Optometry and Vision Sciences - Research Publications
Permanent URI for this collection
Search Results
1 - 4 of 4
-
ItemDifferences in regional grey matter volumes in currently ill patients with anorexia nervosa(WILEY, 2018-01)Neurobiological findings in anorexia nervosa (AN) are inconsistent, including differences in regional grey matter volumes. Methodological limitations often contribute to the inconsistencies reported. The aim of this study was to improve on these methodologies by utilising voxel-based morphometry (VBM) analysis with the use of diffeomorphic anatomic registration through an exponentiated lie algebra algorithm (DARTEL), in a relatively large group of individuals with AN. Twenty-six individuals with AN and 27 healthy controls underwent a T1-weighted magnetic resonance imaging (MRI) scan. AN participants were found to have reduced grey matter volumes in a number of areas including regions of the basal ganglia (including the ventral striatum), and parietal and temporal cortices. Body mass index (BMI) and global scores on the Eating Disorder Examination Questionnaire (EDE-Q) were also found to correlate with grey matter volumes in a region of the brainstem (including the substantia nigra and ventral tegmental area) in AN, and predicted 56% of the variance in grey matter volumes in this area. The brain regions associated with grey matter reductions in AN are consistent with regions responsible for cognitive deficits associated with the illness including anhedonia, deficits in affect perception and saccadic eye movement abnormalities. Overall, the findings suggest reduced grey matter volumes in AN that are associated with eating disorder symptomatology.
-
ItemAn Overlooked Brain Region in the Aetiology of Anorexia Nervosa: The Importance of Behaviourally Driven Neuroimaging Analysis(SAGE PUBLICATIONS LTD, 2018-12-20)The neurobiological contributions to anorexia nervosa (AN) remain poorly understood, hindering the development of effective neurobiological treatments such as medications and brain stimulation. A large number of studies have been undertaken utilising neuroimaging techniques, such as magnetic resonance imaging (MRI), to gain a better understanding of the brain mechanisms involved in the illness. However, the analyses undertaken by many studies have utilised a whole-brain analytical approach as much of this research has been exploratory in nature. This is, however, problematic as small brain regions that differ between groups may not have the statistical power to produce statistically significant results. This is highlighted in a recent study undertaken by our group utilising diffusion-weighted imaging. In this research, we identified widespread white matter microstructural differences in individuals with AN, but only showed differences in a small brain region (the superior colliculus) when a region-of-interest approach that was driven by behavioural findings was utilised. The importance of hypothesis-driven neuroimaging analyses is discussed in this article.
-
ItemSelf perception and facial emotion perception of others in anorexia nervosa(FRONTIERS MEDIA SA, 2015-08-10)BACKGROUND: Whether individuals with anorexia nervosa (AN) are able to accurately perceive emotions from faces of others is unclear. Furthermore, whether individuals with AN process images of their own face differently to healthy individuals has thus far not been investigated. Therefore, the aim of this study was to investigate facial affect processing and the processing of one's own face through measures of emotion identification, functional magnetic resonance imaging (fMRI) and eyetracking. METHODS: Twenty-four females with AN and 25 matched healthy control participants were presented with an implicit emotion processing task during fMRI and eyetracking, followed by an explicit emotion identification task. RESULTS: The AN group were found to 'hyperscan' stimuli and avoided visually attending to salient features of their own face images. RESULTS of the fMRI revealed increased activity to own face stimuli in AN in the right inferior and middle temporal gyri, and right lingual gyrus. AN participants were not found to display emotion identification deficits to the standard emotional face stimuli. DISCUSSION: The findings are discussed in terms of increased anxiety to disorder-relevant stimuli in AN. Potential clinical implications are discussed in relation to the use of eyetracking techniques to improve the perception of self in AN.
-
ItemSaccadic Eye Movements in Anorexia Nervosa(PUBLIC LIBRARY SCIENCE, 2016-03-24)BACKGROUND: Anorexia Nervosa (AN) has a mortality rate among the highest of any mental illness, though the factors involved in the condition remain unclear. Recently, the potential neurobiological underpinnings of the condition have become of increasing interest. Saccadic eye movement tasks have proven useful in our understanding of the neurobiology of some other psychiatric illnesses as they utilise known brain regions, but to date have not been examined in AN. The aim of this study was to investigate whether individuals with AN differ from healthy individuals in performance on a range of saccadic eye movements tasks. METHODS: 24 females with AN and 25 healthy individuals matched for age, gender and premorbid intelligence participated in the study. Participants were required to undergo memory-guided and self-paced saccade tasks, and an interleaved prosaccade/antisaccade/no-go saccade task while undergoing functional magnetic resonance imaging (fMRI). RESULTS: AN participants were found to make prosaccades of significantly shorter latency than healthy controls. AN participants also made an increased number of inhibitory errors on the memory-guided saccade task. Groups did not significantly differ in antisaccade, no-go saccade or self-paced saccade performance, or fMRI findings. DISCUSSION: The results suggest a potential role of GABA in the superior colliculus in the psychopathology of AN.