Role of the vestibular system in the arterial pressure response to parabolic-flight-induced gravitational changes in human subjects

This study examined how different weighting coefficients imposed on individual finger force regulate bimanual finger force coordination patterns under the influence of bilateral coupling and visual information of the force output. The weighted sum of the two forces was computed as the total force output to match two target force levels (10% and 35% MVC) in separate conditions, and visual feedback of the total force output was provided in the experiment. The results revealed higher performance error at 35% in comparison with 10% MVC with the greatest error at the unequal coefficient setting. The correlation between the individual forces and the force output ratios correlated nonlinearly with the weighting coefficient ratios; however, the extent of change was much smaller than the coefficient ratios. The results suggest that bilateral coupling and task constraints interact to determine the coordination strategy. The irregularity of the individual finger forces increased with the weighting coefficient while the irregularity of the total force remained the same. The results support the hypothesis that the organization of redundant motor coordination patterns emerges from the interactive effect of the constraints on movement.     

Intensity dependence of auditory evoked potentials during light interference in migraine

Abnormal decision-making (DM) performance has been reported in several neurobehavioral disorders such as schizophrenia, addiction, and obsessive compulsive disorders. The exploration of DM correlates in terms of symptom formation may add more knowledge about the meanings of DM performance in schizophrenia. We examined the Iowa Gambling Task (IGT) and its relationship with clinical symptoms, evaluated by Positive and Negative Symptom Scale (PANSS), in 40 schizophrenic patients and 20 controls. Schizophrenic patients did worse on IGT performance with a significant difference between the two groups in Net Score. PANSS positive symptoms were negatively correlated with Net Score and advantageous choices and directly with disadvantageous choices. Results suggest that persons with schizophrenia display a pattern of compromised DM related to positive symptoms.     

内、外群体态度与士兵内隐集体自尊效应

目的:考察士兵针对内群体与外群体的评价性态度,验证是否存在内隐集体自尊效应.方法:通过Go/No-go联想测验(Go/No-go Association Task,GNAT)收集被试的行为数据(即d'和反应时),考查"部队群体一积极"与"非部队群体-积极"、"部队群体-消极"以及"非部队群体-消极"之间的d'和反应时是否存在显著差异.结果:GNAT感受性指标上,任务条件的主效应显著,F(3,117)=20.15,P<0.01.反应时指标上,任务条件的主效应显著,F(3,117)=19.70,P<0.01."非部队群体-积极"与"非部队群体-消极"之间的感受性指标与反应时上均不存在显著差异.结论:士兵群体中存在内隐集体自尊效应,内隐集体自尊并不是以贬低外群体为条件的.     

Norwegians GPs’ use of electronic patient record systems

Objective

To evaluate GPs use of three major electronic patient record systems with emphasis on the ability of the systems to support important clinical tasks and to compare the findings with results from a study of the three major hospital-wide systems.

Methods

A national, cross-sectional questionnaire survey was conducted in Norwegian primary care. 247 (73%) of 338 GPs responded. Proportions of the respondents who reported to use the EPR system to conduct 23 central clinical tasks, differences in the proportions of users of different EPR systems and user satisfaction and perceived usefulness of the EPR system were measured.

Results

The GPs reported extensive use of their EPR systems to support clinical tasks. There were no significant differences in functionality between the systems, but there were differences in reported software and hardware dysfunction and user satisfaction. The respondents reported high scores in computer literacy and there was no correlation between computer usage and respondent age or gender. A comparison with hospital physicians’ use of three hospital-wide EPR systems revealed that GPs had higher usage than the hospital-based MDs. Primary care EPR systems support clinical tasks far better than hospital systems with better overall user satisfaction and reported impact on the overall quality of the work.

Conclusion

EPR systems in Norwegian primary care that have been developed in accordance with the principles of user-centered design have achieved widespread adoption and highly integrated use. The quality and efficiency of the clinical work has increased in contrast to the situation of their hospital colleagues, who report more modest use and benefits of EPR systems.     

