The Brentano Illusion Test (BRIT): An implicit task of perceptual processing for the assessment of visual field defects in neglect patients

Influence of hand starting position on radial line bisection

When normal individuals are asked to localize and mark the midpoint of a radial line, they tend to bisect it farther than the true center. It has been suggested that radial misbisection depends on the presence of a visual attentional bias directed toward the far space. The aim of the present study was to investigate whether the localization of the center of radial lines was affected by the starting position of the hand. There were two starting positions: one between the body and the radial line ("near"), the other beyond the radial line ("far"). Thirty-four subjects participated in the experiment. The results showed that (i) participants bisected radial lines farther than the true center, measured with reference to their body, in both near and far condition, and (ii) bisection errors in the near condition were greater than those in the far condition. We suggest that hand starting position and direction of ongoing movement influenced radial line misbisection by modulating visual attentional bias directed to far space.

Sensitivity and Specificity of the Brentano Illusion Test in the Detection of Visual Hemi-Field Deficits in Patients with Unilateral Spatial Neglect

Stroke survivors with right-brain damage (RBD) often present with attentional deficits such as left unilateral spatial neglect. Some patients also present with contralesional visual hemi-field deficits. A late detection of visual hemi-field deficits (VHFD) contributes to hampering neurorehabilitation and functional outcome of patients with neglect. The Brentano Illusion Test (BRIT) may be used for an early detection of VHFD during the neuropsychological assessment. In the present study, we determined the sensitivity and specificity of the BRIT for screening VHFD in patients with neglect. Sixty-four consecutive RBD patients were examined. Forty-five presented with neglect. Of these, 23 presented with VHFD (hemianopia or quadrantanopia) as detected by the Humphrey automated static visual field testing (reference standard). Consecutive patients also included 19 participants without neglect, who did not have any VHFD. The sensitivity and specificity of the BRIT for neglect patients were 78.3% (95% CI: 61.4-95.1) and 90.9 (95% CI: 78.9-100.0), respectively. Positive predictive value (PPV) was 89.6% (95% CI: 76.4-100.0); negative predictive value (NPV) 80.7% (95% CI: 65.2-96.2). No false positives in the group without neglect were identified. We conclude that the BRIT is an effective tool for clinical neuropsychologists to screen for possible VHFD in neglect patients during the neuropsychological assessment, allowing the refinement of the clinical picture in the neuropsychological report. An early detection of VHFD also allows referring the patient to standard diagnostics for a formal visual field examination, right from the first neuropsychological assessment.

Broken Ring enVision Search (BReViS): A New Clinical Test of Attention to Assess the Effect of Layout and Crowding on Visual Search

The assessment of attention in neuropsychological patients could be performed with visual search tests. The Broken Rings enVision Search test (BReViS) here proposed represents a novel open access paper-and-pencil tool in which layout and crowding are varied among four cards. These manipulations allow the assessment of different components of attention: a selective component, the visuo-spatial orientation of attention, and the focal attention, involved in a crowding phenomenon. Our purpose was to determine the characteristics of the BReViS test, provide specific normative data, and assess these components across the lifespan. The test was administered to a sample of 550 participants aged between 20 and 79 years old and to a series of patients. Three indexes targeting different components of visuo-spatial attention (selective attention, strategic orientation of visual attention, focal attention) were obtained by combining execution times and accuracy together with the total errors. The results showed that age, education and gender influenced, in different combinations, the four indexes, for which specific norms were developed. Regression-based norms were provided in percentiles and equivalent scores. All patients showed pathological scores and specific patterns of attentional deficits. The BreViS test proved to be a free and easy valuable tool which can be used in the clinical environment to assess attentional deficits in neuropsychological patients.

A rank subdivision of equivalent score for enhancing neuropsychological test norms

INTRODUCTION

Neuropsychological assessment of cognitive functioning is a crucial part of clinical care: diagnosis, treatment planning, treatment evaluation, research, and prediction of long-term outcomes. The Equivalent Score (ES) method is used to score numerous neuropsychological tests. The ES0 and the ES4 are defined respectively by the outer tolerance limit and the median. The intermediate ESs are commonly calculated using a z-score approach even when the distribution of neuropsychological data is typically non-parametric. To calculate more accurate ESs, we propose that the intermediate ESs need to be calculated based on a non-parametric rank subdivision of the distribution of the adjusted scores.

