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Giuseppe Vallar - One of the best experts on this subject based on the ideXlab platform.
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Spatial neglect and Perseveration in visuomotor exploration.
Neuropsychology, 2012Co-Authors: Roberta Ronchi, Lorella Algeri, Laura Chiapella, Maria Simonetta Spada, Giuseppe VallarAbstract:OBJECTIVE: 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. METHOD: 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. RESULTS: 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. CONCLUSIONS: 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.
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Drawing Perseveration in neglect: Effects of target density
Journal of neuropsychology, 2012Co-Authors: Lorenzo Pia, Raffaella Ricci, Patrizia Gindri, Giuseppe VallarAbstract:In cancellation tasks, patients with unilateral spatial neglect typically fail to mark targets within the side of the sheet contralateral to the side of the lesion (contralesional). Moreover, they can show a perseverative behaviour, which consists in repeatedly cancelling stimuli, mainly in the side of the display ipsilateral to the side of the lesion (ipsilesional). We investigated in 13 right-brain-damaged patients with left spatial neglect and perseverative behaviour whether and how different densities of horizontal targets modulated omission and perseverative errors. We found that the density of targets modulated the patients' distribution of neglect (area of omission), but not its extent, as indexed by the percentage of omissions. Specifically, the area of omissions tightened when target density increased leftwards. On the other hand, target density did not affect the distribution of perseverative behaviour (area of Perseveration), as well as its extent, as indexed by the percentage of Perseverations. Correlation analyses showed that both the extent and the distribution of omissions were positively correlated to clinical measures of spatial neglect. Conversely, Perseverations did not show such a correlation. These findings support the view that two different pathological mechanisms might be involved in left spatial neglect and in ipsilesional perseverative behaviour.
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Perseveration in left spatial neglect drawing and cancellation tasks
Cortex, 2009Co-Authors: Roberta Ronchi, Lucio Posteraro, Paola Fortis, Emanuela Bricolo, Giuseppe VallarAbstract: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.
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productive and defective impairments in the neglect syndrome graphic Perseveration drawing productions and optic prism exposure
Cortex, 2006Co-Authors: Giuseppe Vallar, Martina Gandola, Tiziana Zilli, Gabriella BottiniAbstract:The effects of adaptation to prisms displacing rightwards the field of vision on omission errors, and on Perseveration and other graphic productions in a line cancellation task, were assessed in nine right-brain-damaged patients with left unilateral spatial neglect. Prism adaptation improved both neglect, as indexed by omission errors, and Perseveration behaviour, up to a delay of 60 min. No correlation was found between omission and Perseveration errors in all assessments. The suggestion is made that Perseveration and other complex graphic productions made by right brain-damaged-patients with left spatial unilateral neglect is due to a defective monitoring of complex motor behaviour, frequently associated to cerebral damage involving the right frontal lobe. Interpretations of Perseveration behaviour in terms of allochiria and directional hypokinesia are considered, and their limits discussed.
Kenneth M. Heilman - One of the best experts on this subject based on the ideXlab platform.
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Unilateral Perseveration (P01.008)
Neurology, 2013Co-Authors: Lealani Mae Y Acosta, Ira Goodman, Kenneth M. HeilmanAbstract:OBJECTIVE: This report describes a patient with a parkinsonian syndrome with unilateral motor Perseveration and explores the possible mechanisms of this disorder. BACKGROUND: Motor Perseveration, which has been subdivided into the continuous and recurrent subtypes, is a disengagement disorder, often induced by dysfunction of the executive frontal-subcortical networks that control the action-intentional programming system. Most prior reports have described bilateral upper limb Perseveration. DESIGN/METHODS: Careful clinical evaluation as detailed in this case report revealed a patient with a parkinsonian syndrome with the unique feature of unilateral motor Perseveration. RESULTS: This 68 year old right-handed gentleman with impaired walking and vertical gaze, consistent with a diagnosis of progressive supranuclear palsy (PSP), had continuous Perseveration of the right hand, but not the left hand, on multiple motor tasks. CONCLUSIONS: Unilateral motor Perseveration may be a sign of PSP or corticobasal degeneration (CBD) and future studies should use tasks that assess for this disorder. The mechanism underlying this disorder is not known, but patients with unilateral right frontal-subcortical disease are most likely to reveal bilateral Perseveration. Patients with PSP and CBD have callosal degeneration and perhaps a callosal disconnection of the left hemisphere9s premotor and motor areas from the right frontal lobe induced this disorder; however, further research will be needed to test this postulate. Supported by: In part by the State of Florida Memory Clinics. Disclosure: Dr. Acosta has nothing to disclose. Dr. Goodman has nothing to disclose. Dr. Heilman has received personal compensation for activities with law firms as a consultant. Dr. Heilman has received personal compensation in an editorial capacity for Journal Watch.
