During natural viewing, we often recognize multiple objects, detect their motion, and select one object as the target to track. It remains to be determined how such behavior is guided by the integration of visual form and motion perception. To address this, we studied how monkeys made a choice to track moving targets with different forms by smooth pursuit eye movements in a two-target task. We found that pursuit responses were biased toward the motion direction of a target with a hole. By computing the relative weighting, we found that the target with a hole exhibited a larger weight for vector computation. The global hole feature dominated other form properties. This dominance failed to account for changes in pursuit responses to a target with different forms moving singly. These findings suggest that the integration of visual form and motion perception can reshape the competition in sensorimotor networks to guide behavioral selection.
Animals ; Pursuit, Smooth ; Macaca mulatta ; Motion Perception/physiology* ; Photic Stimulation

Biomechanical Phenomena ; Eye Movements ; Neurons/physiology* ; Pursuit, Smooth ; Saccades

Objective: The aim of the study is to analyze the effects of vestibular spontaneous nystagmus(SN) on the smooth pursuit function of visual ocularmotor system. Methods: A total of 46 patients with acute unilateral peripheral vestibular syndrome with SN (26 cases of vestibular neuritis, 6 cases of Ramsay Hunt Syndrome (RHS) with vertigo, 14 cases of sudden deafness with vertigo) were included in this work. In the study group, the results of SPT and SN test with videonystagmography(VNG) were also reviewed. Taking SPT parameters, the influence of SN intensity on SPT gain, asymmetry and waveform and their correlation were analyzed.SPSS19.0 software was used for statistical analysis. Results: Among the 46 patients, there were 36 cases of SN pointing to the healthy side(SN intensity range of 2.68°/s-32.53°/s), and 10 cases of SN pointing to the affected side (SN intensity range of 2.66°/s-16.54°/s). SN intensity was divided into 3 groups, including light(0.50°/s-5.00°/s), medium(5.01°/s-10.00°/s) and strong(>10.01°/s), accounting for 14 cases(30.4%), 18 cases(39.1%) and 14 cases(30.4%), respectively. The differences of the gain of SPT to the fast phase and slow phase direction in the overall groups and light, medium and strong groups of SN intensity respectively were statistically significant(t_total=13.338, t_light=6.184, t_medium=8.436, t_strong=8.477, all of P<0.001). The difference of SPT gain in SN fast phase direction between groups with different SN intensity was statistically significant(F=9.639, P<0.001),there was no statistically significant difference in SPT gain between the groups on the SN slow phase direction(F=1.137, P=0.330).The SN intensity significantly negatively correlated with the SPT gain of the fast phase direction of SN (r=-0.433, P=0.003), that was, the SPT gain on the fast phase direction of SN decreased with the increase of SN intensity. There was no significant correlation between SN intensity and the gain of SPT on the slow phase direction of SN (r=-0.061, P=0.687). SPT waveform analysis showed that type I, type II and type III accounted for 8 cases(17.4%), 21 cases(45.6%) and 17 cases(37.0%), respectively. The corresponding mean values of SN intensity were (3.71±0.69)°/s, (7.44±1.88)°/s, (20.04±5.53)°/s, respectively, without type IV wave. The intensity of SN was positively correlated with the asymmetric value of the gain of SPT left and right(r=0.450,P=0.002). That was, with the increase of SN strength, the asymmetric value also increased, and the worse the asymmetry of the gain of SPT left and right pursuit was, the worse the SPT waveform was. Conclusion: SPT gain, asymmetry and SPT waveforms are all affected by SN, and the greater the intensity of SN, the greater the influence on the three. When SN is strong, type III waves may occur, suggesting that acute peripheral vestibular syndrome can also affect the visual ocularmotor systems.
Humans ; Nystagmus, Pathologic ; Pursuit, Smooth ; Vertigo ; Vestibular Diseases ; Vestibular Function Tests ; Vestibular Neuronitis

Myasthenia gravis (MG) is an autoimmune disease caused by autoantibodies to the acetylcholine receptors of the neuromuscular junction characterized by weakness and abnormal fatigability of the muscles. Therefore, the diagnosis of MG depends on the recognition of this distinctive pattern of fatigable weakness. Previous studies presented the diagnostic efficacy of saccadic eye movements in patients with ocular MG. We here in report 2 patients of ocular MG showing the fatigue effects during repetitive sustained smooth pursuit, and the effects of the administration of edrophonium on myasthenic smooth pursuit. Changes in smooth pursuits reflecting peripheral and secondary central mechanisms were demonstrated.
Autoantibodies ; Autoimmune Diseases ; Diagnosis ; Edrophonium ; Fatigue ; Humans ; Muscles ; Myasthenia Gravis ; Neuromuscular Junction ; Pursuit, Smooth ; Receptors, Cholinergic ; Saccades

