Ian Nimmo-Smith

Ian Nimmo-Smith
MRC Cognition and Brain Sciences Unit | MRC · Methods Research

PhD - University of Durham

About

102
Publications
90,932
Reads
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10,533
Citations
Additional affiliations
October 1974 - July 2003
University of Cambridge
Position
  • Supervisor in Mathematics and Satistics
September 1972 - September 2010
September 1972 - September 2010
MRC Cognition and Brain Sciences Unit
Position
  • Visiting Scientist, Head of Methods Research (retired 2010)
Education
September 1971 - August 1972
University College London
Field of study
  • Statistics
October 1966 - April 1971
Durham University
Field of study
  • Differential Geometry
September 1963 - June 1966
University of Oxford
Field of study
  • Mathematics

Publications

Publications (102)
Article
In human visual processing, information from the visual field passes through numerous transformations before perceptual attributes such as colour are derived. The sequence of transforms involved in constructing perceptions of colour can be approximated by colour appearance models such as the CIE (2002) Colour Appearance Model, abbreviated as CIECAM...
Article
In human visual processing, information from the visual field passes through numerous transformations before perceptual attributes such as colour are derived. The sequence of transforms involved in constructing perceptions of colour can be approximated by colour appearance models such as the CIE (2002) Colour Appearance Model, abbreviated as CIECAM...
Article
Full-text available
Describing the human brain in mathematical terms is an important ambition of neuroscience research, yet the challenges remain considerable. It was Alan Turing, writing in 1950, who first sought to demonstrate how time-consuming such an undertaking would be. Through analogy to the computer program, Turing argued that arriving at a complete mathemati...
Article
Full-text available
Describing the human brain in mathematical terms is an important ambition of neuroscience research, yet the challenges remain considerable. It was Alan Turing, writing in 1950, who first sought to demonstrate how time-consuming such an undertaking would be. Through analogy to the computer program, Turing argued that arriving at a complete mathemati...
Article
Full-text available
A prominent feature of the auditory system is that neurons show tuning to audio frequency; each neuron has a characteristic frequency (CF) to which it is most sensitive. Furthermore, there is an orderly mapping of CF to position, which is called tonotopic organization and which is observed at many levels of the auditory system. In a previous study...
Article
Full-text available
A prominent feature of the auditory system is that neurons show tuning to audio frequency; each neuron has a characteristic frequency (CF) to which it is most sensitive. Furthermore, there is an orderly mapping of CF to position, which is called tonotopic organization and which is observed at many levels of the auditory system. In a previous study...
Article
Full-text available
Acoustic signals pass through numerous transforms in the auditory system before perceptual attributes such as loudness and pitch are derived. However, relatively little is known as to exactly when these transformations happen, and where, cortically or sub-cortically, they occur. In an effort to examine this, we investigated the latencies and locati...
Article
Full-text available
A primary objective for cognitive neuroscience is to identify how features of the sensory environment are encoded in neural activity. Current auditory models of loudness perception can be used to make detailed predictions about the neural activity of the cortex as an individual listens to speech. We used two such models (loudness-sones and loudness...
Article
Full-text available
Diffusion Imaging in Python (Dipy) is a free and open source software project for the analysis of data from diffusion magnetic resonance imaging (dMRI) experiments. dMRI is an application of MRI that can be used to measure structural features of brain white matter. Many methods have been developed to use dMRI data to model the local configuration o...
Article
Full-text available
Diffusion MR data sets produce large numbers of streamlines which are hard to visualize, interact with, and interpret in a clinically acceptable time scale, despite numerous proposed approaches. As a solution we present a simple, compact, tailor-made clustering algorithm, QuickBundles (QB), that overcomes the complexity of these large data sets and...
Article
Full-text available
Objective Previous research suggested that structural and functional abnormalities within the amygdala and orbitofrontal cortex contribute to the pathophysiology of Conduct Disorder (CD). Here, we investigated whether the integrity of the white-matter pathways connecting these regions is abnormal and thus may represent a putative neurobiological ma...
