Alterations in neural activation in the ventral frontoparietal network during complex magnocellular stimuli in developmental dyslexia associated with READ1 deletion.

BACKGROUND: An intronic deletion within intron 2 of the DCDC2 gene encompassing the entire READ1 (hereafter, READ1d) has been associated in both children with developmental dyslexia (DD) and typical readers (TRs), with interindividual variation in reading performance and motion perception as well as with structural and functional brain alterations. Visual motion perception -- specifically processed by the magnocellular (M) stream -- has been reported to be a solid and reliable endophenotype of DD. Hence, we predicted that READ1d should affect neural activations in brain regions sensitive to M stream demands as reading proficiency changes. METHODS: We investigated neural activations during two M-eliciting fMRI visual tasks (full-field sinusoidal gratings controlled for spatial and temporal frequencies and luminance contrast, and sensitivity to motion coherence at 6%, 15% and 40% dot coherence levels) in four subject groups: children with DD with/without READ1d, and TRs with/without READ1d. RESULTS: At the Bonferroni-corrected level of significance, reading skills showed a significant effect in the right polar frontal cortex during the full-field sinusoidal gratings-M task. Regardless of the presence/absence of the READ1d, subjects with poor reading proficiency showed hyperactivation in this region of interest (ROI) compared to subjects with better reading scores. Moreover, a significant interaction was found between READ1d and reading performance in the left frontal opercular area 4 during the 15% coherent motion sensitivity task. Among subjects with poor reading performance, neural activation in this ROI during this specific task was higher for subjects without READ1d than for READ1d carriers. The difference vanished as reading skills increased. CONCLUSIONS: Our findings showed a READ1d-moderated genetic vulnerability to alterations in neural activation in the ventral attentive and salient networks during the processing of relevant stimuli in subjects with poor reading proficiency.

Perceived Hospital Preparedness Is Negatively Associated With Pandemic-Induced Psychological Vulnerability in Primary Care Employees: A Multicentre Cross-Sectional Observational Study.

OBJECTIVE: The COVID-19 pandemic had a profound negative impact on the psychological wellbeing of healthcare providers (HPs), but little is known about the factors that positively predict mental health of primary care staff during these dire situations. METHODS: We conducted an online questionnaire survey among 702 emergency department workers across 10 hospitals in Switzerland and Belgium following the first COVID-19 wave in 2020, to explore their psychological vulnerability, perceived concerns, self-reported impact and level of pandemic workplace preparedness. Participants included physicians, nurses, psychologists and nondirect care employees (administrative staff). We tested for predictors of psychological vulnerability through both an exploratory cross-correlation with rigorous correction for multiple comparisons and model-based path modelling. RESULTS: Findings showed that the self-reported impact of COVID-19 at work, concerns about contracting COVID-19 at work, and a lack of personal protective equipment were strong positive predictors of Depression, Anxiety, and Stress, and low Resilience. Instead, knowledge of the degree of preparedness of the hospital/department, especially in the presence of a predetermined contingency plan for an epidemic and training sessions about protective measures, showed the opposite effect, and were associated with lower psychological vulnerability. All effects were confirmed after accounting for confounding factors related to gender, age, geographical location and the role played by HPs in the hospital/department. CONCLUSIONS: Difficult working conditions during the pandemic had a major impact on the psychological wellbeing of emergency department HPs, but this effect might have been lessened if they had been informed about adequate measures for minimizing the risk of exposure.

Linguistic structure modulates attention in reading: Evidence from negative concord in Italian.

We report the reading performance of an Italian speaker with egocentric Neglect Dyslexia on sentences with Negative Concord structures, which contain a linguistic cue to the presence of a preceding negative marker and compare it to sentences with no such cue. As predicted, the frequency of reading the whole sentence, including the initial negative marker non, was higher in Negative Concord structures than in sentences which also started with non, but crucially, lacked the medially positioned linguistic cue to the presence of non. These data support the claim that the presence of linguistic cues to sentence structure modulates attention during reading in Neglect Dyslexia.

