ORCID Profile
0000-0002-5313-9845
Current Organisation
University of Aberdeen
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Publisher: Elsevier BV
Date: 2014
DOI: 10.1016/J.NEUROIMAGE.2013.08.061
Abstract: Empathy involves experiencing emotion vicariously, and understanding the reasons for those emotions. It may be served partly by a motor simulation function, and therefore share a neural basis with imitation (as opposed to mimicry), as both involve sensorimotor representations of intentions based on perceptions of others' actions. We recently showed a correlation between imitation accuracy and Empathy Quotient (EQ) using a facial imitation task and hypothesised that this relationship would be mediated by the human mirror neuron system. During functional Magnetic Resonance Imaging (fMRI), 20 adults observed novel 'blends' of facial emotional expressions. According to instruction, they either imitated (i.e. matched) the expressions or executed alternative, pre-prescribed mismatched actions as control. Outside the scanner we replicated the association between imitation accuracy and EQ. During fMRI, activity was greater during mismatch compared to imitation, particularly in the bilateral insula. Activity during imitation correlated with EQ in somatosensory cortex, intraparietal sulcus and premotor cortex. Imitation accuracy correlated with activity in insula and areas serving motor control. Overlapping voxels for the accuracy and EQ correlations occurred in premotor cortex. We suggest that both empathy and facial imitation rely on formation of action plans (or a simulation of others' intentions) in the premotor cortex, in connection with representations of emotional expressions based in the somatosensory cortex. In addition, the insula may play a key role in the social regulation of facial expression.
Publisher: Cambridge University Press (CUP)
Date: 21-09-2022
DOI: 10.1017/S0033291722002720
Abstract: Major depressive disorder (MDD) was previously associated with negative affective biases. Evidence from larger population-based studies, however, is lacking, including whether biases normalise with remission. We investigated associations between affective bias measures and depressive symptom severity across a large community-based s le, followed by examining differences between remitted in iduals and controls. Participants from Generation Scotland ( N = 1109) completed the: (i) Bristol Emotion Recognition Task (BERT), (ii) Face Affective Go/No-go (FAGN), and (iii) Cambridge Gambling Task (CGT). In iduals were classified as MDD-current ( n = 43), MDD-remitted ( n = 282), or controls ( n = 784). Analyses included using affective bias summary measures (primary analyses), followed by detailed emotion/condition analyses of BERT and FAGN (secondary analyses). For summary measures, the only significant finding was an association between greater symptoms and lower risk adjustment for CGT across the s le (in iduals with greater symptoms were less likely to bet more, despite increasingly favourable conditions). This was no longer significant when controlling for non-affective cognition. No differences were found for remitted-MDD v. controls. Detailed analysis of BERT and FAGN indicated subtle negative biases across multiple measures of affective cognition with increasing symptom severity, that were independent of non-effective cognition [e.g. greater tendency to rate faces as angry (BERT), and lower accuracy for happy/neutral conditions (FAGN)]. Results for remitted-MDD were inconsistent. This suggests the presence of subtle negative affective biases at the level of emotion/condition in association with depressive symptoms across the s le, over and above those accounted for by non-affective cognition, with no evidence for affective biases in remitted in iduals.
Publisher: Springer Science and Business Media LLC
Date: 20-10-2015
Publisher: Wiley
Date: 03-11-2021
DOI: 10.1002/HSR2.406
Abstract: Sleepiness influences alertness and cognitive functioning and impacts many aspects of medical care, including clinical reasoning. However, dual processing theory suggests that sleepiness will impact clinical reasoning differently in different in idual, depending on their level of experience with the given condition. Our aim, therefore, was to examine the association between clinical reasoning, neuroanatomical activation, and sleepiness in senior medical students. Our methodology replicated an earlier study but with novices rather than board‐certified physicians. Eighteen final‐year medical students answered validated multiple‐choice questions (MCQs) during an fMRI scan. Each MCQ was projected in three phases: reading, answering, and reflection (modified think aloud). Echo‐planar imaging (EPI) scans gave a time series that reflected blood oxygenation level dependent (BOLD) signal in each location (voxel) within the brain. Sleep data were collected via self‐report (Epworth Sleepiness Scale) and actigraphy. These data were correlated with answer accuracy using Pearson correlation. Analysis revealed an increased BOLD signal in the right dorsomedial prefrontal cortex ( P .05) during reflection (Phase 3) associated with increased self‐reported sleepiness (ESS) immediately before scanning. Covariate analysis also revealed that increased BOLD signal in the right supramarginal gyrus ( P .05) when reflecting (Phase 3) was associated with increased correct answer response time. Both patterns indicate effortful analytic (System 2) reasoning. Our findings that novices use System 2 thinking for clinical reasoning and even a little (perceived) sleepiness influences their clinical reasoning ability to suggest that the parameters for safe working may be different for novices (eg, junior doctors) and experienced physicians.
