Refutation of Poffenberger's inference: an existence proof and a countermodel

Interhemispheric relay time (IHRT) is inferred from simple (visual) reaction time (SRT) by subtracting SRTs in ipsilateral hand-field conditions from SRTs in contralateral hand-field conditions. This index, the "crossed-uncrossed differential" (CUD) is a synonym of IHRT in the current literature. The CUD has been shown to be significantly moderated by experimental variables, including attentional. One reason the CUD = IHRT hypostasy persists today is that no experimental manipulation has yet been able to generate a significantly negative CUD in a subject manifesting a significant positive CUD in classical conditions. We implemented an experimental manipulation, in SRT, consisting of increasing complexity of the response after the initial key press required at detection. In a very large scale single-case experiment, we found that the CUD thus went from significantly positive in classical SRT to significantly negative in the increased response load condition.     

Global cognitive decline in schizophrenia with remission of symptoms?

The relation of symptoms to cognitive dysfunction in schizophrenia is still controversial. This study was aimed (i) at verifying if a homogeneous sample of 10 young treated outpatients in remission from psychotic symptoms displays a characteristic pattern of cognitive dysfunction and (ii) at testing the issue of a general cognitive impairment. The neuropsychological performance of the patients was confronted with a large control group by means of Equivalent Scores, a normative method widely used in Italy, which allows direct, reliable comparison between tests and between patients. We found that our patients, as a group, were affected by a basic activation deficit in attention and by a semantic impairment. These deficits in symptom-free patients could indicate that their brains are in some ways working differently from those of normal controls and that this pattern is not necessarily linked to psychotic symptoms: their neuropsychological impairment might reflect a basic difference in the way of processing information that is always present and is independent of general intellectual decay.     

Measures of visuospatial short-term memory: the Knox Cube Imitation Test and the Corsi Blocks Test compared

The present investigation analyzes the characteristics of two tasks that have been considered as a measure of visuospatial abilities: The Knox Cube Imitation Test and the Corsi Blocks Test. The former was originally devised by Knox (1913) to diagnose mental retardation in potential immigrants to the United States, while the latter has been specifically designed to be used in neuropsychological practice by Corsi (1972). Although both tasks have been widely used in the past, there is little empirical research investigating the characteristics of these tasks from a theoretical point of view. In order to do so, we carried out two parallel experiments in which both tasks were presented in a baseline condition as well as in association with three different concurrent tasks (i.e., articulatory suppression, spatial tapping, and random generation) supposed to tap the various components of working memory. Results showed that neither of the tasks can be considered as a pure measure of visuospatial processing and that, at the same time, it is necessary to reconsider the architecture of working memory in order to suggest a more integrated functioning of the system.     

Imagined and actual limb selection: a test of preference

Imagined and actual motor performance were compared to determine what factor(s) drive limb selection for programming movements in contralateral hemispace. Forty right-handed blindfolded subjects were asked to 'reach' via auditory stimulus for a small object placed at multiple locations in hemispace. Two conditions were included: arms uncrossed and arms crossed. With the uncrossed condition, responses were similar. With arms crossed, subjects had the choice of keeping the limbs crossed, reacting to proximity, or uncrossing the arms to reach ipsilaterally. In this condition subjects 'imagined' that they would maintain the crossedposition and reach with the hand closest to the stimulus in both right and left hemispace. However, during 'actual' reaching, responses differed. For left-field stimuli, participants kept the arms crossed, but in response to right-field stimuli, subjects preferred to uncross the limbs in order to reach with the dominant hand. These findings suggest that while motor dominance is the primary factor in limb choice for action in ipsilateral hemispace, it appears that object proximity drives limb selection for reaching in contralateral hemispace.     

