The effect of intermittent punishment-partial reward training on resistance to continuous punishment.

Investigated the effect of adding a partial reinforcement procedure to an intermittent punishment procedure on subsequent resistance to continuous punishment. 36 naive male albino Wistar rats served as Ss. Results indicate that the addition of partial reinforcement training increases the resistance to continuous punishment. This superior resistance cannot be seen as being equal to a simple sum of resistance due to intermittent punishment alone or partial reward alone. Results are discussed in terms of theories of resistance to fear and frustration. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of ovariectomy on meal pattern in the albino rat.

In a study with 24 female albino Sherman rats, it was found that after ovariectomy most Ss increased food intake while continuing to eat discrete meals. Meal size increased in ovariectomized Ss, whereas meal frequency decreased. It is suggested that ovariectomy impairs the onset of satiety during a meal but not the ability to regulate total intake through modification of intermeal interval. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of paleocerebellar lesions on DRL performance in the albino rat.

18 male albino rats with paleocerebellar lesions and 8 controls were trained to barpress for food on continuous reinforcement (CRF) and differential reinforcement of low response rates (DRL) schedules. Ss with lesions showed normal acquisition of the CRF schedule, but they exhibited a marked deficit on the DRL task. This deficit was related to overresponding that appeared to result from an inability to inhibit the response, rather than from a dysfunction in timing ability or motor capacity. The DRL deficit, however, was overcome by the introduction of a salient stimulus object (wood block) into the operant situation. Although no explicit reinforcement contingencies were placed on interaction with the stimulus object, it appeared that the wood block facilitated the development of "collateral" behaviors that served to mediate the DRL interval. Results are consistent with the suggestion that the cerebellum may contribute to the sequential organization of complex behaviors. (51 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Type of punishment as a determinant of resistance to deviation.

Compared the effectiveness of an aversive stimulus, withholding of resources, withdrawal of love, and reasoning, when used alone and when combined with praise, in a standard laboratory punishment paradigm using 120 1st- and 2nd-grade boys and girls as Ss. Resistance to deviation and stability of resistance to deviation were used as the measures of punishment effectiveness. Sex of child, use of praise, and type of punisher were combined in a 2 * 2 * 5 factorial design, with a female as the punitive agent. An aversive stimulus appeared to produce more suppression of deviant behavior, but the effect was not significant for all response measures. The stability of the deviant response pattern varied for each punisher, but the most stable response pattern resulted from the use of an aversive stimulus. Neither use of praise nor sex of child significantly influenced punisher effectiveness. Results are discussed within the framework of anxiety arousal and information content of the punishers, and the practice of grouping various punishers under the categories of sensitization and induction measures is considered. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of reinforcement and punishment in a minimal social situation.

"Two Ss, isolated from each other, were provided with two push buttons by means of which each could give the other a shock or score. The Ss were divided into a Weak Shock and a Strong Shock group. All Ss were merely told that they could press the two buttons in any manner that they pleased (no information was given concerning the purpose of the buttons). Each S was told to make as many points as possible. His score was indicated on a counter in front of S. It was found that the proportion of the total number of responses (both score and shock) that were correct (score responses) was significantly higher for the Strong Shock group. Learning occurred in the Strong Shock group within the first 5 minutes of the 25 minute experimental session. Learning was not, however, evident in the Weak Shock group." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Septal influences on operant responding in the rat.

In 3 experiments with a total of 74 male albino Sprague-Dawley rats, the afferent and efferent connections of the septum with the hippocampus (fornix) or with the hypothalamus and lower brain stem (medial forebrain bundle) were transected by means of an encephalotome near the point where these pathways enter or leave the septal area. A transection of the fornix that produced minimal direct damage to cellular components of the septum or hippocampus reproduced the effects of large septal lesions on responding in several temporally defined paradigms that involve periods of response suppression (DRL, discriminated Sidman avoidance, FI). Transection of the medial forebrain bundle fibers that interconnect the septum with the hypothalamus and lower brain stem did not affect behavior in any of these paradigms. It is suggested that these observations be viewed in the context of the results of earlier investigations by the authors (see record 1974-27002-001), R. J. Carey (see record 1969-13784-001), and J. M. McDougall et al (see record 1969-13791-001), which showed that transection of the medial forebrain bundle reproduces several other components of the septal lesion syndrome. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of differential rearing on cortical evoked potentials of the albino rat.

