Which processes are involved in cognitive procedural learning?

Procedural memory is characterised by a relative resistance to pathology, making its assessment of the utmost importance. However, few studies have looked at the cognitive processes involved in cognitive procedural learning. In an initial experiment, we studied the role of different cognitive functions in massed cognitive procedural learning. Our results confirmed the existence of three separate learning phases and, for the first time, demonstrated the involvement of episodic memory and executive functions in the first learning phase. In a second experiment, we studied the effect of distributed learning conditions on the dynamics of procedural learning. This second study confirmed our results but showed that these conditions slow down the process of cognitive procedural learning. Our overall findings call into question the status of functionally autonomous memory system that is currently allotted to procedural memory, and suggest that the role of nonprocedural cognitive components should be taken into account in patient rehabilitation.     

White matter in aphasia: A historical review of the Dejerines’ studies

The Objective was to describe the contributions of Joseph Jules Dejerine and his wife Augusta Dejerine-Klumpke to our understanding of cerebral association fiber tracts and language processing.     

Identification of the 1PL Model with Guessing Parameter: Parametric and Semi-parametric Results

In this paper, we study the identification of a particular case of the 3PL model, namely when the discrimination parameters are all constant and equal to 1. We term this model, 1PL-G model. The identification analysis is performed under three different specifications. The first specification considers the abilities as unknown parameters. It is proved that the item parameters and the abilities are identified if a difficulty parameter and a guessing parameter are fixed at zero. The second specification assumes that the abilities are mutually independent and identically distributed according to a distribution known up to the scale parameter. It is shown that the item parameters and the scale parameter are identified if a guessing parameter is fixed at zero. The third specification corresponds to a semi-parametric 1PL-G model, where the distribution G generating the abilities is a parameter of interest. It is not only shown that, after fixing a difficulty parameter and a guessing parameter at zero, the item parameters are identified, but also that under those restrictions the distribution G is not identified. It is finally shown that, after introducing two identification restrictions, either on the distribution G or on the item parameters, the distribution G and the item parameters are identified provided an infinite quantity of items is available.     

Metamemory knowledge and beliefs in patients with schizophrenia and how these relate to objective cognitive abilities

Subjective reports and theories about memory may have an influence on other beliefs and behaviours. Patients with schizophrenia suffer a wide range of deficits affecting their awareness of daily life, including memory. With the Metamemory Inventory in Adulthood (MIA) we ascertained patients’ memory knowledge and thoughts about their own cognitive capacities and about several aspects of cognitive functioning: personal capacities, knowledge of processes, use of strategies, perceived change with ageing, anxiety, motivation and mastery. The participants’ ratings were correlated with their intellectual, cognitive and psychiatric data. Patients felt they had a lower capacity and marginally lower mastery over their memory than comparison subjects. They reported less recourse to strategies, and higher levels of memory-related anxiety. However, their knowledge of basic memory processes, motivation to succeed, and perception of ageing effects were similar. So patients with schizophrenia do not suffer a general and non specific impairment of their metacognitive knowledge.     

On the Bayesian Nonparametric Generalization of IRT-Type Models

We study the identification and consistency of Bayesian semiparametric IRT-type models, where the uncertainty on the abilities’ distribution is modeled using a prior distribution on the space of probability measures. We show that for the semiparametric Rasch Poisson counts model, simple restrictions ensure the identification of a general distribution generating the abilities, even for a finite number of probes. For the semiparametric Rasch model, only a finite number of properties of the general abilities’ distribution can be identified by a finite number of items, which are completely characterized. The full identification of the semiparametric Rasch model can be only achieved when an infinite number of items is available. The results are illustrated using simulated data.     

