
I. Reimert ◽  
E. A. M. Graat ◽  
S. Smeets ◽  
B. Kemp ◽  
...  
Keyword(s):  
Early Life ◽  
Large Reward ◽  
Small Reward ◽  
Affective State ◽  
Negative Contrast ◽  
Lower Probability ◽  
Housing Conditions ◽  
Long Term Effects ◽  
Sensitivity To Reward ◽  
Successive Negative Contrast

Abstract Animals in a negative affective state seem to be more sensitive to reward loss, i.e. an unexpected decrease in reward size. The aim of this study was to investigate whether early-life and current enriched vs. barren housing conditions affect the sensitivity to reward loss in pigs using a successive negative contrast test. Pigs (n = 64 from 32 pens) were housed in barren or enriched conditions from birth onwards, and at 7 weeks of age experienced either a switch in housing conditions (from barren to enriched or vice versa) or not. Allotting pigs to the different treatments was balanced for coping style (proactive vs. reactive). One pig per pen was trained to run for a large reward and one for a small reward. Reward loss was introduced for pigs receiving the large reward after 11 days (reward downshift), i.e. from then onwards, they received the small reward. Pigs housed in barren conditions throughout life generally had a lower probability and higher latency to get the reward than other pigs. Proactive pigs ran overall slower than reactive pigs. After the reward downshift, all pigs ran slower. Nevertheless, reward downshift increased the latency and reduced the probability to get to the reward, but only in pigs exposed to barren conditions in early life, which thus were more sensitive to reward loss than pigs from enriched early life housing. In conclusion, barren housed pigs seemed overall less motivated for the reward, and early life housing conditions had long-term effects on the sensitivity to reward loss.

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