Effects of arachidonic acid on the spatial cognition of aged rats

Abstract:  To examine the effects of arachidonic acid (AA) on age-related cognitive deficits, Fischer 344 rats were given an AA-supplemented powder diet for 12 weeks from 18.6 months old as part of the old AA (OA) group. Other age-matched rats were fed a non-AA-supplemented powder diet as part of the old control (OC) group, and young rats were fed lab pellets as part of the young control (YC) group. When the aged rats reached 20.0 months old, all animals were tested for spontaneous activity in an open field, followed by the Morris water maze place and cue tasks. Escape latencies for the place task showed that the YC rats were fastest, and there was no difference between the OA and OC groups. However, the probe test and the first block of the cue task indicated that the OA rats remembered the location of an invisible platform better than the OC rats. Although the amount of hippocampal AA was larger in the OA rats than in the OC rats, the difference was not significant. The results showed that AA administration to aged animals may alleviate age-related deficits in spatial cognition.     

Matching choices to avoid offending stigmatized group members

People (selectors) sometimes make choices both for themselves and for others (recipients). We propose that selectors worry about offending recipients with their choices when recipients are stigmatized group members and options in a choice set differ along a stigma-relevant dimension. Accordingly, selectors are more likely to make the same choices for themselves and stigmatized group member recipients than non-stigmatized group member recipients. We conducted eight studies to study this hypothesis in different choice contexts (food, music, games, books) and with recipients from different stigmatized groups (the obese, Black-Americans, the elderly, students at lower-status schools). We use three different approaches to show that this effect is driven by people’s desire to avoid offending stigmatized group members with their choices. Thus, although prior research shows that people often want to avoid being associated with dissociative groups, such as stigmatized groups, we demonstrate that people make the same choices for self and stigmatized other to minimize offense.     

SOCIAL COMMUNICATIVE ANXIETY AND THE PERSONNEL SELECTION PROCESS: TESTING THE SIMILARITY EFFECT IN SELECTION DECISIONS

Three studies tested competing predictions about the role of similarity in personnel selection decisions. Previous research suggests a significant role for applicant-selector similarity in the determination of selection decisions. Applicants who are similar to selectors are evaluated, by selectors, more positively than dissimilar applicants. The current investigations found that when the object of similarity is the applicant's and selector's level of anxiety, this relationship fails to appear. Regardless of the selector's own level of anxiety, the high anxious applicant is less positively evaluated than the low anxious one. This effect appears even when the communication demands of the position are specified.     

Pharmacological Shock Therapy as a Psycho-Biological Problem

Five mothers of 50 newborn rat pups were maintained on either standard lab chow or a diet composed of the same chow with onion powder added. Taste preference tests administered during weaning indicated that the pups whose mother was fed the onion chow showed a preference for onion diet, but that such preference dissipated across the five day testing period. A control group of pups who were exposed to any onion diet cues available through channels other than the mother's milk did not show a preference for onion diet. It was concluded that exposure to onion taste in mother's milk was responsible for an initial preference for onion diet.     

Infants rapidly detect human faces in complex naturalistic visual scenes

Infants respond preferentially to faces and face‐like stimuli from birth, but past research has typically presented faces in isolation or amongst an artificial array of competing objects. In the current study infants aged 3‐ to 12‐months viewed a series of complex visual scenes; half of the scenes contained a person, the other half did not. Infants rapidly detected and oriented to faces in scenes even when they were not visually salient. Although a clear developmental improvement was observed in face detection and interest, all infants displayed sensitivity to the presence of a person in a scene, by displaying eye movements that differed quantifiably across a range of measures when viewing scenes that either did or did not contain a person. We argue that infant's face detection capabilities are ostensibly “better” with naturalistic stimuli and artificial array presentations used in previous studies have underestimated performance.     

From field experiments to program implementation: Assessing the potential outcomes of an experimental intervention program for unemployed persons

Demonstrated a procedure suggested by Bloom (1984) to provide estimates for the effects of an intervention on its actual participants compared to global effects on study participants in the intervention group, whether or not they showed up. Analyses were based on data collected in a field experiment that tested a preventive intervention for unemployed persons (Caplan, Vinokur, Price & van Ryn, 1989). Effect size estimates were two to three times larger for the actual participant group than for the entire experimental group on employment outcomes (e.g., earnings) and mental health (anxiety and depression). Further analyses produced results showing that compared to participants, the nonparticipants achieved significantly higher levels of reemployment at posttests and did not differ significantly from participants on all other outcomes. The results suggest that persons who most needed the intervention and benefited from it were drawn into it through self-selection processes.     

