Tim Shallice

International School for Advanced Studies | SISSA · Cognitive Neuroscience Group

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 wi...

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 wi...

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 controvers...

“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. Mo...

The frontal lobes are thought to make a fundamental contribution to fluid intelligence. However, evidence that fluid intelligence is impaired following focal frontal lobe lesions is surprisingly sparse and based on non-verbal tests of fluid intelligence. We investigated performance on Part 1 of the Alice Heim 4 (AH4–1), a verbal test of fluid intel...

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. Method We retrospectively analysed data from pa...

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 whe...

A remembrance of Donald T. Stuss, PhD, OC, OOnt, FRSC, one of the giants of modern neuropsychology, died on September 3, 2019, of complications from pancreatic cancer after a short illness. He was 77.

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; intel...

Fifteen punchy five–minute talks were given in quick succession at the Anniversary Conference this year, the datablitz session sticking to time thanks in part to the evidently well–functioning frontal lobes of those presenting, and in part to highly efficient and only very mildly aggressive chairing by Simon Prangnell (threats of water–pistol attac...

A manual and the apparatus for Tower of London (ToL) task including a normative data set in the Czech population. The test is available in Karolinum Press (the official publishing house of Charles University), please see: http://www.cupress.cuni.cz/ink2_stat/index.jsp?include=podrobnosti&id=20236&jazyk=en.

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 pres...

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

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. We also report on additional assessments with two previ...

Objective: 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 ge...

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.Wediscuss how and why relevant neuropsychological studies should be carried out. The relationships between active thought and both intelligence and langu...

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,...

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., 2014). Thus far, it remai...

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 LG...

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 indiv...

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 requir...

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. and Krikorian et al. The purpose of this study is to provide normative data for four ToL-SS and explore the effects of...

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 I...

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,...

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 inhibi...

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 proces...

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 majo...

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....

Sir, We read with interest the scientific commentary by Hornberger and Bertoux (2015) on our study on the specificity of prefrontal cortex subregions for strategy use, verbal initiation and suppression (Robinson et al. , 2015). We administered Section 1 and 2 of the Hayling sentence completion task (Burgess and Shallice, 1997) to a large group of...

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...

Background. Cognitive effects of brain surgery for the removal of intracranial tumors are still under investigation. For many basic sensory/motor or language-based functions, focal, albeit transient, cognitive deficits have been reported low-grade gliomas (LGGs); however, the effects of surgery on higher-level cognitive functions are still largely u...

Part B of the Trail Making Test (TMT-B) is one of the most widely used neuropsychological tests of “executive” function. A commonly held assumption is that the TMT-B can be used to detect frontal executive dysfunction. However, so far, research evidence has been limited and somewhat inconclusive. In this retrospective study, performance on the TMT-...

Verbal initiation, suppression and strategy generation/use are cognitive processes widely held to be supported by the frontal cortex. The Hayling Test was designed to tap these cognitive processes within the same sentence completion task. There are few studies specifically investigating the neural correlates of the Hayling Test but it has been prim...

Initiation and suppression deficits are documented in patients with frontal lesions although this has typically been with different tasks that are hard to compare. The Hayling Sentence Completion Test (Burgess & Shallice, 1997) was designed to tap initiation, suppression and strategy use within the same sentence completion task. There are few studi...

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 app...

Aim: The aim of the study was to standardize (test construction, administration and scoring) the Czech version of the Tower of London test developed by Tim Shallice in 1982 (TOL). We sought to determine potential of the TOL to differentiate between patients with Parkinson’s disease mild cognitive impairment (PD‑ MCI) and control participants and to...

Patients affected by brain tumours may show behavioural and emotional regulation deficits, sometimes showing flattened affect and sometimes experiencing a true 'change' in personality. However, little evidence is available to the surgeon as to what changes are likely to occur with damage at specific sites, as previous studies have either relied on...

Pure alexia is a selective impairment of reading in the absence of other language de ficits and occurs as a consequence of brain injury in previously literate individuals. The syndrome has intrigued researchers for well over a century and is the most studied of the acquired reading disorders. Pure alexia has been extensively investigated over the l...

The article is concerned with inferences from the behaviour of neurological patients to models of normal function. It takes the letter-by-letter reading strategy common in pure alexic patients as an example of the methodological problems involved in making such inferences that compensatory strategies produce. The evidence is discussed on the possib...

Modification or suppression of reaches occurs in everyday life. We argue that a common modular architecture, based on similar neural structures and principles of kinematic and kinetic control, is used for both direct reaches and for their on-line corrections. When a reach is corrected, both the pattern of neural activity in parietal, premotor and m...

The Cognitive Estimation Test (CET) is widely used by clinicians and researchers to assess the ability to produce reasonable cognitive estimates. Although several studies have published normative data for versions of the CET, many of the items are now outdated and parallel forms of the test do not exist to allow cognitive estimation abilities to be...

We investigated the interplay between stimulus-driven attention and memory retrieval with a novel interference paradigm that engaged both systems concurrently on each trial. Participants encoded a 45-min movie in Day 1 and, on Day 2, performed a temporal order judgment task during fMRI. Each retrieval trial was comprised of three images presented s...

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-matche...

a b s t r a c t 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 5...

