Target Cancellation Task Research Articles

A - 09 Normative Data of Neuropsychological Tests of Attention in Older Adults from Costa Rica.

To generate normative data for the Trail Making Test (TMT) and the Target Cancellation Task for healthy older adults in Costa Rica. 563 healthy Costa Rican adults aged 59-90years (M = 67.15; SD = 7) were assessed. Each participant was administered the two attention tests as part of a more comprehensive neuropsychological battery. Multiple regression models showed a linear effect of education for TMT-A and TMT-B, as well as a linear and curvilinear effect of age for TMT-B and TMT-A, respectively. The model predictors explained between 27.4% and 30.3% of the variance. For the Target Cancellation Task scores, linear effects of education were observed for all 4 scores, as well as a linear effect of age for the TMX time and Rhombus time scores. The correct TMX score showed a curvilinear effect of age. The predictors of the model explained between 2% and 33.3% of the variance. This is the first normative data generated for the TMT and the Target Cancellation Task in older adults from Costa Rica. This normative data will be used in individuals with a variety of neurological conditions that course with attention deficits to establish the neuropsychological profile of those individuals in this area.

Spatial orientation and postural control in patients with Parkinson’s disease

Postural instability is one of the most disabling and risky symptoms of advanced Parkinson's disease (PD). The purpose of this study was to investigate whether and how this is mediated by a centrally impaired spatial orientation. Therefore, we performed a spatial orientation study in 21 PD patients (mean age 68years, SD 8.5 years, 9 women) in a medically on condition and 21 healthy controls (mean age 68.9years, SD 5.5years, 14 women). We compared their spatial responses to the horizontal axis (Sakashita's visual target cancellation task), the vertical axis (bucket-test), the sagittal axis (tilt table test) and postural stability using the Fullerton Advanced Balance Scale (FAB). We found larger deviations on the vertical axis in PD patients, although the direct comparisons of performance in PD patients and healthy controls did not reveal significant differences. While the total scores of the FAB Scale were significantly worse in PD (25.9 points, SD 7.2 points) compared to controls (35.1 points, SD 2.3 points, p<0.01), the results from the spatialorientation task did not correlate with the FAB Scale. In summary, our results argue against a relation between perceptional deficits of spatial information and postural control in PD. These results are in favor of a deficit in higher order integration of spatial stimuli in PD that might influence balance control.

The Use of the Target Cancellation Task to Identify Eloquent Visuospatial Regions in Awake Craniotomies: Technical Note.

The success of awake craniotomies relies on the patient’s performance of function-specific tasks that are simple, quick, and reproducible. Intraoperative identification of visuospatial function through cortical and subcortical mapping has utilized a variety of intraoperative tests, each with its own benefits and drawbacks. In light of this, we developed a simple software program that aids in preventing neglect by simulating a target-cancellation task on a portable electronic device. In this report, we describe the interactive target cancellation task and have reviewed seven consecutive patients who underwent awake craniotomy for parietal and/or posterior temporal infiltrating brain tumors of the non-dominant hemisphere. Each of these patients performed target cancellation and line bisection tasks intraoperatively. The outcomes of each patient and testing scenario are described. Positive intraoperative cortical and subcortical sites involved with visuospatial processing were identified in three of the seven patients using the target cancellation and confirmed utilizing the line-bisection task. No identification of visuospatial function was accomplished utilizing the line-bisection task alone. Complete visuospatial function mapping was completed in less than 10 minutes in all patients. No patients had preoperative or postoperative hemineglect. Our findings highlight the feasibility of the target cancellation technique for use during awake craniotomy to aid in avoiding postoperative hemineglect. Target cancellation may offer an alternative method of cortical and subcortical visuospatial mapping in patients unable to perform other commonly used modalities.

Modified target cancellation in hemispatial neglect

A 70-year-old woman developed left hemispatial neglect following a right parietal haemorrhage (figure 1A). On a standard target cancellation task, she neglected 6/10 left-sided stimuli (figure 1B,C and see online...

Spatial neglect and perseveration in visuomotor exploration.

Right-brain-damaged patients with left spatial neglect make perseveration errors in target cancellation tasks. A recent study (Ronchi, Posteraro, Fortis, Bricolo, & Vallar, 2009) showed that perseveration occurred more frequently in star than in letter cancellation, possibly due to different stimulus disposition. In this study we investigated the role of the spatial organization of targets (scattered vs. arranged) of the star and letter cancellation tasks in eliciting omission and perseveration errors; the role of impairments of divided attentional resources; and the lesion correlates of perseveration. Thirty-three right-brain-damaged patients (27 with neglect, and six without neglect; 17 showing perseveration, 16 of them with spatial neglect) were given two versions of the star and letter cancellation tasks (with stimuli scattered or in rows), and a dual task. A scattered target disposition increased omission and perseveration errors. Target type modulated differently omission and perseveration, with the former being more elicited by verbal targets, and the latter occurring more frequently in the star cancellation task, with scattered stimuli. Perseveration behavior was unrelated to deficits of divided attention, as assessed by the dual task. Lesion analysis indicated damage to the right insula as a neural correlate of perseveration. A display including nonverbal (star) and scattered targets brings about more perseveration errors. Target type and organization modulate in a different fashion omission and perseveration, suggesting the involvement of independent pathological mechanisms, which, however, do not implicate deficits of divided attention. The role of insular damage in motor perseveration in spatial neglect is discussed.

