15 results on '"Bozzali M"'
Search Results
2. Bilateral damage to the mammillo-thalamic tract impairs recollection but not familiarity in the recognition process: A single case investigation
- Author
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Carlesimo, G.A., Serra, L., Fadda, L., Cherubini, A., Bozzali, M., and Caltagirone, C.
- Published
- 2007
- Full Text
- View/download PDF
3. The effect of age on cognitive performance of frontal patients
- Author
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Cipolotti, Lisa, Healy, Colm, Chan, Edgar, MacPherson, Sarah E., White, Mark, Woollett, Katherine, Turner, Martha, Robinson, Gail, Spanò, Barbara, Bozzali, Marco, Shallice, Tim, Cipolotti, L, Healy, C, Chan, E, Macpherson, S, White, M, Woollett, K, Turner, M, Robinson, G, Spanò, B, Bozzali, M, and Shallice, T
- Subjects
Adult ,Male ,Aging ,RAPM, Raven's Advanced Progressive Matrices ,Cognitive Neuroscience ,Experimental and Cognitive Psychology ,behavioral disciplines and activities ,Article ,TBI, traumatic brain injury ,CVA, cerebrovascular accident ,Executive functions ,Behavioral Neuroscience ,Executive Function ,PFC, prefrontal cortex ,Cognition ,Arts and Humanities (miscellaneous) ,WMA, white matter abnormalities ,IL, Incomplete Letters and ,Cognitive performance ,Frontal lesions non-frontal lesions ,Frontal lesions non-frontal lesion ,non-frontal lesions ,Humans ,HC, healthy controls ,Retrospective Studies ,CWMA, Composite White Matter Abnormalities ,Frontal lesions ,Brain Neoplasms ,GNT, Graded Naming Test ,Age Factors ,Brain ,Middle Aged ,Frontal Lobe ,Stroke ,IQ, Intelligence Quotient ,Stroop Test ,Female ,NART, National Adult Reading Test - Abstract
Age is known to affect prefrontal brain structure and executive functioning in healthy older adults, patients with neurodegenerative conditions and TBI. Yet, no studies appear to have systematically investigated the effect of age on cognitive performance in patients with focal lesions. We investigated the effect of age on the cognitive performance of a large sample of tumour and stroke patients with focal unilateral, frontal (n=68), or non-frontal lesions (n=45) and healthy controls (n=52). We retrospectively reviewed their cross sectional cognitive and imaging data. In our frontal patients, age significantly predicted the magnitude of their impairment on two executive tests (Raven's Advanced Progressive Matrices, RAPM and the Stroop test) but not on nominal (Graded Naming Test, GNT) or perceptual (Incomplete Letters) task. In our non-frontal patients, age did not predict the magnitude of their impairment on the RAPM and GNT. Furthermore, the exacerbated executive impairment observed in our frontal patients manifested itself from middle age. We found that only age consistently predicted the exacerbated executive impairment. Lesions to specific frontal areas, or an increase in global brain atrophy or white matter abnormalities were not associated with this impairment. Our results are in line with the notion that the frontal cortex plays a critical role in aging to counteract cognitive and neuronal decline. We suggest that the combined effect of aging and frontal lesions impairs the frontal cortical systems by causing its computational power to fall below the threshold needed to complete executive tasks successfully., Highlights • The effects of age on cognitive performance of frontal and non-frontal patients. • Exacerbated executive impairment in frontal patients. • Exacerbated executive impairment was evident by middle age in frontal patients. • No exacerbated impairment in non-frontal patients on any task.
