The spatial distribution of inhibition of return

Inhibition of return (IOR) refers to the finding that response times (RTs) are typically slower for targets at previously attended (cued) locations than for targets at novel (uncued) locations. Although previous research has indicated that IOR may spread beyond a cued location, the present study is the first to examine the spatial distribution of IOR with high spatial resolution over a large portion of the central visual field. This was done by using a typical IOR procedure (cue, delay, target) with 4 cue locations and 441 target locations (each separated by 1° of visual angle). The results indicate that IOR spreads beyond the cued location to affect the cued hemifield. However, the cues also produced a gradient of RTs throughout the visual field, with inhibition in the cued hemifield gradually giving way to facilitation in the hemifield opposite the cue.     

When the central executive lets us down: schemas, attention, and load in a generative working memory task

Participants were asked to generate a single sequence of numbers in between two bounds. By varying the requested sequence length and way in which the question is posed, this paradigm enables assessment of the contributions to central executive functioning of schema, focus of attention, and load. With sequences of three or four numbers, a quarter of the sample failed fully to comply with the instructions. They generated an incorrect number of numbers or went outside the specified bounds. With sequences of six numbers, more than half of the sample infringed one or more of the constraints. Participants consistently generated sequences with particular generic properties. The overall frequency and patterns of infringements suggest that a substantial proportion of participants focused their conceptual attention on sequence content and often neglected the problem of how thelength and boundary constraints were going to be evaluated either before or during response delivery.     

Effects of LY354740, a novel glutamatergic metabotropic agonist, on nonhuman primate hypothalamic-pituitary-adrenal axis and noradrenergic function

The search for novel anxiolytics and antidepressants has focused on compounds with the potential to reduce excessive hypothalamic-pituitary-adrenal (HPA) axis activity. L-glutamate, an excitatory neurotransmitter ubiquitously present within the central nervous system, conceivably plays an important role in activating the neural sites involved in stress modulation. Deactivation of the HPA axis by glutamatergic neurotransmission modulation may represent a novel therapeutic approach. Accordingly, the acute intravenous effects of the novel metabotropic (mGlu2/3) agonist LY354740 were tested on bonnet macaques (Macaca radiata) undergoing acute infusions of yohimbine, a noradrenergic stimulant. Dependent measures were the magnitude of the increase of plasma cortisol and plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) customarily elicited by yohimbine. Next, the effects of 6 weeks of chronic oral administration of LY354740 on baseline (postcapture) plasma cortisol and MHPG levels in comparison to the identical measure in untreated controls were assessed. Subjects chronically treated with LY354740 received yohimbine infusions which were compared to yohimbine infusions and saline infusions in non-LY354740-treated subjects. Preliminary evidence supports the view that acute LY354740 infusion resulted in a marked diminution of yohimbine-induced stress response, as manifest by a substantial attenuation of cortisol and MHPG response observed in comparison to the saline-treated yohimbine condition. Chronic oral administration of LY354740 led to postcapture baseline cortisol levels which were markedly reduced (approximately 50 percent) in comparison to untreated control subjects; however, there were no significant parallel differences in MHPG levels. Yohimbine infusions elicited an increase in cortisol and MHPG levels in both LY354740-treated and non-LY354740-treated subjects, in comparison to declines in cortisol values observed following vehicle infusions (group X time interaction; P<.0001). Chronic LY354740-treated subjects failed to achieve cortisol levels comparable in range to those of untreated subjects primarily because of their low baseline cortisol levels. In contrast, despite equivalent baselines, yohimbine-induced MHPG values were increased overall in the chronically treated group compared to the saline and yohimbine-alone groups. Thus, LY354740 markedly reduced the acute corticoid and noradrenergic response elicited by yohimbine infusion. Chronic administration of LY354740 appears to present a safe and effective mechanism to markedly down-modulate the HPA axis while retaining noradrenergic responsivity.     

