1
|
Picciotti PM, Mele DA, Settimi S, Mari G, D'Alatri L, Galli J. Subjective visual vertical/horizontal and video head impulse test in dyslexic children. DYSLEXIA (CHICHESTER, ENGLAND) 2024; 30:e1782. [PMID: 39172020 DOI: 10.1002/dys.1782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 06/27/2024] [Accepted: 07/29/2024] [Indexed: 08/23/2024]
Abstract
Different studies have tried to establish a relationship between dyslexia and the vestibular system function. Subjective Visual Vertical/Horizontal (SVV and SVH) and Video Head Impulse Test (VHIT) are useful for studying the vestibular system and can be easily performed in children. Our aim was to evaluate the vestibular function in dyslexic children by SVV/SVH and VHIT. We enrolled 18 dyslexic children (10M/8F; mean age 10.7 ± 2.3 years; range 7-14 years) and 18 age-matched children with typical development of learning abilities. All children performed VHIT, SVV and SVH. We found normal gain and symmetry of vestibulo-ocular-reflex both in dyslexic and typically developing children. Fifteen out of 18 dyslexic children (83.3%) showed a difference of at least one amongst SVV or SVH. The mean value of SVV was 2.3° and the mean value of SVH was 2.6°. Statistical analysis showed a significant difference between typically developing and dyslexic children for both SVV and SVH. We confirm a relationship between dyslexia and the alteration of SVV and SVH. Our results could be related to the pathogenetic hypothesis of a visual processing impairment related to a dysfunction of the magnocellular pathway or to a general deficit related to a multimodal cortical network.
Collapse
Affiliation(s)
- Pasqualina Maria Picciotti
- Unit of Otorhinolaryngology, A. Gemelli University Hospital Foundation IRCCS, Rome, Italy
- Department of Head, Neck and Sensory Organs, Catholic University of Sacred Heart, Rome, Italy
| | - Dario Antonio Mele
- Unit of Otorhinolaryngology, A. Gemelli University Hospital Foundation IRCCS, Rome, Italy
| | - Stefano Settimi
- Unit of Otorhinolaryngology, A. Gemelli University Hospital Foundation IRCCS, Rome, Italy
- Department of Head, Neck and Sensory Organs, Catholic University of Sacred Heart, Rome, Italy
| | - Giorgia Mari
- Unit of Otorhinolaryngology, A. Gemelli University Hospital Foundation IRCCS, Rome, Italy
| | - Lucia D'Alatri
- Unit of Otorhinolaryngology, A. Gemelli University Hospital Foundation IRCCS, Rome, Italy
- Department of Head, Neck and Sensory Organs, Catholic University of Sacred Heart, Rome, Italy
| | - Jacopo Galli
- Unit of Otorhinolaryngology, A. Gemelli University Hospital Foundation IRCCS, Rome, Italy
- Department of Head, Neck and Sensory Organs, Catholic University of Sacred Heart, Rome, Italy
| |
Collapse
|
2
|
Rowe EG, Zhang Y, Garrido MI. Evidence for adaptive myelination of subcortical shortcuts for visual motion perception in healthy adults. Hum Brain Mapp 2023; 44:5641-5654. [PMID: 37608684 PMCID: PMC10619379 DOI: 10.1002/hbm.26467] [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: 02/15/2023] [Revised: 05/27/2023] [Accepted: 08/08/2023] [Indexed: 08/24/2023] Open
Abstract
Conscious visual motion information follows a cortical pathway from the retina to the lateral geniculate nucleus (LGN) and on to the primary visual cortex (V1) before arriving at the middle temporal visual area (MT/V5). Alternative subcortical pathways that bypass V1 are thought to convey unconscious visual information. One flows from the retina to the pulvinar (PUL) and on to medial temporal visual area (MT); while the other directly connects the LGN to MT. Evidence for these pathways comes from non-human primates and modest-sized studies in humans with brain lesions. Thus, the aim of the current study was to reconstruct these pathways in a large sample of neurotypical individuals and to determine the degree to which these pathways are myelinated, suggesting information flow is rapid. We used the publicly available 7T (N = 98; 'discovery') and 3T (N = 381; 'validation') diffusion magnetic resonance imaging datasets from the Human Connectome Project to reconstruct the PUL-MT (including all subcompartments of the PUL) and LGN-MT pathways. We found more fibre tracts with greater density in the left hemisphere. Although the left PUL-MT path was denser, the bilateral LGN-MT tracts were more heavily myelinated, suggesting faster signal transduction. We suggest that this apparent discrepancy may be due to 'adaptive myelination' caused by more frequent use of the LGN-MT pathway that leads to greater myelination and faster overall signal transmission.