Publisher: Elsevier BV
Date: 03-2005
DOI: 10.1016/J.NEUROIMAGE.2004.10.047
Abstract: Although much is now known about eye movement detection, little is known about the higher cognitive processes involved in joint attention. We developed video stimuli which when watched, engender an experience of joint attention in the observer. This allowed us to compare an experience of joint attention to nonjoint attention within an fMRI scanning environment. Joint attention was associated with activity in the ventromedial frontal cortex, the left superior frontal gyrus (BA10), cingulate cortex, and caudate nuclei. The ventromedial frontal cortex has been consistently shown to be activated during mental state attribution tasks. BA10 may serve a cognitive integration function, which in this case seems to utilize a perception-action matching process. The activation we identified in BA10 overlaps with a location of increased grey matter density that we recently found to be associated with autistic spectrum disorder. This study therefore constitutes evidence that the neural substrate of joint attention also serves a mentalizing function. The developmental failure of this substrate in the left anterior frontal lobe may be important in the etiology of autistic spectrum disorder.
Publisher: Elsevier BV
Date: 06-2004
Publisher: American Psychological Association (APA)
Date: 03-2023
DOI: 10.1037/NEU0000850
Publisher: Wiley
Date: 28-04-2020
DOI: 10.1002/BRB3.1593
Abstract: Even though seasonal and sex‐dependent changes in hippoc al and subfield volumes are well known in animals, little is known about changes in humans. We hypothesized that changes in photoperiod would predict changes in hippoc al subfield volumes and that this association would be different between females and males. A total of 10,033 participants ranging in age from 45 to 79 years were scanned by MRI in a single location as part of the UK Biobank project. Hippoc al subfield volumes were obtained using automated processing and segmentation algorithms using the developmental version of the FreeSurfer v 6.0. Photoperiod was defined as the number of hours between sunrise and sunset on the day of scan. Photoperiod correlated positively with total hippoc al volume and all subfield volumes across participants as well as in each sex in idually, with females showing greater seasonal variation in a majority of left subfield volumes compared with males. ANCOVAs revealed significant differences in rate of change in only left subiculum, CA‐4, and GC‐ML‐DG between females and males. PLS showed highest loadings of hippoc al subfields in both females and males in GC‐ML‐DG, CA1, CA4, subiculum, and CA3 for left hemisphere and CA1, GC‐ML‐DG, CA4 subiculum and CA3 for right hemisphere in females GC‐ML‐DG, CA1, subiculum, CA4 and CA3 for left hemisphere CA1, GC‐ML‐DG, subiculum, CA4 and CA3 for right hemisphere in males. The influence of day length on hippoc al volume has implications for modeling age‐related decline in memory in older adults, and sex differences suggest an important role for hormones in these effects.
Publisher: Wiley
Date: 07-05-2022
DOI: 10.1002/ERV.2915
Abstract: Recent research reports Anorexia Nervosa (AN) to be highly dependent upon neurobiological function. Some behaviours, particularly concerning food selectivity are found in populations with both Autism Spectrum Disorder (ASD) and AN, and there is a proportionally elevated number of anorexic patients exhibiting symptoms of ASD. We performed a systematic review of structural MRI literature with the aim of identifying common structural neural correlates common to both AN and ASD. Across 46 ASD publications, a meta‐analysis of volumetric differences between ASD and healthy controls revealed no consistently affected brain regions. Meta‐analysis of 23 AN publications revealed increased volume within the orbitofrontal cortex and medial temporal lobe, and adult‐only AN literature revealed differences within the genu of the anterior cingulate cortex. The changes are consistent with alterations in flexible reward‐related learning and episodic memory reported in neuropsychological studies. There was no structural overlap between ASD and AN. Findings suggest no consistent neuroanatomical abnormality associated with ASD, and evidence is lacking to suggest that reported behavioural similarities between those with AN and ASD are due to neuroanatomical structural similarities.
Publisher: Springer Science and Business Media LLC
Date: 30-06-2022
DOI: 10.1038/S41598-022-15208-4
Abstract: Changes in brain morphology have been reported during development, ageing and in relation to different pathologies. Brain morphology described by the shape complexity of gyri and sulci can be captured and quantified using fractal dimension (FD). This measure of brain structural complexity, as well as brain volume, are associated with intelligence, but less is known about the sexual dimorphism of these relationships. In this paper, sex differences in the relationship between brain structural complexity and general intelligence ( g ) in two erse geographic and cultural populations (UK and Indian) are investigated. 3D T1-weighted magnetic resonance imaging (MRI) data and a battery of cognitive tests were acquired from participants belonging to three different cohorts: Mysore Parthenon Cohort (MPC) Aberdeen Children of the 1950s (ACONF) and UK Biobank. We computed MRI derived structural brain complexity and g estimated from a battery of cognitive tests for each group. Brain complexity and volume were both positively corelated with intelligence, with the correlations being significant in women but not always in men. This relationship is seen across populations of differing ages and geographical locations and improves understanding of neurobiological sex-differences.
