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Torrens WA, Pablo JN, Berryhill ME, Haigh SM. Pattern glare sensitivity distinguishes subclinical autism and schizotypy. Cogn Neuropsychiatry 2024; 29:155-172. [PMID: 38551240 PMCID: PMC11296901 DOI: 10.1080/13546805.2024.2335103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 03/20/2024] [Indexed: 06/27/2024]
Abstract
INTRODUCTION Schizophrenia and autism spectrum disorder are distinct neurodevelopmental disorders sharing clinically relevant behaviours. However, early sensory responses show divergent responses. Individuals with schizophrenia typically exhibit cortical hypo-excitability whereas individuals with autism show cortical hyperexcitability. Identifying reliable neurobiological differences between the disorders can diminish misdiagnosis and optimise treatments. METHODS The pattern glare test (PGT) is a simple measure of behavioural hyperexcitability. It measures the number of illusions seen in a static horizontal grating. We collected PGT data from non-clinical adults varying in traits of autism and schizophrenia (schizotypy). 576 undergraduate students completed an online survey consisting of the Schizotypal Personality Questionnaire - Brief Revised, the Autism Spectrum Quotient, and the PGT. RESULTS Subclinical autism and schizotypy traits were highly positively correlated. However, only schizotypy scores were significantly predictive of reporting more pattern glare (PG) illusions. When assessing the subcomponents of the schizotypy and autism scores, positive and disorganised schizotypy traits were predictive of reporting more PG illusions. Whereas, subclinical autism factors were not predictive of PG illusions. CONCLUSIONS High schizotypy performed the PGT in a manner consistent with behavioural hyperexcitability. The PGT distinguished subclinical autistic traits from schizotypy, suggesting potential clinical application.
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Affiliation(s)
- Wendy A Torrens
- Department of Psychology and Institute for Neuroscience, University of Nevada, Reno, USA
| | - Jenna N Pablo
- Department of Psychology and Institute for Neuroscience, University of Nevada, Reno, USA
| | - Marian E Berryhill
- Department of Psychology and Institute for Neuroscience, University of Nevada, Reno, USA
| | - Sarah M Haigh
- Department of Psychology and Institute for Neuroscience, University of Nevada, Reno, USA
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Haigh SM, Haugland AM, Mendoza LR, Montero M. Auditory discomfort in visually sensitive individuals. Front Psychol 2023; 14:1126481. [PMID: 38098527 PMCID: PMC10720311 DOI: 10.3389/fpsyg.2023.1126481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 10/30/2023] [Indexed: 12/17/2023] Open
Abstract
Introduction Sensory discomfort occurs in clinical and non-clinical populations. While some of the parameters that evoke visual discomfort have been identified, the parameters of sounds that evoke auditory discomfort are largely unknown. Methods We presented various sounds and asked participants to rate the discomfort they experienced. In Experiments 1 and 2 tones were presented at frequencies between 0.25-8 kHz and modulated sinusoidally in amplitude at frequencies between 0-32 Hz. In Experiment 3 tones were swept in frequency from 500 Hz-2 kHz at sweep rates of 5-50 per second. In Experiment 4, sweeps varied in frequency range and central frequency. Results Discomfort increased with frequency. The effects of the amplitude modulation and sweep rate on discomfort were relatively small and were experienced mainly at low modulation frequencies and high sweep rates. Individuals who experienced visuo-perceptual distortions in the Pattern Glare (PG) Test reported greater auditory discomfort. Discussion This suggests that sensory sensitivity in one modality may occur in another.
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Affiliation(s)
- Sarah M. Haigh
- Department of Psychology and Institute for Neuroscience, University of Nevada, Reno, Reno, NV, United States
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3
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Torrens WA, Pablo JN, Shires J, Haigh SM, Berryhill ME. People with high schizotypy experience more illusions in the Pattern Glare Test: Consistent with the hyperexcitability hypothesis. Eur J Neurosci 2023; 57:388-399. [PMID: 36484768 PMCID: PMC9847329 DOI: 10.1111/ejn.15886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022]
Abstract
Individuals diagnosed with schizophrenia spectrum disorders (SSD) exhibit a constellation of sensory and perceptual impairments, including hyporeactivity to external input. However, individuals with SSD also report subjective experiences of sensory flooding, suggesting sensory hyperexcitability. To identify the extent to which behavioural indices of hyperexcitability are related to non-psychotic symptoms of schizophrenia, we tested a non-clinical population measured for schizophrenia-like traits (schizotypy), and a behavioural measure of sensory hyperexcitability, specifically the number of illusions seen in the Pattern Glare Test. Two samples totaling 913 individuals completed an online version of the Schizotypal Personality Questionnaire - Brief Revised (SPQ-BR) and the Pattern Glare Test. Individuals with higher schizotypy traits reported more illusions in the Pattern Glare Test. Additionally, one of the three SPQ-BR factors, the disorganized factor, significantly predicted the number of illusions reported. These data illustrate the potential for research in non-clinical samples to inform clinically relevant research.
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Affiliation(s)
- Wendy A Torrens
- Department of Psychology, University of Nevada, Reno, Reno, Nevada, USA
| | - Jenna N Pablo
- Department of Psychology, University of Nevada, Reno, Reno, Nevada, USA
| | - Jorja Shires
- Department of Psychology, University of Nevada, Reno, Reno, Nevada, USA
| | - Sarah M Haigh
- Department of Psychology, University of Nevada, Reno, Reno, Nevada, USA
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de Tommaso M, La Rocca M, Quitadamo SG, Ricci K, Tancredi G, Clemente L, Gentile E, Ammendola E, Delussi M. Central effects of galcanezumab in migraine: a pilot study on Steady State Visual Evoked Potentials and occipital hemodynamic response in migraine patients. J Headache Pain 2022; 23:52. [PMID: 35484504 PMCID: PMC9052688 DOI: 10.1186/s10194-022-01421-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 04/11/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The discovery of the prominent action of Calcitonin Gene Related Peptide -CGRP- on trigeminal afferents and meningeal vessels, opened a new era in migraine treatment. However, how the block of nociceptive afferents could act on central mechanisms of migraine is still not clear. In this pilot study we aimed to test the effect of 3 months Galcanezumab (CGA) therapy on occipital visual reactivity in migraine patients, using the Steady State Visual Evoked Potentials-SSVEPs and Functional Near Infrared Spectroscopy -fNIRS. METHOD Thirteen migraine patients underwent clinical and neurophysiological examination in basal condition (T0), 1 h after GCA injection (T1) and after 3 months of GCA treatment (T2). Ten healthy volunteers were also evaluated. RESULTS At T2, there was a reduction of headache frequency and disability. At T2, the EEG power significantly diminished as compared to T0 and T1 at occipital sites, and the topographical analysis confirmed a restoration of SSVEPs within normal values. The Oxyhemoglobin levels in occipital cortex, which were basically increased during visual stimulation in migraine patients, reverted to normal values at T2. CONCLUSIONS The present pilot study indicates that Galcanezumab could act on cortical targets located beyond the pain network, restoring the abnormal occipital reactivity. This effect could indicate the possible disease modifying properties of CGRP related monoclonal antibodies.