Collapse
Affiliation(s)
- Elise G. Rowe
- Melbourne School of Psychological SciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Yubing Zhang
- Melbourne School of Psychological SciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Marta I. Garrido
- Melbourne School of Psychological SciencesThe University of MelbourneParkvilleVictoriaAustralia
- Graeme Clark Institute for Biomedical EngineeringThe University of MelbourneParkvilleVictoriaAustralia
| |
Collapse
|
3
|
Elsherif M, Mourad M, Hamouda N, Abdou R, Salem T. Diagnostic performance of a modified visual perception test. HEARING, BALANCE AND COMMUNICATION 2022. [DOI: 10.1080/21695717.2022.2155777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Mayada Elsherif
- Otolaryngology Head and Neck Department, Audiovestibular Unit, Alexandria University Hospitals, Alexandria, Egypt
| | - Mona Mourad
- Otolaryngology Head and Neck Department, Audiovestibular Unit, Alexandria University Hospitals, Alexandria, Egypt
| | - Nesrine Hamouda
- Otolaryngology Head and Neck Department, Phoniatrics Unit, Alexandria University Hospitals, Alexandria, Egypt
| | - Rania Abdou
- Otolaryngology Head and Neck Department, Phoniatrics Unit, Alexandria University Hospitals, Alexandria, Egypt
| | - Taima Salem
- Otolaryngology Head and Neck Department, Audiovestibular Unit, Alexandria University Hospitals, Alexandria, Egypt
| |
Collapse
|
4
|
Fernandes TP, Shoshina II, Oliveira MEC, Andreevna VE, Silva GM, Santos NA. Correlates of clinical variables on early-stage visual processing in schizophrenia and bipolar disorder. J Psychiatr Res 2022; 149:323-330. [PMID: 35339912 DOI: 10.1016/j.jpsychires.2022.03.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 02/27/2022] [Accepted: 03/07/2022] [Indexed: 12/15/2022]
Abstract
The use of noninvasive tools can help understand mental states and changes that are caused by medications, symptom severity, and other clinical variables. We investigated low-level visual processing using the contrast sensitivity function (CSF), a reliable, robust, and widely used approach. Our main purpose was (1) to evaluate visual impairments in schizophrenia (SCZ) and bipolar disorder (BPD) patients and (2) to investigate associations between clinical variables and visual function in both diseases. Fifty-six healthy controls (HCs; mean age = 31.04 years), 42 BPD patients (mean age = 32.84 years) who took only lithium, and 39 SCZ patients who took only olanzapine (mean age = 32.80 years) were recruited for this study. CSF differed between groups. Both groups of patients exhibited lower discrimination at low, mid-, and high spatial frequencies compared with HCs. No differences were observed between patients, with the exception of high spatial frequency. These impairments were also related to clinical variables, revealed by a strong effect in the mediation analyses. These findings may aid investigations of other clinical variables and the role of state- and trait-like effects on visual and cognitive processing in these patient populations. This study underscores the need for visual remediation interventions.
Collapse
Affiliation(s)
- Thiago P Fernandes
- Department of Psychology, Federal University of Paraiba, Joao Pessoa, Brazil; Perception, Neuroscience and Behaviour Laboratory, Federal University of Paraiba, Brazil.
