Effect Of Deprivation Level Research Articles

Effects of deprivation level on probability discounting in pigeons

Effects of deprivation level on probability discounting in pigeons

Effects of contingent tone on concurrent schedule performance at different deprivation levels

The effect of food deprivation on sensitivity to reinforcement and punishment was studied. Rats’ responded on either rich or lean concurrent variable interval (VI) VI schedules. The effects of a tone-punisher that was superimposed over these schedules was examined. The value of the schedule, the presence of punishment, and the deprivation level all influenced overall rates of responding. Response rates increased with the frequency of reinforcement. Tone-punishment had two effects; response suppression, and preference shift towards overmatching. The effects of deprivation level on choice behaviour were less clear. The tendencies observed were that the lower the deprivation, the greater the suppression, and the greater the preference shift towards overmatching obtained.

Effects of Deprivation Level on Humans' Self-Control for Food Reinforcers

Deprivation level was manipulated in fourteen food- and water-deprived adult human females to examine its effects on self-control for food (choice of larger, more delayed access to apple juice over smaller, less delayed access to apple juice). Each subject was exposed to two treatments: (1) consumption of a 500 g tomato soup preload just prior to self-control testing and (2) no soup preload. When subjects had consumed soup, they reported significantly less hunger and showed significantly more self-control as compared to when not having consumed soup. Additionally, when subjects had consumed soup, self-control decreased as a function of session time. Subjects who reported that they were currently dieting drank significantly less juice when they had previously consumed soup than when they had not previously consumed soup. Together, the results indicate that when subjects are more deprived they may be less able to wait for food reinforcers (i.e., show less self-control). Such behavior may be adaptive in situations in which energy is needed to survive periods of food scarcity.

Naloxone and operant responding for food: Effects of deprivation level

Naloxone and operant responding for food: Effects of deprivation level

Choice between delayed reinforcers in a discrete-trials schedule: the effect of deprivation level.

Choice between two reinforcers differing in magnitude and delay was investigated in rats using a discrete-trials schedule in which the two reinforcers were associated with two levers (A and B); in each session 5 free-choice trials (A and B both available) were interspersed among 44 forced-choice trials (A alone, 22 trials; B alone, 22 trials). In Experiment 1, preference for the more concentrated of two sucrose solutions declined as the delay to that reinforcer was progressively increased. In Experiment 2, progressively increasing the delay to both reinforcers by the same amount resulted in a shift in preference away from the less concentrated solution. In Experiment 3, it was found that the decline in preference for the more concentrated solution as a function of the delay to that reinforcer was steeper when the rats were maintained at 90% than when they were maintained at 80% of their free-feeding body weights. This effect of deprivation level on choice is inconsistent with some current models of "self-control".

Effect of Deprivation Level on the Magnitude of Positive Induction in Discriminative Straight-Alley Performance

Groups of rats received discriminative straight-alley training under 75% or 90% predeprivation body weight levels. After training, one-half of the subjects at each body weight level received extinction trials to only the stimulus associated with reward (S +), and one-half received intermixed extinction trials to S + and the stimulus associated with nonreward (S -). In extinction, rats trained under 75% body weight displayed greater persistence when alternated between S + and S - than when extinguished to S + only (positive induction). Subjects trained under 90% body weight levels failed to show evidence of positive induction. These results support an interpretation of positive induction based on deprivation-dependent frustrative reactions.

A homeostatic model of Pavlovian conditioning: Tolerance to scopolamine-induced adipsia.

Several experiments support a model proposing that tolerance to scopolamine-induced adipsia involves an interplay between processes of homeostatic regulation and Pavlovian conditioning. In Experiment 1a, rats given access to water while under the influence of scopolamine developed adipsic tolerance, whereas rats denied access to water in the drug state did not. In Experiment 1b, rats displayed adipsic tolerance only when scopolamine was administered with cues associated with previous drug injections. In Experiment 1c, adipsic-tolerant rats showed a polydipsic response to an injection of phenobarbital (which unconditionally augments water consumption) relative to nontolerant animals with the same pharmacological history. Experiment 2 assessed the effect of deprivation level on the Pavlovian extinction of adipsic tolerance. Rats satiated with water during extinction showed a loss of adipsic tolerance, whereas water-deprived rats did not. The present model is discussed in relation to (a) tolerance in other response systems such as morphine analgesia, (b) theories of extinction for nonpharmacological Pavlovian conditioning, and (c) homeostatic regulation and incentive motivation.

