Dependence of adolescent novelty-seeking behavior on response phenotype and effects of apparatus scaling.

Adult rats have been phenotyped as high (HRs) or low (LRs) responders to novelty, the former associated with high-risk behaviors. Data indicating that adolescent rodents exhibit increased novelty-seeking relative to adults are equivocal, and phenotypic variations in adolescent novel stimulus reactivity are unknown. To determine whether novelty-seeking differs between adolescent and adult rats, reflecting phenotypic variations within each age, activities in an inescapable novel environment and novel object exploration were measured. Adolescents moved further, faster, and more continuously than adults, and exhibited a greater variability and range of activity in the novel environment. Both adolescent and adult LRs habituated to the environment by the second trial, but HRs maintained increased activity throughout 8 trials. In the free-choice paradigm, adolescents approached the novel object more frequently and spent more time in proximity to the object than adults. Similar results were obtained using arenas and objects of the same size or scaled to animal size. Results confirm that novelty-seeking by adolescents is greater than by adults, a behavior attributed primarily to the response magnitude exhibited by adolescents with the HR phenotype. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Artificial rearing causes changes in maternal behavior and c-fos expression in juvenile female rats.

This study investigated the effects of early-rearing experiences on responsiveness to pups and on the pattern of c-fos activation in the brain of juvenile female rats. From Days 4 to 20, littermate females were reared with their mothers (MR) or artificially (AR). AR rats received minimal licking-like tactile stimulation (AR-min) or maximal stimulation (AR-max). On Day 20, rats were exposed to pups for 4 or 8 days, exposed to a playmate for 4 or 8 days, or left in isolation for 4 or 8 days. Compared with MR rats, pup-exposed AR rats engaged in less pup licking, and all AR rats showed significant reductions in c-fos immunoreactivity in the medial preoptic area and the parietal and piriform cortices. The AR-min group showed the greatest difference in Fos-lir compared with the MR groups. Possible mechanisms that mediate the effects of rearing on the development of neural circuits underlying maternal behavior are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential rearing conditions and alcohol-preferring rats: Consumption of and operant responding for ethanol.

Exposing rats to differential rearing conditions during early postweaning development has been shown to produce changes in a number of behaviors displayed during adulthood. The purpose of the present studies was to investigate whether rearing alcohol-preferring (P) and nonpreferring (NP) rats in an environmental enrichment condition (EC), a social condition (SC), or an impoverished condition (IC) would differentially affect self-administration of 10% ethanol. In Experiment 1, rats were tested for consumption of 10% ethanol in limited- and free-access tests. For Experiment 2, rats were trained to respond in an operant chamber for ethanol and then provided concurrent access to 10% ethanol and water. Each solution was presented in a separate liquid dipper after meeting the schedule of reinforcement on distinct levers. After concurrent access tests, the water lever/dipper was inactivated and a progressive ratio (PR) schedule was initiated. Three successive solutions (10% ethanol, 15% ethanol, and 10% sucrose) were tested under the PR. For P rats, rearing in an EC reduced ethanol consumption, preference, and motivation to obtain ethanol, relative to P rats reared in an IC. Thus, exposure to a novel environment immediately after weaning acted to decrease the reinforcing properties of ethanol in an animal model for alcoholism. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Cooperative behavior in dyad as a function of reinforcement parameters.

"Reinforcement parameters for a dyadic cooperative situation were defined and varied in a series of three experiments… . Each S was required to perform the simple motor response of turning a small concealed knob in a series of 50 trials. A reinforcing stimulus was delivered to each S separately after each trial… . The degree to which optimal cooperative behavior… developed in these situations, was studied as a dependent variable… . Other experimental parameters were suggested and the implications of these… for analysis were sketched." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Child rearing attitudes of mothers and fathers as reported by schizophrenic and normal patients.

To determine the significant aspects of family background as perceived by schizophrenics, Ss were asked to think back to the time when they were 13 or 14 and answer a questionnaire on child rearing practices as they were conceived to be reflected in the attitudes of their parents at that time. The responses of schizophrenics with good and poor premorbid backgrounds were compared with each other and to GMS patients. The results indicate that there was a significant and direct relationship between level of adjustment and degree of deviance in postulated parental attitudes. Parents, in general, are perceived to be dominating rather than overprotective or rejecting. Normals and schizophrenics differ significantly in describing familial attitudes, although all seem to perceive father as dominant, mother as over-protective. From Psyc Abstracts 36:04:4JQ76G. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Problem solving as a function of children's defensiveness and parental behavior.

The performance of 2 groups of 16 5th-grade boys, one low defensive and low anxious (LD) and the other high defensive and low anxious (HD) on the Defensiveness and Test Anxiety Scales for Children, was compared on the Porteus Maze Test taken with mothers absent and on a different form of the Porteus plus a jigsaw puzzle test with mothers present. Mothers were rated on a set of rating scales as they helped their sons with the puzzle. The results suggest that (a) discrepancies between ability and qualitative performance in defensive boys are a function of defensiveness whereas such discripancies in quantitative performance are a function of certain salient components of the test situation, and (b) communication is less effective in families of HD boys than in families of LD boys. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cocaine treatment and prenatal environment interact to disrupt intergenerational maternal behavior in rats.