| | - Irina I Shoshina
- Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Milena E C Oliveira
- Department of Psychology, Federal University of Paraiba, Joao Pessoa, Brazil; Perception, Neuroscience and Behaviour Laboratory, Federal University of Paraiba, Brazil
| | | | - Gabriella M Silva
- Department of Psychology, Federal University of Paraiba, Joao Pessoa, Brazil; Perception, Neuroscience and Behaviour Laboratory, Federal University of Paraiba, Brazil
| | - Natanael A Santos
- Department of Psychology, Federal University of Paraiba, Joao Pessoa, Brazil; Perception, Neuroscience and Behaviour Laboratory, Federal University of Paraiba, Brazil
| |
Collapse
|
5
|
Ebrahimi L, Pouretemad H, Stein J, Alizadeh E, Khatibi A. Enhanced reading abilities is modulated by faster visual spatial attention. ANNALS OF DYSLEXIA 2022; 72:125-146. [PMID: 34510363 DOI: 10.1007/s11881-021-00245-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 08/26/2021] [Indexed: 06/13/2023]
Abstract
Research has shown improved reading following visual magnocellular training in individuals with dyslexia. Many studies have demonstrated how the magnocellular pathway controls visual spatial attention. Therefore, we have investigated the relationship between magnocellular pathway and visual spatial attention deficits in dyslexia in order to better understand how magnocellular-based interventions may help children to learn to read. Magnocellular function, visual spatial attention, and reading abilities of thirty elementary school students with dyslexia, aged between 8 and 10, were measured. The experimental group received magnocellular-based visual motion training for 12 sessions, while the control group received neutral sessions. All tests were repeated at the end of the training and after 1 month. The magnocellular functioning, visual spatial attention, and reading abilities of the experimental group improved significantly compared to the controls. Additionally, improvement in reaction time of invalid conditions predicted improvements in saccadic eye movements. We conclude that visual magnocellular training improved saccadic eye movement control, visual spatial orientation, and reading ability.
Collapse
Affiliation(s)
- Leila Ebrahimi
- Institute for Cognitive & Brain Sciences, Shahid Beheshti University, 1983969411, EvinTehran, Iran
| | - Hamidreza Pouretemad
- Institute for Cognitive & Brain Sciences, Shahid Beheshti University, 1983969411, EvinTehran, Iran.
- Department of Psychology, Shahid Beheshti University, Tehran, Iran.
| | - John Stein
- Department of Physiology, Anatomy & Genetics, Oxford University, Oxford, UK
| | - Ebrahim Alizadeh
- Department of Psychology, Shahid Beheshti University, Tehran, Iran
| | - Ali Khatibi
- Centre of Precision Rehabilitation for Spinal Pain, University of Birmingham, Birmingham, UK
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK
| |
Collapse
|
6
|
Visuoperceptive Impairments in Severe Alcohol Use Disorder: A Critical Review of Behavioral Studies. Neuropsychol Rev 2021; 31:361-384. [PMID: 33591477 DOI: 10.1007/s11065-020-09469-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 11/29/2020] [Indexed: 01/13/2023]
Abstract
The present literature review is aimed at offering a comprehensive and critical view of behavioral data collected during the past seventy years concerning visuoperception in severe alcohol use disorders (AUD). To pave the way for a renewal of research and clinical approaches in this very little understood field, this paper (1) provides a critical review of previous behavioral studies exploring visuoperceptive processing in severe AUD, (2) identifies the alcohol-related parameters and demographic factors that influence the deficits, and (3) addresses the limitations of this literature and their implications for current clinical strategies. By doing so, this review highlights the presence of visuoperceptive deficits but also shows how the lack of in-depth studies exploring the visual system in this clinical population results in the current absence of integration of these deficits in the dominant models of vision. Given the predominance of vision in everyday life, we stress the need to better delineate the extent, the specificity, and the actual implications of the deficits for severe AUD.
Collapse
|
7
|
Abstract
Objectives: The present study evaluated early visual processing, in terms of the contrast sensitivity function (CSF), in bipolar disorder (BPD) patients.Methods: Data were recorded in 17 healthy participants and 17 outpatients with type 1 BPD, from 20 to 45 years of age. The CSF was measured at spatial frequencies of 0.2, 0.6, 3.1, 8.0, 16.0 and 20.0 cycles per degree (cpd) using Gabor patches and a two-alternative, forced-choice, logarithmic staircase method. The groups were matched for gender, age and level of education.Results: The CSF differed between groups. Patients with BPD had lower discrimination at spatial frequencies of 0.2 cpd (P < 0.001), 0.6 cpd (P < 0.001), 16.0 cpd (P < 0.001) and 20.0 cpd (P < 0.001) compared with healthy subjects. No differences were observed at 3.1 cpd (P > 0.05) and 8.0 cpd (P > 0.05). This visual impairment was related both to longer duration of illness and to greater severity of manic symptoms.Conclusions: The differences in visual processing were pronounced in patients with BPD, which justifies further investigations of the pathophysiological mechanisms that are involved in sensorial alterations.