Deficits in Free Recall Persist in Asperger’s Syndrome Despite Training in the Use of List-appropriate Learning Strategies

Free recall in adults with Asperger’s Syndrome (AS) was compared with that in matched controls in an experiment including semantically similar, phonologically similar and unrelated word lists. Without supportive instructions, adults with AS were significantly impaired in their recall of phonologically and semantically related lists, but not unrelated lists. Even when trained to make use at study of the relations among the words, the adults with AS recalled fewer words than the control group. Participants rehearsed the study lists out loud and the rehearsal data was analysed. Despite a very slight trend for adults with AS to engage in less elaborative rehearsal and more rote rehearsal, their rehearsal did not differ significantly from that of controls.     

The effect of COMT Val158 Met genotype on decision-making and preliminary findings on its interaction with the 5-HTTLPR in healthy females

Poor decision-making is inherent to several psychiatric conditions for which a genetic basis may exist. We previously showed that healthy female volunteers homozygous for the short allele (s/s) of the serotonin transporter length polymorphic region (5-HTTLPR) chose more often cards from disadvantageous decks in the Iowa Gambling Task (IGT), which measures decision-making, than long (l) allele carriers. The 5-HTTLPR and catechol-O-methyltransferase (COMT) Val¹⁵⁸ Met polymorphism affect the same set of neuronal structures. Therefore, we explored the effect of the (COMT) Val¹⁵⁸ Met polymorphism on IGT performance and its interaction with the 5-HTTLPR in the same subjects in this study. We observed that subjects homozygous for methionine (Met/Met) chose more disadvantageously than subjects homozygous for valine (Val/Val). s/s-Met/Met-subjects appeared to show the poorest IGT performance of all possible combinations of 5-HTTLPR and COMT allelic variants. Using the Expectancy-Valence model, no differences were found for the three different 5-HTTLPR or COMT genotypes regarding (i) attention to wins versus losses, (ii) updating rate, or (iii) response consistency. However, subjects with at least one Met-allele were paying more attention to wins than subjects with no Met-alleles. We discuss whether a common neuronal mechanism relates to s- and Met-allele-related deficits in updating and/or processing of choice outcome to guide subsequent choices in this gamble-based test.     

The Variable Response-Stimulus Interval Effect and Sleep Deprivation: An Unexplored Aspect of Psychomotor Vigilance Task Performance

Study Objectives:

The Psychomotor Vigilance Task (PVT) contains variable response-stimulus intervals (RSI). Our goal is to investigate the effect of RSI on performance to determine whether sleep deprivation affects the ability to attend to events across seconds and whether this effect is independent of impairment in sustaining attention across minutes, as measured by time on task.

Design:

A control group following their normal sleep routines and 3 groups exposed to 54 hours of total sleep deprivation performed a 10-minute PVT every 6 hours for 9 total test runs.

Setting:

Sleep deprivation occurred in a sleep laboratory with continuous behavioral monitoring; the control group took the PVT at home.

Subjects:

Eighty-four healthy sleepers (68 sleep deprivation, 16 controls; 22 women; aged 18-35 years).

Measurements and Results:

Across groups, as the RSI increased from 2 to 10 seconds, mean RT was reduced by 69 milliseconds (main effect of RSI, P < 0.001). There was no interaction between the sleep deprivation and RSI effects. As expected, there was a significant interaction of sleep deprivation and time on task for mean RT (P = 0.002). Time on task and RSI effects were independent. Parallel analyses of percentage of lapses and percentage of false starts produced similar results.

Conclusions:

We demonstrate that the cognitive mechanism of attention responsible for response preparation across seconds is distinct from that for maintaining attention to task performance across minutes. Of these, only vigilance across minutes is degraded by sleep deprivation. Theories of sleep deprivation should consider how this pattern of spared and impaired aspects of attention may affect real-world performance.

Citation:

Tucker AM; Basner RC; Stern Y; Rakitin BC. The variable response-stimulus interval effect and sleep deprivation: an unexplored aspect of psychomotor vigilance task performance. SLEEP 2009;32(10):1393-1395.     