Data
Mean apparent diffusion coefficient (ADC) and λ1 (axial diffusivity), λ2, λ3 (radial diffusivity) eigenvalues in the uncinate fascicle (UF) and inferior frontal-occipital fascicle (IFOF) of male adolescents with Conduct Disorder (CD) and healthy controls. (DOC)
Data
Analyses of Covariance (ANCOVA) results for eigenvalue λ3 when including subject-specific region of interest volume (number of voxels, VOX) of each tract and lifetime/ever attention/deficit hyperactivity disorder (ADHD) symptoms as covariates of no interest. (DOC)
Data
Analyses of Covariance (ANCOVA) results for fractional anisotropy (FA) when including subject-specific region of interest volume (number of voxels, VOX) of each tract and lifetime/ever attention/deficit hyperactivity disorder (ADHD) symptoms as covariates of no interest. (DOC)
Data
Analyses of Covariance (ANCOVA) results for eigenvalue λ1 when including subject-specific region of interest volume (number of voxels, VOX) of each tract and lifetime/ever attention/deficit hyperactivity disorder (ADHD) symptoms as covariates of no interest. (DOC)
Data
Analyses of Covariance (ANCOVA) results for apparent diffusion coefficient (ADC) when including subject-specific region of interest volume (number of voxels, VOX) of each tract and lifetime/ever attention/deficit hyperactivity disorder (ADHD) symptoms as covariates of no interest. (DOC)
Data
Analyses of Covariance (ANCOVA) results for eigenvalue λ2 when including subject-specific region of interest volume (number of voxels, VOX) of each tract and lifetime/ever attention/deficit hyperactivity disorder (ADHD) symptoms as covariates of no interest. (DOC)
Article
Full-text available
Tests of fluid intelligence predict success in a wide range of cognitive activities. Much uncertainty has surrounded brain lesions producing deficits in these tests, with standard group comparisons delivering no clear result. Based on findings from functional imaging, we propose that the uncertainty of lesion data may arise from the specificity and...
Data
SPM{t} map of the activations associated with expected accumulated activity (EAA) from two models in experiment one, rendered on a representative brain in normal space with a lateral view (A, D), top view with frontal lobes towards the left (B, E) and axial glass brain views with frontal lobes toward the left (C, F). In the left hand panels (A, B,...
Article
Full-text available
Race models have been used to explain perceptual, motor and oculomotor decisions. Here we developed a race model to explain how human subjects select actions when there are no overt rewards and no external cues to specify which action to make. Critically, we were able to estimate the cumulative activity of neuronal decision-units for selected and n...
Conference Paper
Full-text available
Algorithms for clustering and classifying diffusion imaging white matter tractographies are typically quite slow often needing days or weeks of processing on a single CPU core. Much of the computational burden of clustering techniques arises from the need for detailed geometric comparisons between pairs of tracks in large datasets often containing...
Conference Paper
Full-text available
Identifying manually corresponding tracks in different brain tractogaphies is a very complicated task, typically requiring lots of expertise, and lots of time. Moreover different local diffusion models and different tractography algorithms generate tractographies with wide differences in numbers of tracks and in shape characteristics. We address th...
Article
Here, we ask whether frontotemporal cortex is functionally dissociated into distributed lexical and category-specific semantic networks. To this end, fMRI activation patterns elicited during the processing of words from different semantic categories were categorized using k-means cluster algorithms. Results showed a distributed pattern of inferiorf...
Article
Full-text available
The frontal lobes play a key role in sequential organization of behavior. Little is known, however, of the way frontal neurons code successive phases of a structured task plan. Using correlational analysis, we asked how a population of frontal cells represents the multiple events of a complex sequential task. Monkeys performed a conventional cue–ta...
Article
Full-text available
Selective neuronal loss (SNL) in the rescued penumbra could account for suboptimal clinical recovery despite effective early reperfusion. Previous studies of SNL used single-photon emission tomography (SPECT), did not account for potential volume loss secondary to collapse of the infarct cavity, and failed to show a relationship with initial hypope...
Article
Reports an error in "Goal neglect and Spearman's g: Competing parts of a complex task" by John Duncan, Alice Parr, Alexandra Woolgar, Russell Thompson, Peter Bright, Sally Cox, Sonia Bishop and Ian Nimmo-Smith (Journal of Experimental Psychology: General, 2008[Feb], Vol 137[1], 131-148). The DOI for the supplemental materials was printed incorrectl...
Article
Full-text available
In goal neglect, a person ignores some task requirement though being able to describe it. Goal neglect is closely related to general intelligence or C. Spearman's (1904) g (J. Duncan, H. Emslie, P. Williams, R. Johnson, & C. Freer, 1996). The authors tested the role of task complexity in neglect and the hypothesis that different task components in...