Publisher: Elsevier BV
Date: 2006
DOI: 10.1016/J.NEUROPSYCHOLOGIA.2005.06.010
Abstract: An association between autistic spectrum disorder and imitative impairment might result from dysfunction in mirror neurons (MNs) that serve to relate observed actions to motor codings. To explore this hypothesis, we employed a functional magnetic resonance imaging (fMRI) protocol previously used to identify the neural substrate of imitation, and human MN function, to compare 16 adolescent males of normal intelligence with autistic spectrum disorder (ASD) and age, sex and IQ matched controls. In the control group, in accord with previous findings, we identified activity attributable to MNs in areas of the right parietal lobe. Activity in this area was less extensive in the ASD group and was absent during non-imitative action execution. Broca's area was minimally active during imitation in controls. Differential patterns of activity during imitation and action observation in ASD and controls were most evident in an area at the right temporo-parietal junction also associated with a 'theory of mind' (ToM) function. ASD participants also failed to show modulation of left amygdala activity during imitation that was evident in the controls. This may have implications for understanding the imitation of emotional stimuli in ASD. Overall, we suggest that ASD is associated with altered patterns of brain activity during imitation, which could stem from poor integration between areas serving visual, motor, proprioceptive and emotional functions. Such poor integration is likely to adversely affect the development of ToM through imitation as well as other aspects of social cognitive function in ASD.
Publisher: Elsevier BV
Date: 07-2013
DOI: 10.1016/J.IJPSYCHO.2013.05.019
Abstract: Mu rhythm is an EEG measure of resting motor neurons, which is normally suppressed by input because of action observation or movement execution. This characteristic has caused mu suppression to be used as proxy marker for mirror neuron activation. However, there is little direct evidence that fluctuations in mu rhythm suppression reflect concurrent fluctuations in mirror neuron activity. A manual imitation paradigm was used to look at correlations between mu rhythm and BOLD response, by recording sequential EEG and fMRI measures to allow within-subject correlation analyses. Participants were instructed to imitate or observe actions involving the movement of a handle with their right hand. Mu power modulation, defined as mu power changes between conditions, correlated negatively with BOLD response in right inferior parietal lobe, premotor cortex and inferior frontal gyrus putative mirror neuron areas. Clusters were also identified in bilateral cerebellum, left medial frontal gyrus, right temporal lobe and thalamus. This suggests that mu suppression involves a range of structures that modulate motor preparation activities and are sensitive to visual input, including but not restricted to the human analogue of the mirror neuron system.
Publisher: Elsevier BV
Date: 2005
DOI: 10.1016/J.NEUROIMAGE.2004.08.049
Abstract: A number of imaging and neuropathological studies have reported structural abnormalities in white matter areas such as the corpus callosum in autism spectrum disorder (ASD). Differences in both global brain volume and the size of specific neural structures have been reported. In order to expand these previously reported findings and to describe more precisely the nature of such structural changes, we performed a voxel-based morphometric whole brain analysis, using a group-specific template, in male adolescents with ASD. Fifteen in iduals with normal intelligence and ASD, and a group of 16 controls, matched for age, sex, and IQ, were investigated. High-resolution T1-weighted 3D data sets were acquired and analysed. Local white matter volume deficits were found in the corpus callosum, particularly in the anterior splenium and isthmus, and right hemisphere. White matter volume deficits were also found in the left middle temporal, right middle frontal, and left superior frontal gyri. No significant areas of increased white matter volume were found. Our findings support the hypothesis that reduced white matter volume in the corpus callosum and right hemisphere may play a role in the pathophysiology of ASD.
Publisher: F1000 Research Ltd
Date: 16-07-2021
DOI: 10.12688/WELLCOMEOPENRES.15538.2
Abstract: STratifying Resilience and Depression Longitudinally (STRADL) is a population-based study built on the Generation Scotland: Scottish Family Health Study (GS:SFHS) resource. The aim of STRADL is to subtype major depressive disorder (MDD) on the basis of its aetiology, using detailed clinical, cognitive, and brain imaging assessments. The GS:SFHS provides an important opportunity to study complex gene-environment interactions, incorporating linkage to existing datasets and inclusion of early-life variables for two longitudinal birth cohorts. Specifically, data collection in STRADL included: socio-economic and lifestyle variables physical measures questionnaire data that assesses resilience, early-life adversity, personality, psychological health, and lifetime history of mood disorder laboratory s les cognitive tests and brain magnetic resonance imaging. Some of the questionnaire and cognitive data were first assessed at the GS:SFHS baseline assessment between 2006-2011, thus providing longitudinal measures relevant to the study of depression, psychological resilience, and cognition. In addition, routinely collected historic NHS data and early-life variables are linked to STRADL data, further providing opportunities for longitudinal analysis. Recruitment has been completed and we consented and tested 1,188 participants.
Publisher: Frontiers Media SA
Date: 2012
Publisher: Elsevier BV
Date: 09-2023
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Gordon Waiter.