Early suicide following discharge from a psychiatric hospital

Social and clinical risk factors for completed suicide occurring shortly after discharge from a psychiatric hospital were examined in this case-control study. Seventy-seven individuals who received "suicide" or "undetermined death" verdicts at inquest, and who had been previously discharged from psychiatric hospitals in Bradford, U.K., were compared with a control group. A history of deliberate self-harm was significantly associated with early suicides compared with both late suicides and controls. A diagnosis of mood disorder, specifically depression, and longer case-notes were also significantly associated with early suicides compared to controls. This study has implications for risk management of recently discharged psychiatric patients.     

The influence of expertise and task factors on age differences in pilot communication

The influence of expertise and task factors on age differences in a simulated pilot-Air Traffic Control (ATC) communication task was examined. Young, middle-aged, and older pilots and nonpilots listened to ATC messages that described a route through an airspace, during which they referred to a chart of this airspace. Participants read back each message and then answered a probe question about the route. It was found that pilots read back messages more accurately than nonpilots, and younger participants were more accurate than older participants. Age differences were not reduced for pilots. Pilots and younger participants also answered probes more accurately, suggesting that they were better able to interpret the ATC messages in terms of the chart in order to create a situation model of the flight. The findings suggest that expertise benefits occur for adults of all ages. High levels of flying experience among older pilots (as compared with younger pilots) helped to buffer age-related declines in cognitive resources, thus providing evidence for the mediating effects of experience on age differences.     

Developmental regulation before and after a developmental deadline: the sample case of "biological clock" for childbearing

This quasi-experimental research investigates developmental regulation around a critical life-span transition, the "biological clock" for childbearing. The action-phase model of developmental regulation proposes contrasting control orientations in individuals approaching versus those having passed a developmental deadline. Individuals in an urgency phase close to the deadline should be invested in goal pursuit, whereas those who have passed the deadline without attaining the goal should focus on goal disengagement and self-protection. In 2 studies, women at different ages and with or without children were compared with regard to various indicators of primary and secondary control striving for goal attainment versus goal disengagement and self-protection. Findings support the action-phase model of developmental regulation. Patterns of control striving congruent with the participants' status as pre- versus postdeadline were associated with superior psychological well-being.     

Beyond the Obvious: Chronic Vividness of Imagery and the Use of Information in Decision Making

The authors investigate two competing hypotheses about how chronic vividness of imagery interacts with the vividness and salience of information in decision making. Results from four studies, covering a variety of decision domains, indicate that chronic imagery vividness rarely amplifies the effects of vivid and salient information. Imagery vividness may, in fact, attenuate the effects of vivid and salient information. This is because, relative to nonvivid imagers, vivid imagers rely less on information that appears obvious and rely more on information that seems less obvious. This tendency is so robust that vividness of imagery may amplify the effects of vivid information only when this information is the only information available in the decision field. The findings seem to reflect vivid imagers' tendency to totally immerse themselves in a decision problem and scrutinize the available information creatively.     

Does IL-6 release ACTH by exerting a direct effect in the rat anterior pituitary

Adult male rats were used to determine whether high circulating levels of the pro-inflammatory cytokine interleukin-6 (IL-6) were capable of releasing ACTH independently of endogenous corticotropin-releasing factor (CRF). On one hand, CRF antibodies or a potent CRF antagonist significantly decreased, but did not totally abolish the ACTH response to the intravenous(i.v.) injection of recombinant rat IL-6. These results suggest that this cytokine might act either directly on the pituitary, or can release ACTH through mechanisms that do not involve CRF. On the other hand, the CRF antagonist or antibodies significantly (but not totally) blocked ACTH secretion due to the i.v. injection of endotoxin (LPS) while enhancing the ability of this immune stimulus to increase serum IL-6 concentrations. These results indicate that during endotoxemia, even very elevated circulating IL-6 concentrations were notable to release large amounts of ACTH in the absence of CRF drive. These data also illustrate the ability of a CRF antagonist or CRF antibodies to significantly augment IL-6 secretion,which indicates an inhibitory influence of the endogenous peptide in the paradigm we used.As comparable findings were obtained in adrenal-intact and adrenalectomized rats, they suggest that endogenous CRF is involved in the IL-6 response to LPS independently of circulating corticosteroids or other adrenal factors.