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Affiliation(s)
- Marina de Tommaso
- Applied Neurophysiology and Pain Unit, Bari Aldo Moro UniversityPoliclinico General Hospital, Piazza Giulio Cesare 11, 70124, Bari, Italy.
| | - Marianna La Rocca
- Dipartimento Interateneo di Fisica 'M. Merlin', Università degli Studi di Bari 'A. Moro', Bari, Italy.,Laboratory of Neuro Imaging, Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Silvia Giovanna Quitadamo
- Applied Neurophysiology and Pain Unit, Bari Aldo Moro UniversityPoliclinico General Hospital, Piazza Giulio Cesare 11, 70124, Bari, Italy
| | - Katia Ricci
- Applied Neurophysiology and Pain Unit, Bari Aldo Moro UniversityPoliclinico General Hospital, Piazza Giulio Cesare 11, 70124, Bari, Italy
| | - Giusy Tancredi
- Applied Neurophysiology and Pain Unit, Bari Aldo Moro UniversityPoliclinico General Hospital, Piazza Giulio Cesare 11, 70124, Bari, Italy
| | - Livio Clemente
- Applied Neurophysiology and Pain Unit, Bari Aldo Moro UniversityPoliclinico General Hospital, Piazza Giulio Cesare 11, 70124, Bari, Italy
| | - Eleonora Gentile
- Applied Neurophysiology and Pain Unit, Bari Aldo Moro UniversityPoliclinico General Hospital, Piazza Giulio Cesare 11, 70124, Bari, Italy
| | - Elena Ammendola
- Applied Neurophysiology and Pain Unit, Bari Aldo Moro UniversityPoliclinico General Hospital, Piazza Giulio Cesare 11, 70124, Bari, Italy
| | - Marianna Delussi
- Applied Neurophysiology and Pain Unit, Bari Aldo Moro UniversityPoliclinico General Hospital, Piazza Giulio Cesare 11, 70124, Bari, Italy
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Dance CJ, Ward J, Simner J. What is the Link Between Mental Imagery and Sensory Sensitivity? Insights from Aphantasia. Perception 2021; 50:757-782. [PMID: 34463590 PMCID: PMC8438787 DOI: 10.1177/03010066211042186] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 08/05/2021] [Indexed: 12/16/2022]
Abstract
People with aphantasia have impoverished visual imagery so struggle to form mental pictures in the mind's eye. By testing people with and without aphantasia, we investigate the relationship between sensory imagery and sensory sensitivity (i.e., hyper- or hypo-reactivity to incoming signals through the sense organs). In Experiment 1 we first show that people with aphantasia report impaired imagery across multiple domains (e.g., olfactory, gustatory etc.) rather than simply vision. Importantly, we also show that imagery is related to sensory sensitivity: aphantasics reported not only lower imagery, but also lower sensory sensitivity. In Experiment 2, we showed a similar relationship between imagery and sensitivity in the general population. Finally, in Experiment 3 we found behavioural corroboration in a Pattern Glare Task, in which aphantasics experienced less visual discomfort and fewer visual distortions typically associated with sensory sensitivity. Our results suggest for the very first time that sensory imagery and sensory sensitivity are related, and that aphantasics are characterised by both lower imagery, and lower sensitivity. Our results also suggest that aphantasia (absence of visual imagery) may be more accurately defined as a subtype of a broader imagery deficit we name dysikonesia, in which weak or absent imagery occurs across multiple senses.
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Affiliation(s)
- C. J. Dance
- School of Psychology, University of Sussex, Brighton, UK
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6
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Tempesta AJ, Miller CE, Litvak V, Bowman H, Schofield AJ. The missing N1 or jittered P2: Electrophysiological correlates of pattern glare in the time and frequency domain. Eur J Neurosci 2021; 54:6168-6186. [PMID: 34374142 PMCID: PMC9290835 DOI: 10.1111/ejn.15419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 07/16/2021] [Accepted: 07/29/2021] [Indexed: 12/04/2022]
Abstract
Excessive sensitivity to certain visual stimuli (cortical hyperexcitability) is associated with a number of neurological disorders including migraine, epilepsy, multiple sclerosis, autism and possibly dyslexia. Others show disruptive sensitivity to visual stimuli with no other obvious pathology or symptom profile (visual stress) which can extend to discomfort and nausea. We used event‐related potentials (ERPs) to explore the neural correlates of visual stress and headache proneness. We analysed ERPs in response to thick (0.37 cycles per degree [c/deg]), medium (3 c/deg) and thin (12 c/deg) gratings, using mass univariate analysis, considering three factors in the general population: headache proneness, visual stress and discomfort. We found relationships between ERP features and the headache and discomfort factors. Stimulus main effects were driven by the medium stimulus regardless of participant characteristics. Participants with high discomfort ratings had larger P1 components for the initial presentation of medium stimuli, suggesting initial cortical hyperexcitability that is later suppressed. The participants with high headache ratings showed atypical N1‐P2 components for medium stripes relative to the other stimuli. This effect was present only after repeated stimulus presentation. These effects were also explored in the frequency domain, suggesting variations in intertrial theta band phase coherence. Our results suggest that discomfort and headache in response to striped stimuli are related to different neural processes; however, more exploration is needed to determine whether the results translate to a clinical migraine population.