The link between impaired maternal behavior (MB) and cocaine treatment could result from drug-induced decreases in maternal reactivity to offspring, prenatal drug exposure (PDE) in offspring that could alter their ability to elicit MB, or the interaction of both, which could subsequently impair MB of the 1st-generation dams. Following chronic or intermittent cocaine or saline treatment during gestation, rat dams rearing natural or cross-fostered litters were compared along with untreated dams for MB. Untreated 1st-generation females with differentially treated rearing dams and PDE were tested for MB with their natural litters. The authors report disruptions in MB in dams and their 1st-generation offspring, attributable to main and interaction effects of maternal treatment, litter PDE, and rearing experience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Previous experience affects subsequent anxiety-like responses in rats bred for novelty seeking.

Novelty-seeking behavior in rats is deemed to model sensation seeking in humans, a personality trait related to some psychiatric conditions, including substance abuse. Animals characterized based on their locomotor response to novelty, namely high and low responders (HRs and LRs, respectively), show differences in anxiety and drug-taking behaviors. This study evaluates the effect of anxiety-provoking situations on subsequent behaviors in these endophenotypes. Selectively bred HR and LR rats were submitted to blocks of tests consisting of two-trial light- dark (LD) and two-trial elevated plus maze (EPM) tests arranged in counterbalanced, alternating order. No differences in anxiety-like behaviors were found in HR-bred and LR-bred rats in either LD trial, regardless of the test order. Repeated exposure to the EPM test, however, resulted in enhanced behavioral response under different test orders as a function of endophenotype. Compared with HR-bred animals, LR-bred animals exhibited increased anxiety on reexposure to EPM but only if both trials were preceded by an LD test session. The emotional responses in HR-bred and LR-bred rats reported here may reflect different degrees of adaptive processing regulated by both genetic and environmental factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Displacement as a function of conflict.

"Miller's theory of displacement was extended by integration with his conflict theory into a three-dimensional model… . To test deductions from this model rats were first trained to get food at one end of an alley and then shocked while eating until they no longer approached the food cup. They then left this alley and entered other alleys differing slightly from the original alley. Here they went closer to the food end than in the original alley. Tracings of their movements followed a pattern predicted from the model… . After making goal responses in the generalized alleys, the rats returned to eat in the original alley, showing a 'therapeutic' effect." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluating and overcoming barriers to taking abuse histories.

Psychologists are frequently faced with issues of whether, when, and how to ask clients if they have been abused. Despite the demonstrated relationship between child abuse and adult psychopathology, researchers report that many clinicians still do not routinely inquire about abuse. A questionnaire completed by 63 psychologists and 51 psychiatrists in New Zealand revealed that factors related to reluctance to ask about abuse include the following: more pressing issues, fear of disturbing clients, a diagnosis of schizophrenia, biological etiology beliefs, and fear of inducing "false memories." Significant differences were found between psychologists and psychiatrists on some of these factors. Practice guidelines for enhancing the frequency and efficacy of abuse inquiry are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral and developmental consequences of early rearing experience for captive giant pandas (Ailuropoda melanoleuca).

Mother-reared (MR) and peer-reared (PR) captive giant panda (Ailuropoda melanoleuca) cubs were compared to evaluate the effects of early removal from mother on behavioral development. Males and females and twins and singletons were compared to assess the effects of social setting on behavioral development. Subjects included 2 PR females, 3 MR females, 3 MR males, and 3 mothers. MR cubs spent more time manipulating bamboo and fell more often than PR cubs. PR cubs spent more time inactive. Male cubs directed more playful behavior at their mothers. Twins spent more time play fighting with their mothers than with their siblings. The results suggest that peer-rearing does not provide young pandas with the same level of social stimulation as mother-rearing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transmission of learned behavior between rats.

"Six rats were trained to follow leader rats in an elevated T maze to secure a reward of water. An incidental cue of two lights was then introduced such that the leaders responded consistently with respect to it. After 100 trials of following leaders who were responding to the incidental cue, Ss were given 20 trials alone. On 77% of these test trials Ss went to the arm marked by the cue to which the leader had been going. This finding was interpreted as a demonstration of transmission of learned behavior between animals, and it was explained on the basis of a continuity theory of discrimination learning." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The conditioning of verbal behavior as a function of the need for social approval.

The hypothesis tested herein is that need for approval will facilitate learning. Need for approval was measured by the M-C Social Desirability Scale (Crowne & Marlowe, 1960); the learning task employed the model of verbal conditioning as used by Greenspoon (1955); the Ss were undergraduate psychology students. The results supported the hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes in children's verbal behavior as a function of social approval and manifest anxiety.

