Sensory preconditioning effects in young and adult rats.

Compared 64 90- and 64 25-day-old hooded rats on a test of sensory preconditioning (spc). Initially, 2 paired stimuli (s1, s2) were presented, following which s2 was paired with shock. The effects of s1 on 3 measures of lick-rate suppression were taken as indices of spc, these being: standard suppression ratio, lick latency following stimulus onset, and lick latency following stimulus offset. Results are as follows: (a) an spc effect was not demonstrated by the standard suppression ratio, and these data are explained by reference to possible habituation mechanisms or preexposure effects; (b) young ss but not adults showed an spc effect using onset latency; and (c) the reverse held true for the offset latency measure. These latter 2 findings are discussed in terms of differences in associative and discriminative capacities between young and adult ss. (french summary) (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of early social deprivation on emotionality in rats.

Following parturition, 95 male Holtzman albino rat pups were separated from their mothers and randomly assigned to rearing conditions (a) with mother and peers, (b) with mother without peers, (c) in incubators with peers, or (d) in incubators in isolation. At 65 days of age Ss were tested daily in an open field for 3 min. over 6 consecutive days. At 113 days of age, Ss were restrained and presented a mild auditory stimulus and subsequently a noxious shock stimulus while heart rate recordings were taken. Higher emotionality in maternally-deprived Ss was evidenced in longer emergence latencies, lower ambulatory scores, and higher urination frequencies in the open field. Maternally-deprived Ss also gave larger heart rate responses to auditory and shock stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensory deprivation versus sensory variation.

Compared verbal and physiological reactions to sensory deprivation (SD) and extreme sensory variation (SV). 22 male undergraduates were confined to a cubicle for 8 hr. in each condition on 2 different occasions. 2 other 8-hr sessions were spent in a relatively normal, nonconfined condition. Ss found SD more boring, dislikable, and anxiety and depression provoking than SV. More unreality stress was reported after SD. However, more autonomic activation was found in SV. Both SD and SV produced more hostility, somatic complaints, and adrenocortical output than control conditions. Trait anxiety was associated with stress response to both conditions. Subjective stress is associated with a condition, SD, which produces less than optimal arousal. Confinement may produce hostility and adrenocortical activation at either extreme of sensory variation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sodium appetite in adrenalectomized rats following dietary sodium deprivation.

Experimented with operated, sham-operated, and comparison male Sprague-Dawley rats (N = 74). Adrenalectomized (Adrex) rats adjusted well during adrenal insufficiency when saline solutions were available. Despite continuous uncontrolled losses of relatively large amounts of sodium in their urine, they managed to maintain body fluids at approximately normal levels by replacing crucial sodium losses, if only temporarily, through frequent intakes of saline. It is concluded that the threshold for sodium appetite in Adrex rats is associated with relatively small sodium deficits, and roughly similar deficits also are effective in stimulating sodium appetite in intact Ss. When more pronounced losses result from maintenance on a sodium-free diet, Adrex Ss rapidly drink more than enough saline to replace their deficits. Thus, it seems evident that mineralocorticoids need not have a vital role in either the initial salt-drinking response of intact Ss to minor sodium deficits or their overcompensation for moderate sodium deficits. (32 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of visual deprivation on depth discrimination of hooded rats.

In a study with hooded rats (N = 530), Ss raised in the dark were compared to light-reared controls. 21-day-old dark-reared (DR) Ss were not different from controls in the discrimination of 4-in depths, but 30-day-old DR Ss were deficient. 60-day-old DR Ss were deficient in discriminating 4-, 6-, and 8-in depths. 30-day-old DR Ss recovered the loss in depth discrimination after 48 hrs in the light. 60-day-old DR Ss had no noticeable recovery to the 4-in depth discrimination, but they did recover discrimination of the 6-in depth after 72 hrs in the light. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Normality and impairment following profound early institutional deprivation: A longitudinal follow-up into early adolescence.