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Affiliation(s)
- Austyn J Tempesta
- School of Psychology, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - Claire E Miller
- School of Psychology, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
| | - Vladimir Litvak
- Wellcome Centre for Human Neuroimaging, University College London, London, UK
| | - Howard Bowman
- School of Psychology, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK.,School of Computing, University of Kent, Canterbury, UK
| | - Andrew J Schofield
- School of Psychology, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK.,School of Psychology, College of Health and Life Sciences, Aston University, Birmingham, UK
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7
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Lindquist LC, McIntire GR, Haigh SM. The effects of visual discomfort and chromaticity separation on neural processing during a visual task. Vision Res 2021; 182:27-35. [PMID: 33588291 PMCID: PMC7987861 DOI: 10.1016/j.visres.2021.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 12/13/2020] [Accepted: 01/14/2021] [Indexed: 01/23/2023]
Abstract
Visual stimuli that are uncomfortable to look at evoke a large neural response suggesting altered processing. While there is some evidence linking uncomfortable achromatic stimuli to impaired visual processing, the effect of uncomfortable chromatic patterns on visual cognition has yet to be explored. Large differences in chromaticity separation (e.g. red and blue) elicit visual discomfort, larger metabolic responses, larger visual evoked potentials, and greater alpha suppression compared to small chromaticity separations (e.g. pink and purple). We investigated the impact of stimuli that varied in their chromaticity separation (calculated in perceptual color space) on a visual task and their effect on neural responses across the cortex. Thirty participants completed a continuous pairs task (letters changed at 3 Hz) while grating patterns that differed in their chromaticity separation alternated with a grey screen at 5 Hz. The different temporal frequencies allowed for steady-state visual evoked potentials (SSVEPs) to the two stimulus-types to be measured simultaneously using electroencephalography (EEG). A subset of participants rated the gratings on a 9-point scale of discomfort. We observed greater ratings of discomfort and increased power at 5 Hz with the larger chromaticity separations. The increase in 5 Hz power with greater chromaticity separation was evident across the cortex. However, there was no significant effect of chromaticity separation on power at 3 Hz, or on reaction times, and no consistent effect on behavioral accuracy. Despite eliciting heightened neural responses across the cortex, short term exposure to uncomfortable chromatic stimuli does not adversely impact visual task performance.
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Affiliation(s)
- Lisa C Lindquist
- Center for Integrative Neuroscience, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV 89557, United States
| | - Gregory R McIntire
- Center for Integrative Neuroscience, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV 89557, United States
| | - Sarah M Haigh
- Center for Integrative Neuroscience, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV 89557, United States.
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8
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Chamanzar A, Haigh SM, Grover P, Behrmann M. Abnormalities in cortical pattern of coherence in migraine detected using ultra high-density EEG. Brain Commun 2021; 3:fcab061. [PMID: 34258580 PMCID: PMC8269966 DOI: 10.1093/braincomms/fcab061] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 01/28/2021] [Indexed: 11/13/2022] Open
Abstract
Individuals with migraine generally experience photophobia and/or phonophobia during and between migraine attacks. Many different mechanisms have been postulated to explain these migraine phenomena including abnormal patterns of connectivity across the cortex. The results, however, remain contradictory and there is no clear consensus on the nature of the cortical abnormalities in migraine. Here, we uncover alterations in cortical patterns of coherence (connectivity) in interictal migraineurs during the presentation of visual and auditory stimuli and during rest. We used a high-density EEG system, with 128 customized electrode locations, to compare inter- and intra-hemispheric coherence in the interictal period from 17 individuals with migraine (12 female) and 18 age- and gender-matched healthy control subjects. During presentations of visual (vertical grating pattern) and auditory (modulated tone) stimulation which varied in temporal frequency (4 and 6 Hz), and during rest, participants performed a colour detection task at fixation. Analyses included characterizing the inter- and intra-hemisphere coherence between the scalp EEG channels over 2-s time intervals and over different frequency bands at different spatial distances and spatial clusters. Pearson's correlation coefficients were estimated at zero-lag. Repeated measures analyses-of-variance revealed that, relative to controls, migraineurs exhibited significantly (i) faster colour detection performance, (ii) lower spatial coherence of alpha-band activity, for both inter- and intra-hemisphere connections, and (iii) the reduced coherence occurred predominantly in frontal clusters during both sensory conditions, regardless of the stimulation frequency, as well as during the resting-state. The abnormal patterns of EEG coherence in interictal migraineurs during visual and auditory stimuli, as well as at rest (eyes open), may be associated with the cortical hyper-responsivity that is characteristic of abnormal sensory processing in migraineurs.
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Affiliation(s)
- Alireza Chamanzar
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Sarah M Haigh
- Department of Psychology, University of Nevada, Reno, NV 89557, USA
- Institute for Neuroscience, University of Nevada, Reno, NV 89557, USA
- Department of Psychology, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Pulkit Grover
- Department of Electrical and Computer Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Marlene Behrmann
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA
- Department of Psychology, Carnegie Mellon University, Pittsburgh, PA, USA
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9
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The possible use of precision tinted lenses to improve social cognition in children with autism spectrum disorders. Vision Res 2020; 170:53-59. [PMID: 32259647 DOI: 10.1016/j.visres.2020.03.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 03/11/2020] [Accepted: 03/12/2020] [Indexed: 11/20/2022]
Abstract
A masked randomised control design compared the effectiveness of precision ophthalmic tints in improving the recognition of emotion in Autism Spectrum Disorders (ASD). Fourteen children aged 10-14 with ASD and 14 control children matched on verbal and non-verbal IQ, wore spectacles with coloured lenses to complete two tasks that involved the observation of coloured video sequences in which social interactions were depicted. On one occasion (randomly first or second) the coloured lenses provided light of a colour that the child had one month previously selected as optimal for the clarity of text. On the other occasion the lenses differed in CIE UCS chromaticity by 0.077. Performance in the ASD group was superior in both social interaction tasks with the lenses that provided the optimal colour of light.
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10
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Yamakawa M, Tachibana A, Tatsumoto M, Okajima K, Ueda S, Hirata K. Hemodynamic responses related to intrinsically photosensitive retinal ganglion cells in migraine. Neurosci Res 2019; 160:57-64. [PMID: 31790724 DOI: 10.1016/j.neures.2019.11.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/18/2019] [Accepted: 11/27/2019] [Indexed: 11/16/2022]
Abstract
To clarify whether photoreception of intrinsically photosensitive retinal ganglion cells (ipRGCs) is related to migraine, we investigated the relationship between hemodynamic responses related to neural activity and visual stimulation of ipRGCs. It has been established that photoreception in ipRGCs is associated with photophobia in migraine. However, the relationship between visual stimulation of ipRGCs and hemodynamic responses in the visual cortex has not been clarified. Hemodynamic responses in the visual cortex were measured using functional near-infrared spectroscopy (fNIRS) as signals reflecting changes in oxygenated and deoxygenated hemoglobin concentrations. Different types of visual stimulation generated by a metamerism method were applied to the peripheral field of the eye of patients with migraine (N = 20) and healthy participants (N = 21). The stimulation intensity on the retina was controlled using an artificial pupil. In the primary visual cortex of patients with migraine, statistically significant changes in fNIRS signals dependent on visual stimulation intensity applied to ipRGCs were observed (p < 0.01), while no such changes were observed in healthy participants. These results reveal that visual stimulation of ipRGCs projecting to the primary visual cortex is involved in hemodynamic responses in patients with migraine, suggesting that ipRGCs, in addition to photometric values related to cones, are associated with migraine.