Harmonizing neuropsychological assessment for mild neurocognitive disorders in Europe.

INTRODUCTION: Harmonized neuropsychological assessment for neurocognitive disorders, an international priority for valid and reliable diagnostic procedures, has been achieved only in specific countries or research contexts. METHODS: To harmonize the assessment of mild cognitive impairment in Europe, a workshop (Geneva, May 2018) convened stakeholders, methodologists, academic, and non-academic clinicians and experts from European, US, and Australian harmonization initiatives. RESULTS: With formal presentations and thematic working-groups we defined a standard battery consistent with the U.S. Uniform DataSet, version 3, and homogeneous methodology to obtain consistent normative data across tests and languages. Adaptations consist of including two tests specific to typical Alzheimer's disease and behavioral variant frontotemporal dementia. The methodology for harmonized normative data includes consensus definition of cognitively normal controls, classification of confounding factors (age, sex, and education), and calculation of minimum sample sizes. DISCUSSION: This expert consensus allows harmonizing the diagnosis of neurocognitive disorders across European countries and possibly beyond.

Accounting for ethnic-cultural and linguistic diversity in neuropsychological assessment of patients with drug-resistant epilepsy: A retrospective study.

Neuropsychological assessment is critical in both diagnosis and prognosis of patients with epilepsy. Beyond electrophysiological and anatomical alterations, other factors including different ethnic-cultural and linguistic backgrounds might affect neuropsychological performance. Only a few studies considered migration and acculturation effects and they typically concerned nonclinical samples. The current study aimed at investigating the influence of ethnic background and time spent in Italy on a full neuropsychological battery administered to both Italian and foreign-born patients and at providing a brief interview for obtaining relevant information on each patient's transcultural and language-related history. Clinical reports from 43 foreign-born patients with drug-resistant epilepsy were collected from the archives of Milan Niguarda Hospital. Epileptogenic zone, age, education, profession, illness duration, seizure frequency, handedness, and gender were considered in selecting 43 Italian controls. Ethnicity (Italian/foreign-born) and years spent in Italy were analyzed as main predictors on 21 neuropsychological scales by means of General(ized) Linear Models. An additional analysis studied two composite scores of overall verbal and nonverbal abilities. Ethnicity significantly affected the following: the verbal overall score, Verbal Fluency, Naming, Token-test, Digit Span, Attentional Matrices, Trail-Making-Test, Line-Orientation-Test, and Raven matrices; no effects were found on the nonverbal overall score, Word Pairs Learning, Episodic Memory, reading accuracy, visual span, Bells test, Rey Figure, and face memory and recognition. No significant effects of years spent in Italy emerged. While years spent in Italy does not predict neuropsychological performance, linguistic background had a strong impact on it. With respect to Italian-speaking patients, those who were foreign-born showed large task-related variability, with an especially low performance on language-related tests. Hence, language tests should not be considered as valid measures of neuropsychological impairment in this population, not even in foreign-born patients with good Italian fluency. Clinicians should consider such asymmetries in order to improve the accuracy of neuropsychological assessment of foreign-born patients.

STIMA: a short screening test for ideo-motor apraxia, selective for action meaning and bodily district.

We propose STIMA, a short test for ideo-motor apraxia, allowing us to quantify the apraxic deficit according to action meaning and affected body segment. STIMA is based on a neurocognitive model holding that there are two processes involved in action imitation (i.e., a semantic route for recognizing and imitating known gestures, and a direct route for reproducing new gestures). The test allows to identify which imitative process has been selectively impaired by brain damage (direct vs. semantic route) and possible deficits depending on the body segment involved (hand/limb vs. hand/fingers). N = 111 healthy participants were administered with an imitation task in two separated blocks of known and new gestures. In each block, half of the gestures were performed mainly with the proximal part of the upper limb and the remaining half with the distal one. It resulted in 18 known gestures (nine proximal and nine distal) and 18 new gestures (nine proximal and nine distal) for a total of 36. Each gesture was presented up to a maximum of two times. Detailed criteria are used to assign the final imitation score. Cut offs, equivalent scores and main percentile scores were computed for each subscale. Participants imitated better known than new gestures, and proximal better than distal gestures. Age influenced performance on all subscales, while education only affected one subscale. STIMA is easy and quick to administer, and compared to previous tests, it offers important information for planning adequate rehabilitation programs based on the functional locus of the deficit.