Modification of planned actions

To elucidate the time course and processes underlying pre-movement modification of planned actions, participants prepared to make an action at a time of their own choosing within a specified temporal window. In some conditions, participants prepared to make a single right index finger key press, whereas in others, they prepared to make a sequence of two key presses consisting of a right index finger key press followed by a right middle finger key press. On a proportion of trials, their internal preparation was interrupted by an auditory tone, in response to which they made either: the same action as they were intending, a different action requiring an additional effector (i.e. switch from preparing a single right index finger key press to executing a right index, middle finger sequence), or a different action requiring one less effector (i.e. switch from preparing a right index, middle finger sequence to executing a right index finger key press). For unmodified actions, switching from an internally generated to an externally triggered mode of response production produced a significant reaction time cost (RT cost) for both single and sequential actions, with the cost for single actions being significantly greater than that for sequential actions. Given that the RT cost did not increase as the complexity of the actions increased it is unlikely that the source of the cost is related to motor execution processes, and it is suggested that it may arise at a higher level cognitive stage of processing. In addition, reaction times to produce modified actions were significantly greater than those to produce unmodified actions. Finally, it took significantly longer to produce modified actions requiring one less effector than to produce modified actions requiring one more effector. We suggest that two time-consuming processes are involved in switching between internally generated and externally triggered actions that are modified or unmodified: a trigger switch cost when the same action has to be produced in response to an external trigger as opposed to an internal trigger, and a switch cost reflecting changes in the pattern of executed motor commands when modification is necessary. It is suggested that such processes may be mediated by regions of the frontal lobes. An erratum to this article can be found at     

Inducing impulsivity leads high and low restrained eaters into overeating, whereas current dieters stick to their diet

Previous research has related impulsivity to overeating and obesity. However, the precise nature of this relation has not been examined yet. One possibility is that impulsivity causes overeating and hence contributes to overweight. To test this possibility we induced impulsivity versus inhibition to see whether this would affect food intake. In the first study participants were cognitively primed with the concepts “impulsivity” or “inhibition”. Caloric intake was significantly higher in the Impulsivity Condition compared to the Inhibition Condition. This effect was even stronger for highly restrained participants. In the second study impulsivity was manipulated via behavioural instructions. Restrained and unrestrained nondieters acted as expected: their caloric intake was significantly higher when impulsivity was induced compared to inhibition. Current dieters sharply reduced their caloric intake following the impulsivity induction. These results are in accordance with Lowe's model that, contrary to restraint theory, states that restraint and current dieting are different constructs that affect eating regulation differently. At least for nondieters it can be concluded that heightened impulsivity versus inhibition leads to a higher food intake in the lab.     

Performance management in healthcare: Performance indicator development, task uncertainty, and types of performance indicators

In healthcare, performance indicators are increasingly used to measure and control quality and efficiency of care-providing teams. This article demonstrates that when controllability is emphasized during indicator development, the level of task uncertainty influences the type of resulting performance indicators. We report findings from a field study in a medical rehabilitation centre in The Netherlands, where four low task uncertain teams (‘hand trauma’, ‘heart failure’, ‘amputation’, ‘chronic pain’), and four high task uncertain teams (‘children with developmental coordination disorders (DCD)’, ‘parkinson's disease’, ‘young children (0–4 years) with developmental disorders’, and ‘acquired brain injuries’) participated in the development of performance indicators using the Productivity Measurement and Enhancement System (ProMES) method. Results show that teams higher on task uncertainty developed relatively more process indicators compared to outcome indicators, whereas the reverse was true for teams lower on task uncertainty. Additionally, process indicators developed by high task uncertain teams were more of a problem solving nature than process indicators developed by low task uncertain teams, which had a more procedural character. The study expands existing knowledge by providing a framework which explicates the task processes to be executed under different levels of task uncertainty, and in line with that appropriate performance indicators for healthcare teams.