Article
Although damage to right posterior parietal cortex (RPPC) produces bias in line bisection, Karnath et al. [Karnath, H.-O., Berger, M. F., Küker, W., & Rorden, C. (2004). The anatomy of spatial neglect based on voxelwise statistical analysis: A study of 140 patients. Cerebral Cortex, 14, 1164-1172] claim that it plays little role in spatial neglect,...
Article
Full-text available
The article describes a collaborative research project between choreographer Wayne McGregor and a team of neuroscientists and psychologists concerned with the relationship between mind and bodily movement. The project comprised several areas of research into the neurological and cognitive basis of movement. The article also discusses the mutual ben...
Article
A previous paper reported high susceptibility to spatial migration (allochiria) of tactile stimuli in about 25% of healthy individuals (High Error subjects). When synchronous stimuli touched the two hands, if the unattended stimulus was temporally modulated when the attended one was not (and was thus more salient than the latter), it "migrated" to...
Article
Full-text available
Eight short sequences of dance were filmed as a part of a larger arts-science project on choreography and cognition. Eleven professional dancers viewed these sequences and ìparsedî them into units of movement. In this paper we describe the methodology and present three ways of representing the quantitative data: piano rolls, overlap traces and dens...
Article
Full-text available
Anosognosia for hemiplegia (AHP) is conventionally defined/diagnosed by generic questions about awareness of limb plegia. However, unawareness of inability to perform tasks requiring bilateral use of limbs is more widespread and outlasts generic unawareness of plegia. Some patients consistently overestimate bilateral task ability. Our aim was to as...
Article
To develop and implement a new audiological fitting procedure for auditory brain stem implants (ABIs), based on an efficient algorithm, and to compare it with two procedures presently used in clinical practice. First, the different procedures were compared by using computer models and simulations with normal-hearing subjects (N = 4). This allows fo...
Article
Full-text available
Among those individuals who habitually wear precision tints, reading speed can vary as a function of the chromaticity of the illuminating light. The reading speed decreases as the chromaticity departs from optimum, whether in saturation or in hue. When the distance in the CIE 1976 UCS diagram between the chromaticity of the illuminating light and t...
Article
Although damage to right posterior parietal cortex (RPPC) produces bias in line bisection, Karnath et al. [Karnath, H.-O., Berger, M. F., Küker, W., & Rorden, C. (2004). The anatomy of spatial neglect based on voxelwise statistical analysis—a study of 140 patients. Cerebral Cortex, 14, 1164–1172] claim that it plays little role in spatial neglect,...
Article
Hypofrontality is not a well-replicated finding in schizophrenia either at rest or under conditions of task activation. Studies comparing whole brain and frontal blood flow/metabolism in schizophrenic patients and normal controls were pooled. Voxel-based studies were also combined to examine the pattern of prefrontal activation in schizophrenia. Wh...
Article
Depression and dysphoric mood states are often accompanied by quantitative or qualitative shifts in performance across a range of retention tasks. This study focuses on the recollection of both autobiographical events and word lists in dysphoric states. Recollection occurs when people are aware of some contextual detail allied to the encoding exper...
Article
This study of anosognosia for hemiplegia investigated: whether it is homogeneous; specificity to plegia of unawareness; extension to different kinds of and objects of awareness regarding plegia; partiality of unawareness. Sixty-four hemiplegic stroke patients were assessed with control subjects on (a) motor and somatosensory function, immediately f...
Article
Migration of tactile sensation was found to occur very frequently in about 25% of normal people (High Error subjects) and very infrequently in others. When synchronous stimuli touched the two hands, if the unattended stimulus was modulated when the attended one was not (and was thus more salient) it "migrated" to the attended hand and fused with or...
Article
Full-text available
The application of functional neuroimaging to the study of human emotion has yielded valuable data; however, the conclusions that may be drawn from any one study are limited. We applied novel statistical techniques to the meta-analysis of 106 PET and fMRI studies of human emotion and tested predictions made by key neuroscientific models. The result...
Article
We report three experiments investigating the recognition of emotion from facial expressions across the adult life span. Increasing age produced a progressive reduction in the recognition of fear and, to a lesser extent, anger. In contrast, older participants showed no reduction in recognition of disgust, rather there was some evidence of an improv...
Article
Full-text available
This paper presents a conceptual model for studying the contribution of each leg to sideways stability of a four-link biped. It was assumed that a linear feedback controller maintained balance with torque related to the deviation from a reference value of the angle made by the trunk with the vertical. Predictions for ground reaction forces produced...
