Dynamic color is an important carrier that takes information in some special occupations. However, up to the present, there are no available and objective tests to evaluate dynamic color processing. To investigate the characteristics of dynamic color processing, we adopted two patterns of visual stimulus called "onset-offset" which reflected static color stimuli and "sustained moving" without abrupt mode which reflected dynamic color stimuli to evoke event-related brain potentials (ERPs) in primary color amblyopia patients (abnormal group) and subjects with normal color recognition ability (normal group). ERPs were recorded by Neuroscan system. The results showed that in the normal group, ERPs in response to the dynamic red stimulus showed frontal positive amplitudes with a latency of about 180 ms, a negative peak at about 240 ms and a peak latency of the late positive potential (LPP) in a time window between 290 and 580 ms. In the abnormal group, ERPs in response to the dynamic red stimulus were fully lost and characterized by vanished amplitudes between 0 and 800 ms. No significant difference was noted in ERPs in response to the dynamic green and blue stimulus between the two groups (P>0.05). ERPs of the two groups in response to the static red, green and blue stimulus were not much different, showing a transient negative peak at about 170 ms and a peak latency of LPP in a time window between 350 and 650 ms. Our results first revealed that some subjects who were not identified as color blindness under static color recognition could not completely apperceive a sort of dynamic red stimulus by ERPs, which was called "dynamic red blindness". Furthermore, these results also indicated that low-frequency ERPs induced by "sustained moving" may be a good and new method to test dynamic color perception competence.
Adult ; Color Perception ; physiology ; Color Vision Defects ; diagnosis ; physiopathology ; Event-Related Potentials, P300 ; physiology ; Evoked Potentials, Visual ; physiology ; Female ; Humans ; Male ; Pattern Recognition, Visual ; physiology ; Young Adult

Color vision is a major component of vision function. Examination of color vision mostly relies on subjectivity at present. It is important to establish an objective method of color vision examination that would have particular clinical significance and forensic medicine value. With the development of new technology, the examination of visual electrophysiology has become a basic method of clinical diagnosis and investigation. Electroretinogram (ERG) could discriminate different cone cells and color abnormality. Visual evoked potential (VEP) generated characteristic negative wave after stimulation with different colors. Different visual electrophysiology detection methods were reviewed and in particular important new advancement of color vision research of ERG, F-VEP and P-VEP were introduced. The application prospect of color vision research in the clinical forensic medicine was also discussed. It is likely that color vision research study and visual electrophysiology will provide objective evaluation of retina and brain function.
Color Vision/physiology* ; Electrophysiology ; Electroretinography ; Evoked Potentials, Visual ; Forensic Medicine ; Humans

PURPOSE: Our objective was to estimate the maximum color contrast sensitivity (MCCS) thresholds in individuals with chiasma opticum damage. METHODS: The pilot study tested 41 people with pituitary adenoma (PA) and 100 age- and gender-matched controls. Patients were divided into two groups according to PA size, PA ≤1 cm or PA >1 cm. A new MCCS test program was used for color discrimination. RESULTS: The mean total error score (TES) of MCCS was 1.8 in the PA ≤1 cm group (standard deviation [SD], 0.38), 3.5 in the PA >1 cm group (SD, 0.96), and 1.4 in the control group (SD, 0.31; p < 0.001). There was a positive correlation between tumor size and MCCS result (r = 0.648, p < 0.01). In the group that had PA-producing hormones, the TES was 2.5 (SD, 1.09), compared to 4.2 value in the non-functioning PA group of patients that did not have clinically significant hormone excess (SD, 3.16; p < 0.01). In patients with normal visual acuity (VA) or visual field MCCS, the TES was 3.3 (SD, 1.8), while that in patients with VA <0.00 was 4.6 (SD, 2.9). CONCLUSIONS: Results of the MCCS test TES were 1.9 times better in patients with PA ≤1 cm compared to patients with PA >1 cm (p < 0.01). In PA patients with normal VA, the TES was 2.35 times worse than that of healthy persons (p < 0.01).
Adenoma/*complications/diagnosis ; Adolescent ; Adult ; Aged ; Color Perception/physiology ; Color Perception Tests/*methods ; Contrast Sensitivity/*physiology ; *Early Diagnosis ; Female ; Humans ; Male ; Middle Aged ; *Optic Chiasm ; Pilot Projects ; Pituitary Neoplasms/*complications/diagnosis ; Time Factors ; Vision Disorders/*diagnosis/etiology/physiopathology ; Visual Fields ; Young Adult