Aandacht voor visuele inattentie. De Balloons Test in de psychogeriatrie

The Balloons Test is a paper-and-pencil target cancellation task designed to detect visual inattention. The test consists of two subtests: subtest A for parallel, automatic processing and detection of twenty circles with an adjoining vertical line ('balloons') among a much larger number of circles as distractors. Subtest B asks for serial and effortful search of twenty circles among balloons. Among 191 consecutive participants of a psychogeriatric day care program (mean age 78 yr) 28.2% scored below 17 on subtest B, which is indicative of generalized visual inattention. Bivariate analyses showed that visual inattention was associated with deficiencies on tasks of visuospatial, constructional and executive mental control functions. Using multivariate logistic regression analysis, two tests of visuospatial perception (clock reading and picture description) retained an independent effect in the association with visual inattention. Only three participants (1.6%) were unable to take the Balloons Test. The results of this clinical study are in favour of the Balloons Test as a useful addition to inattention measurement in psychogeriatric patients.

Testing for Spatial Neglect with Line Bisection and Target Cancellation: Are Both Tasks Really Unrelated?

Damage to the parietal lobe can induce a condition known as spatial neglect, characterized by a lack of awareness of the personal and/or extrapersonal space opposite the damaged brain region. Spatial neglect is commonly assessed clinically using either the line bisection or the target cancellation task. However, it is unclear whether poor performance on each of these two tasks is associated with the same or different lesion locations. To date, methodological limitations and differences have prevented a definitive link between task performance and lesion location to be made. Here we report findings from a voxel-based lesion symptom mapping (VLSM) analysis of an unbiased selection of 44 patients with a recent unifocal stroke. Patients performed both the line bisection and target cancellation task. For each of the two tasks a continuous score was incorporated into the VLSM analysis. Both tasks correlated highly with each other (r = .76) and VLSM analyses indicated that the angular gyrus was the critical lesion site for both tasks. The results suggest that both tasks probe the same underlying cortical deficits and although the cancellation task was more sensitive than the line bisection task, both can be used in a clinical setting to test for spatial neglect.

Relationship between Hemispatial Inattention and Performance of Activities of Daily Living in Patients with Schizophrenia

This study investigated the relation of hemispatial inattention to the performance of daily functions in 32 patients with schizophrenia or schizoaffective disorder and in 31 healthy controls. They were tested on the relationship between a target cancellation task and the Activities of Daily Living Rating Scale-II (ADLRS-II). According to the results of the hemispatial inattention test, the patients with schizophrenia made more omissions in the cancellation test than the controls. In addition, the results showed a significant correlation between number of omissions on the cancellation test and the ADLRS-II score in the study participants. A statistically significant relationship was observed between hemispatial inattention and the functional status of patients with schizophrenia, and suggests the need to incorporate measures of visual attention into psychiatric rehabilitation assessments.

Perseveration in left spatial neglect: Drawing and cancellation tasks

Perseveration in target cancellation tasks and in drawing by copy and from memory was investigated in 21 right-brain-damaged patients, seven with no evidence of left visuo-spatial neglect, and 14 with neglect. Eight such neglect patients showed perseveration in both cancellation and drawing tasks, although no correlation was found with the severity of neglect. Patients with perseveration were not disproportionately impaired in tasks assessing executive (fluency, Stroop colour–word interference, and Weigl's sorting test), and visuo-spatial short-term memory function. In the context of a two-component hypothesis, graphic perseveration (the first component) is a specific disorder that manifests in a variety of tasks, particularly those requiring serial graphic production. Unilateral spatial neglect (the second component) may trigger and facilitate the production of perseveration errors, with a contra-ipsilateral gradient of increasing severity.

