Shock-induced suppression and potentiation of instrumental responding by rats.

A total of 20 female Long-Evans rats trained to press a retractable lever for food in a discrete trials situation were subsequently punished for responding. After suppression of responding, response-independent shocks were presented, with intensity increased on successive daily sessions. Shock induced responding, and number of responses, increased and response latencies decreased with increasing shock intensity. Control Ss initially given uncorrelated lever-food presentations responded significantly less to response-independent shock, and their responding was not systematically related to shock intensity. Results are consistent with the view that shock induces or disinhibits prepotent responses and inconsistent with the view that, to be effective in suppressing behavior, punishment must induce responses incompatible with the punished response. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Punished behavior: increases in responding after d-amphetamine

Responding maintained in squirrel monkeys under a 10-min fixed-interval schedule of food presentation was suppressed by presenting a shock after every 30th response (punishment). During alternate 10-min periods of the same experimental session, but in the presence of a different discriminative stimulus, responding either had no effect (extinction) or postponed delivery of an electric shock (avoidance). During sessions when the avoidance schedule was not in effect, d-amphetamine sulfate decreased punished responding. When the avoidance schedule was present during alternate 10-min periods, however, d-amphetamine (0.01 minus 0.56 mg/kg, i.m.) markedly increased responding during punishment components. Increases in responding during avoidance components were also evident. The effects of d-amphetamine on punished responding depend on the context in which that responding occurs.     

Punishment alters the discriminative stimulus effects of midazolam.

Experiment 1 examined the effects of punishment on the discriminative stimulus (DS) effects of midazolam (M) and pentobarbital (P) in 3 pigeons. Sessions began with a fixed-interval (Fl) 3-min schedule of food reinforcement. After 40 min, either saline (S) or 0.56 mg/kg of M was injected. A drug-discrimination (DD) component began 10 min later. Pecking the left key produced grain after S injections, whereas pecking the right key produced grain after M. Dose-response curves for M and P were obtained under these conditions and also when every 30th peck during the Fl was punished by shock. The introduction of punishment increased sensitivity to the DS effects of M and P. Experiment 2 examined whether a punishment history increases sensitivity to the DS effects of M. After DD training and testing, pecking was punished for 10 sessions. This history shifted the M dose-response curve to the left for 3 of 4 pigeons. These results emphasize the contribution of behavioral variables to the DS effects of drugs. Environmental variables appear to play a prominent role in guiding sensitivity to the subjective effects of drugs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Free-operant avoidance behavior in rats with lateral septal lesions: Effect of shock intensity

The purpose of experiment 1 was to examine the relationship between shock intensity and normal rats' free-operant (Sidman) avoidance performance on a 3-component, multiple schedule. The results showed an inverted U-shaped relation between response rate and shock intensity, but no consistent relation between shock rate and shock intensity was found. Experiment 2 showed that lateral sptal lesions produced a bidirectional change in reactivity to electric shock. An increased reactivity was observed in the initial sessions starting on the 11th day after the surgery, while a reduced reactivity was observed in the final sessions when stable performance had been reacquired. These changes were not a function of the waning of general hyperreactivity with post-operative recovery: the septal lesions in this study did not produce any "sham rage". From 40 to 80% of the variance in response rates was accounted for by this bidirectional change in the reactivity to shock.     

Exposure to the unconditioned stimulus alone: Effects on retention and acquisition of conditioned suppression.

In 3 experiments with 104 male Sprague-Dawley rats, repeated exposure to an electric-shock UCS resulted in a decrement in retention of conditioned suppression evoked by a previously established excitatory CS and retarded subsequent acquisition of conditioned suppression to a novel CS paired with shock. Exp I showed that 10 sessions of exposure to shock alone were required to produce a decrement in retention of conditioned suppression, whereas retardation in the acquisition of conditioned suppression was obtained following either 5 or 10 sessions of exposure to shock alone. Exp II demonstrated that both of these effects were directly related to the intensity of the shocks. In Exp III, the decrement in retention of conditioned suppression produced by 10 sessions of exposure to shock alone was inversely related to the interval between the last exposure to shock and the test of the target CS. Findings are discussed in terms of associative and nonassociative accounts of the effects of UCS-alone procedures. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pavlovian and instrumental determinants of response suppression in the pigeon.