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Unilateral Perseveration.
Cognitive and behavioral neurology : official journal of the Society for Behavioral and Cognitive Neurology, 2013Co-Authors: Lealani Mae Y Acosta, Ira J Goodman, Kenneth M. HeilmanAbstract:The brain's action-intentional ("when") programming system helps to control when to and when not to initiate an action, when to persist at an action, and when to terminate an action. Motor Perseveration is a failure to terminate an action. This disengagement disorder most often results from dysfunction of the executive frontal-subcortical networks that control the action-intentional programming system. Reports of unilateral Perseveration are unusual. Here we describe a patient with a form of progressive supranuclear palsy (PSP) who exhibited continuous right-hand motor Perseveration. This 68-year-old right-handed man had impaired walking and vertical gaze, consistent with PSP. He often repeated words, and on many motor tasks he showed continuous Perseveration of his right but not his left hand. Unilateral motor Perseveration may be a sign of PSP, the corticobasal syndrome, or a subtype of these disorders. Future studies of patients with both disorders should use tasks that assess for asymmetric hand Perseveration. The mechanism of the unilateral Perseveration must also be determined. Bilateral Perseveration is found most often in patients with unilateral right frontal-subcortical (basal ganglia) or insula dysfunction. Because patients with PSP or corticobasal syndrome have callosal degeneration, their unilateral Perseveration might result from a callosal disconnection of the right frontal lobe from the left hemisphere's premotor and motor as well as speech areas.
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Spatially adherent graphemic Perseveration.
Cognitive and behavioral neurology : official journal of the Society for Behavioral and Cognitive Neurology, 2010Co-Authors: Waldo R. Guerrero, Abhay Kumar, Aunali Khaku, Kenneth M. HeilmanAbstract:BACKGROUND There are several forms of agraphia, including: aphasic agraphia, where patients have impairments in writing the correct words or correctly spelling words; apraxic agraphia, where patients are impaired in making the movements needed to write letters; and spatial agraphia, where patients might fail to write letters on one side of a word or write on one side of a page. In several of these agraphic disorders, patients can make perseverative errors, and perseverative errors can even be seen in patients who do not have aphasia or apraxic agraphia. Patients who make continuous perseverative errors repeatedly writes the same letter (fruuuit) or word, and patients with recurrent Perseverations change their letters, but then incorrectly use letter or word that was previously used (fruiut). We report a patient who demonstrated a different form of graphic Perseveration. METHODS AND RESULTS A 61-year-old man with a right parietal lobe lesion and left-sided neglect developed an inability to write. When attempting to write, he repeatedly wrote the same letter that he first wrote, and wrote these in the same spatial position as the first letter. When spelling, reading aloud, and using a keyboard to write he did not perseverate letters or words. When performing the cancellation test and drawings, he also perseverated. CONCLUSIONS This patient demonstrated a novel form of perseverative behavior. Although the mechanism of this spatially adherent graphemic Perseveration remains to be elucidated fully we provide evidence that this patient's right parietal lesion caused a visuomotor disengagement disorder.
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Motor perseverative behavior on a line cancellation task.
Neurology, 1999Co-Authors: John C. Adair, Y. Kang, C.s. Chung, Kyung-han Lee, Kenneth M. HeilmanAbstract:Objectives: To study the behavioral and neuroanatomic characteristics of perseverative behavior encountered on a target cancellation task in patients with neglect. Methods: Motor perseverative behavior during line cancellation task was evaluated retrospectively in 60 patients with left hemispatial neglect from right hemispheric stroke. Results: 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. Conclusions: 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.
Lauren J Moskowitz - One of the best experts on this subject based on the ideXlab platform.
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Perseveration in the connected speech of boys with fragile x syndrome with and without autism spectrum disorder
Ajidd-american Journal on Intellectual and Developmental Disabilities, 2012Co-Authors: Gary E Martin, Joanne E Roberts, Nancy Helmestabrooks, John Sideris, Jacqueline Vanderbilt, Lauren J MoskowitzAbstract:Abstract Verbal Perseveration is a frequently reported language characteristic of males with Fragile X syndrome and may be a defining feature or hallmark of the syndrome. We compared the verbal Perseveration of boys with Fragile X syndrome with (n = 29) and without (n = 30) autism spectrum disorder, boys with Down syndrome (n = 27), and typically developing boys (n = 25) at similar nonverbal mental ages. During a social interaction, boys with both Fragile X syndrome and autism spectrum disorder produced significantly more topic Perseveration than all other groups. In social interaction as compared to narration, boys with Fragile X syndrome (regardless of autism status) produced significantly more topic Perseveration. These findings suggest that autism status, as well as language sampling context, affect Perseveration in boys with Fragile X syndrome.
