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Previously, it was difficult to detect mild neglect or a lack of stimulus-driven attention in patients using conventional assessments such as the Behavioral Inattention Test, usually performed on patients with unilateral spatial neglect. Here, we developed a method that randomly generates balloons in the left-right, up-down, and near-far spaces on a monitor using a head-mounted display. A head-mounted display can be used as an objective tool to evaluate and treat mild neglect symptoms by quantifying how quickly and accurately a patient can perceive the appearing balloons. In this study, we evaluated a lack of stimulus-driven attention case that was undetected by the paper and pencil test. We could identify mild neglect with our virtual reality method, as later confirmed using the Catherine Bergego scale. In addition to using virtual reality in a three-dimensional space to effectively detect mild neglect, this method can be used for treatment. After repeated practice under a tilted background space condition, the patient demonstrated a reduction in the time needed to perceive the appearing balloons, suggesting a therapeutic effect., 東京都立大学学位論文甲第1160号 副論文

We developed Stimulus-driven Attention Tests (SAT) for a patient with unilateral spatial neglect (USN) and longitudinally investigated the results and compared them to two conventional assessments. The patient suffered a right putaminal hemorrhage resulting in left-side USN. On the 12th, 22nd, and 28th days from the onset, the Behavioral Inattention Test (BIT) and the Catherine Bergego Scale (CBS), which are conventional USN assessments, and our two Stimulus-driven Attention Tests (SAT-1 and SAT-2) were performed. Our assessment tests comprise two tasks in which participants respond to suddenly appearing stimuli and to a target stimulus among distractors. A longitudinal comparison of all assessments was performed to observe the clinical course of the USN. On the 12th day, scores were low on the BIT, CBS, and both SATs, but on the 22nd day, BIT improved above the cutoff; however, the CBS and SATs did not improve. On the 28th day, response to a target stimulus among distractors in the SAT remained low, and CBS scores did not change significantly. We were able to detect USN with the SAT when the participant showed improvement on the paper-and-pencil tests. Moreover, the number of distractors in the SAT was thought to reveal covert USN.

Individuals with left unilateral spatial neglect (USN) following a right hemisphere lesion show difficulty in orienting their attention toward stimuli presented on the left. In normal cognition, others' gaze direction and a pointing arrow naturally guide visual attention. Here, we explore a method to identify patients who may benefit from these skills as a base for compensation during rehabilitation. We tested gaze and arrow cueing effects in 26 healthy participants and in 13 patients with USN. Our data show that brain injuries causing USN do not affect gaze and arrow cueing in a consistent manner from one patient to another.

Unilateral spatial neglect (USN) is usually assessed by means of individual stimuli or single arrays of stimuli. Seldom are stimuli presented as multiple objects or in spatially separated blocks, except in some tests for object-based neglect. The distance between individual objects or blocks of stimuli in such stimuli is implicitly considered irrelevant. We report on the case of a patient, EC, who showed severe USN in his everyday behavior, yet performed normally on standard tests for USN. Presented with stimuli in separate blocks, he performed flawlessly with 4 cm gaps between blocks, yet ignored all leftward blocks of stimuli when the gap was larger than this. EC's dissociation between good performance on standard tasks and severe neglect with separate groups of stimuli, and the distance-mediated nature of his USN are novel observations with relevant theoretical and clinical implications.

We report results of our investigation of the case of a 34-year-old woman (YJ) who showed persistent left unilateral spatial neglect (USN) in daily living, frequently hitting obstacles or bumping into the wall, although her visuospatial ability was mostly preserved in paper and pencil neuropsychological tests. In order to clarify this apparent discrepancy, her eye fixation pattern was monitored in testing situations and in natural daily activities using an eye camera. The results showed that when taking the standard tests YJ tended to shift her fixation point to the left edge of the testing frame to overcome over-searching tendency to the right as left hemianopics without left USN would do. However in natural situations, this compensatory leftward fixation was not found. This may be due to the lack of adequate frames of reference in the natural environment. Our findings suggest limitation of laboratory neuropsychologicial testing to fully appreciate the scope of a patient's disability in natural settings.

Neglect dyslexia is a reading disorder often associated with right-sided brain lesions. In reading single words, errors are mostly substitutions or omissions of letters that occupy the left-sided positions. Typically, these errors have been thought to depend on a single mechanism. Conversely, we propose that they are due to different mechanisms. In particular, a visuo-spatial mechanism is responsible for omissions and a perceptual integration process for substitution errors. We measured the performance of six patients with both neglect and neglect dyslexia, analyzing their reading errors as a function of letter spacing. According to our conjecture, letter spacing should increase omissions by moving part of the string further in the unattended space, while it should reduce substitutions by restoring the integration processes. Furthermore, we predict that letter spacing should be more effective with pseudowords compared to words, in that in this latter case lexical effects are supposed to influence attentional and perceptual processes. Accordingly, we found that for pseudowords only the two types of errors are differently affected by this manipulation and only omissions correlate with the severity of the disorder in visuo-spatial tasks. © 2010 Psychology Press.

Right half-field eye-patched glasses intervention was performed in two chronic stroke patients with unilateral spatial neglect. Eye movement on the neglect side, the center of gravity as an index of the internal midline bias, neglect sign tests, and the regional cerebral blood flow (rCBF) were measured before and after intervention. The improvement of eye movement was not shown clearly after intervention. The center of gravity shifted significantly to the right and backward. Letter and star cancellation tests were improved in both the cases. Line bisection test showed improvement in one patient. However, line cancellation and line bisection tests were worsened in the other. The rCBF was not changed after intervention. This case study suggests that right half-field eye patching might not be an effective intervention.

The difficulty that patients with unilateral spatial neglect (USN) have in exploring into the contralesional space may be explained by motor or attentional disorder. We experienced a patient with severe USN following cerebral infarction in the right postrolandic region, who showed a strong resistance to leftward movement. We devised two sets of tasks using a whiteboard. In the first experiment, the patient showed great difficulty in tracing a line from the right endpoint to the left endpoint. The examiner barely made him start further tracing even by pushing the hand leftward. By contrast, he quickly erased a whole line leftward with an eraser pen. In the second experiment, he was required to erase a line with or without an attention-attracting stimulus at the right endpoint. Not only the leftward extent, but also the velocity of erasing, were decreased when there was a stimulus at the right endpoint. The results of the two experiments suggest that the ability of leftward movement itself was pres...

Patlents with hemianopis following unilateral brain damage occasionally report seeing visual shapes such as squares and circles as complete, even though a significant portion of the shape falls within their objectively blind hemffield. In addition, some individuals report that partial shapes appear to be complete (e.g. they see a semicircle as a complete circle) when the half-shapes are presented entirely within the Intact hemffield, such that their amputated edge is aligned with the border of the field defect. These phenomena are referred to collectively as ‘pathological visual completion’. The phenomena are distinct from ‘blindsight’, in the sense that patients claim to ‘see’ parts of visual stimuli that fall within their blind hemffield (i.e. they appear to have conscious, veridical perception within their blind hemffield), or else they claim to see visual information that Is physically absent from the display altogether (i.e. they appear to have conscious, non-veridical or confabulatory perce...

A 54-year-old art teacher, experienced a right putaminal hemorrhage, and thereafter suffered severe left hemiplegia and unilateral spatial neglect, and was transferred to the rehabilitation department of the University Hospital 1 month after the onset. Although the unilateral spatial neglect was improving, the patient was unable to paint the left quarter of a watercolor, but there was no error in line drawing. The occurrence of errors only in a watercolor suggests that the neural process for painting a watercolor is different from that of line drawing.