Cognitive behavioral group intervention for Alzheimer caregivers.

Long-term caregiving of patients with Alzheimer disease (AD) frequently induces a relevant distress enhanced by inadequate coping strategies. This study aimed to explore the impact of cognitive and behavioral therapy (CBT) group intervention on AD patients' caregivers. In particular, reduction in caregivers' global care needs and in anxiety and depression has been investigated. About 100 caregivers were divided into the following groups: CBT group intervention, self-help manual, and control have been enrolled in the study. CBT group intervention seems to be more effective than the other 2 conditions in reducing caregivers' anxiety. Furthermore, only caregivers of the CBT group showed significant needs related to reduction in care. The proposed treatment could be the core of a more structured and systematic intervention for AD patients' caregivers in Italy.

Perceptual and response-related components of unilateral neglect may evolve independently of one another: evidence from five single-case studies.

The Milner Landmark Task allows the disentanglement of perceptual and response-related components of unilateral neglect. If these two components reflect separate functional systems, then cases should be observed in which the two components evolve differently across time. To test this hypothesis we surveyed a continuous series of 21 right hemisphere stroke patients. Five patients from the sample were affected by unilateral neglect at the outset and could be submitted to repeated administrations of the Landmark task in the first weeks post stroke. Two versions of the task were used, Landmark-Manual and Landmark-Verbal, differing in the type of response required. Two patients showed independent changes in the perceptual and the response-related component of neglect, hence confirming the view of separate functional systems underlying them. Dissociations between the task versions were found, witnessing a role of the type of response. Unexpectedly, one patient showed an initial leftward deviation of the subjective midpoint of the stimulus line, which later reversed to a classical rightward deviation. We interpreted such a pattern in terms of co-existing "productive" and "negative" components of perceptual neglect.

Revisiting Multifactor Models of Dyslexia: Do They Fit Empirical Data and What Are Their Implications for Intervention?

Developmental dyslexia can be viewed as the result of the effects of single deficits or multiple deficits. This study presents a test of the applicability of a multifactor-interactive model (MFi-M) with a preliminary set of five variables corresponding to different neuropsychological functions involved in the reading process. The model has been tested on a sample of 55 school-age children with developmental dyslexia. The results show that the data fit a model in which each variable contributes to the reading ability in a non-additive but rather interactive way. These findings constitute a preliminary validation of the plausibility of the MFi-M, and encourage further research to add relevant factors and specify their relative weights. It is further discussed how subtype-based intervention approaches can be a suitable and advantageous framework for clinical intervention in a MFi-M perspective.

Paradoxical decrease of imitation performance with age in children.

Imitation development was studied in a cross-sectional design involving 174 primary-school children (aged 6-10), focusing on the effect of actions' complexity and error analysis to infer the underlying cognitive processes. Participants had to imitate the model's actions as if they were in front of a mirror ('specularly'). Complexity varied across three levels: movements of a single limb; arm and leg of the same body side; or arm and leg of opposite body sides. While the overall error rate decreased with age, this was not true of all error categories. The rate of 'side' errors (using a limb of the wrong body side) paradoxically increased with age (from 9 years). However, with increasing age, the error rate also became less sensitive to the complexity of the action. This pattern is consistent with the hypothesis that older children have the working memory (WM) resources and the body knowledge necessary to imitate 'anatomically', which leads to additional side errors. Younger children might be paradoxically free from such interference because their WM and/or body knowledge are insufficient for anatomical imitation. Yet, their limited WM resources would prevent them from successfully managing the conflict between spatial codes involved in complex actions (e.g. moving the left arm and the right leg). We also found evidence that action side and content might be stored in separate short-term memory (STM) systems: increasing the number of sides to be encoded only affected side retrieval, but not content retrieval; symmetrically, increasing the content (number of movements) of the action only affected content retrieval, but not side retrieval. In conclusion, results suggest that anatomical imitation might interfere with specular imitation at age 9 and that STM storages for side and content of actions are separate.