- Published
- 2015
4. Conceptual proposition selection and the LIFG: neuropsychological evidence from a focal frontal group
- Author
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Tim Shallice, Gail Robinson, Lisa Cipolotti, Marco Bozzali, Robinson, G, Shallice, T, Bozzali, M, and Cipolotti, L
- Subjects
Adult ,Male ,Speech production ,Cognitive Neuroscience ,Concept Formation ,Decision Making ,Prefrontal Cortex ,Experimental and Cognitive Psychology ,Proposition ,Neuropsychological Tests ,Functional Laterality ,Statistics, Nonparametric ,conceptual proposition selection ,Behavioral Neuroscience ,Executive Function ,Neuroimaging ,Aphasia ,medicine ,Selection (linguistics) ,Humans ,Prefrontal cortex ,Neurologic Examination ,Language Disorders ,Language Tests ,Mechanism (biology) ,Neuropsychology ,Middle Aged ,Magnetic Resonance Imaging ,Semantics ,Pattern Recognition, Visual ,Brain Injuries ,Female ,medicine.symptom ,Psychology ,Cognition Disorders ,Photic Stimulation ,Cognitive psychology - Abstract
Much debate surrounds the role of the left inferior frontal gyrus (LIFG). Evidence from lesion and neuroimaging studies suggests the LIFG supports a selection mechanism used in single word generation. Single case studies of dynamic aphasic patients with LIFG damage concur with this and extend the finding to selection of sentences at the conceptual preparation stage of language generation. A neuropsychological group with unselected focal frontal and non-frontal lesions is assessed on a sentence generation task that varied the number of possible conceptual propositions available for selection. Frontal patients with LIFG damage when compared to Frontal patients without LIFG damage and Posterior patients were selectively impaired on sentence generation tests onlywhenstimuli activated multiple conceptual propositions that compete with each other for selection. We found that this selective impairment is critical for reduced speech rate, the core deficit of dynamic aphasia, and we would argue it is causative for one form of dynamic aphasia associated with LIFG lesions. These results provide evidence that the LIFG is crucial for selecting among multiple competing conceptual propositions for language generation. Crown Copyright © 2010 Published by Elsevier Ltd. All rights reserved.
- Published
- 2009
5. The impact of different aetiologies on the cognitive performance of frontal patients
- Author
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Cipolotti, Lisa, Healy, Colm, Chan, Edgar, Bolsover, Fay, Lecce, Francesca, White, Mark, Spanò, Barbara, Shallice, Tim, Bozzali, Marco, Cipolotti, L, Healy, C, Chan, E, Bolsover, F, Lecce, F, White, M, Spanò, B, Shallice, T, and Bozzali, M
- Subjects
Adult ,Male ,Frontal lesion ,Cognitive Neuroscience ,Experimental and Cognitive Psychology ,Neuropsychological Tests ,behavioral disciplines and activities ,Article ,Executive functions ,Behavioral Neuroscience ,Executive Function ,Arts and Humanities (miscellaneous) ,Humans ,Aetiology ,Cognitive performance ,Aged ,Frontal lesions ,Brain Neoplasms ,Middle Aged ,Frontal Lobe ,Stroke ,Cerebrovascular Disorders ,Female ,Tumour ,Meningioma ,Psychomotor Performance - Abstract
Neuropsychological group study methodology is considered one of the primary methods to further understanding of the organisation of frontal ‘executive’ functions. Typically, patients with frontal lesions caused by stroke or tumours have been grouped together to obtain sufficient power. However, it has been debated whether it is methodologically appropriate to group together patients with neurological lesions of different aetiologies. Despite this debate, very few studies have directly compared the performance of patients with different neurological aetiologies on neuropsychological measures. The few that did included patients with both anterior and posterior lesions. We present the first comprehensive retrospective comparison of the impact of lesions of different aetiologies on neuropsychological performance in a large number of patients whose lesion solely affects the frontal cortex. We investigated patients who had a cerebrovascular accident (CVA), high (HGT) or low grade (LGT) tumour, or meningioma, all at the post-operative stage. The same frontal ‘executive’ (Raven's Advanced Progressive Matrices, Stroop Colour-Word Test, Letter Fluency-S; Trail Making Test Part B) and nominal (Graded Naming Test) tasks were compared. Patients' performance was compared across aetiologies controlling for age and NART IQ scores. Assessments of focal frontal lesion location, lesion volume, global brain atrophy and non-specific white matter (WM) changes were undertaken and compared across the four aetiology. We found no significant difference in performance between the four aetiology subgroups on the ‘frontal’ executive and nominal tasks. However, we found strong effects of premorbid IQ on all cognitive tasks and robust effects of age only on the frontal tasks. We also compared specific aetiology subgroups directly, as previously reported in the literature. Overall we found no significant differences in the performance of CVA and tumour patients, or LGT and HGT patients or LGT, HGT and meningioma's on our four frontal tests. No difference was found with respect to the location of frontal lesions, lesion volume, global brain atrophy and non-specific WM changes between the subgroups. Our results suggest that the grouping of frontal patients caused by different aetiologies is a pragmatic, justified methodological approach that can help to further understanding of the organisation of frontal executive functions., Highlights • Impact of different aetiology on frontal patient's performance. • No difference between aetiology subgroups in frontal lesion characteristics. • No difference between aetiology subgroups in neuropsychological performance. • The importance of accounting for age, NART IQ and lesion characteristics. • Grouping frontal patients by different aetiologies is methodologically appropriate.