Abnormal behavior after intracerebral injection of polypeptides from wheat gliadin: Possible relevance to schizophrenia

Accumulating evidence suggests that: (1) gluten-like proteins in cereal grains may produce psychiatric symptoms in schizophrenics as well as in celiac patients; (2) the genotypes for these two disorders may have one or more but not all, genes in common. Gluten fed to treated schizophrenics on a cereal grain-free, milk-free diet exacerbates their symptoms; ingestion of polypeptides resulting from peptic-pancreatic digestion of wheat gliadin (from gluten) produces psychiatric and other symptoms in celiac patients. To test their effect on behavior of normal rats we bypassed the protective barrier systems by intracerebral injection of a potent subfraction of gliadin polypeptides which produces psychiatric symptoms in celiacs. Eighteen exploratory experiments in 4 rats demonstrated that intracerebral injection of these polypeptides may variably produce stereotyped movements, prolonged “chewing in air,” “catelepsy” and seizures, all after an unusually long latent period. The lowest dose producing “catalepsy” was 600 μg, and that for seizures was 500 μg. Since we used a mixture, one or more polypeptides in it may be considerably more potent. The accumulated evidence suggests the following working hypothesis: One or more of the polypeptides produced by peptic-pancreatic digestion of certain glutamine-proline rich food proteins(e.g., cereal grain glutens) are psychotoxic and may enter the brain of the schizophrenic or celiac because the small gut, and possibly other, barrier systems (enzymatic, immunologic, membranous, other) suffer defects of an unknown nature due to one or more abnormal genes common to both diseases; and that the differences in the two diseases are determined largely by the dissimilar components of the genotypes.     

Perspective-taking ability in bilingual children: Extending advantages in executive control to spatial reasoning

Monolingual and bilingual 8-year-olds performed a computerized spatial perspective-taking task. Children were asked to decide how an observer saw a four-block array from one of three different positions (90°, 180°, and 270° counter-clockwise from the child's position) by selecting one of four responses – the correct response, the egocentric error, an incorrect choice in which the array was correct but in the wrong orientation for the viewer, and an incorrect choice in which the array included an internal spatial error. All children performed similarly on background measures, including fluid intelligence, but bilingual children were more accurate than monolingual children in calculating the observer's view across all three positions, with no differences in the pattern of errors committed by the two language groups. The results are discussed in terms of the effect of bilingualism on modifying performance in a complex spatial task that has implications for academic achievement.     

Revisiting ‘What works for whom?’: A qualitative framework for evaluating clinical effectiveness in child psychotherapy

This paper describes a framework for evaluating the effectiveness of child psychotherapy used by child psychotherapists in an inner city Child and Adolescent Mental Health Service (CAMHS). The Hopes and Expectations for Treatment Approach (HETA) involves using the assessment for psychotherapy that normally precedes treatment to derive a baseline from which to generate a set of hopes/expectations as regards the effects of the treatment on the part of parents and the psychotherapist, to be revisited one year after the start of the psychotherapy and/or at its completion. The Strength and Difficulties Questionnaire, for parents and schools, was also administered before and after the treatment. The characteristics of the first 30 children referred for psychotherapy over a particular time period are described. Of the first 15 children in this group to complete one year of individual psychotherapy, all showed change or significant change in the areas concerning parents' and therapists' hopes at the end-of-year review, as rated by parents and psychotherapists. A case of a child with conduct disorder is used to describe how the assessment generated a psychoanalytic formulation, how the therapist's understanding was fed back to the parents, and how the parents' and therapist's hopes and expectations were derived and recorded. This case illustrates powerfully the impact of trauma in the parents' backgrounds on the internal world of the child, and how the method provides a useful bridge between parent and child work. Feedback from the psychotherapists, the parents and the referrers using the framework is reviewed, and in conclusion the paper argues for the framework's value in promoting good practice in the treatment and management of complex cases and in enhancing awareness of the nature and scope of the psychotherapy process.     

Hypothalamic expression of NPY mRNA, vasopressin mRNA and CRF mRNA in response to food restriction and central administration of the orexigenic peptide GHRP-6

In this study, we examined the effects of restricted feeding and of central administration of an orexigenic ghrelin agonist GHRP-6 on peptide mRNA expression in the hypothalamus. We compared rats fed ad libitum with rats that were allowed food for only 2?h every day, and treated with a continuous chronic i.c.v. infusion of GHRP-6 or vehicle. Ad libitum fed rats exposed to GHRP-6 increased their food intake and body weight over 6 days, but, at the end of this period, neuropeptide Y mRNA expression in the arcuate nucleus was not different to that in control rats. By contrast, expression of neuropeptide Y mRNA in the arcuate nucleus was elevated in food-restricted rats, consistent with the interpretation that increased expression reflects increased hunger. However, neuropeptide Y mRNA expression was no greater in food-restricted rats infused with GHRP-6 than in food-restricted rats infused with vehicle; thus if the drive to eat was stronger in rats infused with GHRP-6, this was not reflected by higher levels of neuropeptide Y mRNA expression. Expression of vasopressin mRNA and corticotrophin releasing factor (CRF) mRNA in the paraventricular nucleus (PVN) was not changed by food restriction. GHRP-6 infusion increased CRF mRNA expression in ad libitum rats only.     

