P50 suppression in recent-onset schizophrenia: Clinical correlates and risperidone effects.

Chronic schizophrenic patients often do not suppress the auditory P50 component of the event-related potential to the second of 2 clicks, presented 500 ms apart, suggesting a loss of normal inhibition. This study attempted to replicate the P50 suppression deficit in patients with recent-onset schizophrenia and to examine whether P50 is related to clinical symptoms or is affected by an atypical antipsychotic medication. Data from 22 recent-onset schizophrenia patients and 11 normal controls revealed that disruption in P50 suppression is present during the early stages of illness. In addition, impaired P50 suppression covaried with clinical ratings of anxiety, depression, and anergia; results also suggested that the P50 inhibitory deficit may be related to the degree of patients' attentional impairment. Finally, risperidone, compared with a typical antipsychotic medication, improved inhibition of P50 to the second click. These results support P50 suppression as a measure of disordered neurocognition in schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychological distortions of the research process: A summary of psychotherapeutic explorations.

Presents the results of a psychotherapeutic research project concerning psychological blocks to research and creativity. Clients were 10 established researchers and postgraduate students who were offered psychoanalytically based focal-insight therapy. Some of the crucial personal-dynamic problems that hindered the normal development of the knowledge constructing aims of the researcher were anxiety-identity, separation, fear of criticism, competition and envy, research as a means of aggressive outlet, and intellectualization as a mechanism of defense. Illustrative case material is presented. The constructive role of anxiety in research is discussed together with the necessity of viewing research not only as an intellectual but also as an emotional activity. Findings reveal the impact of life situation on research and show a relationship between insight in therapy and the research process. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reference frame and effects of orientation on finding the tops of rotated objects.

Investigated effects of stimulus orientation across trial blocks and the spatial reference frame with a task in which Ss, with their heads upright or tilted, judged a dot to be near the top or the bottom of rotated line drawings of objects. Objects used in this task were also named. Response times from the 1st block of trials increased linearly for objects rotated from 0 to 120° from the upright. Across blocks, orientation effects diminished for naming but remained the same for top–bottom discriminations. Practice with top–bottom discriminations diminished orientation effects when the same objects were subsequently named. The spatial reference frame for top–bottom discrimination was midway between retinal and environmental coordinates. Specifying the location of object features is of greater importance for top–bottom discriminations than for naming and underlies orientation effects in these tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The intensity dimension of thought: Pupillometric indices of sentence processing.

Explored the intensity of processing during sentence comprehension by measuring pupillary response during reading. Two experiments with 76 college students contrasted the processing of simpler vs more complex sentences. The 2 more complex sentence types, object-relative center-embedded sentences and filler-gap sentences, not only took longer to process than their simpler counterparts, but they also produced a larger change in pupil diameter. It is proposed that the pupillary response is an indicator of how intensely the processing system is operating. Results are integrated within a resource-limited computational model of comprehension. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inspecting the emperor's clothes: Evidence that random selection of leaders can enhance group performance.

This article tests the hypothesis that group performance might be superior when leaders are randomly rather than systematically selected. In Experiment 1 groups with randomly selected leaders performed a survival task better than groups whose leaders were systematically selected. This effect was replicated in Experiment 2: Groups with a random leader also performed better than groups with no appointed leader and followers adhered more strongly to the group decision. In Experiment 3, naive participants' experimental expectations confirmed the counterintuitive nature of these findings. Results suggest that systematically selected leaders can undermine group goals and group maintenance. The possibility that this occurs because leaders assert their personal superiority at the expense of shared social identity is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparison of normal forgetting, psychopathology, and information-processing models of reported amnesia for recent sexual trauma.

This study assessed memories for sexual trauma in a nontreatment-seeking sample of recent rape victims and considered competing explanations for failed recall. Participants were 92 female rape victims assessed within 2 weeks of the rape; 62 were also assessed 3 months postassault. Memory deficits for parts of the rape were common 2 weeks postassault (37%) but improved over the 3 month window studied (16% still partially amnesic). Hypotheses evaluated competing models of explanation that may account for reported recall deficits. Results are most consistent with information processing models of traumatic memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparing borderline definitions: DSM-III borderline and schizotypal personality disorders.

Compared the two types of borderline disorder formally defined by Diagnostic and Statistical Manual of Mental Disorders (DSM-III), borderline personality disorder and schizotypal personality disorder (SPD), at the diagnostic category and individual criterion level. Unlike previous research in this area, which had focused on inpatient and outpatient populations, the sample was a psychometrically defined, nonpatient sample including Ss meeting DSM-III criteria for each disorder. The results indicated that the two diagnostic categories each define a type of borderline with distinctive combinations of features. Perceptual and cognitive distortion, however, seem to be present in both and define an area of overlap between the two disorders. The implications of these findings for the revision of the SPD diagnostic criteria in DSM-III are discussed, and the theoretical separation of two subtypes of borderline personality is affirmed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of chronic haloperidol and intermittent cocaine administration on behavior elicited by apomorphine.

Relatively little is known about the behavioral or neurophysiological effects resulting from the concurrent administration of haloperidol and cocaine. To investigate this drug interaction the effects of chronic, daily administration of haloperidol, intermittent cocaine injections, or the combination of both drug treatments on locomotion and stereotypy elicited by apomorphine in rats (Rattus norvegicus) were compared. The results indicated that, in comparison to treatment with either drug alone, the combination of daily haloperidol and intermittent injections of cocaine produced unique behavioral effects. Rats coadministered both drugs exhibited significant increases in apomorphine-induced locomotion that were maintained throughout the 64 days following suspension of drug treatment. These results are discussed in terms of the possible neurophysiological mechanisms underlying the observed behavioral changes and are related to the consequences of psychostimulant abuse in human neuroleptic treated populations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acoustic analysis of lexical tone in Mandarin infant-directed speech.

Using Mandarin Chinese, a "tone language" in which the pitch contours of syllables differentiate words, the authors examined the acoustic modifications of infant-directed speech (IDS) at the syllable level to test 2 hypotheses: (a) the overall increase in pitch and intonation contour that occurs in IDS at the phrase level would not distort lexical pitch at the syllable level and (b) IDS provides exaggerates cues to lexical tones. Sixteen Mandarin-speaking mothers were recorded while addressing their infants and addressing an adult. The results indicate that IDS does not distort the acoustic cues that are essential to word meaning at the syllable level; evidence of exaggeration of the acoustic differences in IDS was observed, extending previous findings of phonetic exaggeration to the lexical level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Landsat Image Mosaic of Antarctica

The Landsat Image Mosaic of Antarctica (LIMA) is the first true-color, high-spatial-resolution image of the seventh continent. It is constructed from nearly 1100 individually selected Landsat-7 ETM⁺ scenes. Each image was orthorectified and adjusted for geometric, sensor and illumination variations to a standardized, almost seamless surface reflectance product. Mosaicing to avoid clouds produced a high quality, nearly cloud-free benchmark data set of Antarctica for the International Polar Year from images collected primarily during 1999–2003. Multiple color composites and enhancements were generated to illustrate additional characteristics of the multispectral data including: the true appearance of the surface; discrimination between snow and bare ice; reflectance variations within bright snow; recovered reflectance values in regions of sensor saturation; and subtle topographic variations associated with ice flow. LIMA is viewable and individual scenes or user defined portions of the mosaic are downloadable at http://lima.usgs.gov. Educational materials associated with LIMA are available at http://lima.nasa.gov.