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6. Effect of frontal lobe lesions on the recollection and familiarity components of recognition memory
- Author
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Sarah E. MacPherson, Lisa Cipolotti, Tim Shallice, Raymond J. Dolan, Jeremy Rees, Marco Bozzali, MACPHERSON SE, BOZZALI M, CIPOLOTTI L, DOLAN RJ, REES JH, and SHALLICE T
- Subjects
Adult ,Male ,medicine.medical_specialty ,Adolescent ,Frontal lobes ,Cognitive Neuroscience ,Experimental and Cognitive Psychology ,Neuropsychological Tests ,Audiology ,recognition memory ,Article ,Recognition memory ,Behavioral Neuroscience ,Recollection ,Confidence Intervals ,medicine ,Humans ,Prefrontal cortex ,Episodic memory ,Recall ,Memoria ,Recognition, Psychology ,Cognition ,Middle Aged ,Familiarity ,Magnetic Resonance Imaging ,Frontal Lobe ,Lobes of the brain ,medicine.anatomical_structure ,ROC Curve ,Frontal lobe ,Brain Injuries ,Mental Recall ,Female ,Psychology ,Neuroscience - Abstract
Single-process theories assume that familiarity is the sole influence on recognition memory with decisions being made as a continuous process. Dual-process theories claim that recognition involves both recollection and familiarity processes with recollection as a threshold process. Although, the frontal lobes of the brain play an important role in recognition memory, few studies have examined the effect of frontal lobe lesions on recollection and familiarity. In the current study, the nonverbal recognition memory of 24 patients with focal frontal lesions due to turnout or stroke was examined. Recollection and familiarity were estimated using the receiver operating characteristic (ROC) method. A secondary analysis was also conducted using standard signal detection theory methodology. Both analyses led to similar conclusions where only the familiarity component of recognition memory was impaired in frontal patients compared to healthy controls whilst the recollection-type (or variance ratio) processes remained intact. (c) 2008 Elsevier Ltd. All rights reserved.
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7. Fluency test generation and errors in focal frontal and posterior lesions.
- Author
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Robinson GA, Tjokrowijoto P, Ceslis A, Biggs V, Bozzali M, and Walker DG
- Subjects
- Humans, Mental Processes, Neuropsychological Tests, Prefrontal Cortex pathology, Frontal Lobe diagnostic imaging, Frontal Lobe physiology, Verbal Behavior physiology
- Abstract
The number produced on fluency tasks is widely used to measure voluntary response generation. To further evaluate the relationship between generation, errors, and the area of anatomical damage we administered eight fluency tasks (word, design, gesture, ideational) to a large group of focal frontal (n = 69) and posterior (n = 43) patients and controls (n = 150). Lesions were analysed by a finer-grained frontal localisation method, and traditional subdivisions (anterior/posterior, left/right frontal). Thus, we compared patients with Lateral lesions to patients with Medial lesions. Our results show that all fluency tasks are sensitive to frontal lobe damage for the number of correct responses and, for the first time, we provide evidence that seven fluency tasks show frontal sensitivity in terms of errors (perseverations, rule-breaks). Lateral (not Medial) patients produced the highest error rates, indicative of task-setting or monitoring difficulties. There was a right frontal effect for perseverative errors when retrieving known or stored items and rule-break errors when creating novel responses. Left lateral effects were specific to phonemic word fluency rule-breaks and perseverations for meaningless gesture fluency. In addition, our generation output and error findings support a frontal role in novelty processes. Finally, we confirm our previous generation findings suggesting critical roles of the superior medial region in energization and the left inferior frontal region in selection (Robinson et al., 2012). Overall, these results support the notion that frontal functions comprise a set of highly specialised cognitive processes, supported by distinct frontal regions., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
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8. Non-linear spelling in writing after a pure cerebellar lesion.