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Affiliation(s)
- Masahiko Yamakawa
- Graduate School of Environment and Information Sciences, Yokohama National University, Kanagawa, Japan.
| | - Atsumichi Tachibana
- Department of Histology & Neurobiology, Dokkyo Medical University, Tochigi, Japan
| | - Muneto Tatsumoto
- Department of Neurology, Dokkyo Medical University, Tochigi, Japan
| | - Katsunori Okajima
- Faculty of Environment and Information Sciences, Yokohama National University, Kanagawa, Japan
| | - Shuichi Ueda
- Department of Histology & Neurobiology, Dokkyo Medical University, Tochigi, Japan
| | - Koichi Hirata
- Department of Neurology, Dokkyo Medical University, Tochigi, Japan
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11
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Haigh SM, Chamanzar A, Grover P, Behrmann M. Cortical Hyper‐Excitability in Migraine in Response to Chromatic Patterns. Headache 2019; 59:1773-1787. [DOI: 10.1111/head.13620] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Sarah M. Haigh
- Department of Psychology, Institute for Neuroscience University of Nevada Reno NV USA
- Department of Psychology, Center for the Neural Basis of Cognition Carnegie Mellon University Pittsburgh PA USA
| | - Alireza Chamanzar
- Department of Electrical and Computer Engineering Carnegie Mellon University Pittsburgh PA USA
| | - Pulkit Grover
- Department of Electrical and Computer Engineering Carnegie Mellon University Pittsburgh PA USA
| | - Marlene Behrmann
- Department of Psychology, Center for the Neural Basis of Cognition Carnegie Mellon University Pittsburgh PA USA
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12
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Fong CY, Takahashi C, Braithwaite JJ. Evidence for distinct clusters of diverse anomalous experiences and their selective association with signs of elevated cortical hyperexcitability. Conscious Cogn 2019; 71:1-17. [DOI: 10.1016/j.concog.2019.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 03/08/2019] [Accepted: 03/12/2019] [Indexed: 10/27/2022]
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13
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Schytz HW, Amin FM, Selb J, Boas DA. Non-invasive methods for measuring vascular changes in neurovascular headaches. J Cereb Blood Flow Metab 2019; 39:633-649. [PMID: 28782410 PMCID: PMC6446419 DOI: 10.1177/0271678x17724138] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Vascular changes during spontaneous headache attacks have been studied over the last 30 years. The interest in cerebral vessels in headache research was initially due to the hypothesis of cerebral vessels as the pain source. Here, we review the knowledge gained by measuring the cerebral vasculature during spontaneous primary headache attacks with the use of single photon emission tomography (SPECT), positron emission tomography (PET), magnetic resonance imaging (MRA) and transcranial Doppler (TCD). Furthermore, the use of near-infrared spectroscopy in headache research is reviewed. Existing TCD studies of migraine and other headache disorders do not provide solid evidence for cerebral blood flow velocity changes during spontaneous attacks of migraine headache. SPECT studies have clearly shown cortical vascular changes following migraine aura and the differences between migraine with aura compared to migraine without aura. PET studies have shown focal activation in brain structures related to headache, but whether the changes are specific to different primary headaches have yet to be demonstrated. MR angiography has shown precise changes in large cerebral vessels during spontaneous migraine without aura attacks. Future development in more precise imaging methods may further elucidate the pathophysiological mechanisms in primary headaches.
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Affiliation(s)
- Henrik W Schytz
- 1 Danish Headache Center and Department of Neurology, Rigshospitalet Glostrup, University of Copenhagen, Copenhagen, Denmark
| | - Faisal M Amin
- 1 Danish Headache Center and Department of Neurology, Rigshospitalet Glostrup, University of Copenhagen, Copenhagen, Denmark
| | - Juliette Selb
- 2 Department of Radiology, MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA
| | - David A Boas
- 2 Department of Radiology, MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA, USA
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Ward J. Individual differences in sensory sensitivity: A synthesizing framework and evidence from normal variation and developmental conditions. Cogn Neurosci 2018; 10:139-157. [PMID: 30526338 DOI: 10.1080/17588928.2018.1557131] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
For some people, simple sensory stimuli (e.g., noises, patterns) may reliably evoke intense and aversive reactions. This is common in certain clinical groups (e.g., autism) and varies greatly in the neurotypical population. This paper critically evaluates the concept of individual differences in sensory sensitivity, explores its possible underlying neurobiological basis, and presents a roadmap for future research in this area. A distinction is made between subjective sensory sensitivity (self-reported symptoms); neural sensory sensitivity (the degree of neural activity induced by sensory stimuli); and behavioral sensory sensitivity (detection and discrimination of sensory stimuli). Whereas increased subjective and neural sensory sensitivity are assumed to increase together, the status of behavioral sensory sensitivity depends on the extent to which the increased neural activity is linked to signal or noise. A signal detection framework is presented that offers a unifying framework for exploring sensory sensitivity across different conditions. The framework is discussed, in more concrete terms, by linking it to four existing theoretical accounts of atypical sensory sensitivity (not necessarily mutually exclusive): increased excitation-to-inhibition ratio; predictive coding; increased neural noise; and atypical brain connectivity.