Effects of the benzodiazepine lorazepam on monitoring and control processes in semantic memory

Lorazepam has been repeatedly shown to induce memory impairments. The effects of this benzodiazepine on the processes involved in the strategic regulation of memory accuracy have not as yet been explored. An experimental procedure that delineates the role of monitoring and control processes was used. Fifteen lorazepam and 15 placebo subjects were examined using a semantic memory task that combined both a forced- and a free-report option and a no-incentive and an incentive condition. Memory accuracy was lower in the lorazepam than in the placebo group. Lorazepam impaired control sensitivity (the extent to which volunteering of answers is affected by the confidence judgments). While the absolute aspect of monitoring was impaired (calibration scores), both the discriminative aspect (the ability to distinguish between correct and incorrect answers) and the response criterion setting (the confidence threshold set for volunteering a report) were spared. The pharmacological dissociation between monitoring effectiveness and control sensitivity indicates that these two components involve distinct processes.     

Eating Disorders Inventory: Assessment of its Construct Validity in a Nonclinical French Sample of Adolescents

Recent studies have questioned the appropriateness of the original Eating Disorders Inventory (EDI) in nonclinical samples of adolescents. The main objective of the present series of studies is to systematically test the construct validity of the EDI (i.e. content, factorial, convergent, discriminant and discriminative) in a nonclinical sample of French adolescents. A total sample of 1,323 adolescents was involved in these five studies. The factorial validity and the measurement invariance of the EDI were verified through confirmatory factorial analyses. Correlation and student t-tests were also used to test the convergent and discriminative validity of the EDI. Results from the first study confirmed the unsuitability of the French original EDI for young adolescents. Items were re-worded and an adaptation for adolescents was developed (EDI-A). The following four studies provided support for the factorial validity, measurement invariance, reliability, convergent validity and discriminant validity for a short form (i.e. 24 items) of the EDI-A. The present results thus provide preliminary evidence regarding the construct validity of the 24-item EDI-A for French nonclinical adolescents. Recommendations for future uses and research activities with this instrument in French speaking adolescents are outlined.     

Automatic analysis of altered gait in arylsulphatase A-deficient mice in the open field

In current research with laboratory animals, observing their dynamic behavior or locomotion is a laborintensive task. Automatic continuous monitoring can provide quantitative data on each animal’s condition and coordination ability. The objective of the present work is to develop an automated mouse observation system integrated with a conventional open-field test for motor function evaluation. Data were acquired from 86 mice having a targeted disruption of the arylsulphatase A (ASA) gene and having lowered coordinated locomotion abilities as a symptom. The mice used were 36 heterozygotes (12 females) and 50 knockout mice (30 females) at the age of 6 months. The mice were placed one at a time into the test setup, which consisted of a Plexiglas cage (53× 34.5 × 26 cm) and two fluorescent bulbs for proper illumination. The transparent cage allowed images to be captured from underneath the cage, so image information could be obtained about the dynamic variation of the positions of the limbs of the mice for gait reconstruction. Every mouse was recorded for 10 min. Background subtraction and color filtering were used to measure and calculate image features, which are variables that contain crucial information, such as the mouse’s position, orientation, body outline, and poßible locations for the mouse’s paws. A set of heuristic rules was used to prune implausible paw features and label the remaining ones as front/hind and left/right. After we had pruned the implausible paw features, the paw features that were consistent over subsequent images were matched to footprints. Finally, from the measured footprint sequence, eight parameters were calculated in order to quantify the gait of the mouse. This automatic observation technique can be integrated with a regular open-field test, where the trajectory and motor function of a free-moving mouse are measured simultaneously.     

The right parahippocampal gyrus contributes to the formation and maintenance of bound information in working memory

Working memory is devoted to the temporary storage and on-line manipulation of information. Recently, an integrative system termed the episodic buffer has been proposed to integrate and hold information being entered or retrieved from episodic memory. Although the brain system supporting such an integrative buffer is still in debate, the medial temporal lobe appears to be a promising candidate for the maintenance of bound information. In the current work, binding was assessed by comparing two conditions in which participants had to retain three letters and three spatial locations presented either bound or separate. At the behavioral level, lower performance was found for bound information than for separate information. When contrasting the two conditions, activation in the right parahippocampal gyrus was greater for the encoding and maintenance of bound information. No activation was observed in the medial temporal lobe during the retrieval of bound information. Together, our results suggest that the parahippocampal gyrus may underlie the integrative and maintenance functions of the episodic buffer.