- Author
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Lupo M, Siciliano L, Olivito G, Masciullo M, Bozzali M, Molinari M, Cercignani M, Silveri MC, and Leggio M
- Subjects
- Adult, Cerebellar Diseases complications, Cerebellar Diseases diagnostic imaging, Connectome, Female, Humans, Language Disorders diagnostic imaging, Language Disorders etiology, Language Disorders pathology, Magnetic Resonance Imaging, Nerve Net diagnostic imaging, Nerve Net pathology, Cerebellar Diseases pathology, Cerebellar Diseases physiopathology, Language Disorders physiopathology, Nerve Net physiopathology, Psychomotor Performance physiology, Writing
- Abstract
The most common deficits in processing written language result from damage to the graphemic buffer system and refer to semantic and lexical problems or difficulties in phoneme-graphene conversion. However, a writing disorder that has not yet been studied in depth is the non-linear spelling phenomenon. Indeed, although some cases have been described, no report has exhaustively explained the cognitive mechanism and the anatomical substrates underlying this process. In the present study, we analyzed the modality of non-linear writing in a patient affected by a focal cerebellar lesion, who presented with an alteration of the normal trend to write the order of the letters. Based on this evidence, we analyzed the functional connectivity between the cerebellum and the brain network that subtends handwriting and demonstrated how the cerebellar lesion of the patient affected the connections between the cerebellum and cortical areas that support the anatomical system of writing. This is the first report of non-linear spelling in a patient with a lesion outside the fronto-parietal network, specifically with a focal cerebellar lesion. We propose that non-linear writing can be interpreted in view of the role of the cerebellum in timing and sequential processing. Thus, considering the current functional connectivity data, we hypothesize that the cerebellum might be relevant in the mechanism that allows the correct activation timing of letters within a string and placement of the letters in a specific sequential writing order., (Copyright © 2019 Elsevier Ltd. All rights reserved.)
- Published
- 2019
- Full Text
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9. Cognitive reserve and cognitive performance of patients with focal frontal lesions.
- Author
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MacPherson SE, Healy C, Allerhand M, Spanò B, Tudor-Sfetea C, White M, Smirni D, Shallice T, Chan E, Bozzali M, and Cipolotti L
- Subjects
- Adult, Aged, Analysis of Variance, Executive Function physiology, Female, Frontal Lobe diagnostic imaging, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Neuropsychological Tests, Tomography Scanners, X-Ray Computed, Brain Injuries complications, Brain Injuries pathology, Cognition Disorders etiology, Cognitive Reserve physiology, Frontal Lobe pathology
- Abstract
The Cognitive reserve (CR) hypothesis was put forward to account for the variability in cognitive performance of patients with similar degrees of brain pathology. Compensatory neural activity within the frontal lobes has often been associated with CR. For the first time we investigated the independent effects of two CR proxies, education and NART IQ, on measures of executive function, fluid intelligence, speed of information processing, verbal short term memory (vSTM), naming, and perception in a sample of 86 patients with focal, unilateral frontal lesions and 142 healthy controls. We fitted multiple linear regression models for each of the cognitive measures and found that only NART IQ predicted executive and naming performance. Neither education nor NART IQ predicted performance on fluid intelligence, processing speed, vSTM or perceptual abilities. Education and NART IQ did not modify the effect of lesion severity on cognitive impairment. We also found that age significantly predicted performance on executive tests and the majority of our other cognitive measures, except vSTM and GNT. Age was the only predictor for fluid intelligence. This latter finding suggests that age plays a role in executive performance over and above the contribution of CR proxies in patients with focal frontal lesions. Overall, our results suggest that the CR proxies do not appear to modify the relationship between cognitive impairment and frontal lesions., (Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2017
- Full Text
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10. Inhibition processes are dissociable and lateralized in human prefrontal cortex.