Collapse
Affiliation(s)
- Thiago P Fernandes
- Department of Psychology, Perception, Neuroscience and Behaviour Laboratory, Joao Pessoa, Brazil
| | - Steven M Silverstein
- Department of Psychiatry Division of Schizophrenia Research, Rutgers University Behavioural Health Care, Piscataway, NJ, USA
| | - Natalia L Almeida
- Department of Psychology, Perception, Neuroscience and Behaviour Laboratory, Joao Pessoa, Brazil
| | - Natanael A Santos
- Department of Psychology, Perception, Neuroscience and Behaviour Laboratory, Joao Pessoa, Brazil
| |
Collapse
|
8
|
Magnocellular Based Visual Motion Training Improves Reading in Persian. Sci Rep 2019; 9:1142. [PMID: 30718620 PMCID: PMC6361887 DOI: 10.1038/s41598-018-37753-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 12/12/2018] [Indexed: 11/26/2022] Open
Abstract
The visual magnocellular system is thought to play a crucial role in learning to read. Here therefore, we examined whether magnocellular based training could improve reading in children with visual reading problems. The participants were 24 male primary school students aged between 9–11 (Mean = 9.76, SD = 0.59) with specific reading difficulty. Experimental and control groups were matched for age, sex, educational level, IQ, reading abilities (measured by APRA), magnocellular performance as assessed by a random dot kinematogram (RDK) paradigm and recordings of their saccadic eye movements. The experimental group received twelve magnocellular based visual motion training sessions, twice a week over 6 weeks. During the same period, the control group played a video game with the help of a practitioner. All measures were made just prior to the training and were repeated at the 6th, 12th training session and one month later. The experimental group showed significant improvements in magnocellular function, visual errors and reading accuracy during the course of intervention. Follow-up assessment confirmed that these effects persisted one month later. Impaired magnocellular functioning appeared to be an important cause of poor reading in Persian. Hence magnocellular based training could help many children with specific reading difficulties. Also testing magnocellular function could be used as screening tool for detecting dyslexia before a child begins to fail at school.
Collapse
|
9
|
Fernandes TMP, Silverstein SM, Almeida NLD, Santos NAD. Psychophysical evaluation of contrast sensitivity using Gabor patches in tobacco addiction. J Clin Neurosci 2018; 57:68-73. [DOI: 10.1016/j.jocn.2018.08.034] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 08/13/2018] [Indexed: 10/28/2022]
|
10
|
Fernandes TMP, de Andrade MJO, Santana JB, Nogueira RMTBL, dos Santos NA. Tobacco Use Decreases Visual Sensitivity in Schizophrenia. Front Psychol 2018; 9:288. [PMID: 29559947 PMCID: PMC5845747 DOI: 10.3389/fpsyg.2018.00288] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 02/20/2018] [Indexed: 12/27/2022] Open
Abstract
Smoking prevalence in patients who are diagnosed with schizophrenia (SCZ) is higher than in the general population. Chronic tobacco use in SCZ patients may reduce the side effects of antipsychotic drugs, thus serving as a self-medication for such side effects. Understanding the ways in which chronic tobacco use influences visual sensitivity has clinical implications, which may serve as a tool for non-invasively diagnosing early-stage visual processing deficits. The present study evaluated the effects of chronic tobacco use on visual sensitivity in SCZ patients. Our purpose was to provide new directions for future research, mainly psychophysical and electrophysiological studies. In the present study, 40 smoker controls (SC), 20 SCZ tobacco users, and 20 SCZ tobacco nonusers were recruited from the Psychosocial Care Center. Visual sensitivity was compared between both SCZ groups and the SC group. Patients with SCZ who were chronic tobacco users presented lower visual sensitivity for chromatic (p < 0.001) and achromatic (p < 0.001) stimuli compared with the other groups. Our findings highlight the need to evaluate possible addictive behavior in patients with SCZ, which may contribute to public policies that seek to improve the quality of life of SCZ patients and their families.