Longitudinal analyses on normal versus impaired functioning across 7 domains were conducted in children who had experienced profound institutional deprivation up to the age of 42 months and were adopted from Romania into U.K. families. Comparisons were made with noninstitutionalized children adopted from Romania and with nondeprived within-U.K. adoptees placed before the age of 6 months. Specifically, the validity of the assessment, the degree of continuity and change in levels of functioning from 6 to 11 years, and the factors in the pre- and postadoption environment accounting for heterogeneity in outcome were examined. Pervasive impairment was significantly raised in children experiencing institutional deprivation for ≥6 months of life, with a minority within this group showing no impairment. There was no additional significant effect of duration of deprivation beyond the 6-month cutoff, and few other predictors explained outcome. The pattern of normality/impairment was mainly established by 6 years of age, with considerable continuity at the individual level between 6 and 11 years. The findings are discussed in terms of the possibility of a sensitive period for development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensory deprivation and the enhancement of hypnotic susceptibility.

Investigated the effect of sensory deprivation upon hypnotic susceptibility. 10 volunteer college-age females initially resistant to hypnosis were placed in a light- and sound-attenuated sensory deprivation cubicle for a maximum of 6 hr. or until sensory deprivation phenomena were elicited. A hypnotic induction was undertaken via a communication system, while S remained in the deprivation cubicle, at a point when E judged that the sensory deprivation was sufficiently intense. Approximately 1 wk. following the experimental session, Ss submitted once again to a standard induction procedure. A control group of resistant Ss was included. Only the experimental group manifested a significant enhancement of hypnotic susceptibility, and this new level of susceptibility was maintained in the follow-up session. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Down-regulation of beta-adrenergic receptor following long-term monocular deprivation in cat visual cortex

To examine how adrenergic receptor binding is modified by experimental manipulation of sensory afferent, we carried out binding experiments (membrane fraction and in vitro autoradiography) for both alpha 2- and beta-adrenergic receptors in the brain of cats which had been deprived of vision in one eye. In the cerebral cortex of control animals, beta-adrenergic receptor (beta-AR) binding was found to be higher in the occipital regions than in other regions, while alpha 2-AR binding was relatively uniform. Monocular deprivation throughout the postnatal sensitive period (1-7 month of age) significantly decreased beta-AR binding in the visual cortex and lateral geniculate nucleus. Scatchard plot analysis in the visual cortex showed ca. 50% reduction in Bmax and little change in Kd. No significant difference was found in alpha 2-AR binding following monocular deprivation. Similar extent of down-regulation in beta-AR binding was confirmed in all layers of visual cortex using autoradiography.     

Absence of oxidative stress following paradoxical sleep deprivation in rats

With an aim of creating new, high affinity dopaminergic ligands, six different 3- and 4-substituted 1-[2-[5-(1H-benzimidazole-2-thione)] ethyl]piperidines and nine related heterocyclic congeners were synthesized and evaluated for in vitro binding affinity at D1 and D2 dopamine receptors. Synaptosomal membranes prepared from fresh bovine caudate nuclei were used as a source of the dopamine receptors. Only 4-[bis-(4-fluorophenyl)methylene]-piperidines, compounds 9e, 10d, and 11d, expressed moderate affinity for the D1 receptors, while all other compounds were inactive competitors of [3H]SCH 23390. Compounds 9c, 9d, 10c, 11a, and 11c were inactive in the D2 receptor binding assay, as well. Derivatives of 4-phenylpiperidine (9-11b) and 3-phenylpiperidine (10a) expressed a moderate to low affinity for the D2 receptors. However, racemic (+/-)-1-[2-[5-(1H-benzimidazole-2-thione)] ethyl]-3-phenylpiperidine 9a and its enantiomer (+)-9a behaved as selective, high affinity D2 receptor ligands, the latter being some four times more active than the racemate.     

A deficit in ambient visual guidance following superior colliculus lesions in rats.

21 male black-hooded rats were tested for their ability to locate a hidden platform in the Morris swimming pool, in which extrapool cues are required to guide locomotion. At the end of each trial, Ss were either removed immediately or allowed to remain on the platform for 60 sec. As in a previous experiment by the present authors (see record 1984-06177-001), bilateral lesions of the superior colliculus (SC) produced a severe deficit. Permitting the Ss to stay on the platform did not significantly affect performance in either Ss with SC lesions or sham-operated controls. Results indicate that the reduced orienting behavior on the platform observed in the rats with lesions in the previous experiment was not the cause of their navigational impairment. It is concluded that the impairment following SC lesions came about during the swimming itself; therefore, it may be attributed to a disturbance of, or a failure to utilize, ambient vision. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recovery of associative function following early amygdala lesions in rats.