Exp I demonstrated the formation of a discriminated punishment effect in the absence of a conditioned emotional response. Electric shocks were delivered at random intervals to 3 naive male White Carneaux pigeons pecking for food on a variable-interval schedule. During a 1-min visual conditioned stimulus (CS), scheduled shocks were delayed until a response occurred (punishment). Differential suppression to the CS was observed in addition to overall suppression. Suppression was related to shock intensity. In Exp II with the same Ss, CS suppression was related to the CS and was not an artifact of response pattern or discrimination of shock patterns. The punishment contingency without the CS did not suppress behavior, and the CS without the punishment contingency did not relieve suppression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of punishment (electric shock) on perceptual learning.

3 experiments were conducted to explore the consequences of the association of punishment with percepts and to trace its residual effects. Electric shock was associated with tactual profiles of faces. Voltage, temporal contiguity, and ability to escape shock were varied. The results showed that there was more reporting of the non-shocked profile as intensity of shock increased, that escape conditions lead to more reporting of the shocked profiles, the shocked profile is recalled more vividly, and as the delay between exposure and recall increases there is more reporting of the nonshocked profile. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delay of punishment and choice behavior in the rat.

Trained 4 groups of female Sprague-Dawley albino rats (N = 24) to press each of 2 bars for reward delayed 120 sec. A different set of distinctive cues prevailed between bar press and food depending on which bar was pressed. For experimental Ss shocks were then introduced following each response to the preferred bar. The response-shock interval was 1.5, 12, or 96 sec. Experimental Ss' preference shifted from the shock bar; preference remained the same for no-shock controls. The rate of changes was a negative function of delay of shock, but final percentage of responses to the nonshock bar was the same for all delays. Results support the hypothesis that delay of punishment as such has no effect on choice at asymptote. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Curvilinear effects of severity of punishment on species-typical aggressive display in Betta splendens..

Three experiments examined the effects of the severity of punishment, defined in terms of intensity/voltage (Exp I), duration (Exp II), and frequency combined with 2 levels of intensity (Exp III), on the aggressive display of Siamese fighting fish. Findings show that display duration was a curvilinear function of punishment severity regardless of whether severity was defined as intensity, duration, or frequency. Relative to nonpunished conditions, moderate levels of punishment increased display duration, whereas strong punishment led to suppression. Increased biting was observed with moderate levels of punishment frequency. Results are discussed in terms of adaptive significance of the organism's reaction to counteraggression. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental differences in rats of suppressive effects of extinction as a function of extinction sessions.

Used 1 or 2 extinction sessions, 2 extinction procedures, and 2 ages of rats (23 and 95-120 days old) in a developmental analysis of the effects of extinction. Ss were 96 male Long-Evans hooded rats. The apparatus was a Y maze with 3 discriminably different arms. After 10 sessions of positive reinforcement, Ss received either 1 or 2 extinction sessions in which responding in 1 arm was no longer reinforced. Following extinction, responding in all 3 arms was again reinforced. Recovery data show that (a) the suppressive effects of extinction were greater for adults than infants and (b) the 2nd extinction session had a greater impact on the adults. Results support the hypothesis that younger rats have greater difficulty than older ones in inhibiting a response. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of US intensity and number of CS-US pairings on maintenance of vicious-circle behavior in rats by secondary punishment.