Collapse
Affiliation(s)
- Thiago M. P. Fernandes
- Department of Psychology, Federal University of Paraiba, João Pessoa, Brazil
- Perception, Neuroscience and Behavior Laboratory, Federal University of Paraiba, João Pessoa, Brazil
| | - Michael J. Oliveira de Andrade
- Department of Psychology, Federal University of Paraiba, João Pessoa, Brazil
- Perception, Neuroscience and Behavior Laboratory, Federal University of Paraiba, João Pessoa, Brazil
| | - Jessica B. Santana
- Department of Psychology, Federal University of Paraiba, João Pessoa, Brazil
- Perception, Neuroscience and Behavior Laboratory, Federal University of Paraiba, João Pessoa, Brazil
| | | | - Natanael A. dos Santos
- Department of Psychology, Federal University of Paraiba, João Pessoa, Brazil
- Perception, Neuroscience and Behavior Laboratory, Federal University of Paraiba, João Pessoa, Brazil
| |
Collapse
|
11
|
Fernandes TMP, Andrade SM, de Andrade MJO, Nogueira RMTBL, Santos NA. Colour discrimination thresholds in type 1 Bipolar Disorder: a pilot study. Sci Rep 2017; 7:16405. [PMID: 29180712 PMCID: PMC5703961 DOI: 10.1038/s41598-017-16752-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 11/16/2017] [Indexed: 11/09/2022] Open
Abstract
Although some studies have reported perceptual changes in psychosis, no definitive conclusions have been drawn about visual disturbances that are related to bipolar disorder (BPD). The purpose of the present study was to evaluate colour vision in BPD patients. Data were recorded from 24 participants: healthy control group (n = 12) and type 1 BPD group (n = 12). The participants were 20-45 years old and they were free from neurological disorders and identifiable ocular disease and had normal or corrected-to-normal visual acuity. Colour discrimination was evaluated using the Lanthony D-15d, Trivector and Ellipse tests, using a psychophysical forced-choice method. The relationship of visual measures to mood state and cognitive function was also investigated. The results showed that BPD patients had higher colour discrimination thresholds in the D15d (p < 0.001), Trivector (p < 0.001) and Ellipse (p < 0.01) tests compared with healthy controls. Linear regression analysis showed that mood state was related to colour discrimination. BPD individuals were not impaired in cognitive tasks. The present study provided new evidence of potential links between type 1 BPD and visual processing impairments. This research suggests a new direction for studies and the need for research in this field of study.
Collapse
Affiliation(s)
- Thiago Monteiro Paiva Fernandes
- Cognitive Neuroscience and Behaviour Program, Federal University of Paraiba, Joao Pessoa, Brazil.
- Perception, Neuroscience and Behaviour Laboratory, Federal University of Paraiba, Joao Pessoa, Brazil.