Continuous reinforcement of responding for water in rats with medial or dorsolateral septal lesions: Effect of deprivation level

The purpose of the present study was to examine differential effects of medial and dorsolateral septal lesions and level of water deprivation on lever pressing for water using a continuous reinforcement schedule. Five levels of water deprivation were used: 0, 6, 12, 24, and 48 hr. In addition to lever presses for water, responses on a second lever which were reinforced by onset of the cue lights above this lever and the amount of time the rat spent in the part of the cage where there were no levers were also recorded. The results showed that rats with dorsolateral, but not medial, septal lesions were significantly hypoactive when little deprived. These rats had reduced water-reinforced lever-press response rates when the level of deprivation was either 6 or 12 hr; they had reduced rates of sensory-reinforced (light-onset) responses and spent less time in the part of the cage most distant from the levers. Neither of the groups differed in ad libitum water intake. It is concluded that rats with dorsolateral, but not medial, septal lesions are hypomotivated when the level of water deprivation is low.

Differential reinforcement of lever-press durations: Effects of deprivation level and reward magnitude

Three experiments investigated the performance of rats on a task involving differential reinforcement of lever-press durations. Experiment 1, which employed a discrete-trials procedure, manipulated deprivation level between subjects and reward magnitude within subjects. The minimum lever-press duration which would result in reward was varied from .4 to 6.4 sec. It was found that low deprivation resulted in longer mean durations and less response variability at the higher criterial values than did high deprivation. The magnitude of reward was not found to affect performance. Experiment 2 manipulated reward magnitude between subjects while holding deprivation level constant, and used the same general procedures as in Experiment 1. Small reward resulted in longer mean lever-press durations and less variability in responding than did large reward at the higher criterial values. The intertrial intervals were omitted in Experiment 3 in which deprivation level was varied between subjects and reinforcement was delivered only for response durations extending between 6.0 and 7.6 sec. Low deprivation resulted in longer mean lever-press durations and less response variability than did high deprivation, but the probability of a rewarded press duration did not differ between groups. The results overall are consistent with the hypothesis that low deprivation and small reward magnitude lead to weaker goal-approach responses and, hence, to less competition with lever holding. The deprivation and reward magnitude manipulations did not appear to influence lever holding performance by affecting the ability of animals to form temporal discriminations.

The effect of deprivation level during noncontingent pairings and instrumental learning on subsequent instrumental performance

In Experiment 1, rats received either response-noncontingent pairings of a tone stimulus with food or response-contingent instrumental training during which only responses in the presence of the tone were reinforced. During this training rats were maintained at either 70 or 90% of their growth-adjusted predeprivation body weights. In a subsequent test phase, one-half of the subjects in each training condition were tested under either 70 or 90% body weight. Subjects which had received response-contingent instrumental training under 70% body weight responded significantly faster to presentations of the tone than did 90% body weight-trained subjects, regardless of test deprivation condition. There was no effect of the deprivation level in effect during response-noncontingent pairings. In Experiment 2, rats received noncontingent tone-reward pairings or nonpairings under either 70 or 90% body weight. In a later test phase under 90% body weight, instrumental responding to the tone was significantly faster for subjects which had received the tone-reward pairings. Deprivation level during the pairings again produced no effect. These results support two conclusions. First, the expectancy learning process appears to be relatively independent of deprivation conditions in effect when such learning takes place; and secondly, deprivation conditions in effect during instrumental learning affect the strength of S-R associative bonds formed.

Overnight decrement in maze performance of mice running for food reward.

Mice were run in a T-maze for food reward, to investigate possible effects of deprivation level on “overnight decrement,” i.e., worse performance on the first trial of a given day than on the last trial of either the previous or the same day. Following an initial training period, each mouse received a series of massed trials on 22 consecutive days. On half of these days, the mice were deprived of food in their home cages; on the other half, they were not deprived. Overnight decrement was substantial only when the mice were not deprived. These results have important implications concerning the comparability of positively reinforcing brain stimulation and more conventional rewards.

