Graph lesion-deficit mapping of fluid intelligence.

Fluid intelligence is arguably the defining feature of human cognition. Yet the nature of its relationship with the brain remains a contentious topic. Influential proposals drawing primarily on functional imaging data have implicated 'multiple demand' frontoparietal and more widely distributed cortical networks, but extant lesion-deficit studies with greater causal power are almost all small, methodologically constrained, and inconclusive.

Multi-model mapping of phonemic fluency.

The voluntary generation of non-overlearned responses is usually assessed with phonemic fluency. Like most frontal tasks, it draws upon different complex processes and systems whose precise nature is still incompletely understood. Many claimed aspects regarding the pattern of phonemic fluency performance and its underlying anatomy remain controversial.

Progressive macrographia for block letter writing: A case study.

"Macrographia", a relatively rare symptom generally following cerebellar diseases, consists of an abnormally large handwriting. The case reported in the present investigation shows several outstanding features. First, it is of the progressive variety, letters increase in size as one goes through the word towards the lower-right portion of space.

Is the Weigl Colour-Form Sorting Test Specific to Frontal Lobe Damage?

Objective: The Weigl Colour-Form Sorting Test is a brief, widely used test of executive function. So far, it is unknown whether this test is specific to frontal lobe damage. Our aim was to investigate Weigl performance in patients with focal, unilateral, left or right, frontal, or non-frontal lesions.

Cognitive Reserve Proxies Do Not Differentially Account for Cognitive Performance in Patients with Focal Frontal and Non-Frontal Lesions.

Objective: Cognitive reserve (CR) suggests that premorbid efficacy, aptitude, and flexibility of cognitive processing can aid the brain's ability to cope with change or damage. Our previous work has shown that age and literacy attainment predict the cognitive performance of frontal patients on frontal-executive tests. However, it remains unknown whether CR also predicts the cognitive performance of non-frontal patients.

Fluency and rule breaking behaviour in the frontal cortex.

Design (DF) and phonemic fluency tests (FAS; D-KEFS, 2001) are commonly used to investigate voluntary generation. Despite this, several important issues remain poorly investigated. In a sizeable sample of patients with focal left or right frontal lesion we established that voluntary generation performance cannot be accounted for by fluid intelligence.

Impairments of auditory-verbal short-term memory: Do selective deficits of the input phonological buffer exist?

The existence of the functional syndrome of auditory-verbal short-term storage impairment was used as strong supporting evidence for the presence of a phonological buffer in the first version of the Baddeley-Hitch working memory model. In later versions the syndrome corresponded to the selective impairment of the phonological input buffer. The present paper considers whether the correspondence between the functional syndrome, represented by 20 published cases, and a Baddeley-Hitch model component is still of value to memory theory.

Localizing Memory Functions in Brain Tumor Patients: Anatomical Hotspots over 260 Patients.

Objective: Memory complaints are common in patients after brain tumor, but is difficult to map memory functions during awake surgery, to preserve them. Thus we analyzed one of the largest data sets on clinical, surgical, and anatomical correlates of memory in patients with brain tumor to date, providing anatomical hotspots for short and long-term memory functions.

Methods: A total of 260 patients with brain tumor (130 high-grade gliomas; 76 low-grade gliomas [LGG]; 54 meningiomas) were tested on 2 commonly used short-term memory (Digit Span Forward and Corsi Spatial Span) and 2 long-term memory tasks (Narrative Memory and Delayed Recall of Rey Figure).

When mild pure alexia may not be reducible to hemianopic alexia.

Individuals with pure alexia often have visual field defects such as right homonymous hemianopia. Relatively few attempts have been made to develop criteria to differentiate pure alexia from hemianopic alexia. In this Commentary we provide concrete suggestions to distinguish the two disorders.

The Influence of Fluid Intelligence, Executive Functions and Premorbid Intelligence on Memory in Frontal Patients.

It is commonly thought that memory deficits in frontal patients are a result of impairments in executive functions which impact upon storage and retrieval processes. Yet, few studies have specifically examined the relationship between memory performance and executive functions in frontal patients. Furthermore, the contribution of more general cognitive processes such as fluid intelligence and demographic factors such as age, education, and premorbid intelligence has not been considered.

The Prefrontal Cortex and Neurological Impairments of Active Thought.