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Affiliation(s)
- Jamie Ward
- a School of Psychology , University of Sussex , Brighton , UK
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15
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Evans BJW, Allen PM, Wilkins AJ. A Delphi study to develop practical diagnostic guidelines for visual stress (pattern-related visual stress). JOURNAL OF OPTOMETRY 2017; 10:161-168. [PMID: 27890547 PMCID: PMC5484780 DOI: 10.1016/j.optom.2016.08.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/26/2016] [Accepted: 08/28/2016] [Indexed: 05/12/2023]
Abstract
PURPOSE Visual stress (VS) is characterised by symptoms of visual perceptual distortions and eyestrain when viewing text, symptoms that are alleviated by individually prescribed coloured filters. A recent review supports the existence of VS and its treatment, but noted that controversy remains, in part due to inconsistencies in the diagnosis of the condition. The present paper reviews the diagnostic criteria for VS in the literature and reports a Delphi analysis of the criteria currently used in clinical practice. METHODS Twenty-six eyecare practitioners were invited to participate in a Delphi study. They were selected because they were frequent prescribers of precision tinted lenses. In the first round they were sent a list of the indicators for which there is literature to suggest a relevance in the diagnosis of VS. The practitioners were invited to rank the indicators and add any additional criteria they use in diagnosis. In the second round a revised list was circulated, including items added from the responses in the first round. RESULTS The respondents included optometrists, orthoptists and opticians. In the first round the response rate was 85%. Ninety-one percent of those who participated in the first round also responded in the second round. Strong indicators in the second round included the symptom of words moving when reading, voluntary use of an overlay for a prolonged period, improved performance of ≥15% with an overlay on the Wilkins Rate of Reading test, and an abnormally high score on the Pattern Glare Test. CONCLUSIONS The strongest diagnostic criteria are combined in a diagnostic tool. This is proposed as a guide for clinical practice and further research.
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Affiliation(s)
- Bruce J W Evans
- Institute of Optometry, London, UK; Division of Optometry & Visual Science, City, University London, UK.
| | - Peter M Allen
- Department of Vision and Hearing Sciences and Vision and Eye Research Unit, Anglia Ruskin University, Cambridge, UK
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16
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Haigh SM. Variable sensory perception in autism. Eur J Neurosci 2017; 47:602-609. [DOI: 10.1111/ejn.13601] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 04/27/2017] [Accepted: 04/28/2017] [Indexed: 12/31/2022]
Affiliation(s)
- Sarah M. Haigh
- Clinical Neurophysiology Research Laboratory; Western Psychiatric Institute and Clinic; Department of Psychiatry; University of Pittsburgh School of Medicine; 3501 Forbes Avenue Suite 420 Pittsburgh PA 15213 USA
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Ward J, Hoadley C, Hughes JEA, Smith P, Allison C, Baron-Cohen S, Simner J. Atypical sensory sensitivity as a shared feature between synaesthesia and autism. Sci Rep 2017; 7:41155. [PMID: 28266503 PMCID: PMC5339734 DOI: 10.1038/srep41155] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 12/15/2016] [Indexed: 12/23/2022] Open
Abstract
Several studies have suggested that there is a link between synaesthesia and autism but the nature of that link remains poorly characterised. The present study considers whether atypical sensory sensitivity may be a common link between the conditions. Sensory hypersensitivity (aversion to certain sounds, touch, etc., or increased ability to make sensory discriminations) and/or hyposensitivity (desire to stimulate the senses , or a reduced response to sensory stimuli are a recently introduced diagnostic feature of autism spectrum conditions (ASC). Synaesthesia is defined by unusual sensory experiences and has also been linked to a typical cortical hyper-excitability. The Glasgow Sensory Questionnaire (GSQ) was administered to synaesthetes and people with ASC. Both groups reported increased sensory sensitivity relative to controls with a large effect size. Both groups also reported a similar pattern of both increased hyper- and hypo-sensitivities across multiple senses. The AQ (Autism-Spectrum Quotient) scores were elevated in the synaesthetes, and one subscale of this measure (attention to detail) placed synaesthetes within the autistic range. A standard laboratory test of visual stress (the Pattern Glare Test), administered online, corroborated the findings of increased sensitivity to aversive visual stimuli in synaesthetes. We conclude that atypical sensory sensitivity is an important shared feature between autism and synaesthesia.
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Affiliation(s)
- Jamie Ward
- School of Psychology and Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
| | - Claire Hoadley
- School of Psychology and Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
| | - James E. A. Hughes
- School of Psychology and Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
| | - Paula Smith
- Autism Research Centre, Department of Psychiatry, University of Cambridge, UK
| | - Carrie Allison
- Autism Research Centre, Department of Psychiatry, University of Cambridge, UK
| | - Simon Baron-Cohen
- Autism Research Centre, Department of Psychiatry, University of Cambridge, UK
| | - Julia Simner
- School of Psychology and Sackler Centre for Consciousness Science, University of Sussex, Brighton, UK
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O'Hare L. Steady-state VEP responses to uncomfortable stimuli. Eur J Neurosci 2016; 45:410-422. [DOI: 10.1111/ejn.13479] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 11/07/2016] [Accepted: 11/10/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Louise O'Hare
- University of Lincoln; Brayford Pool Lincoln LN6 7TS UK
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Evans BJW, Allen PM. A systematic review of controlled trials on visual stress using Intuitive Overlays or the Intuitive Colorimeter. JOURNAL OF OPTOMETRY 2016; 9:205-18. [PMID: 27425262 PMCID: PMC5030324 DOI: 10.1016/j.optom.2016.04.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 03/24/2016] [Accepted: 04/03/2016] [Indexed: 05/25/2023]
Abstract
Claims that coloured filters aid reading date back 200 years and remain controversial. Some claims, for example, that more than 10% of the general population and 50% of people with dyslexia would benefit from coloured filters lack sound evidence and face validity. Publications with such claims typically cite research using methods that have not been described in the scientific literature and lack a sound aetiological framework. Notwithstanding these criticisms, some researchers have used more rigorous selection criteria and methods of prescribing coloured filters that were developed at a UK Medical Research Council unit and which have been fully described in the scientific literature. We review this research and disconfirm many of the more extreme claims surrounding this topic. This literature indicates that a minority subset of dyslexics (circa 20%) may have a condition described as visual stress which most likely results from a hyperexcitability of the visual cortex. Visual stress is characterised by symptoms of visual perceptual distortions, headaches, and eyestrain when viewing repetitive patterns, including lines of text. This review indicates that visual stress is distinct from, although sometimes co-occurs with, dyslexia. Individually prescribed coloured filters have been shown to improve reading performance in people with visual stress, but are unlikely to influence the phonological and memory deficits associated with dyslexia and therefore are not a treatment for dyslexia. This review concludes that larger and rigorous randomised controlled trials of interventions for visual stress are required. Improvements in the diagnosis of the condition are also a priority.