Transfer of spatial behaviour controlled by a landmark array with a distinctive shape

In two experiments, rats swam to a submerged platform in one corner of a rectangular or kite-shaped array created by four identical landmarks attached to the walls of a circular pool. After training in the rectangular array, rats expressed a preference for the corner in the kite-shaped array that was geometrically equivalent to where the platform was located previously. After training in either array, the removal of two landmarks from the rectangular array, or the landmark at the apex of the kite-shaped array, did not affect the control over searching exerted by the remaining landmarks. The results imply that rats use local rather than global spatial representations when searching for a hidden goal with reference to an array of landmarks.     

Selectors' Decision Strategies when Assessing Immigrant Job Applicants

Immigrant job applicants are often not fluent in the majority language. This raises the question whether selectors adjust their decision strategy when selecting immigrants. In two field studies (N = 1,949 and N = 156), we examined the decision strategies of professional selectors. Selectors used differential strategies, giving less weight to the test scores and impression scores of immigrants. Dutch language proficiency served as a moderator variable; test scores were considered less important in the employment recommendation especially for immigrants with low language skills. Yet professional selectors also used similar strategies for different groups; the same test scores led to the same recommendations, regardless of ethnicity. In sum, personnel selectors adjusted their decision strategy for immigrants, but this did not lead to immigrants receiving higher recommendations than majority applicants with similar test scores.     

Epinephrine Effects on Memory Are Not Dependent on Hepatic Glucose Release

Epinephrine released or administered soon after a given training task modulates memory processes. Since epinephrine does not readily cross the blood–brain barrier, studies have suggested that some of the central effects of epinephrine might be mediated by peripheral release of glucose. These experiments examined the involvement of blood glucose levels in the posttraining effects of peripherally administered epinephrine. The effects of the administration of epinephrine (25 and 625 mg/kg) on memory of an inhibitory avoidance task were evaluated in fed and fasted rats (depleted glycogen stores in liver). Blood glucose levels after the task in each group were also measured. Female Wistar rats were divided in two groups. Fed and 48-h-fasted animals were submitted to the inhibitory avoidance task and received ip epinephrine or saline immediately after training. The test session was carried out 48 h after training. Epinephrine (25 or 625 mg/kg) caused an increased glycemia in fed rats, but no effect was observed in fasted animals. Administration of epinephrine 25 mg/kg induced a facilitation of memory, while epinephrine 625 mg/kg impaired retention (either in fasted or in fed animals). There was no relation between increased glycemia induced by epinephrine and its effects on memory, since this drug presented its classical effects independently of the previous state of the animal (fed or fasted). The results of the present study suggest that the effects of systemic released or administered epinephrine on memory processes are not dependent on hepatic glucose release.     

GENDER AND CULTURE INTERACTION EFFECTS ON SCHOLASTIC APTITUDE TEST PERFORMANCE: SOME ISRAELI FINDINGS

The major aim of this study was to assess the degree of interaction between gender and cultural group background in determining scholastic aptitude test attainment among college student candidates. The analyses were based on the college entrance aptitude test scores of 1778 Jewish and 1017 Arab student candidates applying for admission to a major Israeli university. A Manova of the subtest scores revealed significant main effects for both culture and gender and a significant gender × culture interaction effect. Separate Anovas for each of the individual subtests show significant gender × culture interaction effects for both the Mathematical and Figural Reasoning subtests, with a larger gender group differential - in favor of the males - among Jews than among Arabs. The interaction effect was attributed, in part, to two complementary culture-specific factors, namely: (a) the positive self-selection of Arab female college candidates of relatively high scholastic ability, thus serving to narrow the gender gap in the Arab group; (b) the varied opportunities for advanced technical training, enrichment and experience available mainly to Jewish males during their period of compulsorly military service, serving to enhance the gender gap in the Jewish group. In sum, the data suggest that culture may serve as an important moderator variable in determining the size of gender group differences in scholastic aptitude test attainment.     

Children's self-selection into prevention programs: Evaluation of an innovative recruitment strategy for children of alcoholics

Systematically evaluated the efficacy of a self-selection strategy to recruit elementary-aged children into a school-based prevention program for children of alcoholics. Recruitment involved: a film about parental alcoholism, a follow-up meeting, and an invitation to participate in a prevention program. Of the 844 4th-6th graders exposed to recruitment, 67% showed no interest in the program, 26% attended the follow-up meeting, and 11% obtained parental permission. Analyses focused on group differences according to selection classification on measures of symptomatology and resources available to the child. Significant differences were noted on level of concern about parents' drinking, depression, conduct disorder, and self-worth. Children interested in the program tended to score higher on measures of symptomatology. The potential of a self-selection model for identifying children at risk and areas for future research are discussed.     