This article reviews the effects of lesions to the frontal cortex on the ability to carry out active thought, namely, to reason, think flexibly, produce strategies, and formulate and realize plans. We discuss how and why relevant neuropsychological studies should be carried out. The relationships between active thought and both intelligence and language are considered.

Cognitive estimation: Performance of patients with focal frontal and posterior lesions.

The Cognitive Estimation Test (CET) is a widely used test to investigate estimation abilities requiring complex processes such as reasoning, the development and application of appropriate strategies, response plausibility checking as well as general knowledge and numeracy (e.g., Shallice and Evans, 1978; MacPherson et al.

Anatomical Modularity of Verbal Working Memory? Functional Anatomical Evidence from a Famous Patient with Short-Term Memory Deficits.

Cognitive skills are the emergent property of distributed neural networks. The distributed nature of these networks does not necessarily imply a lack of specialization of the individual brain structures involved. However, it remains questionable whether discrete aspects of high-level behavior might be the result of localized brain activity of individual nodes within such networks.

Long-Term Cognitive Functioning and Psychological Well-Being in Surgically Treated Patients with Low-Grade Glioma.

Objective: The aim of this work is to provide an in-depth investigation of the impact of low-grade gliomas (LGG) and their surgery on patients' cognitive and emotional functioning and well-being, carried out via a comprehensive and multiple-measure psychological and neuropsychological assessment.

Patients And Methods: Fifty surgically treated patients with LGG were evaluated 40 months after surgery on their functioning over 6 different cognitive domains, 3 core affective/emotional aspects, and 3 different psychological well-being measures to obtain a clearer picture of the long-term impact of illness and surgery on their psychological and relational world. Close relatives were also involved to obtain an independent measure of the psychological dimensions investigated.

Major Thought Restructuring: The Roles of Different Prefrontal Cortical Regions.

An important question for understanding the neural basis of problem solving is whether the regions of human prefrontal cortices play qualitatively different roles in the major cognitive restructuring required to solve difficult problems. However, investigating this question using neuroimaging faces a major dilemma: either the problems do not require major cognitive restructuring, or if they do, the restructuring typically happens once, rendering repeated measurements of the critical mental process impossible. To circumvent these problems, young adult participants were challenged with a one-dimensional Subtraction (or Nim) problem [Bouton, C.

A Comparative Study of Tower of London Scoring Systems and Normative Data.

Objective: Tower of London (ToL) is a planning ability task that includes multiple versions. The original ToL was developed by Shallice together with two scoring systems (ToL-SS). Another two ToL-SS were proposed by Anderson et al.

Cognitive reserve and cognitive performance of patients with focal frontal lesions.

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.

Inhibition processes are dissociable and lateralized in human prefrontal cortex.

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.

Cognitive neuropsychology and its vicissitudes: The fate of Caramazza's axioms.

Cognitive neuropsychology is characterized as the discipline in which one draws conclusions about the organization of the normal cognitive systems from the behaviour of brain-damaged individuals. In a series of papers, Caramazza, later in collaboration with McCloskey, put forward four assumptions as the bridge principles for making such inferences. Four potential pitfalls, one for each axiom, are discussed with respect to the use of single-case methods.

When does a strategy intervention overcome a failure of inhibition? Evidence from two left frontal brain tumour cases.

Introduction: Initiation and inhibition of responses are crucial for appropriate behaviour across different settings. Initiation and inhibition difficulties are well documented following frontal damage, although task differences have limited our understanding. The Hayling Sentence Completion Test was designed to assess verbal initiation and inhibition within the same task.

Zero in the brain: A voxel-based lesion-symptom mapping study in right hemisphere damaged patients.

Transcoding numerals containing zero is more problematic than transcoding numbers formed by non-zero digits. However, it is currently unknown whether this is due to zeros requiring brain areas other than those traditionally associated with number representation. Here we hypothesize that transcoding zeros entails visuo-spatial and integrative processes typically associated with the right hemisphere.

The Doors and People Test: The effect of frontal lobe lesions on recall and recognition memory performance.

Objective: Memory deficits in patients with frontal lobe lesions are most apparent on free recall tasks that require the selection, initiation, and implementation of retrieval strategies. The effect of frontal lesions on recognition memory performance is less clear with some studies reporting recognition memory impairments but others not. The majority of these studies do not directly compare recall and recognition within the same group of frontal patients, assessing only recall or recognition memory performance.