By factorial arrangement, 8 groups of male hooded Long-Evans rats (N = 80) received either 3 or 15 buzzer presentations associated with a shock of 0, 55, 70, or 85 V in a conditioning apparatus. 1 other group was administered buzzer and shock presentations randomly paired in time; the final group had 15 pairings of buzzer and an 85-V shock. During extinction of a runway avoidance response, each group received continuous buzzer punishment except the final group, which received no buzzer. It was found that alley running speed and trials to extinction were increasing functions of shock intensity presented during fear conditioning. While the number-of-pairings variable was somewhat more equivocal in its effects, results largely substantiate expectations of a conditioned-fear interpretation of secondary self-punitive behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facilitative and suppressive effects of punishment on species-typical aggressive display in Betta splendens.

Determined effects of moderate and intense punishment on aggressive behavior. Following either 15 or 45 massed presentations to a mirror, 35 Siamese fighting fish were punished for aggressive display (gill extension). Intense shock punishment led to complete suppression of the display. Recovery of the display depended on the level of habituation, i.e., only the fish given 15 mirror presentations prior to punishment showed recovery. Given "room" for an increase, a moderate level of punishment led to longer displays. A 2nd experiment with 6 Ss confirmed this latter finding with spaced (daily) blocks of trials. (23 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reinforced alternative behavior during punishment and extinction with rats.

Evaluated the suppressive effect of a reinforced alternative response during extinction and during punishment plus extinction in a discrimination learning paradigm with 36 male hooded rats. Although reinforcement of the alternative response did augment the suppression produced by extinction and by punishment plus extinction, the recovery which resulted when reinforcement for alternative behavior was discontinued eliminated any net reduction in extinction responses. Therefore, under the particular conditions of this study, no significant overall savings in regular extinction or in punished extinction resulted from the temporary reinforcement of alternative behavior. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related deficits in acquisition of a passive avoidance response.

In Exp. I, 80 male albino rats 10, 15, 20, 30, or 100 days old received a brief inescapable shock contingent upon making a step-off response. Step-off latencies increased for all age groups, but rate of learning was significantly faster in older Ss. Learning appeared to be based primarily upon punishment effects rather than general emotionality, since yoked Ss shocked after being placed directly on the grids did not acquire the avoidance response. Exp. II with 120 Ss employed 3 training conditions with independent groups 12, 15, 18, or 21 days old. The step-off response resulted in shock that was either: (a) escapable; (b) inescapable, 1-sec duration; or (c) inescapable, yoked duration. Younger Ss were again significantly inferior to more mature Ss. Escapable shock improved acquisition at 2 age levels, but the effect appeared to be more related to shock duration than to the response contingency. It is suggested that the requirement of withholding a punished response may represent a category of learning that is especially sensitive to maturational changes. (French summary) (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rats prefer signaled over unsignaled shock-free periods.

Three experiments with 48 female rats investigated Ss' preference for a schedule of shock containing signaled shock-free periods (SSF schedule) or the same shock schedule without signals (unsignaled schedule). Exp I was a replication of the shuttle-box experiment reported by M. S. Fanselow (see record 1981-00807-001), in which rats preferred unsignaled shock over the SSF schedule. Contrary to Fanselow's results, Ss in Exp I failed to develop a preference. In Exp II, forced-exposure training was added, testing was extended from 2 165-min sessions to 8, and a reversal phase was added. Results show that 3 of 4 Ss preferred the SSF schedule, and 2 of these continued to prefer it after reversal. In Exp III, forced-exposure training was eliminated, but signals were lengthened from 30 to 60 sec, and the test was extended to 12 sessions. Results show that Ss choosing between the unsignaled and SSF schedules chose the SSF schedule, whereas a random control group chose the unsignaled schedule. Findings indicate that choice between active schedules is determined by the relative aversiveness of all stimuli presented and not, as implied by contextual fear analysis, by that of contextual stimuli alone. (25 ref) (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Loss of cognitive skill across delays: Constraints for theories of cognitive skill acquisition.