- Author
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Cipolotti L, Spanò B, Healy C, Tudor-Sfetea C, Chan E, White M, Biondo F, Duncan J, Shallice T, and Bozzali M
- Subjects
- Brain Mapping, Brain Neoplasms physiopathology, Brain Neoplasms psychology, Female, Humans, Intelligence physiology, Intelligence Tests, Magnetic Resonance Imaging, Male, Middle Aged, Neural Pathways physiology, Neuropsychological Tests, Prefrontal Cortex physiopathology, Retrospective Studies, Stroke physiopathology, Stroke psychology, Executive Function physiology, Functional Laterality physiology, Inhibition, Psychological, Prefrontal Cortex physiology
- Abstract
The prefrontal cortex (PFC) is known to make fundamental contributions to executive functions. However, the precise nature of these contributions is incompletely understood. We focused on a specific executive function, inhibition, the ability to suppress a pre-potent response. Functional imaging and animal studies have studied inhibition. However, there are only few lesion studies, typically reporting discrepant findings. For the first time, we conducted cognitive and neuroimaging investigations on patients with focal unilateral PFC lesions across two widely used inhibitory tasks requiring a verbal response: The Hayling Part 2 and Stroop Colour-Word Tests. We systematically explored the relationship between inhibition, fluid intelligence and lesion location using voxel-based lesion symptom mapping (VLSM). We found that PFC patients were significantly impaired compared with healthy comparison group (HC) on both suppression measures of the Hayling and on the Stroop, even when performance on a fluid intelligence test was covaried. No significant relationship was found between patients' performance on each Hayling suppression measure and the Stroop, once fluid intelligence was partialled out, suggesting that the two tests may involve different kinds of inhibition. After accounting for fluid intelligence, we found a significant interaction between tests, Hayling or Stroop, and site, left or right, of PFC damage. This finding suggesting lateralized functional organization was complemented and extended by our VLSM results. We found that performance on both Hayling suppression measures significantly relied on the integrity of a similar and relatively circumscribed region within the right lateral PFC, in the right lateral superior and middle frontal gyri. In stark contrast, performance on the Stroop relies on the integrity of left lateral superior and middle frontal gyri. Thus, lesion location, right or left PFC, is critical in producing impairments on two inhibitory tasks loading similarly on verbal control. This suggests that the two suppression measures of the Hayling and the Stroop are likely to assess dissociable components of executive functions, related to anatomically defined and lateralized PFC circuits. Our findings also suggest that inhibition may actually comprise qualitatively different forms with different neural substrates. This has clinical implications for the diagnosis and treatment of disinhibition impairments, a common behavioural problem caused by PFC lesions. Our results highlight the need to assess inhibition using a variety of tasks and to develop different types of treatments., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
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11. The impact of different aetiologies on the cognitive performance of frontal patients.