Dissociations in neuropsychological single-case studies: Should one subtract raw or standardized (z) scores?

This work tackles the problem of whether the dissociation between two performances in a single-case study should be computed as the difference between the raw or between the standardized (e.g. z) scores. A wrong choice can lead to serious inflation of the probability of finding false dissociations and missing true dissociations. Two common misconceptions are that (i) standardized scores are a universally valid choice, or (ii) raw scores can be subtracted when the two performances concern the same "task/test", otherwise standardized scores are better. These and other rules are shown to fail in specific cases and a solution is proposed in terms of in-depth analysis of the meaning of each score. The scores that should be subtracted are those that better reflect "deficit severities" - the latent, unobservable degrees of damage to the cognitive systems that are being compared. Thus explicit theoretical modelling of the investigated cognitive function(s) - the "scenario" - is required. A flowchart is provided that guides such analysis, and shows how a given neuropsychological scenario leads to the selection of an appropriate statistical method for detecting dissociations, introducing the critical concept of "deficit equivalence criterion" - the definition of what exactly a non-dissociation should look like. One further, overlooked problem concerning standardized scores in general (as measures of effect size, of which neuropsychological dissociations are just one example) is that they cannot be meaningfully compared if they have different reliabilities. In conclusion, when studying dissociations, increases in false-positive and false-negative risks are likely to occur when no explicit neuropsychological theory is offered that justifies the definition of what are to be considered as equivalent deficit severities in both performances, and which would lead to appropriate selection of raw, standardized, or any other type of score. More generally, the choice of any measure in any research context needs explicit theoretical modelling, without which statistical risks cannot be controlled.

Italian Normative Data for the Original Version of the Tower of London Test: A Bivariate Analysis on Speed and Accuracy Scores.

The Tower of London (ToL) test is traditionally used to assess strategical reasoning, problem-solving, and mental planning in clinical populations. Here, we provide the Italian standardization norms for the original, 12-problem version of the ToL test. The performance of 216 Italian individuals ranging 18 to 89 in age was scored in terms of both Time (Speed) and Accuracy-the time, and the number of attempts, necessary to find a solution. We performed univariate analyses on separate Time and Accuracy scores, using Age in years, Education in years, and Sex (male vs. female) as predictors. z scores and equivalent scores were provided. Moreover, we performed a bivariate analysis for the assessment of individuals' performance in terms of Time and Accuracy simultaneously. This standardization allows clinicians to use the original, most widespread version of ToL with the Italian population, thus optimizing comparability with other clinical and experimental research worldwide. Critically, this article offers a new statistical perspective on how Time and Accuracy scores, which are typically related to each other, can be combined to obtain a single, consistent clinical categorization that captures most of the information contained in the patient's performance.

Homocysteine, Cognitive Functions, and Degenerative Dementias: State of the Art.