Article
"Attention" is not a unitary brain process. Evidence from adult studies indicates that distinct neuroanatomical networks perform specific attentional operations and that these are vulnerable to selective damage. Accordingly, characterising attentional disorders requires the use of a variety of tasks that differentially challenge these systems. Here...
Article
“Attention” is not a unitary brain process. Evidence from adult studies indicates that distinct neuroanatomical networks perform specific attentional operations and that these are vulnerable to selective damage. Accordingly, characterising attentional disorders requires the use of a variety of tasks that differentially challenge these systems. Here...
Article
The combined results from a number of imaging studies involving related tasks produce a three-dimensional map of activation foci that may characterise regional specialisation. Two classes of studies produce two maps.
Article
The physical differences between facial expressions (e.g. fear) and a reference norm (e.g. a neutral expression) were altered to produce photographic-quality caricatures. In Experiment 1, participants rated caricatures of fear, happiness and sadness for their intensity of these three emotions; a second group of participants rated how 'face-like' th...
Article
Gesture production was studied in children with developmental coordination disorder (DCD) and specific language impairment (SLI) in comparison to normally developing age-matched and younger control children. The pattern of error production was investigated to characterize the praxis skills seen in these two developmental disorders as well as to inf...
Article
A range of tests of everyday attention is described, based on ecologically plausible activities such as searching maps, looking through telephone directories, and listening to lottery number broadcasts. An age-, sex- and IQ-stratified sample of 154 normal participants was given these tests, along with a number of existing tests of attention. The fa...
Article
A series of experiments investigated concurrent discriminations of surface and nonsurface attributes, including color, brightness, texture, length, location, and motion. In all cases but one, results matched those previously reported: Interference occurred when two discriminations concerned different objects, but not when they concerned the same on...
Article
Full-text available
Beyond specific conflicts between tasks that are obviously similar (e.g. two verbal tasks) and limits specific to speeded responses, is there a general limitation on what tasks can be done simultaneously? In two experiments, we examined dual-task combinations designed to avoid known sources of specific interference. Under these circumstances, a gen...
Article
Full-text available
A series of experiments investigated concurrent discriminations of surface and nonsurface attributes, including color, brightness, texture, length, location, and motion. In all cases but one, results matched those previously reported: Interference occurred when two discriminations concerned different objects, but not when they concerned the same on...
Article
Full-text available
Stimulus-independent thoughts (SITs) are streams of thoughts and images unrelated to immediate sensory input. Four experiments examined the contribution of aspects of working memory to production of SITs. In Experiments 1 and 2, interventions that were targeted on, respectively, phonological and visuospatial components of working memory both interf...
Article
Full-text available
Many studies have shown a co-variation of unilateral neglect with nonlateralised attentional functions. Recently, Posner has argued that there are two separate neural systems that influence the posterior attentional system which is presumed to be impaired in unilateral neglect, namely, the posterior system itself (located partly in the inferior par...
Article
Full-text available
FORMAT The TEA consists of eight sub-tests delivered and scored using a variety of mediums. The assessment pack comes in a black portable carry-case which contains: one manual, which covers Standardisation, Validation, Interpretation and Administration guidelines, one A4 ring-bound stimulus book covering three parallel versions, three audio tapes c...
Article
This paper is concerned with the recall of naturally-occurring intentions during the interval between their formulation and their enactment, hours, days, or months later. When these intentions were spontaneously recalled, subjects recorded the prevailing cognitive and affective circumstances, and current events and actions. This task was undertaken...
Article
The development of a test aimed at estimating premorbid intelligence is described. The test, Spot-the-Word, involves presenting the subject with pairs of items comprising one word and one non-word, and requiring the subject to identify the word. Data show that performance correlates highly with verbal intelligence as estimated by Mill Hill Vocabula...
Article
Full-text available
A simple optical method for mixing coloured light is described. The observer has intuitive and approximately independent control over hue and saturation at constant brightness. The method facilitates colour matching by unpracticed observers. It allows children with reading difficulties to select a colour that reduces perceptual distortion of text....
Article
Full-text available
A system for therapeutic precision tinting is described. Some individuals who are subject to perceptual distortion of text no longer perceive the distortion when the text has a particular colour. A simple colorimeter enables an observer to illuminate text with light of a particular chromaticity, varying first CIE 1976 hue angle (huv), then saturati...