Sleep Disorders and Cognitive Dysfunctions in Parkinson’s Disease: A Meta-Analytic Study

Neuropsychology Review - A relationship between sleep disorders and cognitive dysfunctions was reported in Parkinson’s Disease (PD), however, some studies did not confirm the link. A...     

Students’ self-evaluation bias of school competence and its link to teacher judgment in elementary school

Social Psychology of Education - Research on the self-evaluation bias of students' school competence has focused mainly on its correlates for students' school adaptation. This study focused...     

A New Explanation and Proof of the Paradoxical Scoring Results in Multidimensional Item Response Models

In multidimensional item response models, paradoxical scoring effects can arise, wherein correct answers are penalized and incorrect answers are rewarded. For the most prominent class of IRT models, the class of linearly compensatory models, a general derivation of paradoxical scoring effects based on the geometry of item discrimination vectors is given, which furthermore corrects an error in an established theorem on paradoxical results. This approach highlights the very counterintuitive way in which item discrimination parameters (and also factor loadings) have to be interpreted in terms of their influence on the latent ability estimate. It is proven that, despite the error in the original proof, the key result concerning the existence of paradoxical effects remains true—although the actual relation to the item parameters is shown to be a more complicated function than previous results suggested. The new proof enables further insights into the actual mathematical causation of the paradox and generalizes the findings within the class of linearly compensatory models.     

On the relative role of inhibition in age-related working memory decline

In this cross-sectional study, the mediating role of inhibition relative to speed in age-related working memory decline on different tasks was investigated. It was hypothesized that the role of inhibition is marginal or absent in a relatively "passive" or simple working memory task, but present in a relatively "active" or complex task in which the processing, rather than the storage capacity of working memory, is addressed. This hypothesis was tested with a structural equation model that was fitted on a subsample (N = 213) of the Maastricht Aging Study (MAAS). The first trial of the Verbal Learning Test (VLT) served as the passive test and the Self-Paced Auditory Serial Addition Task (SPASAT) as the active test. Results showed that the role of inhibition was absent in predicting VLT performance, whereas it was comparable to the role of speed in predicting SPASAT performance. These findings suggest a relative, task-dependent role of inhibition in explaining age-related memory decline.     

A video multitracking system for quantification of individual behavior in a large fish shoal: Advantages and limits

The capability of a new multitracking system to track a large number of unmarked fish (up to 100) is evaluated. This system extrapolates a trajectory from each individual and analyzes recorded sequences that are several minutes long. This system is very efficient in statistical individual tracking, where the individual’s identity is important for a short period of time in comparison with the duration of the track. Individual identification is typically greater than 99%. Identification is largely efficient (more than 99%) when the fish images do not cross the image of a neighbor fish. When the images of two fish merge (occlusion), we consider that the spot on the screen has a double identity. Consequently, there are no identification errors during occlusions, even though the measurement of the positions of each individual is imprecise. When the images of these two merged fish separate (separation), individual identification errors are more frequent, but their effect is very low in statistical individual tracking. On the other hand, in complete individual tracking, where individual fish identity is important for the entire trajectory, each identification error invalidates the results. In such cases, the experimenter must observe whether the program assigns the correct identification, and, when an error is made, must edit the results. This work is not too costly in time because it is limited to the separation events, accounting for fewer than 0.1% of individual identifications. Consequently, in both statistical and rigorous individual tracking, this system allows the experimenter to gain time by measuring the individual position automatically. It can also analyze the structural and dynamic properties of an animal group with a very large sample, with precision and sampling that are impossible to obtain with manual measures.     

Neural functional organization of hallucinations in schizophrenia: Multisensory dissolution of pathological emergence in consciousness

Although complex hallucinations are extremely vivid, painful symptoms in schizophrenia, little is known about the underlying mechanisms of multisensory integration in such a phenomenon. We investigated the neural basis of these altered states of consciousness in a patient with schizophrenia, by combining state of the art neuroscientific exploratory methods like functional MRI, diffusion tensor imaging, cortical thickness analysis, electrical source reconstruction and trans-cranial magnetic stimulation. The results shed light on the functional architecture of the hallucinatory processes, in which unimodal information from different modalities is strongly functionally connected to higher-order integrative areas.     

Counter-stereotypic beliefs in math do not protect school girls from stereotype threat

The threat of being negatively stereotyped in math impairs performance of highly qualified females on difficult math tests, a phenomenon known as “stereotype threat”—ST. Perhaps more alarmingly, recent studies based on unselective samples of elementary-, middle-, and high-school students show that ST also operates in girls from the general population. Here we offer first evidence that ST does operate (with large effect sizes) even in middle-school girls who deny the negative gender stereotype. Children’s beliefs about the two genders math ability, therefore, do not necessarily moderate their susceptibility to ST, an important issue that remained unclear so far. This new finding is also of great practical significance: School girls’ counter-stereotypic beliefs cannot be taken as sufficient evidence for deciding whether the struggle against ST is or is not needed. Appropriate interventions should be the default option when aiming for true gender equality in math and science achievements.     

Temporal context affects the perceived time of visual events

We investigated whether the moment at which an event is perceived depends on its temporal context. Participants learned a mapping between time and space by watching the hand of a clock rotating a full revolution in a fixed duration. Then the hand was removed, and a target disc was flashed within a fixed-interval duration. Participants were to indicate where the hand would have been at the time of the target. In three separate experiments, we estimated the disruption from a distractor disc that was presented before or after the target disc, with a variable time between them. The target was either revealed at the end of the trial or cued beforehand, and in the latter case, was cued by either color or temporal order. We found an attraction to the presentation time of the distractor when both events were attended equally (target revealed at the end). When the target was cued beforehand, the reported time was under- or overestimated, depending on whether the nature of distractor had to be decoded (precued by color) or not (precued by order). In summary, the perceived time of an event is always affected by other events in temporal proximity, but the nature of this effect depends on how each event is attended.

     

Geometry Versus Drawing: Changing the Meaning of the Task as a Means to Change Performance

There is now much convincing evidence that the context in which children are given cognitive tasks can have a huge effect on their performance in those tasks, even when the experimental and control conditions make exactly the same logical and cognitive demands. According to this, we found that children faced with a cognitive-perceptual task (the Rey–Osterrieth's complex figure reproduction test) performed better or worse in one context (geometry) than in another (drawing), depending on their performance history in these contexts, although the task was the same in both conditions. These effects are discussed both in relation to underlying processes and in perspective with another phenomenon (stereotype threat) which also provides evidence for the social regulation of cognitive functioning in the school environment. This revised version was published online in August 2006 with corrections to the Cover Date.     

Wherein Lies the Normative Dimension in Meaning and Mental Content?

Philosophical Studies -