Laura Bertella

Decision-making in obesity: A study using the Gambling Task

The present study addresses the issue of whether a “decision-making disorder” could account for the behavioral problems of severely obese patients (BMI score >34) who are not classified by traditional psychiatric Eating Disorder tests. The neuropsychological test employed, the Gambling Task (GT), is not directly related to the food domain, but it is sensitive to failure in making long-term advantageous choices. A comparison was made of 20 obese subjects (OS) and 20 normal-weight subjects (NWS) matched in age, education and IQ. The subjects’ personalities and food behavior were assessed from psychological questionnaires, and then the Gambling Task was administered. The number of “good” choices made by the two groups during GT performance differed significantly, and the OS did not learn to maximize advantageous choices like the NWS did. OS behavior could be consistent with a prefrontal cortex defect that implies difficulties in inhibition of excessive food intake.

Virtual Environments in the Diagnosis, Prevention, and Intervention of Age-Related Diseases: A Review of VR Scenarios Proposed in the EC VETERAN Project

A group of worldwide virtual reality and health-care researchers have decided to combine their efforts in a multidisciplinary project titled VETERAN-virtual environments in the diagnosis, prevention and intervention of age-related diseases. The main goal of the VETERAN project is the tuning and testing of different virtual environments, designed to address the cognitive/functional impairments that may occur due to the aging process and age-related disorders. In particular the developed modules will address the problems commonly found in the following pathologies that have a strong impact on the elderly health care policy: Alzheimers disease and other senile dementias; stroke and unilateral spatial neglect; mobility-related accidents within specific environments (e.g., falls, shocks). The project will focus on research into clinical aspects of age-related diseases and disorders of high morbidity and specifically target goals of prevention, treatment, or delay in onset. Another goal of the VETERAN project is to define and develop new protocols and tools to be used for general rehabilitation purposes. These tools will aim to provide systematic restorative training within the context of functionally relevant, ecologically valid simulated environments. This approach is hoped to optimise the degree of transfer of training and/or generalisation of learning to the persons real world environment.

Is math lateralised on the same side as language? Right hemisphere aphasia and mathematical abilities

The main purpose of the present study was to learn how mathematical abilities are located and develop in the brain with respect to language. Mathematical abilities were assessed in six right-handed patients affected by aphasia following a lesion to their non-dominant hemisphere (crossed aphasia) and in two left-handed aphasics with a right-sided lesion. Acalculia, although in different degrees, was found in all cases. The type of acalculia depended on the type of aphasia, following patterns that have been previously observed in the most common aphasias resulting from left hemisphere lesions. No sign of right hemisphere or spatial acalculia (acalculia in left lateralised right-handed subjects) was detected. These results suggest that, as a rule, language and calculation share the same hemisphere. A primitive computational mechanism capable of recursion may be the precursor of both functions.

Genetics and mathematics : Evidence from Prader-Willi syndrome

Mathematical abilities were tested in people with Prader-Willi syndrome (PWS), using a series of basic mathematical tasks for which normative data are available. The difference between the deletion and the disomy variants of this condition was explored. While a wide phenotypic variation was found, some basic findings emerge clearly. As expected from previous literature, deletion and disomy participants were found to differ in their degree of impairment, with disomy being overall the most spared condition. However, the tasks selectively spared in the disomy condition are not necessarily the easiest ones and those that discriminate less the PWS group from controls. It rather seems that disomy patients are spared, with respect to deletion, in tasks entailing transcoding and comparison of numbers in the Arabic code. Overall a particular difficulty was detected in reliably performing parity judgments. This task has been shown to be very frequently spared after a brain injury, even in severe aphasic conditions. The most interesting result is the sparing in analog number scale, whereby PWS seem, overall, to outperform controls. This finding may help in understanding previously reported, surprising results about cognitive skills in PWS. Elevated performances in PWS may result from life-long hyper-reliance on one visuo-spatial system in presence of underdevelopment of the other.

When two and too don't go together: A selective phonological deficit sparing number words

We report the case of an Italian speaker (GBC) with classical Wernickes aphasia syndrome following a vascular lesion in the left posterior middle temporal region. GBC exhibited a selective phonological deficit in spoken language production (repetition and reading) which affected all word classes irrespective of grammatical class, frequency, and length. GBCs production of number words, in contrast, was error free. The specific pattern of phonological errors on non-number words allows us to attribute the locus of impairment at the level of phonological form retrieval of a correctly selected lexical entry. These data support the claim that number words are represented and processed differently from other word categories in language production.

Virtual Environment for Topographical Orientation (VETO): Clinical Rationale and Technical Characteristics

The lack of spatial orientation often serves as a warning light for a diffused cerebral impairment, such as the one at the origin of a confusional state or of a mental disorder. Topographical orientation disorders may be the expression of memory or attention deficits, unilateral spatial negligence, or elementary visuoperceptive disorders. In a minority of cases, spatial disorientation presents as an isolated disorder and is the expression of a focal brain lesion. The paper describes the clinical rationale and the technical characteristics of the Virtual Environment for Topographical Orientation (VETO). VETO is used both as a complementary tool for the assessment of topographical orientation disorders and to increase the possibilities of management of these patients from a rehabilitative point of view. VETO is based on the recent theoretical model of wayfinding in virtual environments proposed by Chen and Stanney (1999). This model suggests that wayfinders generally start from the direct perception of the environment or from the recall of a cognitive map. In terms of direct perception of the environment, landmark knowledge is acquired by directly viewing indirect representation such as photographs. In terms of cognitive mapping, procedure/route knowledge is acquired through direct experience or through simulated experience and stored in memory. Our hypothesis is that the study of spatial orientation through specific VETO tasks, both in normal samples and in subjects affected by topographical disorientation, can bring greater comprehension and validation of the cognitive models of spatial orientation present in literature.

Exploring Patterns of Unwanted Behaviours in Adults with Prader-Willi Syndrome

BACKGROUND Obsessive-compulsive (O-C) traits, and excessive food intake are well known behavioural manifestations among individuals with Prader-Willi Syndrome (PWS). Other unwanted behaviours are also frequently observed, but they need a more specific investigation, especially in the adult population. METHODS The behaviour of 31 PWS adults was investigated via the Symptom Checklist-90-Revised (SCL-90-R), the Yale-Brown Obsessive Compulsive Scale Symptom Checklist (Y-BOCS-SC), and the Prader-Willi Behavioural Checklist (PBC). The PBC is a quick screening questionnaire prompted specifically for the investigation on adults with PWS. RESULTS Statistical clustering revealed two patterns of unwanted behaviours from the PBC. Behaviours belonging to the first cluster (e.g., Excessive food intake, Skin picking) appear to be linked to the usual phenotypic manifestation of PWS. By contrast, many other behaviours (e.g., some O-C symptoms and aggressive actions) could show a relationship also to individual psychopathologies. CONCLUSIONS Both internal (Anxiety and Depression) and external (Hostility) difficulties in managing impulses should account for individually distinct behaviours in adults with PWS.

A relative vowel deficit in aphasia sparing the lexicon of numbers

It is a well-known fact that, in general, in patients affected by aphasia (as well as in normal speakers) phonemic errors occur more frequently on consonants than on vowels (Blumstein, 1988). Perhaps just because this effect has been studied on groups of patients, where individual differences are easily lost, reports of the reverse effect, more errors on vowels than on consonants, are extremely rare. Indeed, only two studies reporting a superiority in the production of consonants with respect to vowels appear in literature (Caramazza, Chialant, Capasso, & Miceli, 2000; Romani, Grana, & Semenza, 1996).