Deprived Subjects Research Articles

Correlated behavioral and cardiac activity: Amygdala mediated amnesia or fear gradients

Little information concerning specific brain structures that are involved in the formation of autonomic and skeletal indexes of memory can be gleaned from past electroconvulsive shock studies. The present study examined the effects of a single pulse, intracranial stimulation (ICS) delivered unilaterally to the amygdala at subseizure levels on skeletal and cardiac indexes of memory. Male rats were prepared with chronically implanted EKG and bipolar ICS electrodes. Food deprived subjects were trained to descend from a platform and cross a grid floor to approach food. After meeting a performance criterion, a treatment trial consisting of footshock followed by ICS was administered. Tests 24 and 48 hrs later revealed significant memory modification for skeletal and autonomic responses, but at a lower threshold for the former. There was a significant correlation between skeletal and cardiac indexes. The degree of memory modification observed was dependent upon ICS intensity. The role of the amygdala in the processing of aversive events was discussed, and an alternative interpretation of ICS intensity dependent amnesia gradients was proposed.

Visual deficits and recovery following monocular lid closure in a prosimian primate

The behavioral consequences of long-term monocular lid closure in 6 deprived and 2 normal prosimian primates (Galago crassicaudatus) were examined using a visual field perimetry technique and a variety of visuomotor tests. Deprived galagos had their right lid sutured either within 8 (n = 4) or 38 (n = 2) days postpartum and were reared under these conditions for at least 8 months. Normal galagos responded briskly on all visuomotor tests including tracking, response to visual threat, ability to descend from a platform, and obstacle avoidance. Perimetry tests of these animals showed that the visual field with both eyes open was 180 degrees while each eye tested individually had a 135 degrees field. Deprived galagos tested with their experienced eye exhibited normal visuomotor behavior and normal visual fields. Following reverse suture all deprived animals behaved initially as if blind on all tests. Over the next 4-8 weeks these animals showed some limited recovery on the visuomotor tasks. Tests of perimetry indicated that by the end of four weeks of testing, vision was limited to the deprived monocular segment where it remained stable to the end of the testing period. With both eyes open, deprived galagos exhibited a normal 180 degrees visual field. Curiously, however, when stimuli were introduced simultaneously in corresponding points in both monocular segments of the field, the majority of orienting responses of deprived subjects favored the right deprived eye. Under similar testing conditions one normal subject favored its right eye and the other its left eye. The reversibility of monocular deprivation was explored further either by extending the period of forced use of the deprived eye in one animal or by removing the non-deprived eye in another animal. No further improvement in visual field perimetry was seen following a longer period of forced use of the deprived eye. In contrast, a substantial increase in the visual field could be demonstrated one month following removal of the originally experienced eye: the deprived eye field expanded to include the entire 90 degrees ipsilateral hemifield. The contralateral field of the deprived eye, however, continued to remain blind even after one year. These behavioral results suggest that although the original binocular competitive disadvantage suffered by the deprived eye during development is relatively permanent, it can partially be ameliorated by late removal of the non-deprived eye.

The effects of increasing distance to food and deprivation level on food-hoarding behavior in Rattus norvegicus

Hooded rats, both deprived and not deprived of food, were allowed to hoard various sized food pellets from remote sites that varied in distance from a well-established home nest site. As the distance between the remote and home sites increased the deprived subjects hoarded larger sized food pellets. This trend was not as clear for nondeprived subjects. Increasing distance between the two sites was correlated with decreases in several measures of hoarding strength and with an increase in nonhoarding activities. At the greatest distance, less time was devoted to hoarding and less food was returned to the home site while exploratory and scent-marking activities increased in frequency. The data suggest that whereas food deprivation facilitates food hoarding, it is not a necessary condition for it. The implications of these data for optimal foraging strategies are discussed.

Successive Negative Contrast as a Function of Deprivation Condition Following Shifts in Sucrose Concentration

Successive negative contrast was measured in terms of lick rate following reduction in sucrose concentration in both deprived and ad lib rats. The ad lib group showed substantial decrements in lick rate that did not diminish over four postshift days. The deprived group showed a large but transient contrast effect. When downshifted a second time, the deprived subjects showed a decrement to control levels, whereas ad lib subjects again showed durable contrast. In a second phase of the experiment, deprivation conditions were reversed and the groups showed patterns of contrast appropriate to the current deprivation condition regardless of prior deprivation history. The findings are discussed in terms of the hypothesis that ad lib and deprived subjects attend to different aspects of reward.

Changes in critical flicker frequency during prolonged visual deprivation

Subjects were tested on the critical flicker frequency during a 1-week period of visual deprivation (either homogeneous illumination or darkness). Deprived subjects showed no significant differences from a confined control group. Results were discussed in relation to previous research, Schultz’s theory of “sensoristasis” and Sharpless’ revision of the “law of denervation.”

Sleep deprivation and measures of emotionality in rats.