Self-injurious behavior: gene-brain-behavior relationships

This paper summarizes a conference held at the National Institute of Child Health and Human Development on December 6-7, 1999, on self-injurious behavior [SIB] in developmental disabilities. Twenty-six of the top researchers in the U.S. from this field representing 13 different disciplines discussed environmental mechanisms, epidemiology, behavioral and pharmacological intervention strategies, neurochemical substrates, genetic syndromes in which SIB is a prominent behavioral phenotype, neurobiological and neurodevelopmental factors affecting SIB in humans as well as a variety of animal models of SIB. Findings over the last decade, especially new discoveries since 1995, were emphasized. SIB is a rapidly growing area of scientific interest to both basic and applied researchers. In many respects it is a model for the study of gene-brain-behavior relationships in developmental disabilities.     

Age-of-acquisition and cumulative frequency have independent effects

Lewis (1999) argued that effects of age of acquisition (AoA) are entirely attributable to cumulative frequency. He reported an instance-based model in which the number of instances of the stimulus stored in memory predicts reaction time. We note four aspects of the literature on AoA that cannot be explained by this instance-based approach. Firstly, an effect of AoA has been observed in the absence of an effect of frequency. Secondly, an effect of AoA has been observed when cumulative frequency has been controlled. Thirdly, the effect of AoA is dependent on task. Fourthly, the effect of word frequency is dependent on stimulus modality. Lewis reported an experiment in which participants make a decision based on identity-specific semantic information to celebrity faces to demonstrate an effect of the number of instances in memory, which he interpreted as an effect of AoA. We note that effects of AoA have been found in lexical and perceptual tasks, but to date all attempts to demonstrate an advantage for early-acquired items in semantic classification tasks have failed. We conclude that the effects of AoA cannot be attributed solely to the effects of cumulative frequency.     

A culturally sensitive approach to therapy with immigrant families: the case of Jewish emigrants from the former Soviet Union

This article is based on accumulated clinical experience in Israel with families that emigrated from the former Soviet Union. It describes a culturally sensitive systemic intervention with two such families: a single-parent family, and a family that exhibited physical violence. Relevant cultural characteristics of family patterns and parent-child relationships in Jewish-Soviet families are reviewed. It is demonstrated how a cross-cultural perspective may affect the interpretation of presented problems and result in a less pathological perspective. It is further illustrated how universal intervention techniques combined with culturally sensitive approaches may produce positive effects in therapy.     

Temperament and loving-styles in college women: associations with eating attitudes

The purpose of the present study was to examine the associations of temperament and love attitudes with eating behaviors in 190 college-aged nonclinical women who completed a survey that included measures of temperament, loving-style, and eating attitudes. Certain temperament and loving-style variables showed significant statistical association with scores on eating attitudes. Specifically, both obsessive and game-playing love-styles were related to the Dieting and Bulimia-Food Preoccupation dimensions of the eating scales, while temperamental fear and anger were related to bulimia and oral control. The role of interpersonal relationships and self-perceptions of temperament may provide a useful perspective for understanding the etiology of eating disorders.     

MMPI screening scales for somatization disorder

44 items on the MMPI were identified which appear to correspond to some of the symptoms in nine of the 10 groups on the Perley-Guze checklist for somatization disorder (hysteria). This list was organized into two scales, one reflecting the total number of symptoms endorsed and the other the number of organ systems with at least one endorsed symptom. Full MMPIs were then obtained from 29 women with primary affective disorder and 37 women with somatization disorder as part of a follow-up study of a consecutive series of 500 psychiatric clinic patients seen at Washington University. Women with the diagnosis of somatization disorder scored significantly higher on the somatization disorder scales created from the 44 items than did women with only major depression. These new scales appeared to be slightly more effective in identifying somatization disorder than the use of the standard MMPI scales for hypochondriasis and hysteria. Further development is needed.     

Defense mechanisms in alexithymia

The Polish version of the Toronto Alexithymia Scale-20 and Defense Mechanisms Questionnaire were completed by 387 university students. Scores on alexithymia correlate significantly with scores on the whole group of 12 immature defenses (Pearson r = .39, p < .001) and with scores on such individual immature defense mechanisms as Autistic Fantasy (r = .39), Somatization (r = .37), Projection (r = .32), and Displacement (r = .32). These results support other findings indicating that alexithymia is significantly associated with immature ego defenses.