PURPOSE: To investigate patterns of functional magnetic resonance imaging (fMRI) activation during sentence reading before and after wearing color-tinted lenses. METHODS: A total of 15 Meares-Irlen syndrome patients with a mean age of 23.4 years (range, 13 to 42 years) with no history of neurological or psychiatric disorders were scanned using a 3T MR scanner (Siemens, Tim-Trio, Germany). Each patient underwent two sessions of fMRI imaging (before and after MISViS color-tinted lens application). The fMRI paradigm included a block design of 20 seconds of rest (cross), 20 seconds of activation (sentence reading), and ten blocks (a total of 200 echo-planar image volumes) repeated for each session. Data preprocessing and analyses were performed using the SPM8 software package. RESULTS: The reading speed of patients improved more than 20% while wearing the selected lenses. When compared to the before-lens session, the after-lens session identified significant regions of activation in the left middle and superior temporal gyri (paired t-test; maximal z score, 5.38; Montreal Neurological Institute coordinate, -60 / -39 / 0; threshold at p < 0.05; corrected for multiple comparisons using family-wise error). No region of activation at the same threshold was found in the before-lens session as compared to the after-lens session. CONCLUSIONS: In the current study, we confirmed activation in the left middle and superior temporal gyri during sentence reading after wearing color-tinted lenses. These results could explain the effectiveness of color-tinted lenses in patients with Meares-Irlen syndrome.
Adolescent ; Adult ; Brain/*pathology/physiopathology ; Color Perception/*physiology ; Dyslexia/*diagnosis/physiopathology ; *Eyeglasses ; Female ; Humans ; Magnetic Resonance Imaging/*methods ; Male ; Perceptual Disorders/*diagnosis/physiopathology ; Pilot Projects ; Reading ; Syndrome ; Vision Disorders/*diagnosis/physiopathology ; Young Adult

OBJECTIVE: To investigate the difference in color pattern reversal visual evoked potential (CPR-VEP)between primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG) patients. METHODS: Vision Monitor visual electrophysiograph made by Metro Vision Inc. in France was used to record CPR-VEP in 17 eyes of 12 POAG patients, 56 eyes of 41 PACG patients, and 26 eyes of 13 age-equivalent normal persons at an ascending series of temporal frequency (1, 2, 4, 8, 16, and 32 Hz) and color stimulation (black/white, red/green, and blue/yellow). P(100) wave amplitudes and latencies of these patients were compared respectively with those of the normal group. RESULTS: With black/white stimulation, the P(100) wave amplitudes were reduced with the increase of temporal frequency in the 3 groups. The P(100) wave latencies were extended with the increase of temporal frequency with different color stimulations. The P(100) amplitudes were PACG group > NC group > POAG group and black/white > blue/yellow > red/green. The P(100) wave latencies in the POAG group and the PACG group were extended compared with the NC group, but there was no significant difference between PACG group and POAG group. CONCLUSION CPR-VEP P(100) amplitudes in the PACG group and POAG group have their own characteristics. The P(100) amplitude of PACG is higher, and POAG is lower than normal. The P(100) wave latencies of PACG and POAG are extended.
Adult ; Aged ; Aged, 80 and over ; Color Vision ; Evoked Potentials, Visual ; physiology ; Female ; Glaucoma, Angle-Closure ; physiopathology ; Glaucoma, Open-Angle ; physiopathology ; Humans ; Male ; Middle Aged ; Photic Stimulation ; methods ; Young Adult