3 groups of Sprague-Dawley albino rats were reared in different environments from weaning to the age of 95 days. One group was in a visually enriched environment (n = 8), a 2nd group was in an auditorily enriched environment (n = 8) and a 3rd group, controls, received no enrichment (n = 16). Photic and auditory evoked potentials were recorded in unanesthetized Ss from chronically implanted epidural electrodes over the visual and auditory cortex. Ss whose enrichment included visual stimulation yielded significantly shorter latencies in their photic evoked responses recorded over the visual cortex than latencies recorded from controls or from Ss whose enrichment excluded visual stimulation. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Trigeminal denervation and operant behavior in the rat.

39 male Wistar rats underwent selective sectioning of trigeminal sensory and motor nerves in 2 experiments to examine the contribution of the sensorimotor system to the control of instrumental responses reinforced with food or water. It was hypothesized that trigeminal denervation would disrupt motivational systems mediating Ss' thirst and hunger. Results show that unilateral sectioning of either Section V sensory or V motor nerves had no significant effect on leverpressing. Bilateral sectioning significantly reduced leverpressing, and the deficit was greatest in Ss with trigeminal motor nerve sectioning. It is concluded that trigeminal orosensory or oromotor denervation disrupts performance on a food- or water-reinforced task in which execution does not require a trigeminally mediated response. Findings are discussed in terms of motivational and reinforcement accounts of instrumental learning. (32 ref) (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)     

Effects of auditory cortical lesions on pure-tone sound localization by the albino rat.

Used 2-choice and 3-choice tests to evaluate the effects of bilateral auditory cortical lesions on pure-tone sound localization by 10 male albino rats. Both tests required that Ss approach a distant sound source to obtain water reinforcement. Stimuli were single noise and tone bursts, 65 msec in duration including 20-msec rise and fall times. Tone frequencies were 2, 4, 8, 16, and 32 kHz adjusted to 40 dB (sound pressure level) above the S's absolute threshold. Five Ss were tested in the 2-choice situation following bilateral ablation of auditory cortex. Some reduction in performance was observed relative to normals, but impairments were not severe. Similar results were obtained for 2 brain-damaged Ss tested in the 3-choice situation. Thus, the ability to localize sounds in space remained intact after complete destruction of auditory cortex, and there was no indication of a frequency-dependent deficit. Findings are considered in relation to the more severe deficits observed in other mammals after lesions of the auditory cortex. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of the schedule of reinforcement on operant conditioning of a verbal response in the autokinetic situation.

The autokinetic effect was employed to compare the effect of 2 different schedules of reinforcement on verbal behavior. One group of Ss was given 20 reinforcements of "Right" under a regular reinforcement schedule for emitting verbally the estimate designated as the response. A second group was given similar reinforcement under a variable interval schedule. The regular reinforcement group reached the criterion of extinction in 10 to 35 verbal emissions while no S in the variable interval group extinguished within 10 to 80 verbal emissions. 15 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of punishment on response latency in extraverts.

Previous findings indicate that in comparison to introverts, extraverts are prone to form responses that are resistant to interruption by punishment. Because the tendency to stop and reflect following punishment may be crucial for subsequent learning, the present study examined differences between introverts' and extraverts' reactions to punishment using response latency on the trial following punishment as the dependent variable. 66 extraverted and 66 introverted male undergraduates, selected on the basis of Eysenck Personality Questionnaire scores, performed a pattern-matching task in which they received noncontingent 50% success and 50% failure feedback under 3 incentive conditions: reward only, punishment only, or both. As predicted, a significant interaction was found in the both incentive condition, reflecting the tendency of extraverts to respond more quickly and introverts more slowly following punishment than reward. No significant effects were found in the other 2 conditions, although extraverts tended to respond more quickly overall when only reward was given. A 2nd experiment, with 101 male undergraduates, that used reward-only and punishment-only feedback replicated this finding and yielded a significant group?×?condition interaction. Results indicate that in contrast to introverts, extraverts are activated by the availability of reward and, paradoxically, that punishment may facilitate rather than interrupt extraverts' reward-seeking behavior. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning in the intact cockroach (Periplaneta americana) when placed in a punishment situation.

Examined whether 40 intact cockroaches, Periplaneta americana, in a yoked-control punishment paradigm exhibit escape or avoidance learning, or both. Evidence for avoidance learning was unequivocal. Escape learning was not found. Asymptotic avoidance learning was found by 1.5 min. of training. The advantages of defining learning by experimental-control differences developing during training are discussed. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory sensitivity of the albino rat.