Professor Jon Driver made significant contributions to cognitive neuroscience. This paper pays tribute to that work and to the personal qualities of Jon that so many of his colleagues were fortunate enough to experience.

Two views on the semantics of concrete words are that their core mental representations are feature-based or are reconstructions of sensory experience. We argue that neither of these approaches is capable of representing the semantics of abstract words, which involve the representation of possibly hypothetical physical and mental states, the bindin...

Damage to the posterior parietal cortex (PPC) can lead to Optic Ataxia (OA), in which patients misreach to peripheral targets. Recent research suggested that the PPC might be involved not only in simple reaching tasks toward peripheral targets, but also in changing the hand movement trajectory in real time if the target moves. The present study inv...

Neuroscience research relevant to cognitive processes has grown dramatically in the past two decades, largely due to the increasing availability of sophisticated technologies such as those used in neuroimaging. This growth has led to great advances in our understanding of the brain bases of cognitive processes, but in our view this progress is bein...

It is widely recognized that mental rotation is a cognitive process which engages a distributed cortical network including the frontal, premotor and parietal regions. Like other visual-spatial transformations it could require operations on both metric and categorical spatial representations. Previous reports have implicated respectively the right h...

We studied the ability of patients with lesions arising from operation for an anterior or posterior (left or right) brain tumour to read a set of words and pronounceable nonwords. In line with previous works, we observed that damage to the left posterior or left anterior cortex can give rise to phonological alexia, where the reading performance of...

Diffusion tensor imaging (DTI) tractography and image registration were used to investigate a patient with a massive left-sided brain tumor, whose size was largely disproportionate to his subtle neurological deficits. MRI was obtained from the patient and his healthy identical twin, who acted as anatomical reference for DTI and as a control for qua...

Our book had a number of major themes, but also took a variety of positions on specific issues. Naturally each commentary addresses a different concern or focuses primarily on a different aspect of cognition. Nevertheless, there is much common ground. Harley (in this issue) and Goel (in this issue) challenge major themes of the book, which Chatham...

Episodic memory provides information about the "when" of events as well as "what" and "where" they happened. Using functional imaging, we investigated the domain specificity of retrieval-related processes following encoding of complex, naturalistic events. Subjects watched a 42-min TV episode, and 24h later, made discriminative choices of scenes fr...

Fluency tasks have been widely used to tap the voluntary generation of responses. The anatomical correlates of fluency tasks and their sensitivity and specificity have been hotly debated. However, investigation of the cognitive processes involved in voluntary generation of responses and whether generation is supported by a common, general process (...

Existing studies on task switching in Parkinson's disease (PD) patients have led to somewhat different results. In particular, it is unclear whether PD patients have a deficit in attentional control. In this study, we assessed task-switching abilities in samples of non-demented PD patients and elderly controls. We used a paradigm in which there was...

The ROBBIA set of studies (see Stuss & Alexander, 2007) on frontal lobe functions is discussed with respect to two main issues. The first concerns the neuropsychological group study methodology employed. This was to use anatomically-based groups with the anatomical criteria concerning the localisation of lesions for group inclusion being both coars...

The paper addresses a weakness in the Schwartz and Dell paper (2010)-namely, its discussion of the inclusion criteria for case series. The paper distinguishes the different types that exist and how they constrain the theoretical conclusions that one can draw about the organization of the normal cognitive system. Four different types of inclusion cr...

This is a rejoinder in response to the book review by Max Coltheart on the book The Organization of Mind, edited by Tim Shallice and Richard P. Cooper, Oxford: Oxford University Press, 2011, pp. 608. ISBN 978-0-19-957924-2.

This paper examines Stroud's theory that the perceptual input is quantized in time (the perceptual moment hypothesis). A model of the detection of change based on the theory is compared with other models derived from statistical quality control methods; in particular those using simple and geometric moving averages. They are compared theoretically...

In four experiments, a computerized Corsi-like paradigm was used to assess which of the many reference frames are used in visuospatial short-term memory. By varying the relative orientation (slanted +/-45° or in an upright position) of the head and the displays, we modulate the utility of the allocentric, egocentric (eye- and head-centred), and tem...

Objective: Existing studies on memory interference in Parkinson's disease (PD) patients have provided mixed results and it is unknown whether PD patients have problems in overcoming interference from retrieval cues. We investigated this issue by using a part-list cuing paradigm. In this paradigm, after the study of a list of items, the presentation...

Despite the recent interest in the neuroanatomy of inductive reasoning processes, the regional specificity within prefrontal cortex (PFC) for the different mechanisms involved in induction tasks remains to be determined. In this study, we used fMRI to investigate the contribution of PFC regions to rule acquisition (rule search and rule discovery) a...

Several lines of evidence exist, coming from neuropsychology, neuroimaging and behavioural investigations on healthy subjects, suggesting that an interaction might exist between the systems devoted to object identification and those devoted to online object-directed actions and that the way an object is acted upon (manipulability) might indeed infl...

While many behavioural studies on refractory phenomena in lexical/semantic access have focused on the mechanisms involved in the oral production of names, comprehension tasks have been almost exclusively used in neuropsychological studies on brain damaged patients. We report the results of two experiments on healthy participants conducted by means...