There is strong evidence that homocysteine is a risk factor not only for cerebrovascular diseases but also for degenerative dementias. A recent consensus statement renewed the importance and the role of high levels of homocysteine in cognitive decline in several forms of degenerative dementia, such as Alzheimer's disease. Although the molecular mechanisms by which homocysteine causes cell dysfunction are known, both the impact of homocysteine on specific cognitive functions and the relationship between homocysteine level and non-Alzheimer dementias have been poorly investigated. Most of the studies addressing the impact of hyperhomocysteinemia on dementias have not examined the profile of performance across different cognitive domains, and have only relied on screening tests, which provide a very general and coarse-grained picture of the cognitive status of the patients. Yet, trying to understand whether hyperhomocysteinemia is associated with the impairment of specific cognitive functions would be crucial, as it would be, in parallel, learning whether some brain circuits are particularly susceptible to the damage caused by hyperhomocysteinemia. These steps would allow one to (i) understand the actual role of homocysteine in the pathogenesis of cognitive decline and (ii) improve the diagnostic accuracy, differential diagnosis and prognostic implications. This review is aimed at exploring and revising the state of the art of these two strictly related domains. Suggestions for future research are provided.

Cognitive development in Dravet syndrome: a retrospective, multicenter study of 26 patients.

PURPOSE: To clarify the role of epilepsy and genetic background in determining the cognitive outcome of patients with Dravet syndrome. METHODS: In this retrospective study, we reviewed the clinical history and cognitive development of 26 patients who had been followed with standardized evaluations since seizure onset. The cognitive outcome was quantified as differential general quotient (dGQ) between ages 12 and 60 months. Statistical analysis correlated the dGQ with genotype and epilepsy course. KEY FINDINGS: Epilepsy started at the mean age of 5.6 months. All patients experienced prolonged convulsive seizures, whereas absences and myoclonus were reported in 17. Cognitive outcome was poor in almost all patients; the mean dGQ was 33 points, varying from 6-77 points. The analysis of individual cognitive profiles identified seven patients in whom the dGQ was <20 points; the main clinical characteristic in this subset of patients was lack of early absences and myoclonus. The statistical analysis of the whole series failed to reveal significant differences in cognitive outcome with regard to the presence of SCN1A mutations and their type. In particular, mutation-carrier patients with the best cognitive outcome harbored either missense or truncating mutations. SIGNIFICANCE: Dravet syndrome encompasses different epileptic and cognitive phenotypes that probably result from both genetic and epigenetic factors. In this series, early appearance of myoclonus and absences was associated with the worst cognitive outcome.

When fruits lose to animals: Disorganized search of semantic memory in Parkinson's disease.

OBJECTIVE: The semantic fluency task is widely used in both clinical and research settings to assess both the integrity of the semantic store and the effectiveness of the search through it. Our aim was to investigate whether nondemented Parkinson's disease (PD) patients show an impairment in the strategic exploration of the semantic store and whether the tested semantic category has an impact on multiple measures of performance. METHOD: We compared 74 nondemented PD patients with 254 healthy subjects in a semantic fluency test using relatively small (fruits) and large (animals) semantic categories. Number of words produced, number of explored semantic subcategories, and degree of order in the produced sequences were computed as dependent variables. RESULTS: PD patients produced fewer words than healthy subjects did, regardless of the category. Number of subcategories was also lower in PD patients than in healthy subjects, without a significant difference between categories. Critically, PD patients' sequences were less semantically organized than were those of controls, but this effect appeared in only the smaller category (fruits), thus pointing to a lack of strategy in exploring the semantic store. CONCLUSIONS: Our results show that the semantic fluency deficit in PD patients has a strategic component, even though that may not be the only cause of the impaired performance. Furthermore, our evidence suggests that the semantic category used in the test influences performance, hence providing an explanation for the failure by previous studies, which often used large categories such as animals, to detect strategy deficits in PD. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Association between homocysteine levels and cognitive profile in Alzheimer's Disease.