"This study investigated the operant conditioning of a class of verbal behavior as a function of manifest anxiety and of two types of social approval in grade school children. Anxiety levels were inferred from the Children's Manifest Anxiety Scale. Social reinforcers consisted of a 'head nod' and the verbalization 'good.' Acquisition of a verbal conditioned response was obtained in both reinforcement groups with the verbal reinforcer being significantly better than physical movement. Anxiety effects were not demonstrable." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Children's achievement-related expectancies as a function of academic performance histories and sex.

60 male and 60 female 1st and 3rd graders, classified by teacher ratings as high, average, and low achievers, were compared on (a) their expectations for success prior to an anagrams task, (b) their subsequent perceptions of the cause of failure on the task, and (c) their expectations for future success. Results indicate that boys with a history of low academic success in school had lower expectations for success on the task and tended to be more likely to attribute failure to lack of ability than boys with a history of average or high academic success. In contrast, high-achieving girls had lower expectations for success than low- and average-achieving girls. Furthermore, Ss who attributed failure to low ability reported relatively low expectations for future success. This finding suggests that children's perceptions of the causes of past performance outcomes mediate their subsequent expectations, as is claimed by attribution theorists. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Kindling-induced emotional behavior in male and female rats.

Modeling fear in animals is a critical approach for identifying the neural mechanisms involved in human disorders such as generalized anxiety and panic. Amygdala kindling has proven useful in this regard because it produces dramatic increases in fearful behavior. The purpose of this experiment was to compare the behavioral effects of kindling in male and female rats. Compared with the sham-stimulated rats, the kindled male and female rats showed similar increases in fearful behavior, with some sex differences in fear-related open-field activity. They also showed decreased immobility in the forced-swim test and increased sucrose consumption. These results suggest that kindling-induced fear is generally similar in male and female rats and that kindling does not appear to induce depression-like behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delinquency and school dropout behavior as a function of impulsivity and nondominant values.

This study tested the hypotheses (a) that over and above social class differences, delinquents and school dropouts are more impulsive than nondeviants; and (b) that these deviant groups maintain a nondominant value system. The data were collected prior to the occurrence of the deviant behavior. Ss were selected from 4 Texas nonurban areas. The deviant groups differed significantly from the nondeviant group on 3 psychomotor tasks, 2 tasks that require the maintenance of a convergent set, and surgency. These findings are consistent with the impulsivity postulate. Self-reported values were not found to differentiate the groups. By and large, the delinquents and school dropouts were similar in performance on the measures included in this investigation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reading difficulties as a cause of behavior problems in adolescence.

It is difficult to state whether the learning and reading problems cause the socially deviant behaviour, or whether the emotional problems lead to the reading and learning problems in adolescents of normal intelligence. This may be a difficult question to answer in general, but in a given specific case with proper assessment, it is not hard to decide which came first. It has been stated that no deviant child among exceptional children suffers more in the way of retaliatory and rejecting attitudes on the part of those around him than does the delinquent youngster. It has also been found that teachers and youth workers do not like to deal with a delinquent child. This is in fact a sad state of affairs because though these youngsters may be difficult and lack motivation however, they do possess the potential to become successful criminals or tax paying citizens of our Community of tomorrow. Very much depends upon the help provided during the difficult years of adolescence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cooperative behavior of laboratory rats (Rattus norvegicus) in an instrumental task.

Cooperation is a cognitively demanding, complex social behavior, found primarily in primates. Here we investigated mutualism in rats (Rattus Norvegicus), a simple form of cooperation in which two subjects work on operant task, receiving immediate and simultaneous sucrose reward for a joint action. To receive the sucrose reward, familiar pairs of rats were required to nose poke simultaneously. Following 44 training days, we examined the relation of social contact and ultrasonic vocalizations to the rat's cooperative behavior by testing the effects of inserting opaque, wire-mesh, or no partition - between subjects. Cooperative behavior (simultaneous nose-poking): (a) increased gradually during initial training; (b) decreased with the opaque partition (restricting visual, acoustic, and physical communication); (c) increased with a wire mesh partition restricting only physical contact); and (d) increased with the number of 50 kHz USV “happy” calls and the intensity of social interaction. The possibility of studying the development of cooperative behavior in laboratory rats using a simple procedure based on commercially available equipment may prove useful in modeling determinants of social behavior. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A search for relations between brain chemistry and behavior.

This report summarizes the results of unpublished and widely scattered published studies on the inter-relationship of acetylcholine (ACh) and cholinesterase (ChE) on the adaptive behavior of rats. 2 early hypotheses, now rejected, generated several findings of considerable interest leading to the development of a 3rd hypothesis which has so far stood the test of empirical verification. A brief summary of current and projected studies are included. (PsycINFO Database Record (c) 2010 APA, all rights reserved)