MATERIAL AND METHODS

We make three simulations to explain the differences between the classical z-score approach, the rank-based approach, and the direct subdivision of the dependent variable.

RESULTS

The results show that the rank procedure permits dividing the region between ES0 and ES4 into three areas with the same density. The z-score procedure is quite similar to the direct subdivision of the dependent variable and different from the rank subdivision.

CONCLUSIONS

By subdividing intermediate ESs using the rank-subdivision, neuropsychological tests can be scored more accurately, also considering that the two essential points for diagnosis (ES = 0 and ES = 4) remain the same. Future normative data definition should consider the best procedure for scoring with ES.

Normative Values of the Groffman Visual Tracing Test for the Assessment of Oculomotor Performance in the Adult Population

The Groffman visual tracing (GVT) test is an indirect psychometric measure of oculomotor performance, used for the clinical assessment of eye movements. The test consists of two cards with five contorted lines of increasing overlap, crowding, and difficulty. The task starts from each of the letters at the top of the page, follows the line from the letter to the corresponding number at the bottom of the page, and the number is named. Although the GVT test was developed for the evaluation of children, it has also been applied to adults with visual and cognitive deficits. However, it lacks reference values. Therefore, the aim of the study was to assess oculomotor behavior across the typical human lifespan and to define normative data in an adult population. A total of 526 adults aged between 20 and 79 years, all without neurological or psychiatric deficits, were enrolled in the study. The results were analyzed by considering the accuracy and execution times separately. An influence of age, education and sex for accuracy was found, and age for the execution times was found. Norms for adults were developed considering the specific structure of the test and the accuracy and the execution time separately. The GVT test can now be applied in healthy and neurological adult populations for the evaluation of oculomotor performance.

Prism Adaptation and Optokinetic Stimulation Comparison in the Rehabilitation of Unilateral Spatial Neglect

Prism adaptation (PA) is one of the most effective treatments for the rehabilitation of unilateral spatial neglect. Optokinetic stimulation (OKS) has also been demonstrated to be effective in ameliorating symptoms of neglect. The aim of this study is to compare the effectiveness of these two methods in a group of neglect patients using a crossover design. A group of 13 post-acute brain-damaged patients with unilateral spatial neglect, who had never been rehabilitated, were treated using PA and OKS. Each treatment was applied for 10 sessions, twice a day, to all patients with both treatments in crossed order (i.e., PA followed by OKS or vice versa). Neuropsychological assessments were performed: before the first (T1), at the end of the first/beginning of the second (T2) and at the end of the second training sessions (T3), and two weeks after the end of treatment (T4). Both procedures produced a significant improvement in clinical tests at T2, independent of the type of training. The results suggest that either PA or OKS induces a significant amelioration of neglect in right brain-damaged patients, mainly in the first block of treatment. Since no differences between treatments were found, they could be applied in clinical practice, according to the requirements of the individual patient.

Open-source open-access reaction time test (OORTT): an easy tool to assess reaction times

The speed of information processing is one of the most reliable indices of cognitive efficiency. The most common way to evaluate this ability is to assess reaction times (RTs). The technical limitations of previous tasks, aimed at measuring RT, have motivated us to develop a new battery for their evaluation. The aim of this study is to build an open-source, open-access reaction time test (OORTT), which has the following characteristics: rapid and easy administration, robust Italian normative data based on a wide age range, a simple scoring system, compatibility with all operating systems, no license or activation costs, and based on an open-source software platform. The battery is composed of three tasks: simple reaction times (SRT), Go/No-Go (GNG) condition, and four-position reaction times (4PRT). The battery was administered to 300 healthy participants aged between 14 and 89, and 3 groups of patients: 24 right brain-damaged; 21 left brain-damaged, and 19 degenerative cognitively impaired. We have developed specific norms for each task of the test battery: SRT, GNG, and 4PRT. Compared with healthy individuals, all groups obtained lower scores. More specifically, cognitively impaired patients obtained significantly longer RTs than healthy participants as well as unilateral brain-damaged patients. In the 4PRT task, right brain-damaged patients obtained a significantly left > right difference in RTs. In conclusion, the OORTT test battery proved to be a valuable tool which can be used in the clinical environment for cases of different attentional deficits after focal or degenerative brain damage.