BACKGROUND: Growing evidence suggests that hyperhomocysteinemia (HHcy) constitutes a risk factor for Alzheimer's Disease (AD). The impact of HHcy on cognitive functions has mainly been investigated using screening neuropsychological tests that provide general, unspecific measures of cognitive level. Since an association between HHcy and temporo-mesial atrophy has been documented, we predicted that a fine-grained analysis of neuropsychological performance should show stronger Hcy effects on memory scores than on other cognitive scores. OBJECTIVE: To determine the influence of Hcy level on cognitive profile evaluated with specific, sensitive neuropsychological tests in a wide AD cohort. METHODS: 323 patients with AD were enrolled in a cross-sectional study and underwent a neuropsychological examination exploring several cognitive domains (memory, language, visuoperception, visuospatial abilities, executive function, constructional praxis, ideomotor praxis). The effects of Hcy levels and other risk factors (including cholesterol, smoking habits, triglycerides, apoEε4 allele) were analysed. RESULTS: Generalized Linear Model detected a significant drop in performance with increasing Hcy in 6/19 measures of cognitive functions, namely, in memory performance tasks as well as in Luria's motor planning test, with effect sizes ranging 1.4%-2.8% (Eta-squared), partialling out effects of other predictors. CONCLUSIONS: HHcy was associated with poor performance in short and long-term spatial and verbal memory more than with other cognitive dysfunctions. These results support the hypothesis that medial temporal networks might be vulnerable to HHcy, consistently with data from neuroimaging studies suggesting a link in AD between temporal atrophy and HHcy; the effect on Luria's motor planning task suggests further involvement of frontal structures.

ORCA.IT: A New Web-Based Tool for Assessing Online Reading, Search and Comprehension Abilities in Students Reveals Effects of Gender, School Type and Reading Ability.

ORCA.IT, a new online test of online research and comprehension was developed for the Italian population. A group of 183 students attending various types of upper secondary schools in Northern Italy were tested with the new tool and underwent further cognitive and neuropsychological assessment. The different school types involved in the study are representative of the school population in the Italian system, but can also be easily compared with the educational systems of other countries. The new test turned out to have good psychometric properties after accurate item construction and final selection. In particular, Version 1 showed better characteristics than Version 2. Subsequently, comparison with one-way ANOVAs were performed to test whether differences exist between different school types, between groups with and without reading difficulties, and between males and females. Such differences are sometimes reported in the literature, but many remain controversial. Further, Pearson's bivariate correlations were calculated to analyze associations between scores on the ORCA.IT and cognitive/neuropsychological variables. Finally, a stepwise regression analysis was performed on aggregated scores to identify the predictors of performance on each of the two versions. The test, especially in the most complete version (Version 1), appears to accurately and reliably capture students' web searching abilities and online reading comprehension. The tool could highlight differences in online search and comprehension ability between students with and without reading difficulties, not penalizing overall performance but allowing very specific weaknesses to be pointed out. Further, it seems to be able to capture differences due to both educational pathways (different school types) and social attitudes (differences between males and females). Most interestingly, it shows to be clearly resting on specific cognitive and neuropsychological abilities, including language, memory, and attentional skills, which explain a large portion of the total variance. Offline text reading comprehension is a crucial predictor of online reading performance, while decoding ability is not. Prior knowledge also influences the results, as expected. The new tool turns out to be rather independent of previous Internet experience and to measure more cognitively grounded processes related to information gathering, processing, and communicating.

Pitch as the Main Determiner of Italian Lexical Stress Perception Across the Lifespan: Evidence From Typical Development and Dyslexia.

The study deals with the issue of lexical stress perception in both a developmental (comparing children and adults with typical development) and a clinical perspective (comparing typically developing children and children with dyslexia). The three parameters characterizing the acoustic profiles of words and non-words in a certain language are duration, pitch and intensity of its syllables. Based on (sparse) previous literature on Italian and other European languages, it was expected that syllable duration would be the parameter predominantly determining the perception of stress position. It was furthermore anticipated that children with dyslexia may be found to have an altered perception of lexical stress, due to their impairments in auditory processing of either pitch, duration or (more controversial) intensity. Systematic manipulation of the pitch, duration and intensity profiles of three Italian trisyllabic non-words produced a series of 81 stimuli, that were judged with respect to stress position (perceived on the ultimate, penultimate, or antepenultimate syllable) by the three groups of participants. The results showed, contrarily to expectations, that the pitch component is the most reliable acoustic cue in stress perception for both adults, in whom this dominance is very strong, and typically developing children, who showed a similar but quantitatively less marked pattern. As to children with dyslexia, they did not seem to rely on any parameter for their judgments, and rather gave random responses, which point to a general inability to process the various acoustic modulations that normally contribute to stress perception. Performance on the stress perception task strongly correlates with language (morphosyntactic) measures in the whole sample of children, and with reading abilities in the group with dyslexia, confirming the strict relationship between the two sets of skills. These findings seem to support a language-specific approach, suggesting that the set of acoustic parameters required for the development of stress perception is language-dependent rather than universal.