Changing Lick Rate of Rats by Manipulating Deprivation and Type of Solution

3 experiments examined the effects of deprivation level, sodium saccharin concentration, and sucrose concentration on uninterrupted bursts of licking in adult male albino rats. All dipsogenic treatments produced statistically significant changes in lick rate. The findings are viewed as challenging the hypothesized invariance of mammalian lick rates and as offering an improved measure for the study of drinking behavior in mammals.

Operant responding for water in rats with septal lesions: Effect of deprivation level

A continuous reinforcement schedule for water was used for studying the parametric relationship between response rate and level of water deprivation in rats with septal lesions. Relative to control rats, the experimental rats, which did not show increased ad lib. water intake, had an increased response rate when the level of water deprivation was 48 hr and a reduced response rate when the level of deprivation was 12 hr. Water intake during the initial 20 min of the recuperation periods was the same in both groups. The results suggest reduced sensitivity to drive stimuli in rats with septal lesions when the level of deprivation was low and increased sensitivity to drive stimuli when the level of water deprivation was high.

Deprivation level and frustration in the rat: effect of deprivation level on persistence of the partial reinforcement effect.

Deprivation level and frustration in the rat: effect of deprivation level on persistence of the partial reinforcement effect.

Effect of deprivation level on span of attention in a multi-dimension discrimination task

Twelve male hooded rats were trained on a discrimination task in which two perfectly correlated cues (size and shape) were present. Half of the Ss were trained under moderate level of water deprivation (MOD group) while the other group was highly water-deprived (HI group). Not only did MOD Ss learn the task more quickly than HI Ss, but the former made fewer errors on tests utilizing only the shape cues. This study supports the hypothesis that span of attention is inversely related to drive level.

Effect of Deprivation Level and Overtraining on Differential Conditioning and Reversal

60 rats received 60 or 204 differential instrumental conditioning trials under 3-, 19- or 43-hr. water deprivation, followed by 60 reversal trials. In early acquisition speeds to both S+ and S—were greater with increased deprivation, but the subsequent onset of differentiation was most rapid in groups run at 43-hr. deprivation, this produced by their slower running to S—. Reversal performance was but little affected by deprivation, not was there any interaction between deprivation level and amount of prior training in the determination of reversal performance. Reversal performance was related to amount of prior training in a complicated fashion depending on the stimulus, the point of response measurement and the stage of training: First, number of prior reinforcements increased both start and run speeds to the old positive stimulus in early reversal but had no effect on start speeds and decreased run speeds in later reversal; second, number of prior non-reinforcements did not affect speed acquisition to the new positive stimulus.

Effect of deprivation level on responses to novel alleys in albino rats

After learning to run an L-shaped alley for sucrose solution, male albino rats were presented novel alleys (N-alleys) in the same and opposite direction as the goal turn-off alley. Moderately water deprived Ss (MOD group) entered both types of N-alleys more frequently than highly deprived Ss (HI group). MODs also showed the typical exploration gradient, of entering alleys nearest the start box more frequently than those nearer to the goal. HIs, however, entered an N-alley on the goal side most frequently when it was nearest the goal. The results were interpreted as based on combined goal anticipatory and exploratory behavior.

Effect of deprivation level on exploratory behavior in the albino rat.

Effect of deprivation level on exploratory behavior in the albino rat.

Effects of deprivation level on alternation and preference behavior

Twenty four rats received 38 pairs of trials in an E maze with equal reinforcement on each arm under high (Group H) or low (Group L) deprivation. Within-pair alternation declined over trials, more so in Group H. On the first member of each pair Ss in Group H had less initial side preference but in terminal trials more Ss in Group H were trapped on one side. This effect on preference precludes a conclusion about deprivation effects on the processes responsible for stimulus alternation (SA). More generally, it is suggested that investigations of the effect of any variable on SA should be accompanied by an evaluation of preference behavior.

DELAY OF REINFORCEMENT AND RESISTANCE TO EXTINCTION: A SUPPLEMENTARY REPORT.

The effects of deprivation level, goal-related cues, and delay of reinforcement on the extinction of a position discrimination response were observed. Deprivation level and cues did not differentially affect rate of extinction or the number of perseveration responses. Delay of reinforcement resulted in a lower level of performance at the end of acquisition and during extinction, and for immediate reinforcement Ss, the rate of decline during extinction was faster although they showed greater initial perseveration.