- Author
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Cipolotti L, Healy C, Chan E, Bolsover F, Lecce F, White M, Spanò B, Shallice T, and Bozzali M
- Subjects
- Adult, Aged, Female, Humans, Male, Middle Aged, Neuropsychological Tests, Brain Neoplasms pathology, Brain Neoplasms physiopathology, Cerebrovascular Disorders pathology, Cerebrovascular Disorders physiopathology, Executive Function physiology, Frontal Lobe pathology, Frontal Lobe physiopathology, Meningioma pathology, Meningioma physiopathology, Psychomotor Performance physiology
- Abstract
Neuropsychological group study methodology is considered one of the primary methods to further understanding of the organisation of frontal 'executive' functions. Typically, patients with frontal lesions caused by stroke or tumours have been grouped together to obtain sufficient power. However, it has been debated whether it is methodologically appropriate to group together patients with neurological lesions of different aetiologies. Despite this debate, very few studies have directly compared the performance of patients with different neurological aetiologies on neuropsychological measures. The few that did included patients with both anterior and posterior lesions. We present the first comprehensive retrospective comparison of the impact of lesions of different aetiologies on neuropsychological performance in a large number of patients whose lesion solely affects the frontal cortex. We investigated patients who had a cerebrovascular accident (CVA), high (HGT) or low grade (LGT) tumour, or meningioma, all at the post-operative stage. The same frontal 'executive' (Raven's Advanced Progressive Matrices, Stroop Colour-Word Test, Letter Fluency-S; Trail Making Test Part B) and nominal (Graded Naming Test) tasks were compared. Patients' performance was compared across aetiologies controlling for age and NART IQ scores. Assessments of focal frontal lesion location, lesion volume, global brain atrophy and non-specific white matter (WM) changes were undertaken and compared across the four aetiology. We found no significant difference in performance between the four aetiology subgroups on the 'frontal' executive and nominal tasks. However, we found strong effects of premorbid IQ on all cognitive tasks and robust effects of age only on the frontal tasks. We also compared specific aetiology subgroups directly, as previously reported in the literature. Overall we found no significant differences in the performance of CVA and tumour patients, or LGT and HGT patients or LGT, HGT and meningioma's on our four frontal tests. No difference was found with respect to the location of frontal lesions, lesion volume, global brain atrophy and non-specific WM changes between the subgroups. Our results suggest that the grouping of frontal patients caused by different aetiologies is a pragmatic, justified methodological approach that can help to further understanding of the organisation of frontal executive functions., (Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
12. Impairments in proverb interpretation following focal frontal lobe lesions.
- Author
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Murphy P, Shallice T, Robinson G, MacPherson SE, Turner M, Woollett K, Bozzali M, and Cipolotti L
- Subjects
- Adult, Aged, Brain Injuries etiology, Brain Injuries physiopathology, Female, Frontal Lobe injuries, Functional Laterality physiology, Humans, Male, Middle Aged, Neuropsychological Tests, Stroke complications, Stroke physiopathology, Comprehension physiology, Frontal Lobe physiopathology, Metaphor
- Abstract
The proverb interpretation task (PIT) is often used in clinical settings to evaluate frontal "executive" dysfunction. However, only a relatively small number of studies have investigated the relationship between frontal lobe lesions and performance on the PIT. We compared 52 patients with unselected focal frontal lobe lesions with 52 closely matched healthy controls on a proverb interpretation task. Participants also completed a battery of neuropsychological tests, including a fluid intelligence task (Raven's Advanced Progressive Matrices). Lesions were firstly analysed according to a standard left/right sub-division. Secondly, a finer-grained analysis compared the performance of patients with medial, left lateral and right lateral lesions with healthy controls. Thirdly, a contrast of specific frontal subgroups compared the performance of patients with medial lesions with patients with lateral frontal lesions. The results showed that patients with left frontal lesions were significantly impaired on the PIT, while in patients with right frontal lesions the impairments approached significance. Medial frontal patients were the only frontal subgroup impaired on the PIT, relative to healthy controls and lateral frontal patients. Interestingly, an error analysis indicated that a significantly higher number of concrete responses were found in the left lateral subgroup compared to healthy controls. We found no correlation between scores on the PIT and on the fluid intelligence task. Overall our results suggest that specific regions of the frontal lobes contribute to the performance on the PIT., (© 2013 The Authors. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