Mastering a cognitive skill requires many practice sessions, occurring over a period of days, weeks, months, or even years. Although a large body of research describes and explains gains made within a given practice session, few studies have investigated what happens to these gains across a delay, and none have examined effects of delays on item-general gains. Across 3 experiments, participants performed alphabet arithmetic verification in an initial practice session followed by a test session after a delay (from 0 to 30 days). All experiments included conditions yielding item-general practice gains; Experiments 2–3 also included an item-specific practice condition. Surprisingly, item-general gains were relatively well preserved across a delay (e.g., only 6.7% decrease in practice effects after 2 days), whereas item-specific gains showed sizeable losses across a delay (e.g., 25.9% loss after 2 days). Results provide important empirical constraints to theories of cognitive skill acquisition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Extinction and reinforcement of alternative behavior.

Examined the course of extinction of 1 behavior as a function of the presence and subsequent absence of reinforcement for alternative behavior. 4 experiments were conducted, using a total of 102 male hooded rats in 3 experiments and 30 adult White Carneaux pigeons in the 4th. Major findings are: (a) Topography and reinforcement schedule for alternative behavior had little differential effect. (b) High-frequency reinforcement of alternative behavior increased suppressive effects of extinction, and low-frequency reinforcement did not. (c) Reinforced alternative behavior maintained for a relatively long period decreased subsequent recovery of the original response programed for extinction, resulting in a substantial saving in total number of extinction responses. (d) Temporary reinforcement of alternative behavior produced more permanent suppression in the context of simple extinction than in the context of SD (change in stimulus) periods in discrimination learning. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some observations of the effects of intertrial interval and delay on delayed matching to sample in pigeons.

Accuracy of delayed matching to sample was studied in 12 Silver King pigeons at different combinations of length of intertrial interval (ITI) and length of delay. When ITI and delay were varied between sessions in Exps I and II, accuracy increased monotonically with ITI and decreased monotonically with delay. Evidence was found for constancy of performance at equivalent ratios of ITI to delay, and percentage of correct choices was linearly related to the log of this ratio. In Exps III and IV, ITI was manipulated as a within-sessions variable. In contrast to the effect of this variable when manipulated between sessions, accuracy improved only from the shortest interval to the next shortest interval and remained constant at all longer intervals. In Exp IV, it was found that performance improved as a direct function of the mean ITI for sessions and that this relation was not affected by the degree of ITI variability within sessions. Findings resemble the effects of temporal variables on autoshaping, and the possibility that some common processes are involved in delayed matching and autoshaping is discussed. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intermittent punishment of self-stimulation: Effectiveness during application and extinction.

Performed 2 studies comparing the effectiveness of FR and VR schedules of punishment during application and extinction. In Study 1, the self-stimulatory behavior of a young boy was punished on both an FR 1 and a VR 5 schedule using a multi-element, multiple-baseline reversal design. Study 2 investigated the effects of FR 1 and VR 5 schedules of punishment on multiple forms of self-stimulation in a young girl using a multi-element multiple-baseline reversal design. Both studies indicated no difference in the suppressive effects of the FR 1 and VR 5. Study 2 indicated that the VR schedule produced superior resistance to extinction. Both studies found significant positive "side effects" of punishment in terms of increased play and social behavior as well as increased performance of academic tasks. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Students' predictions of prose forgetting and the effects of study strategies.

377 high school students read and were immediately tested on a prose passage, scored their own tests, then estimated how well they would have scored if tested after a delay of 1, 8, or 15 days. Data for these 3 hypothetical delay periods provided a "predicted forgetting function." An actual forgetting function was also obtained by administering a retention test with comparable questions after 1, 8, or 15 days. Within each of the 9 groups defined by the hypothetical and actual delay factors, there were 2 strategy groups—Ss who could only read the passage and those who took notes. After the immediate test, Ss in each strategy group estimated how well they would have scored if they had employed the alternate strategy. Results indicate a difference between predicted and actual forgetting, with Ss expecting a larger amount of forgetting than actually occurred. Note taking had a small facilitative effect on learning. However, Ss failed to predict positive effects of note taking. Ss' expectations about effects of other strategies were also examined, and implications regarding metamemory and study skills are discussed. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)