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Affiliation(s)
| | - Peter M Allen
- Department of Vision and Hearing Sciences and Vision and Eye Research Unit, Anglia Ruskin University, Cambridge, UK
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Conway ML, Evans BJW, Evans JC, Suttle CM. Does Gender Influence Colour Choice in the Treatment of Visual Stress? PLoS One 2016; 11:e0163326. [PMID: 27648842 PMCID: PMC5029909 DOI: 10.1371/journal.pone.0163326] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 09/06/2016] [Indexed: 11/19/2022] Open
Abstract
Purpose Visual Stress (VS) is a condition in which words appear blurred, in motion, or otherwise distorted when reading. Some people diagnosed with VS find that viewing black text on white paper through coloured overlays or precision tinted lenses (PTLs) reduces symptoms attributed to VS. The aim of the present study is to determine whether the choice of colour of overlays or PTLs is influenced by a patient’s gender. Methods Records of all patients attending a VS assessment in two optometry practices between 2009 and 2014 were reviewed retrospectively. Patients who reported a significant and consistent reduction in symptoms with either overlay and or PTL were included in the analysis. Overlays and PTLs were categorized as stereotypical male, female or neutral colours based on gender preferences as described in the literature. Chi-square analysis was carried out to determine whether gender (across all ages or within age groups) was associated with overlay or PTL colour choice. Results 279 patients (133 males and 146 females, mean age 17 years) consistently showed a reduction in symptoms with an overlay and were included. Chi-square analysis revealed no significant association between the colour of overlay chosen and male or female gender (Chi-square 0.788, p = 0.674). 244 patients (120 males and 124 females, mean age 24.5 years) consistently showed a reduction in symptoms with PTLs and were included. Chi-square analysis revealed a significant association between stereotypical male/female/neutral colours of PTLs chosen and male/female gender (Chi-square 6.46, p = 0.040). More males preferred stereotypical male colour PTLs including blue and green while more females preferred stereotypical female colour PTLs including pink and purple. Conclusions For some VS patients, the choice of PTL colour is influenced not only by the alleviation of symptoms but also by other non-visual factors such as gender.
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Affiliation(s)
- Miriam L. Conway
- Division of Optometry and Visual Science, School of Health Sciences, City, University of London, London, United Kingdom
| | - Bruce J. W. Evans
- Division of Optometry and Visual Science, School of Health Sciences, City, University of London, London, United Kingdom
- Neville Chappell Research Clinic, Institute of Optometry, London, United Kingdom
| | - Josephine C. Evans
- Division of Optometry and Visual Science, School of Health Sciences, City, University of London, London, United Kingdom
| | - Catherine M. Suttle
- Division of Optometry and Visual Science, School of Health Sciences, City, University of London, London, United Kingdom
- * E-mail:
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Lee MJ, Chu MK, Choi H, Choi HA, Lee C, Chung CS. Longitudinal changes in cerebral blood flow velocities in different clinical courses of migraine. Cephalalgia 2016; 37:927-937. [PMID: 27381854 DOI: 10.1177/0333102416658715] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective To assess longitudinal changes in cerebral blood flow velocities (ΔCBFVs) according to the clinical course of migraine. Methods We retrospectively included migraine patients with two or more attacks per month at baseline who were followed up within 2 years with transcranial Doppler in a tertiary headache clinic. ΔCBFVs were analyzed in relation to clinical courses, defined as remission (0-1 headache days/month), persistence (2-14/month), or progression (≥15/month) in episodic migraine (EM), and conversion to EM (<15/month) and persistence (≥15/month) in chronic migraine (CM). Results A total of 166 patients (90 EM and 76 CM) were included. In EM, the remission group ( n = 30) showed a decrease in CBFV in the middle cerebral artery (MCA) and the basilar artery (BA). The progression group ( n = 10) showed increasing CBFVs in the bilateral MCAs. Patients with the persistence course ( n = 50) showed generally unchanged CBFVs. In CM, ΔCBFVs decreased in the BA and increased in the posterior cerebral artery (PCA) after conversion to EM ( n = 61), whereas they remained unchanged in the persistence group ( n = 15). In all patients, % change in headache days was positively correlated with the %ΔCBFVs of the bilateral MCAs and the BA. Conclusions CBFV changes are associated with the different clinical courses of migraine. The association is more prominent in EM than CM.
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Affiliation(s)
- Mi Ji Lee
- 1 Department of Neurology, Neuroscience Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Min Kyung Chu
- 2 Department of Neurology, Kangnam Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
| | - Hanna Choi
- 3 Department of Neurology, Eulji University Hospital, Eulji University School of Medicine, Daejeon, Korea
| | - Hyun Ah Choi
- 1 Department of Neurology, Neuroscience Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Chungbin Lee
- 1 Department of Neurology, Neuroscience Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Chin-Sang Chung
- 1 Department of Neurology, Neuroscience Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Begus K, Lloyd-Fox S, Halliday D, Papademetriou M, Darboe MK, Prentice AM, Moore SE, Elwell CE. Using fNIRS to Study Working Memory of Infants in Rural Africa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 876:273-279. [PMID: 26782222 DOI: 10.1007/978-1-4939-3023-4_34] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A pilot study was conducted to assess the feasibility of using fNIRS as an alternative to behavioral assessments of cognitive development with infants in rural Africa. We report preliminary results of a study looking at working memory in 12-16-month-olds and discuss the benefits and shortcomings for the potential future use of fNIRS to investigate the effects of nutritional insults and interventions in global health studies.
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Affiliation(s)
- K Begus
- Centre for Brain and Cognitive Development, Birkbeck College, University of London, London, UK.