Eye Movement Desensitization and Reprocessing Integrative Group Treatment Protocol (EMDR-IGTP) Applied to Caregivers of Patients With Dementia.

Caregivers of patients with dementia experience high levels of stress and burden, with effects comparable to those of a traumatic event. Eye Movement Desensitization and Reprocessing (EMDR) appear to be effective in recovering post-traumatic stress disorder (PTSD). We aimed at investigating the effectiveness of the Eye Movement Desensitization and Reprocessing Integrative Group Treatment Protocol (EMDR-IGTP) on the "caregiver syndrome". Forty-four primary caregivers entered the study. They were randomly assigned to either the "immediate" branch, who received the treatment soon after recruitment, or to the "delayed" branch, who received it two months after recruitment. The treatment consisted of eight group sessions (one per week) spanning over two months. Emotional distress was measured before the treatment, immediately after the end of it, and two months later (follow-up), by means of several clinical scales (Impact of Event Scale-Revised, IES-R; Caregiver Needs Assessment, CNA; Caregiver Burden Inventory, CBI; Anxiety and Depression Scale-Reduced Form, AD-R). The "immediate" branch improved significantly more than the "delayed" (control) branch on The Impact of Event Scale-Revised, the Anxiety, and the Depression scales; however, after treatment such an improvement was maintained only in the first scale. The "delayed" branch took less advantage of the treatment, showing significant reduction only on the Depression scale, an effect which disappeared at follow-up. These preliminary results show for the first time that EMDR-IGTP reduces stress-related symptoms, anxiety, and depression in caregivers of patients with dementia. Interestingly, caregivers who were inserted in a waiting list after recruitment showed smaller treatment effects. Larger samples are needed to better interpret such differential clinical profiles.

Measuring and diagnosing unilateral neglect: a standardized statistical procedure.

OBJECTIVE: Unilateral neglect is usually investigated by adminstering stimuli (targets) in different positions, with targets being responded to by the patient (Hit) or omitted. In spite of this homogeneity of data type, neglect indices and diagnostic criteria vary considerably, causing inconsistencies in both clinical and experimental settings. We aimed at deriving a standard analysis which would apply to all tasks sharing this data form. METHODS: A-priori theoretical reasoning demonstrated that the mean position of Hits in space (MPH) is an optimal index for correctly diagnosing and quantifying neglect. Crucially MPH eliminates the confounding effects of deficits that are different from neglect (non-lateral) but which decrease Hit rate. We ran a Monte Carlo study to assess MPH's (so far overlooked) statistical behavior as a function of numbers of targets and Hits. RESULTS: While average MPH was indeed insensitive to non-lateral deficits, MPH's variance (like that of all other neglect indices) increased dramatically with increasing non-lateral deficits. This instability would lead to alarmingly high false-positive rates (FPRs) when applying a classical diagnostic procedure that compares one patient with a control sample. We solved the problem by developing an equation that takes into account MPH instability and provides correct cut-offs and close-to-nominal FPRs, even without control subjects. We developed a computerized program which, given the raw data, yields the MPH, a z-score and a p-value. CONCLUSIONS: We provided a standard method that allows clinical and experimental neuropsychologists to diagnose and measure neglect in a consistent way across the vast majority of tasks.