13. Frontal subregions mediating Elevator Counting task performance.
- Author
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MacPherson SE, Turner MS, Bozzali M, Cipolotti L, and Shallice T
- Subjects
- Adult, Analysis of Variance, Female, Frontal Lobe physiopathology, Humans, Male, Middle Aged, Neuropsychological Tests, Statistics, Nonparametric, Attention physiology, Brain Diseases pathology, Frontal Lobe pathology, Mathematics
- Abstract
Deficits in sustained attention may lead to action slips in everyday life as irrelevant action sequences are inappropriately triggered internally or by the environment. While deficits in sustained attention have been associated with damage to the frontal lobes of the brain, little is known about the role of the frontal lobes in the Elevator Counting subtest of the Test of Everyday Attention. In the current study, 55 frontal patients subdivided into medial, orbital and lateral subgroups, 18 patients with posterior lesions and 82 healthy controls performed the Elevator Counting task. The results revealed that patients with medial and left lateral prefrontal lesions were significantly impaired on the task compared to healthy controls. Research suggests that patients with medial lesions are susceptible to competition from task irrelevant schema; whereas the left lateral group in the current study may fail to keep track of the tones already presented., (Copyright © 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
14. Conceptual proposition selection and the LIFG: neuropsychological evidence from a focal frontal group.
- Author
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Robinson G, Shallice T, Bozzali M, and Cipolotti L
- Subjects
- Adult, Brain Injuries complications, Cognition Disorders etiology, Executive Function physiology, Female, Functional Laterality physiology, Humans, Language Disorders etiology, Language Disorders physiopathology, Language Tests, Magnetic Resonance Imaging methods, Male, Middle Aged, Neurologic Examination methods, Neuropsychological Tests, Pattern Recognition, Visual, Photic Stimulation, Semantics, Statistics, Nonparametric, Brain Injuries pathology, Cognition Disorders pathology, Concept Formation physiology, Decision Making physiology, Prefrontal Cortex physiopathology
- Abstract
Much debate surrounds the role of the left inferior frontal gyrus (LIFG). Evidence from lesion and neuroimaging studies suggests the LIFG supports a selection mechanism used in single word generation. Single case studies of dynamic aphasic patients with LIFG damage concur with this and extend the finding to selection of sentences at the conceptual preparation stage of language generation. A neuropsychological group with unselected focal frontal and non-frontal lesions is assessed on a sentence generation task that varied the number of possible conceptual propositions available for selection. Frontal patients with LIFG damage when compared to Frontal patients without LIFG damage and Posterior patients were selectively impaired on sentence generation tests only when stimuli activated multiple conceptual propositions that compete with each other for selection. We found that this selective impairment is critical for reduced speech rate, the core deficit of dynamic aphasia, and we would argue it is causative for one form of dynamic aphasia associated with LIFG lesions. These results provide evidence that the LIFG is crucial for selecting among multiple competing conceptual propositions for language generation., (2010. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
15. Effect of frontal lobe lesions on the recollection and familiarity components of recognition memory.
- Author
-
MacPherson SE, Bozzali M, Cipolotti L, Dolan RJ, Rees JH, and Shallice T
- Subjects
- Adolescent, Adult, Confidence Intervals, Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Neuropsychological Tests, ROC Curve, Brain Injuries pathology, Frontal Lobe physiopathology, Mental Recall physiology, Recognition, Psychology physiology
- Abstract
Single-process theories assume that familiarity is the sole influence on recognition memory with decisions being made as a continuous process. Dual-process theories claim that recognition involves both recollection and familiarity processes with recollection as a threshold process. Although, the frontal lobes of the brain play an important role in recognition memory, few studies have examined the effect of frontal lobe lesions on recollection and familiarity. In the current study, the nonverbal recognition memory of 24 patients with focal frontal lesions due to tumour or stroke was examined. Recollection and familiarity were estimated using the receiver operating characteristic (ROC) method. A secondary analysis was also conducted using standard signal detection theory methodology. Both analyses led to similar conclusions where only the familiarity component of recognition memory was impaired in frontal patients compared to healthy controls whilst the recollection-type (or variance ratio) processes remained intact.
- Published
- 2008
- Full Text
- View/download PDF
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