| | - S Lloyd-Fox
- Centre for Brain and Cognitive Development, Birkbeck College, University of London, London, UK.,Department of Medical Physics and Bioengineering, University College London, London, UK
| | - D Halliday
- Department of Medical Physics and Bioengineering, University College London, London, UK
| | - M Papademetriou
- Department of Medical Physics and Bioengineering, University College London, London, UK
| | - M K Darboe
- MRC International Nutrition Group, Keneba Field Station, Keneba, The Gambia
| | - A M Prentice
- MRC International Nutrition Group, Keneba Field Station, Keneba, The Gambia.,MRC International Nutrition Group, London School of Hygiene and Tropical Medicine, London, UK
| | - S E Moore
- MRC International Nutrition Group, Keneba Field Station, Keneba, The Gambia.,MRC Human Nutrition Research, Cambridge, UK
| | - C E Elwell
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
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Braithwaite JJ, Marchant R, Takahashi C, Dewe H, Watson DG. The Cortical Hyperexcitability Index (CHi): a new measure for quantifying correlates of visually driven cortical hyperexcitability. Cogn Neuropsychiatry 2016; 20:330-48. [PMID: 26016993 DOI: 10.1080/13546805.2015.1040152] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Aberrations of visual experience, including visual hallucinations and visual distortions, are known to be associated with increased cortical hyperexcitability. As a consequence, the presence, intensity and frequency of certain experiences may well be indicative of an underlying increase in cortical hyperexcitability. METHODS The current study presents a new proxy measure of cortical hyperexcitability, the Cortical Hyperexcitability Index (CHi). Two hundred and fifty healthy participants completed the CHi with the results subjected to exploratory factor analysis (EFA). RESULTS The EFA revealed a three-factor model as the most parsimonious solution. The three factors were defined as: (1) heightened visual sensitivity and discomfort; (2) negative aura-type visual aberrations; and (3) positive aura-type visual aberrations. The identification of three factors suggests that multiple mechanisms underlie the notion of cortical hyperexcitability, providing researchers with new and greater precision in delineating these underlying features. CONCLUSIONS The factorial structure of the CHi and the increased precision could aid the interpretation of findings from neuroscientific (i.e., brain imaging/stimulation) examinations of cortical processes underlying aberrant perceptions across a host of clinical, neurological and pathological conditions. As a consequence, the CHi is a useful and comprehensive proxy measure of cortical hyperexcitability with considerable scientific and clinical utility.
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Affiliation(s)
- Jason J Braithwaite
- a Behavioural Brain Sciences Centre, School of Psychology , University of Birmingham , Edgbaston, Birmingham B15 2TT, UK
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24
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Haigh S, Cooper N, Wilkins A. Cortical excitability and the shape of the haemodynamic response. Neuroimage 2015; 111:379-84. [DOI: 10.1016/j.neuroimage.2015.02.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Revised: 01/14/2015] [Accepted: 02/16/2015] [Indexed: 11/29/2022] Open
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Gilchrist JM, Allen PM. Lexical decisions in adults with low and high susceptibility to pattern-related visual stress: a preliminary investigation. Front Psychol 2015; 6:449. [PMID: 25926810 PMCID: PMC4396132 DOI: 10.3389/fpsyg.2015.00449] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 03/30/2015] [Indexed: 11/25/2022] Open
Abstract
Pattern-related visual stress (PRVS) is a form of sensory hypersensitivity that some people experience when viewing high contrast repeating patterns, notably alternating dark and light stripes. Those susceptible to PRVS typically have a strong aversion to such stimuli, and this is often accompanied by experiences of visual discomfort and disturbance. The patterns most likely to elicit symptoms of PRVS have a square-wave grating configuration of spatial frequency ~3 cycles/degree. Such stimuli are characteristic of printed text in which lines of words and the spaces between them present a high contrast grating-like stimulus. Consequently, much printed reading material has the potential to elicit PRVS that may impair reading performance, and this problem appears to be common in individuals with reading difficulties including dyslexia. However, the manner in which PRVS affects reading ability is unknown. One possibility is that the early sensory visual stress may interfere with the later cognitive word recognition stage of the reading process, resulting in reading performance that is slower and/or less accurate. To explore the association of PRVS with word recognition ability, lexical decision performance (speed and accuracy) to words and pronounceable non-words was measured in two groups of adults, having low and high susceptibility to PRVS. Results showed that lexical decisions were generally faster but less accurate in high-PRVS, and also that high-PRVS participants made decisions significantly faster for words than for non-words, revealing a strong lexicality effect that was not present in low-PRVS. These findings are novel and, as yet, unconfirmed by other studies.
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Affiliation(s)
- James M Gilchrist
- School of Optometry and Vision Science, University of Bradford Bradford, UK
| | - Peter M Allen
- Vision and Eye Research Unit, Department of Vision and Hearing Sciences, Anglia Ruskin University Cambridge, UK
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Stimulating the aberrant brain: Evidence for increased cortical hyperexcitability from a transcranial direct current stimulation (tDCS) study of individuals predisposed to anomalous perceptions. Cortex 2015; 69:1-13. [PMID: 25967083 DOI: 10.1016/j.cortex.2015.03.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 02/11/2015] [Accepted: 03/30/2015] [Indexed: 11/21/2022]
Abstract
Findings from neurological and clinical groups have shown that increased predisposition to anomalous experience/aura reflects an elevation in aberrant neural processes in the brain. However, studies of anomalous experiences in non-clinical/non-neurological groups are less clear on this matter and are more typically confined to subjective questionnaire measures alone. The current investigation, the first to our knowledge, carried out a transcranial Direct Current Stimulation (tDCS) study of cortical hyperexcitability, and its association with anomalous experience in non-clinical/non-neurological groups. Sixty participants completed; (i) both excitatory (anodal) and inhibitory (cathodal) brain stimulation conditions of the visual cortex; (ii) a computerised pattern-glare task, where observers reported phantom visual distortions from viewing highly irritable visual patterns (a metric of cortical hyperexcitability), and; (iii) questionnaire measures of predisposition to anomalous perceptions. There were no reliable signs of cortical hyperexcitability (via pattern-glare tasks) when collapsed across the whole sample. However, a significant positive correlation between predisposition to anomalous experience and elevated signs of cortical hyperexcitability was observed. Crucially, there was a significant negative correlation between tDCS stimulatory conditions. A visual cortex that reacted more strongly to excitatory stimulation, responded less well to inhibitory suppression, and this pattern was related to predisposition to anomalous perceptions. Both findings are consistent with the presence of a hyperexcitable cortex. Collectively the present findings provide objective evidence that the brains of individuals predisposed to anomalous experiences/hallucinations can be hyperexcitable - even in the non-clinical/non-neurological population. These data are consistent with continuum models of anomalous experience and have important implications for contemporary theories of aberrations in self-consciousness.
