A study of EEG coherence in DCD children during motor synchronization task

This paper investigates the hypothesis that the coordination difficulties of DCD children are associated with an increased coherence in the cortical motor regions, which persists with age. Forty-eight children participated in the study (24 DCD and 24 Controls). Their ages ranged from 8 to 13 years, divided into three groups (8-9, 10-11, and 12-13 years old). Children were required to perform finger flexion or extension either in synchrony or in syncopation with a rhythmic metronome, while a 32-channel EEG was recorded. Along with stability measures of motor performance, we analyzed the spectral EEG coherence between intrahemispheric (left frontal/left central; left central/left parietal) and interhemispheric (left central/right central) sites. Spectral coherence assesses functional coupling between distant areas of the brain. Two frequency bands related to sensorimotor activation were chosen: alpha (8-12 Hz) and beta (12-30 Hz). The synchrony task was chosen as a rest condition against which the two syncopation conditions at 0.5 Hz and 1.3 Hz were contrasted. For intrahemispheric comparison, 8-9-year-old DCD children showed that coherence between fronto-central regions increased for both rhythms and conditions, as compared to controls. No difference was found for interhemispheric comparisons. As frontal sites are related to motor planning, our results suggest that youngest DCD children were forced to maintain a high level of pre-programming to compensate for the difficulties caused by the perceptual-motor requirements of the task in light of their coordination disorder.     

Cortical regions activated by the subjective sense of perceptual coherence of environmental sounds: A proposal for a neuroscience of intuition

According to the Oxford English Dictionary, intuition is “the ability to understand or know something immediately, without conscious reasoning.” In other words, people continuously, without conscious attention, recognize patterns in the stream of sensations that impinge upon them. The result is a vague perception of coherence, which subsequently biases thought and behavior accordingly. Within the visual domain, research using paradigms with difficult recognition has suggested that the orbitofrontal cortex (OFC) serves as a fast detector and predictor of potential content that utilizes coarse facets of the input. To investigate whether the OFC is crucial in biasing task-specific processing, and hence subserves intuitive judgments in various modalities, we used a difficult-recognition paradigm in the auditory domain. Participants were presented with short sequences of distorted, nonverbal, environmental sounds and had to perform a sound categorization task. Imaging results revealed rostral medial OFC activation for such auditory intuitive coherence judgments. By means of a conjunction analysis between the present results and those from a previous study on visual intuitive coherence judgments, the rostral medial OFC was shown to be activated via both modalities. We conclude that rostral OFC activation during intuitive coherence judgments subserves the detection of potential content on the basis of only coarse facets of the input.     

Exaggerated leftward bias in the mental number line of patients with schizophrenia

Several visuo-motor tasks can be used to demonstrate biases towards left hemispace in schizophrenic patients, suggesting a minor right hemineglect. Recent studies in neglect patients used a new number bisection task to highlight a lateralized defect in their visuo-spatial representation of numbers. To test a possible lateralized representational deficit in schizophrenia, we used the number bisection task in 11 schizophrenic patients compared to 11 healthy controls. Participants were required to orally indicate the central number of an interval orally presented. Whereas healthy subjects showed no significant bias, schizophrenic patients presented a significant leftward bias. Therefore, these results suggest an impairment in higher order representations of the number space in patients with schizophrenia, an impairment that is qualitatively similar to the deficit described in neglect patients.     

Is absolute identification always relative? Comment on Stewart, Brown, and Chater (2005)

N. Stewart, G. D. A. Brown, and N. Chater's relative judgment model includes three core assumptions that enable it to predict accurately the vast majority of "classical" phenomena in absolute identification choices, but not the time taken to make them, including sequential effects, such as assimilation and contrast. These core assumptions, coupled with the parameter values used in the above-mentioned article, lead to the prediction that identification accuracy is low when a large stimulus on 1 trial is followed by a small stimulus on the next trial and vice versa. Data do not support this prediction. The authors identify a set of parameters that allow the model to better fit the data, but problems remain when the data are analyzed with a version of the discrimination measure (d') from signal detection theory. The fundamental problem is that the model fits data on average but at the expense of making incorrect predictions in detail.     