| | - Suellen Marinho Andrade
- Cognitive Neuroscience and Behaviour Program, Federal University of Paraiba, Joao Pessoa, Brazil
| | | | | | - Natanael Antonio Santos
- Cognitive Neuroscience and Behaviour Program, Federal University of Paraiba, Joao Pessoa, Brazil
- Perception, Neuroscience and Behaviour Laboratory, Federal University of Paraiba, Joao Pessoa, Brazil
| |
Collapse
|
12
|
Fernandes TMDP, Almeida NL, Dos Santos NA. Comparison of color discrimination in chronic heavy smokers and healthy subjects. F1000Res 2017; 6:85. [PMID: 28928940 PMCID: PMC5580434 DOI: 10.12688/f1000research.10714.3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/01/2017] [Indexed: 11/20/2022] Open
Abstract
Background: Cigarette smoke is probably the most significant source of exposure to toxic chemicals for humans, involving health-damaging components, such as nicotine, hydrogen cyanide and formaldehyde. The aim of the present study was to assess the influence of chronic heavy smoking on color discrimination (CD). Methods: All subjects were free of any neuropsychiatric disorder, identifiable ocular disease and had normal acuity. No abnormalities were detected in the fundoscopic examination and in the optical coherence tomography exam. We assessed color vision for healthy heavy smokers ( n = 15; age range, 20-45 years), deprived smokers ( n = 15, age range 20-45 years) and healthy non-smokers ( n = 15; age range, 20-45 years), using the psychophysical forced-choice method. All groups were matched for gender and education level. In this test, the volunteers had to choose the pseudoisochromatic stimulus containing a test frequency at four directions (e.g., up, down, right and left) in the subtest of Cambridge Colour Test (CCT): Trivector. Results: Performance on CCT differed between groups, and the observed pattern was that smokers had lower discrimination compared to non-smokers. In addition, deprived smokers presented lower discrimination to smokers and non-smokers. Contrary to expectation, the largest differences were observed for medium and long wavelengths. Conclusions: These results suggests that cigarette smoking, chronic exposure to its compounds, and withdrawal from nicotine affect color discrimination. This highlights the importance of understanding the diverse effects of nicotine on attentional bias.
Collapse
Affiliation(s)
| | | | - Natanael Antonio Dos Santos
- Department of Psychology, Federal University of Paraiba, Joao Pessoa, Brazil.,Perception, Neuroscience and Behavior Laboratory, Federal University of Paraíba, Joao Pessoa, Brazil
| |
Collapse
|
13
|
Bonfiglio L, Bocci T, Minichilli F, Crecchi A, Barloscio D, Spina DM, Rossi B, Sartucci F. Defective chromatic and achromatic visual pathways in developmental dyslexia: Cues for an integrated intervention programme. Restor Neurol Neurosci 2016; 35:11-24. [PMID: 27858722 DOI: 10.3233/rnn-160636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE As well as obtaining confirmation of the magnocellular system involvement in developmental dyslexia (DD); the aim was primarily to search for a possible involvement of the parvocellular system; and, furthermore, to complete the assessment of the visual chromatic axis by also analysing the koniocellular system. METHODS Visual evoked potentials (VEPs) in response to achromatic stimuli with low luminance contrast and low spatial frequency, and isoluminant red/green and blue/yellow stimuli with high spatial frequency were recorded in 10 dyslexic children and 10 age- and sex-matched, healthy subjects. RESULTS Dyslexic children showed delayed VEPs to both achromatic stimuli (magnocellular-dorsal stream) and isoluminant red/green and blue/yellow stimuli (parvocellular-ventral and koniocellular streams). To our knowledge, this is the first time that a dysfunction of colour vision has been brought to light in an objective way (i.e., by means of electrophysiological methods) in children with DD. CONCLUSION These results give rise to speculation concerning the need for a putative approach for promoting both learning how to read and/or improving existing reading skills of children with or at risk of DD. The working hypothesis would be to combine two integrated interventions in a single programme aimed at fostering the function of both the magnocellular and the parvocellular streams.
Collapse
Affiliation(s)
- Luca Bonfiglio
- Department of Translational Research on New Technologies in Medicine and Surgery, School of Physical Medicine and Rehabilitation, University of Pisa, Pisa, Italy
| | - Tommaso Bocci
- Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy
| | - Fabrizio Minichilli
- Unit of Environmental Epidemiology, Institute of Clinical Physiology, National Council of Research, Pisa, Italy
| | - Alessandra Crecchi
- Department of Translational Research on New Technologies in Medicine and Surgery, School of Physical Medicine and Rehabilitation, University of Pisa, Pisa, Italy
| | - Davide Barloscio
- Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy
| | - Donata Maria Spina
- Children's Neuropsychiatric Medical Facility, Local Health Authority of Viareggio (USL 12), Lido di Camaiore (LU), Italy
| | - Bruno Rossi
- Department of Translational Research on New Technologies in Medicine and Surgery, School of Physical Medicine and Rehabilitation, University of Pisa, Pisa, Italy
| | - Ferdinando Sartucci
- Department of Clinical and Experimental Medicine, Cisanello Neurology Unit, Pisa University Medical School, Pisa, Italy
| |
Collapse
|