Recognition memory for complex visual discriminations is influenced by stimulus interference in rodents with perirhinal cortex damage

Rats with perirhinal cortex (PRC), hippocampal, or sham lesions were trained on a successive discrimination go/no-go task to examine recognition memory for an array of visual objects with varying interference among the objects in the array. Rats were trained to recognize a target array consisting of four particular objects that could be presented in any one of four possible configurations to cover baited food wells. If the four target objects were presented, the rat should displace each object to receive food. However, if a novel object replaced any one or more of the target objects, then the rat should withhold its response. The number of novel objects presented on nonrewarded trials varied from one to four. The fewer the number of novel objects in the array, the more interference the array shared with the target array, therefore increasing task difficulty. An increased number of novel objects should result in less interference with the target array and decreased task difficulty. Although accuracy was slightly lower in rats with hippocampal lesions compared with controls, the learning of the groups was not statistically different. In contrast, rats with PRC lesions were significantly impaired in learning compared with both control and hippocampal-lesioned rats. The results suggest that recognition memory for complex visual discriminations is affected by stimulus interference in rodents with PRC damage.     

Sex differences in maternal behaviors of immature rats: The role of emotionality

Immature rats are able to give maternal care to pups and may increase their inclusive fitness by helping newborn siblings. Immature males are generally reported to be more maternal than females. In this research we studied sex differences and the extent to which they may be due to a different emotional response to novelty. We studied maternal response in two groups of immature rats of both sexes: in the naive group, juveniles aged from 18 to 30 days were given one test and showed clear-cut sex differences. The experience group was submitted to repeated tests from 18 to 30 days of age, thus eliminating the effects of novelty: as a result, all differences between sexes disappeared. A second experiment was designed in 24-day-old females to differentiate the effects of repeated handling and exposure to the test situation from that of repeated exposure to pups; moreover, the effects of an anxiety-reducing drug (diazepam) were studied. Exposure to pups is particularly efficient in facilitating maternal response. Diazepam injection was also effective, but its control showed that the injection per se was responsible for the effect. In conclusion, our results stress the importance of response to novelty and suggest that sex differences in maternal behavior of immature rats may be modulated by different emotional responses by males and females. In fact, emotionality competes with, and may exert an inhibitory effect on, the expression of a vast array of behaviors. © 1994 Wiley-Liss, Inc.     

Nimodipine Counteracts Corticosterone-Induced Habituation Impairments

Corticosterone or placebo sustained-release pellets (4 pellets of 200 mg each, released over 90 days) were implanted subcutaneously in young Fischer-344 rats, fed with either regular food or with food containing 860 ppm of nimodipine. Following 2 weeks of treatment, the habituation of the rats to a new environment was studied. On the first test day, placebo-implanted rats explored the new environment and exhibited a characteristic habituation. On the second test day, 48 hr later, low activity was measured in the already familiar environment. This habituation was absent in corticosterone-implanted rats fed with regular food. However, corticosterone-implanted rats fed with food containing nimodipine behaved during the second test similarly to the placebo-implanted group. The data indicated that the behavioral deficit, induced in Fischer-344 rats by the high corticosterone levels, was reversed by the nimodipine treatment. Thus, nimodipine may be useful in counteracting certain prolonged stress-related cognitive impairments.     

Organizing for group counseling

Young people who participate in group counseling need help in understanding the goals of the group because these goals may otherwise act as hidden agenda items and because they have no norms for understanding whether or not the group is functioning effectively. A three-step process described here is designed to increase member commitment and understanding of the group: first, a self-selection process, second, an intake interview procedure, and third, a discussion of sharing goals.     

Ingroup and outgroup differences in face detection

Humans show improved recognition for faces from their own social group relative to faces from another social group. Yet before faces can be recognized, they must first be detected in the visual field. Here, we tested whether humans also show an ingroup bias at the earliest stage of face processing – the point at which the presence of a face is first detected. To this end, we measured viewers' ability to detect ingroup (Black and White) and outgroup faces (Asian, Black, and White) in everyday scenes. Ingroup faces were detected with greater speed and accuracy relative to outgroup faces (Experiment 1). Removing face hue impaired detection generally, but the ingroup detection advantage was undiminished (Experiment 2). This same pattern was replicated by a detection algorithm using face templates derived from human data (Experiment 3). These findings demonstrate that the established ingroup bias in face processing can extend to the early process of detection. This effect is ‘colour blind’, in the sense that group membership effects are independent of general effects of image hue. Moreover, it can be captured by tuning visual templates to reflect the statistics of observers' social experience. We conclude that group bias in face detection is both a visual and a social phenomenon.