Gary E Martin - One of the best experts on this subject based on the ideXlab platform.
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Perseveration in the connected speech of boys with fragile x syndrome with and without autism spectrum disorder
Ajidd-american Journal on Intellectual and Developmental Disabilities, 2012Co-Authors: Gary E Martin, Joanne E Roberts, Nancy Helmestabrooks, John Sideris, Jacqueline Vanderbilt, Lauren J MoskowitzAbstract:Abstract Verbal Perseveration is a frequently reported language characteristic of males with Fragile X syndrome and may be a defining feature or hallmark of the syndrome. We compared the verbal Perseveration of boys with Fragile X syndrome with (n = 29) and without (n = 30) autism spectrum disorder, boys with Down syndrome (n = 27), and typically developing boys (n = 25) at similar nonverbal mental ages. During a social interaction, boys with both Fragile X syndrome and autism spectrum disorder produced significantly more topic Perseveration than all other groups. In social interaction as compared to narration, boys with Fragile X syndrome (regardless of autism status) produced significantly more topic Perseveration. These findings suggest that autism status, as well as language sampling context, affect Perseveration in boys with Fragile X syndrome.
Gabriella Bottini - One of the best experts on this subject based on the ideXlab platform.
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how many forms of Perseveration evidence from cancellation tasks in right hemisphere patients
Neuropsychologia, 2013Co-Authors: Martina Gandola, Alessio Toraldo, P Invernizzi, Laura Corrado, Maurizio Sberna, Ignazio Santilli, Gabriella Bottini, E PaulesuAbstract:Neglect patients' performance during cancellation tasks is characterized by left sided omissions and, in many cases, by the production of inappropriate material of various kinds in the ipsilesional space, e.g. additional marks over already cancelled targets, marks drawn away from targets, scribbles, irrelevant drawings. It is unclear whether these behaviours, which have collectively been called perseverative, are functionally and anatomically connected and whether they correlate with the severity of neglect. Here we report a retrospective study on 33 right brain damaged patients with neglect after right hemisphere lesions in whom we measured the intensity of Perseveration of the three following kinds: (1) 'additional marks' (AM) Perseveration where patients cancelled a target with two or more well separated marks; (2) 'scribble' Perseveration, where patients, instead of cancelling the target with a single pen stroke as required by the task, performed multiple pen strokes without breaking the pen-to-paper contact, with the final product being a scribble; (3) 'flying marks' (FM) Perseveration where patients produced cancellation marks well away from the targets. We found that AM and FM Perseveration correlated with neglect severity, while 'scribble' Perseveration did not. The lesion-symptom mapping showed three separate anatomical areas in the right hemisphere: 'scribble' Perseveration was associated with lesions of the orbitofrontal cortex and caudate nucleus; AM Perseveration was associated with damage to the rolandic operculum, superior temporal gyrus and inferior frontal gyrus; FM Perseveration was associated with damage to the dorsal premotor cortex and the temporal pole. Neglect severity followed damage to a region which grossly corresponds to the sum of the regions associated with AM and FM Perseveration respectively. This complex behavioural and anatomical pattern is interpreted in terms of a three-factor model, in which AM Perseveration is caused by a deficit of disengagement of attention from the right side (also causing omissions), FM Perseveration is caused by directional hypokinesia (also causing left-side omissions), and 'scribble' Perseveration is the consequence of a failure to inhibit an initiated motor act, which is completely separate (both anatomically and functionally) from the disorder inducing omissions.
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productive and defective impairments in the neglect syndrome graphic Perseveration drawing productions and optic prism exposure
Cortex, 2006Co-Authors: Giuseppe Vallar, Martina Gandola, Tiziana Zilli, Gabriella BottiniAbstract:The effects of adaptation to prisms displacing rightwards the field of vision on omission errors, and on Perseveration and other graphic productions in a line cancellation task, were assessed in nine right-brain-damaged patients with left unilateral spatial neglect. Prism adaptation improved both neglect, as indexed by omission errors, and Perseveration behaviour, up to a delay of 60 min. No correlation was found between omission and Perseveration errors in all assessments. The suggestion is made that Perseveration and other complex graphic productions made by right brain-damaged-patients with left spatial unilateral neglect is due to a defective monitoring of complex motor behaviour, frequently associated to cerebral damage involving the right frontal lobe. Interpretations of Perseveration behaviour in terms of allochiria and directional hypokinesia are considered, and their limits discussed.