Adult rats with amygdala lesions made at either Postnatal Day (PND) 10 or PND40 were tested on a series of reversal tasks that tap the ability to form stimulus–reward associations. PND40 rats were significantly impaired relative to both controls and PND10 rats on learning rate of the original discrimination and subsequent reversals. Analyses of discrete learning phases revealed that the impairment was specific to the postchance phase. The PND10 group was not impaired relative to controls on any measure. These results confirm prior findings that amygdala lesions sustained in adulthood impair the formation of stimulus–reward associations. They also demonstrate that substantial sparing or recovery of function is possible when the lesion is made during early development. Furthermore, the findings support the view that behavioral recovery may be more likely if the lesion is sustained near the time of peak synaptogenesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensory integration of auditory and visual information.

In exp. I with 3 male and 1 female o, the bisensory recognition of simultaneously presented auditory and visual verbal information was measured as a function of auditory and visual recognition. It is shown that bisensory performance is superior to performance predicted by a model that assumes the 2 modalities are processing the information independently. Instead integrative processing is suggested. In previous studies using theory of signal detectability (tsd), independent processing of bisensory presentations of mathematically equivalent stimuli has been shown. Present results suggest that the mathematically equated stimuli in those studies were not cognitively equivalent. Exp. Ii with 3 male os lends support to this notion by (a) using verbal information in a tsd paradigm, and (b) showing that when the stimuli are equivalent the results are consistent with a model in which bisensory processing occurs integratively on a common decision axis. However, when the stimuli to each mode are not equivalent, results are consistent with a model in which bisensory processing occurs independently on separate decision axes. (french summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Orogastric, hydrational, and behavioral controls of drinking following water deprivation in rats.

Studied drinking and its associated behaviors in 168 female Sprague-Dawley rats deprived of fluid for 8, 24, or 48 hrs. The behavior of Ss drinking water could be divided into 3 successive stages: (a) an initial intense burst of drinking that could not be easily disrupted; (b) intermittent drinking, often distinguished by the brief appearance of conflict behavior directed at the drinking spout; and (c) termination of drinking. Drinking stopped well before the fluid loss, reflected in a sizable extracellular deficit, was restored. Intake of water was terminated when serum hyponatremia and hypoosmolality (and presumably cellular overhydration) developed in temporal continguity with drinking. These and other considerations suggest that the cellular fluid phase exerts significant inhibitory as well as excitatory control over drinking. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensory deprivation, attitude change, and defense against persuasion.

Used frequent toothbrushing as the target attitude with 120 college students in a study with the following independent variables: (a) sensory deprivation or nonconfinement for 12 hrs before an inoculation message and before a counterattitudinal message, and (b) the kind of inoculation (refutational, supportive, or none). Results show that refutational inoculation was most effective, was recalled best, and led to reduced recall of the subsequent attack. Postinoculation tests reduced later persuasibility, and in the supportive inoculation condition led to a more extreme adherence to the S's original position. Sensory deprivation before the inoculation message increased belief instability; before the counterattitudinal message, it increased persuasibility. Sensory deprivation functions as a cognitive disorganizer, whose effects on persuasibility are probably mediated by impaired processing of complex information and consequent belief instability. (French summary) (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus intensity in sensory preconditioning of rats.

Examined the sensory preconditioning (SPC) analogs to UCS and CS intensity in 2 experiments with male hooded rats (N= 144). In Exp. I, Ss received S1-S2 (light and tone, counterbalanced) pairings with 1 of 3 different intensities of S2, followed by conditioned emotional response (CER) training to S2. Suppression of drinking by S1 (SPC groups) and S2 (CER groups) was tested. Amount of SPC was not significantly affected by S2 intensity, but the strength of the CER was an increasing function of S2 (CS) intensity. In Exp. II, amount of SPC was a monotonically increasing function of S1 intensity. Results are interpreted in terms of the similarities and differences between SPC and classical conditioning. (French summary) (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal changes in cutaneous sensitivity during prolonged visual deprivation.