Task Selection is Critical for the Demonstration of Reciprocal Patterns of Sex Differences in Hand/Arm Motor Control and Near/Far Visual Processing

Women have been reported to perform better with hand rather than arm movements ( Sanders and Walsh, 2007 ) and with visual stimuli in near rather than far space ( Sanders, Sinclair and Walsh, 2007 ). Men performed better with the arm and in far space. These reciprocal patterns of sex differences appear as Muscle*Sex and Space*Sex interactions. We investigated these claims using target cancellation tasks in which task difficulty was manipulated by varying target size or the number of distracters. In Study 1 we did not find the Muscle*Sex or the Space*Sex interaction. We argue that ballistic movement was too simple to reveal the Muscle*Sex interaction. However, a trend for the Space*Sex interaction suggested task difficulty was set too high. Study 2 introduced easier levels of difficulty and the overall Space*Sex interaction narrowly failed to reach significance ( p = 0.051). In Study 3 the Space*Sex interaction was significant ( p = 0.001). A review of the present, and four previously published, studies indicates that task selection is critical if the Space*Sex interaction and its associated reciprocal within-sex differences are to be demonstrated without the obscuring effects of Space and Difficulty. These sex differences are compatible with predictions from the hunter-gatherer hypothesis. Implications for two-visual-system-models are considered.

Mapping of Visuospatial Functions during Brain Surgery

Mapping of Visuospatial Functions during Brain Surgery

Lorazepam induces multiple disturbances in selective attention: attentional overload, decrement in target processing efficiency, and shifts in perceptual discrimination and response bias

There is a general consensus that benzodiazepines affect attentional processes, yet only few studies have tried to investigate these impairments in detail. The purpose of the present study was to investigate the effects of a single dose of Lorazepam on performance in a target cancellation task with important time constraints. We measured correct target detections and correct distractor rejections, misses and false positives. The results show that Lorazepam produces multiple kinds of shifts in performance, which suggests that it impairs multipLe processes: (a) the evolution of performance over time was not the same between the placebo and the Lorazepam groups, with the Lorazepam affecting performance quite early after the beginning of the test. This is suggestive of a depletion of attentional resources during sequential attentional processing; (b) Lorazepam affected differently target and distractor processing, with target detection being the most impaired; (c) misses were more frequent under Lorazepam than under placebo, but no such difference was observed as far as false positives were concerned. Signal detection analyses showed that Lorazepam (d) decreased perceptual discrimination, and (e) reliably increased response bias. Our results bring new insights on the multiple effects of Lorazepam on selective attention which, when combined, may have deleterious effects on human performance.

The influence of contralesional targets on the cancellation of ipsilesional targets in unilateral neglect

Neglect of contralesional stimuli and perseverative behavior on ipsilesional stimuli may co-occur on a target cancellation task. Our aim was to investigate whether the presence vs. absence of contralesional targets can modify perseveration on ipsilesional targets. We studied four right brain-damaged patients with left neglect and perseverative behavior on screening cancellation tasks. We compared their cancellation performance in two conditions: (i) targets equally distributed on both sides of space and (ii) targets confined to the right side. One patient showed no significant difference in perseveration between these two conditions; in contrast, three patients perseverated significantly more in condition (i) than in condition (ii). These results suggest that, at least in some patients, information from the ‘neglected’ targets is not completely lost, but rather it affects behavior in the ipsilesional side. The traditional dichotomy ‘bad space–good space’ would not apply here.

Motor perseverative behavior on a line cancellation task.

To study the behavioral and neuroanatomic characteristics of perseverative behavior encountered on a target cancellation task in patients with neglect. Motor perseverative behavior during line cancellation task was evaluated retrospectively in 60 patients with left hemispatial neglect from right hemispheric stroke. More than 30% of the patients (21 of 60) showed perseveration, manifested as either repetitive cancellation of the same target (18/21) or cancelling extra lines created by the patients themselves (3/21). Neglect severity correlated positively with the frequency of perseverative errors. Perseveration was most prominent in the rightmost portion of the array. Anterior lesions or massive lesions involving anterior and posterior regions were more likely to be associated with motor perseveration than were lesions restricted to posterior areas. Although the mechanism of motor perseveration remains to be elucidated, our findings suggest that the combination of aberrant approach behaviors associated with frontal lobe injury and an attentional or intentional bias toward the rightsided targets might explain the behavior.

Visual hemispatial inattention: stimulus parameters and exploratory strategies.

Patients with unilateral hemispheric lesions were given visual target cancellation tasks. As expected, marked contralateral and less severe ipsilateral visual inattention were observed in patients with right-sided cerebral lesions whereas those with left-sided lesions showed only mild contralateral neglect. Stimulus material (shapes vs letters) and array (random vs structured) interacted in a complex manner to influence target detection only in patients with right-sided lesions. Furthermore, the search strategy of these patients tended to be erratic, particularly when the stimuli were in an unstructured array. A structured array prompted a more systematic and efficient search. It appears, therefore, that stimulus content and spatial array affect neglect behaviour in patients with right-sided lesions and that a lack of systematic visual exploration within the extrapersonal space is one factor that contributes to visual hemispatial inattention.