Beyond positive and negative affect: Achievement goals and discrete emotions in the elementary physical education classroom

ObjectivesBased on the Achievement Goal perspective [Dweck, C. S., Leggett, E. L. (1988). A social-cognitive approach to motivation and personality. Psychological Review, 95, 256–273; Nicholls, J. G. (1984). Achievement motivation: conceptions of ability, subjective experience, task choice, and performance. Psychological Review, 91, 328–346] and on Pekrun et al.'s [(2004). Beyond test anxiety: development and validation of the test emotions questionnaire (TEQ). Anxiety, Stress, and Coping, 17, 287–316] model of discrete class-related emotions, this study investigated the relation of achievement goals to discrete emotions in the Physical Education (PE) class.DesignCross-sectional.MethodParticipants were 319 Greek upper elementary school students who responded to a set of questionnaires assessing their achievement goal orientation, perceived competence, and the class-related emotions they experienced in the PE classes.ResultsHierarchical regression analyses showed that, after controlling for perceived competence and gender differences, task goals were positively related to positive activating emotions and negatively related to negative emotions. Ego goals exhibited a mixed picture as they were positively associated with pride and all the negative emotions. Furthermore, the relations between ego goals and emotions were qualified by an ego by task goal and by an ego by perceived competence interaction suggesting that ego goals were especially linked to emotional maladjustment when task goals were low and when competence perceptions were high rather than low.ConclusionUnique associations between task and ego goals and specific emotions were found, rendering insightful the disentanglement of positive and negative emotions into its components. The pursuit of task goals might help to counteract the emotional burden associated with ego goal pursuit whereas feeling competent to outperform when one endorses ego goals might perhaps put extra pressure on the pupils and, hence, have negative implications for their emotional adjustment.     

The inhibitory avoidance test optimized for discovery of cognitive enhancers

In the present article, we describe a new protocol for the inhibitory avoidance test, with a dual purpose: (1) to provide a leß variable and more reliable aßeßment of the efficacy of potential cognitive enhancers in antagonizing scopolamine-induced long-term-memory deficits, and (2) to secure a high throughput for pharmacological screening of cognitive enhancers. The new protocol consists of two acquisition trials that are followed 24 h later by a single retention trial. In the present study, this protocol clearly dißociated the frequency distributions of retention latencies between scopolamine- and vehicle-treated groups and allowed validation by means of two acetylcholinesterase inhibitors—tacrine and donepezil—that proved to be active in counteracting the scopolamine-induced memory deficit. This protocol also produced stability of the behavioral response to pharmacological agents over a 3-year period. A statistical power analysis indicated that, depending on the efficacy of the drug/dose, a sample size of 5–12 mice was required in order to show a reversal of the scopolamineinduced memory deficit. The double-trial acquisition protocol is suitable for testing cognitive enhancers, while also providing a clearly enhanced throughput.     

Theory change in immunology part I: Extended theories and scientific progress

This two-part article examines the competition between the clonal selection theory and the instructive theory of the immune response from 1957–1967. In Part I the concept of a temporally ‘extended theory’ is introduced, which requires attention to the hitherto largely ignored issue of theory individuation. Factors which influence the acceptability of such an extended theory at different temporal points are also embedded in a Bayesian framework, which is shown to provide a rational account of belief change in science. In Part II these factors, as elaborated in the Bayesian framework, are applied to the case of the success of the clonal selection theory and the failure of the instructive theory.     

Prehension movements in a patient (AC) with posterior parietal cortex damage and posterior callosal section

Prehension movements of the right hand were recorded in a right-handed man (AC), with an injury to the left posterior parietal cortex (PPC) and with a section of the left half of the splenium. The kinematic analysis of AC's grasping movements in direct and perturbed conditions was compared to that of five control subjects. A novel effect in prehension was revealed--a hemispace effect--in healthy controls only. Movements to the left hemispace were faster, longer, and with a smaller grasp aperture; perturbation of both object position and distance resulted in the attenuation of the direction effect on movement time and the time to velocity peak, with a reverse pattern in the time to maximum grip aperture. Nevertheless, the correlation between transport velocity amplitude and grasp aperture remained stable in both perturbed and non-perturbed movements, reflecting the coordination between reaching and grasping in control subjects. In contrast, transport and grasp, as well as their coordination in both direct and perturbed conditions, were negatively affected by the PPC and splenium lesion in AC, suggesting that transport and grasp rely on two functionally identifiable subsystems.