Infantile handling and the extinction of responses acquired under food reward

A comparison was made of the runway behaviour of rats which had been handled from Days 1-21 and their non-handled litter mates. The training began on Day 70 after the animals were habituated to a restricted food schedule for 10 days. The subjects were given six trials each day in the runway and were rewarded with a 0.045 g. Noyes pellet. After 10 days of rewarded training trials, subjects were given 6 extinction trials a day for 10 days. Results showed that handled rats ran faster than non-handled rats during acquisition and during the first 3 days of extinction. The extinction data suggested that the relationship between emotionality and effects of frustrative non-reward should be re-evaluated.     

Order of partial and consistent reward,reward magnitude shift,and resistance to extinction

In a separate-phase runway experiment with rats, four schedules involving partial (P) and consistent (C) reward (CC, CP, PC, and PP) were crossed with three reward magnitude shift conditions (upshift, nonshift, and downshift). The data revealed three major findings: (a) Reward magnitude downshift generally led to rapid extinction; (b) consistent reward prior to partial reward (CP) resulted in slower extinction than the reverse order (PC) under conditions of reward magnitude shift (particularly downshift); and (c) the relative performance of PC and CP under conditions of reward magnitude shift was reversed from postshift to extinction. On the basis of these data it was suggested that processes not presently identified by reinforcement level theory and stimulus analyzer theory influence extinction following separate-phase acquisition. A modification of reward level theory was presented to provide an account of extinction performance following separate-phase reward reduction.     

Partial reward training level and reward magnitude: Effects on acquisition and extinction

Two groups of 10 rats each received either a large magnitude (0.90 g) or a small magnitude (0.18 g) of partial reward (PR) and seven successive acquisition-extinction sessions in the runway. The large magnitude PR group ran much faster than the small magnitude PR group in the early acquisition sessions with differences between the groups declining over sessions. In the early extinction sessions, the large magnitude PR group showed greater resistance to extinction than the small magnitude PR group, but in the late extinction sessions this relation reversed itself. Finally, resistance to extinction decreased over sessions, this decrease being greater under a large than under a small magnitude of PR.     

Effects of frustration and magnitude of reward on selective attention, size estimation, and verbal evaluation

A high expectancy of success in playing a “fishing game” was established for all subjects (fourth-grade children) Subjects then played the fishing game for money A nonsense syllable was associated with the money. Half of the subjects were frustrated in their attempts to obtain the money, while the remaining subjects were rewarded in their attempts The dependent measures indicated that, relative to rewarded and control subjects, frustrated subjects (a) looked at pictures of money more often, (b) overestimated the size of money, and (c) attributed more positive statements to the syllable associated with reward Subjects frustrated on a larger reward showed these effects to a greater extent than subjects frustrated on a smaller reward These data support the hypothesis that the incentive value of a reward, and of salient neutral stimuli associated with the reward, is increased by frustration, and that this effect is strengthened by the use of larger rewards.     

Effects of reward and nonreward on frustration and attention in attention deficit disorder

The effects of reward schedule (100%, 50%, and 30%) and termination of rewards (extinction) on 30 attention deficit disorder with hyperactivity (ADD-H) and 30 normal children were studied using measures of frustration (speed/strength of lever pulling) and attention (reaction time to a light signal). ADD-Hs pulled harder on the lever than controls during extinction and on the lowest (30%) partial schedule, providing empirical evidence that they respond with greater frustration than normals when expected rewards fail to appear. The groups did not differ on the attentional measure on 100% reward. However, the partial schedules appeared to have an alerting or motivating effect on the controls, so that they responded more quickly and consistently than ADD-Hs on the partial schedules. Findings are discussed with reference to opposing theories regarding the nature of the abnormal response of ADD-Hs to reward.This research was supported by grant MA 11252 from the Medical Research Council of Canada.     

Effect of interpolated extinction after partial delay of reward training on subsequent reacquisition and extinction

Four groups of albino rats were run four trials a day in a straight runway for 44 days. On the first 15 days, two groups were given continuous immediate reward (IR) and two groups a 50 per cent, schedule of 30-sec. partial delay of reward (PDR). On the next 15 days, one IR group and one PDR group were extinguished, while the other IR and PDR groups remained on their original schedules. In the third phase, all groups received 8 days of training on IR. Finally, all groups were given 6 days of extinction training. In the first extinction, PDR produced greater resistance to extinction than IR. In the second extinction period, the PDR group which had previously been given extinction and the two IR groups extinguished relatively rapidly and at approximately the same rates, while the PDR group which had not been extinguished was significantly more resistant to extinction than the other three groups.     

Anger, frustration, and aversiveness

The review of the literature on anger by L. Berkowitz and E. Harmon-Jones (2004) evaluates leading theories of anger for which they offer their own theory of aggression as an integration. Their article leads to a number of empirical questions.