Determined the auditory sensitivity of the Sprague-Dawley albino rat by the conditioned suppression technique. The 3 Ss tested were found to have a range of hearing from 250 Hz to 80 kHz at 70 db (SPL). They were most sensitive to tones of 8 kHz but were almost as sensitive at 38 kHz. In contrast to previously published data, there was no evidence for a highly specialized tuning of the audiogram to tones in the 30–40 kHz region. In general, the audiogram of this strain of albino rat is quite typical of mammals of the same size and, furthermore, closely approximates the mammalian mean in most essential features. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The retention and generalization of operant conditioning effects in an interview situation.

In a study of the conditioning of complex verbal habits, each of 30 female Ss had her established verbal habits assessed in 2 sessions by being asked to talk about herself. In subsequent sessions, the Ss in the experimental groups were positively reinforced (by a head nod and an "mm-hm") for either independence or affection statements, whereas control groups Ss were reinforced every 30 sec. regardless of the content of their speech. The results showed that: conditioning occurred, i.e., the experimental Ss increased in their use of the reinforced category; retention also occurred, i.e., the conditioning effects were stable over a 24-hr. period; and generalization did not occur. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of D-cycloserine on the extinction of appetitive operant learning.

Four experiments with rat subjects examined whether D-cycloserine (DCS), a partial NMDA agonist, facilitates the extinction of operant lever-pressing reinforced by food. Previous research has demonstrated that DCS facilitates extinction learning with methods that involve Pavlovian extinction. In the current experiments, operant conditioning occurred in Context A, extinction in Context B, and then testing occurred in both the extinction and conditioning contexts. Experiments 1A and 1B tested the effects of three doses of DCS (5, 15, and 30 mg/kg) on the extinction of lever pressing trained as a free operant. Experiment 2 examined their effects when extinction of the free operant was conducted in the presence of nonresponse-contingent deliveries of the reinforcer (that theoretically reduced the role of generalization decrement in suppressing responding). Experiment 3 examined their effects on extinction of a discriminated operant, that is, one that had been reinforced in the presence of a discriminative stimulus, but not in its absence. A strong ABA renewal effect was observed in all four experiments during testing. However, despite the use of DCS doses and a drug administration procedure that facilitates the extinction of Pavlovian learning, there was no evidence in any experiment that DCS facilitated operant extinction learning assessed in either the extinction or the conditioning context. DCS may primarily facilitate learning processes that underlie Pavlovian, rather than purely operant, extinction. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Social deprivation and stimulus satiation in the albino rat.

Conducted 2 experiments, with a total of 288 male Sprague-Dawley albino rats, to explore the mechanisms whereby social deprivation leads to increased sociability in rats. Exp I housed Ss alone or in pairs with additional nonsocial stimulation, with additional response opportunities, or with no added social surrogates for 3 wks prior to testing for sociability. Social deprivation led to a strong increase in sociability, and this was not ameliorated by stimulus or response enrichment. Exp II exposed alone or pair-housed Ss to handling, human contact, or no stimulation and found that human exposure did serve a social surrogate function. This result suggests that sociability in rats represents to some degree a search for complex and unpredictable stimulation. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Grooming behavior and competitive dominance in the albino rat.

Compared dominance in 28 male Wistar rats manifested in water competition under 2 levels of deprivation, with grooming activity in a nondeprived state. While competitive dominance was significantly related to motivational level, grooming emerged as a more stable indicator of social ascendance and did not require prior manipulation of a biological state. Implications of this observation for broader aspects of social motivation are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early weaning in the rat: Effects on whole-brain RNA and free amino acids.

Each of 67 CAW:CFE(SD)spf rat litters was reared with its mother or with its mother and a virgin female ("aunt"). At pup age 15 days, some litters were deprived of their mothers, some remained with mothers whose nipples were cauterized to prevent suckling, and some remained intact until 21 days when all pups were housed individually or in peer groups until tested at 56 days. While increases in whole-brain free aspartic acid were attributed to loss of opportunity for suckling since they occurred in pups without mothers or with cauterized mothers, decreases in brain RNA caused by deprivation were prevented by the presence of mother or aunt. Rearing with aunts increased brain weight and emotional reactivity. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)