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27
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Cortical hyperexcitability and sensitivity to discomfort glare. Neuropsychologia 2015; 69:194-200. [DOI: 10.1016/j.neuropsychologia.2015.02.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 01/16/2015] [Accepted: 02/04/2015] [Indexed: 11/16/2022]
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Braithwaite JJ, Broglia E, Brincat O, Stapley L, Wilkins AJ, Takahashi C. Signs of increased cortical hyperexcitability selectively associated with spontaneous anomalous bodily experiences in a nonclinical population. Cogn Neuropsychiatry 2014; 18:549-73. [PMID: 23441857 DOI: 10.1080/13546805.2013.768176] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
INTRODUCTION The current study examined the presence of cortical hyperexcitability, in nonclinical hallucinators, reporting different forms of anomalous bodily experiences (ABEs). Groups reporting visual out-of-body experiences and nonvisual sensed-presence experiences were examined. It was hypothesised that only those hallucinators whose experiences contained visual elements would show increased signs of visual cortical hyperexcitability. METHODS One hundred and eighty-two participants completed the "Pattern-glare task" (involving the viewing of striped gratings with spatial frequencies irritable to visual cortex)-a task known to reflect degrees of cortical hyperexcitability associated with hallucinatory/aura experiences in neurological samples. Participants also completed questionnaire measures of anomalous "temporal-lobe experience" and predisposition to anomalous visual experiences. RESULTS Those reporting increased levels of anomalous bodily experiences provided significantly elevated scores on measures of temporal-lobe experience. Only the visual OBE group reported significantly elevated levels of cortical hyperexcitability as assessed by the pattern-glare task. CONCLUSIONS Collectively, the results are consistent with there being an increased degree of background cortical hyperexcitability in the cortices of individuals predisposed to some ABE-type hallucinations, even in the nonclinical population. The present study also establishes the clinical utility of the pattern-glare task for examining signs of aberrant visual connectivity in relation to visual hallucinations.
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Affiliation(s)
- Jason J Braithwaite
- a Behavioural Brain Sciences Centre, School of Psychology , University of Birmingham , Birmingham , UK
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Functional near infrared spectroscopy (fNIRS) to assess cognitive function in infants in rural Africa. Sci Rep 2014; 4:4740. [PMID: 24751935 PMCID: PMC5381189 DOI: 10.1038/srep04740] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 03/17/2014] [Indexed: 01/20/2023] Open
Abstract
Cortical mapping of cognitive function during infancy is poorly understood in low-income countries due to the lack of transportable neuroimaging methods. We have successfully piloted functional near infrared spectroscopy (fNIRS) as a neuroimaging tool in rural Gambia. Four-to-eight month old infants watched videos of Gambian adults perform social movements, while haemodynamic responses were recorded using fNIRS. We found distinct regions of the posterior superior temporal and inferior frontal cortex that evidenced either visual-social activation or vocally selective activation (vocal > non-vocal). The patterns of selective cortical activation in Gambian infants replicated those observed within similar aged infants in the UK. These are the first reported data on the measurement of localized functional brain activity in young infants in Africa and demonstrate the potential that fNIRS offers for field-based neuroimaging research of cognitive function in resource-poor rural communities.
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Tedeschi G, Russo A, Conte F, Salemi F, Tessitore A. The role of BOLD-fMRI in elucidating migraine pathophysiology. Neurol Sci 2014; 34 Suppl 1:S47-50. [PMID: 23695045 DOI: 10.1007/s10072-013-1383-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Migraine is a neurologic disorder characterized by disabling attacks of throbbing headache with specific features and associated symptoms. Despite the recent discoveries in basic neurosciences, migraine pathophysiology is not completely understood. Nevertheless, in the last decades, advances in functional magnetic resonance imaging (fMRI) have significantly provided new insights into migraine mechanisms. Blood oxygen level dependent (BOLD) fMRI technique is the most commonly used method to explore brain function and connectivity due to high temporal and spatial resolution. The purpose of this review is to present a synthesis of recent BOLD-fMRI studies which have allowed us to elucidate the complex process involved in migraine pathophysiology.
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Affiliation(s)
- G Tedeschi
- Headache Center, Department of Neurology, Second University of Naples, Naples, Italy.
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31
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Discomfort and the cortical haemodynamic response to coloured gratings. Vision Res 2013; 89:47-53. [DOI: 10.1016/j.visres.2013.07.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 06/26/2013] [Accepted: 07/03/2013] [Indexed: 11/19/2022]
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Obrig H. NIRS in clinical neurology - a 'promising' tool? Neuroimage 2013; 85 Pt 1:535-46. [PMID: 23558099 DOI: 10.1016/j.neuroimage.2013.03.045] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 03/14/2013] [Accepted: 03/21/2013] [Indexed: 12/13/2022] Open
Abstract
Near-infrared spectroscopy (NIRS) has become a relevant research tool in neuroscience. In special populations such as infants and for special tasks such as walking, NIRS has asserted itself as a low resolution functional imaging technique which profits from its ease of application, portability and the option to co-register other neurophysiological and behavioral data in a 'near natural' environment. For clinical use in neurology this translates into the option to provide a bed-side oximeter for the brain, broadly available at comparatively low costs. However, while some potential for routine brain monitoring during cardiac and vascular surgery and in neonatology has been established, NIRS is largely unknown to clinical neurologists. The article discusses some of the reasons for this lack of use in clinical neurology. Research using NIRS in three major neurologic diseases (cerebrovascular disease, epilepsy and headache) is reviewed. Additionally the potential to exploit the established position of NIRS as a functional imaging tool with regard to clinical questions such as preoperative functional assessment and neurorehabilitation is discussed.
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Affiliation(s)
- Hellmuth Obrig
- Clinic for Cognitive Neurology, University Clinic Leipzig, Leipzig, Germany; Max-Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Dept. Neurology, Charité, University Medicine Berlin, Berlin, Germany.
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Haigh SM, Jaschinski W, Allen PM, Wilkins AJ. Accommodation to Uncomfortable Patterns. Perception 2013; 42:208-22. [DOI: 10.1068/p7397] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Grating patterns can cause discomfort and perceptual distortions. Individuals who experience discomfort and are susceptible to these distortions generally show weaker accommodation than those who are less susceptible. We measured the accommodative response to grating patterns known to differ in the discomfort they evoke because of differences in their colour, motion, or spatial frequency. The parameters known to affect discomfort and distortion had no influence on the mean or variance in the accommodative response, even when accommodative demand was manipulated systematically and the accommodative response varied as expected.
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Affiliation(s)
- Sarah M Haigh
- Visual Perception Unit, Department of Psychology, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK
| | - Wolfgang Jaschinski
- Leibniz-Institute für Arbeitsforschung an der TU Dortmund, Ardeystrasse 67, D-44139 Dortmund, Germany
| | - Peter M Allen
- Vision and Eye Research Unit, Postgraduate Medical Institute, Anglia Ruskin University, Cambridge CB1 1PT, UK
| | - Arnold J Wilkins
- Visual Perception Unit, Department of Psychology, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK
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