Helen B. Daly

Reinforcing Properties of Escape From Frustration Aroused In Various Learning Situations

Publisher Summary This chapter summarizes research from various learning situations involving reward manipulations in which frustration is typically introduced to account for the results. These researches provides empirical support for the frustration interpretation by using an escape-from-frustration response to measure independently the relative amounts of frustration present. The experiments presented in these researches indicate that the subjects learn a new response to escape from frustration-arousing stimuli. They also demonstrate that rats learn a hurdle-jump response to escape stimuli paired with nonreward or a reduced reward previously paired with a large reward. This result is obtained under various conditions and learning situations, such as following alley acquisition or direct placements on a continuous reinforcement schedule with solid food or sucrose rewards, in combination with stimuli paired with shock or with an increase in delay of reward, and following alley acquisition on a partial or varied reinforcement schedule. These experiments also demonstrate that the amount of discrimination training influences escape behavior from both S+ and S–, and that the stimuli associated with the absence of an “observing response” are more aversive than the stimuli associated with the presence of an “observing response.”

Ingestion of environmentally contaminated lake Ontario salmon by laboratory rats increases avoidance of unpredictable aversive nonreward and mild electric shock

To determine what behavioral changes are caused by consumption of Lake Ontario salmon, a 30% diet of Lake Ontario or control Pacific Ocean salmon was fed to rats for 20 days. In Experiments 1 and 2 (preference-for-predictability E-maze test), rats fed Lake Ontario salmon developed a preference for predictable food rewards more quickly than did the control rats. In Experiments 3 (passive avoidance) and 4 (conditioned suppression), rats fed Lake Ontario salmon suppressed responding to food far more after the introduction of mild electric shocks than did control rats. All results supported the hypothesis that ingestion of Lake Ontario salmon, contaminated with polychlorinated biphenyls, mercury, lead, etc., increases the reactivity of rats to aversive events. The results were successfully simulated by DMOD, a mathematical model of learning, using the assumption that rats fed Lake Ontario salmon find unpredictable nonreward and mild shock more aversive.

Reward reductions found more aversive by rats fed environmentally contaminated salmon

Pacific salmon stocked in Lake Ontario concentrate persistent toxic chemicals such as PCBs, DDT, DDE, mercury and dioxin. The present experiments support earlier findings that consumption of these salmon by laboratory rats increases their behavioral reactions to negative events. For 20 days rats were fed a diet consisting of 30% Lake Ontario salmon or a control diet of Pacific Ocean salmon or no salmon. They were then trained to run down an alley to receive a large 15-pellet or small 1-pellet food reward (6 trials/day). Following 72 trials the 15-pellet groups were shifted to 1 pellet for 90 trials, and showed a contrast (depression) effect: they ran more slowly than the groups always given 1 pellet. Rats previously fed Lake Ontario salmon showed a much larger contrast effect than the two control groups. These results were replicated in a second experiment, and a group fed a 10% diet of Lake Ontario salmon for 60 days showed the same size contrast effect as the group fed a 30% diet for 20 days.

Learning to escape cues paired with reward reductions following single- or multiple-pellet rewards

In Experiment 1, three groups of rats were given 60 runway acquisition trials (6/day) to either one 500-mg pellet (Group 1L), 25 20-mg pellets (Group 25S), or one 20-mg pellet (Group IS). Rate of approach to asymptote was faster for Group 25S than for Group 1L, and at asymptote, they ran faster than Group IS. All groups then received one 20-mg pellet for 30 trials. Group 25S showed a greater depression effect than did Group 1L. The acquisition results were replicated in Experiment 2, and, during a third phase in which Ss were given hurdle-jump training, both shifted groups jumped faster than Group IS, but Group 25S jumped the fastest. It was concluded that greater amounts of frustration are elicited when both reward magnitude and number of pellets are reduced than when only reward magnitude is reduced.

Changes in learning about aversive nonreward accounts for ontogeny of paradoxical appetitive reward effects in the rat pup: a mathematical model (DMOD) integrates results.

Baby rats do not show any paradoxical appetitive reward effects (e.g., faster extinction following partial than continuous reinforcement, contrast effects when large and small rewards are given) until they are at least 12-14 days old, but can learn to pattern when reward and nonreward are alternated (e.g., Amsel, 1986). These results have been puzzling, but are now successfully integrated by DMOD (Daly MODification of Rescorla and Wagners [1972] mathematical model; Daly & Daly, 1982). It was assumed that young rats do not have the capacity to learn about aversive nonreward but slowly gain this ability between 12 and 26 days (1 parameter reflecting the rate of conditioning of aversive nonreward, beta 1 for Vav, is increased from 0 to .15 beginning at 12 days). This theoretical integration has implications for understanding behavioral and neurological development of altricial organisms, and effects of neurological damage and toxic substances.