Conducted 2 experiments with a total of 62 male undergraduates and 60 controls in which various measures of cutaneous sensitivity were administered at intervals of 0, 1/2, 1, 2, 3, 5, and 7 days of visual deprivation (darkness). Relative to controls results reveal no significant differences in performance on the 2-point threshold and on measures of pressure and pain sensitivity, although on the last 2 measures a definite trend toward an improvement was observed after the 3rd day. However, results on the tactual fusion threshold reveal a linear improvement in performance as a function of increasing duration of visual deprivation, a facilitatory effect which was already present, to a statistically significant degree, at the 1st test period of 12 hr. Results of a 3rd experiment, also with 32 experimental ss and 30 controls, indicate that this improvement on the tactual fusion task 1st appeared somewhere between 4 and 12 hr. Of deprivation. Various hypotheses are offered to account for these differential results and findings are related to D. P. Schultz's sensoristatic theory. (french summary) (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensory responsiveness and avoidance learning in rats.

Conducted an analysis of sensory responsiveness and avoidance learning in 3 experiments using 5 rat strains: MNR/Har/Lu, MR/Har/Lu, RCA/Lu, RHA/Lu, and RLA/Lu. Ss totaled 470. There were significant differences among the strains in response to electric footshock. Also, the strain-specific shock intensity as the UCS elicited significantly higher rates of avoidance learning as compared with the rates of avoidance learning under an equal but average level of shock intensity as the UCS. In general, discrete auditory and visual sensory modes as the CS produced almost the same rate of avoidance learning. The proportion of variation in avoidance learning attributable to strains was significant under all 6 experimental conditions except the no-discrete CS and strain-specific UCS conditions. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensory and cognitive components of visual information acquisition.

Describes a theory of visual information acquisition and visual memory. The theory has 2 major components. First, the visual system's initial sensory response to a short-duration, low-contrast stimulus is generated by a linear, low-pass temporal filter that operates on the stimulus's temporal waveform. Second, information is acquired from a stimulus through an independent-sampling process whose sampling rate at time t following stimulus onset is jointly proportional to (1) the magnitude by which the sensory response exceeds some threshold and (2) the proportion of still unacquired information. The theory was successfully tested in 5 variants of a digit recall task in which temporal waveform of the stimulus was systematically manipulated. In a final experiment, the theory simultaneously accounted for performance in detection and identification tasks. Implications for visual information processing, low-contrast detection, and binocular combination of information are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensory deprivation and autocontrolled aversive stimulation in the reduction of snake avoidance.

Selected 30 female snake-aversive college students based on responses to the Fear Survey Schedule. Ss in Group 1 (n = 10) underwent 5 hrs of sensory deprivation. Periodically during 3 subsequent hours, they could initiate the presentation of slides which showed snakes in varying degrees of realism. 5 of these Ss saw the slides in random order, and 5 saw them in order of increasing verisimilitude. 10 other Ss could do the same without previous deprivation; 10 more, without deprivation, saw the slides with frequencies yoked to an S in Group 1. Deprived Ss evidenced significantly more fear reduction, both on approach behavior to a live snake and on a self-report measure, than the other 2 groups. Random presentations evoked more viewing responses, and more fear reduction in deprived Ss, than hierarchical order. Results suggest that sensory deprivation may be a useful tool in behavior modification contexts. (French summary) (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of auditory deprivation on visual resolving power.

Conducted 2 experiments in which changes in the critical flicker fusion (CFF) were determined during and after auditory deprivation (silence). In Exp I, 36 male undergraduates were exposed to 1 wk of auditory deprivation, measurements of the CFF being taken at daily intervals and at Days 1, 2, 3, and 7 after the termination of the experimental condition. Results show that the experimental group exhibited a significant progressive improvement in visual resolving power as a function of auditory deprivation and, following its termination, a gradual decline towards the pre-experimental baseline. On the other hand, 2 control conditions, a group of confined Ss, and a non-confined group showed no systematic changes in the CFF. In Exp II with 6 new Ss, the period of auditory deprivation was extended to 14 days. Results again reveal a progressive improvement on the CFF during the 1st wk of silence followed by an asymptotic performance during the 2nd wk. (PsycINFO Database Record (c) 2010 APA, all rights reserved)