ABSTRACTPredictions from two theories which attempt to explain the function of active sleep (AS) were tested on 144 rats. Total sleep deprived, activity control, stationary control, active steep deprived, large pedestal control, or homecage control conditions were imposed on 30‐day and 90‐day‐old subjects for 5 days. Open‐field (OF) and startle response measures and adrenal and body weights permitted examination of changes in emotionality. Increases in OF activity and decreases in defecation in this paradigm are attributed primarily to AS deprivation, while reductions in quiet sleep may account for elevated startle responsivity in totally deprived subjects. Limited support for the Ontogenetic hypothesis is found in the treatment by age effect for OF activity, but the P‐hypothesis prediction of increased emotionality in AS deprived subjects is contradicted by our data.

Pattern discrimination in monocularly reared cats

Four monocularly reared cats were trained to solve various pattern discrimination problems using the deprived eye. The animals succeeded in the task although the number of trials to reach the criterion of learning was much greater than when the normal eye was used. Head movements in front of the discriminanda characterized the learning with the deprived eye. Implications of these findings on the problem of pattern recognition in deprived subjects are discussed.

The effects of p-chlorophenylalanine on behavior: III. facilitation of brightness discrimination in satiated rats

Rats, maintained with food and water available ad lib. , learned a brightness discrimination with saccharin as the reward. Half of the subjects were injected every third day with p-chlorophenylalanine (PCPA) in Steroid Suspending Vehicle and half with the vehicle only. Facilitation of learning by PCPA was found. In a second experiment, no differences were found in acceptance of successively more concentrated solutions of quinine hydrochloride between water deprived rats injected with PCPA, and those injected with the vihicle only. It was concluded that facilitation of brightness discrimination by PCPA is not dependent upon the use of water deprived subjects, and occurs under conditions of both moderately high and low motivation.

Training Non-Readers in “Listening Achievement”

The major purpose of this study was to determine whether listening experience for children resulted in improved ability to recognize information heard. Subjects were five-year-old children randomly selected from five kindergartens of an average population and randomly assigned to three groups. Between pretests and posttests different amounts and kinds of training in listening were applied for each of the three groups. Resulting data indicated that different treatments did not make for a difference in performance. Comparison with data of another study by the author, in which the subjects were culturally deprived children, indicated that immediate feedback seemed to produce comparable levels of listening achievement regardless of whether the subjects are culturally deprived or of the general population. No feedback to culturally deprived Head Start subjects resulted in their significantly lower listening achievement level.

Maternal Deprivation: Its Influence on Visual Exploration in Infant Monkeys

Visual exploration was studied in maternally reared and maternally deprived monkeys. When an animal pressed a bar an opaque screen was raised providing a brief view of either of a pair of stimuli. Subjects reared by their mothers pressed more to see animate than inanimate objects. With increasing age, the number of bar-pressing responses decreased for an adult female stimulus, increased for an age peer and for food, and remained low for geometric forms and an empty chamber. Maternally deprived subjects established uniformly low response levels to all stimuli.

MATERNAL DEPRIVATION: ITS INFLUENCE ON VISUAL EXPLORATION IN INFANT MONKEYS.

Visual exploration was studied in maternally reared and maternally deprived monkeys. When an animal pressed a bar an opaque screen was raised providing a brief view of either of a pair of stimuli. Subjects reared by their mothers pressed more to see animate than inanimate objects. With increasing age, the number of bar-pressing responses decreased for an adult female stimulus, increased for an age peer and for food, and remained low for geometric forms and an empty chamber. Maternally deprived subjects established uniformly low response levels to all stimuli.

The effect of brief sensory deprivation upon responses to a word association test

It has been assumed that in the absence of external stimulation, an individual’s behavior is influenced noticeably by the primary process. Consequently, it was hypothesized that under conditions of sensory deprivation subjects would respond in a more deviant manner to projective test stimuli. Using Rapaport’s Word Association Test, the responses of 20 college subjects exposed to three hours of sensory deprivation were compared to those of 20 non-deprived college subjects in terms of reaction time, popular associations, errors in recall, and reactions to traumatic words. The two groups did not differ significantly on any of the four criteria. The specific hypothesis was not supported.

Personality Factors Related to Success and Failure in Sensory Deprivation Subjects

Personality Factors Related to Success and Failure in Sensory Deprivation Subjects

Modification of affect, social behavior and performance by sleep deprivation and drugs

A 37-hour period of sleep deprivation proved sufficient to induce reliable changes in how men working together in small groups felt and how they acted. These changes generally reflected both more negative affect and more negative behavior. However, while verbal reports of hostility increased, overt aggressive behavior did not. The subjects worked on both group and individual performance tasks, none of which showed effects of sleep loss. A combination of amphetamine and secobarbital moved reports of affect in a “positive” direction, with effects usually greater with sleep deprived subjects. Task performance was improved by the drugs while overt social behavior usually was unchanged. No evidence was found that the group performance changes were mediated by changes in interpersonal affect.