MATERNAL CONSUMPTION OF LAKE ONTARIO SALMON IN RATS PRODUCES BEHAVIORAL CHANGES IN THE OFFSPRING

The current study assessed the effects of maternal, paternal, or combined parental consumption of Lake Ontario salmon in rats on the behavior of their offspring. Adult female Sprague-Dawley rats were put on a 30 day diet of either ground rat chow containing 30% Lake Ontario salmon (LAKE) or 30% Pacific Ocean salmon (OCEAN). These females were then mated with adult male rats similarly exposed (LAKE or OCEAN). An additional control group of males and females who were fed ground rat chow (MASH) only were also mated. These pairing combinations resulted in five offspring groups: LAKE-LAKE, LAKE-OCEAN, OCEAN-LAKE, OCEAN-OCEAN, MASH-MASH. When the offspring reached 80 days of age, they were tested for reactivity to frustrative nonreward using runway successive negative contrast, which has been repeatedly shown to be increased in adult rats fed Ontario salmon. Consistent with previous work, results showed that the behavior of the OCEAN-OCEAN rats did not differ from the MASH- MASH group, indicating that a salmon diet per se does not cause behavioral change. However, the offspring of dams who consumed Lake Ontario salmon (LAKE-LAKE and OCEAN-LAKE) showed an increased depression effect relative to controls. There was little evidence of a paternal effect. A follow-up experiment employed cross-fostering to determine the relative contribution of pre- and/or postnatal exposure to Lake Ontario salmon consumption on offspring behavior. Rat pups were cross-fostered to or from dams who consumed Lake Ontario salmon during gestation and parturition. Results from two separate replications indicated that prenatal (LAKE to OCEAN) exposure alone or postnatal (OCEAN to LAKE) exposure alone produced a large increase in successive negative contrast relative to controls (OCEAN to OCEAN). These data are strong evidence of behavioral changes produced by maternal consumption of Lake Ontario salmon in the offspring rat. Further, they indicate that either prenatal or postnatal exposure alone is sufficient to produce behavioral changes in the offspring.

Infantile stimulation and its effects on frustration- and fear-motivated behavior in rats

Abstract Infant rats that were either removed from the nest each day (handled) or left undisturbed (nonhandled) were, in adulthood, given 72 food-reinforced runway acquisition trials followed by 24 trials of extinction training with or without shock. Handled and nonhandled control animals were given runway training without food reinforcement. Reinforced rats ran faster than nonreinforced rats, and handled rats ran faster than nonhandled rats during the initial trials of runway acquisition irrespective of the reinforcement condition. Nonhadled rats stopped running sooner than handled rats when shock was introduced in the goalbox, but differences between handled and nonhandled rats given extinction training without shock were small. Results of a second experiment showed no differences between handled and non-handled rats in the magnitude of the depression effect after an incentive shift. It was concluded that infantile handling had little effect on frustration-motivated behavior, but did affect fear-motivated behavior.

A computer simulation/mathematical model of learning: Extension of DMOD from appetitive to aversive situations

AbstractThe computer simulation/mathematical model called DMOD, which can simulate over 35 different phenomena in appetitive discrete-trial and simple free-operant situations, has been extended to include aversive discrete-trial situations. Learning (V) is calculated using a three-parameter equationn% MathType!MTEF!2!1!+-% feaagCart1ev2aaatCvAUfKttLearuqr1ngBPrgarmWu51MyVXgatC% vAUfeBSjuyZL2yd9gzLbvyNv2CaeHbd9wDYLwzYbItLDharyavP1wz% ZbItLDhis9wBH5garqqtubsr4rNCHbGeaGqiVu0Je9sqqrpepC0xbb% L8F4rqqrFfpeea0xe9Lq-Jc9vqaqpepm0xbba9pwe9Q8fs0-yqaqpe% pae9pg0FirpepeKkFr0xfr-xfr-xb9adbaqaaeGaciGaaiaabeqaam% aaeaqbaaGcbaGaeuiLdqecbaGae8NvayLae8xpa0JaeqySdeMaeqOS% diMae8hkaGcccaGae43UdWMae4NeI0Iaf8NvayLbaebacqWFPaqkaa% a!4743!nn

The combined effects of frustrative nonreward and shock on aggression between rats

Delta V = alpha beta (lambda - bar V)