BACKGROUND AND PURPOSE: During transient global amnesia (TGA), selective impairment of episodic memory is assumed to occur due to alteration in the neuronal network between the hippocampus and parietooccipital cortices that also include a hub for smooth pursuit (SP) eye movements. This study aimed to determine whether SP is impaired during TGA, and to identify any anatomical and functional linkage present between the oculomotor and memory systems. METHODS: Within a median of 1.0 day of TGA, horizontal SP was evaluated in 145 patients with a target moving at peak velocities of 10°/s and 20°/s. The average SP gains of patients were compared with those of the age-matched controls. RESULTS: The patients with TGA showed lower SP gains in both directions for both peak target velocities. While the normal controls showed symmetric SP in the rightward and leftward directions, in the TGA patients the SP gain was lower during rightward than leftward SP regardless of bilaterality or the side of the lesions. CONCLUSIONS: The cortical regions processing information about visual motion appeared to be affected during or soon after an amnestic episode of TGA, and more so in the right hemisphere. This means that disturbed processing of dynamic visual information may be related to the impaired spatial orientation observed during TGA.
Amnesia, Transient Global ; Eye Movements ; Hippocampus ; Humans ; Memory ; Memory, Episodic ; Neurons ; Pursuit, Smooth

Abnormal eye movements are commonly observed in movement disorders. Ocular motility examination should include bedside evaluation and laboratory recording of ocular misalignment, involuntary eye movements, including nystagmus and saccadic intrusions/oscillations, triggered nystagmus, saccades, smooth pursuit (SP), and the vestibulo-ocular reflex. Patients with Parkinson's disease (PD) mostly show hypometric saccades, especially for the self-paced saccades, and impaired SP. Early vertical saccadic palsy is characteristic of progressive supranuclear palsy-Richardson's syndrome. Patients with cortico-basal syndrome typically show a delayed onset of saccades. Downbeat and gaze-evoked nystagmus and hypermetric saccades are characteristic ocular motor findings in ataxic disorders due to cerebellar dysfunction. In this review, we discuss various ocular motor findings in movement disorders, including PD and related disorders, ataxic syndromes, and hyperkinetic movement disorders. Systemic evaluation of the ocular motor functions may provide valuable information for early detection and monitoring of movement disorders, despite an overlap in the abnormal eye movements among different movement disorders.
Ataxia ; Cerebellar Diseases ; Eye Movements ; Humans ; Hyperkinesis ; Movement Disorders ; Paralysis ; Parkinson Disease ; Parkinsonian Disorders ; Pursuit, Smooth ; Reflex, Vestibulo-Ocular ; Saccades

BACKGROUND AND PURPOSE: Although traditionally regarded as spared, a range of oculomotor dysfunction has been recognized in amyotrophic lateral sclerosis (ALS) patients. ALS is nowadays considered as a neurodegenerative disorder of a third compartment comprising widespread areas of extra-motor brain including cerebellum. Our objective was to perform an observational study to examine for ocular motor dysfunction in patients with ALS and for any differences between bulbar-onset and spinal-onset patients. METHODS: Thirty two ALS patients (bulbar onset: 10, spinal onset: 22) underwent the standardized systemic evaluations using video-oculography. RESULTS: Oculomotor dysfunctions such as square wave jerks, saccadic dysmetria, abnormal cogwheeling smooth pursuits and head shaking and positional nystagmus of central origin have been observed in the ALS patients at a relatively early stage. Abnormal smooth pursuits and saccadic dysmetria were increased in the bulbar-onset compared to the spinal-onset (p < 0.05). CONCLUSIONS: These oculomotor abnormalities may be a marker of neuro-degeneration beyond motor neurons in ALS, especially in bulbar-onset disease. Future longitudinal studies of eye movement abnormalities have provided insights into the distribution and nature of the disease process.
Amyotrophic Lateral Sclerosis* ; Brain ; Cerebellar Ataxia ; Cerebellum ; Eye Movements ; Head ; Humans ; Longitudinal Studies ; Motor Neurons ; Neurodegenerative Diseases ; Nystagmus, Physiologic ; Observational Study ; Pursuit, Smooth

OBJECTIVES: According to previous studies, the Chromogranin B (CHGB) gene could be an important candidate gene for schizophrenia which is located on chromosome 20p12.3. Some studies have linked the polymorphism in CHGB gene with the risk of schizophrenia. Meanwhile, smooth pursuit eye movement (SPEM) abnormality has been regarded as one of the most consistent endophenotype of schizophrenia. In this study, we investigated the association between the polymorphisms in CHGB gene and SPEM abnormality in Korean patients with schizophrenia. METHODS: We measured SPEM function in 24 Korean patients with schizophrenia (16 male, 8 female) and they were divided according to SPEM function into two groups, good and poor SPEM function groups. We also investigated genotypes of polymorphisms in CHGB gene in each group. A logistic regression analysis was performed to find the association between SPEM abnormality and the number of polymorphism. RESULTS: The natural logarithm value of signal/noise ratio (Ln S/N ratio) of good SPEM function group was 4.19 ± 0.19 and that of poor SPEM function group was 3.17 ± 0.65. In total, 15 single nucleotide polymorphisms of CHGB were identified and the genotypes were divided into C/C, C/R, and R/R. Statistical analysis revealed that two genetic variants (rs16991480, rs76791154) were associated with SPEM abnormality in schizophrenia (p = 0.004). CONCLUSIONS: Despite the limitations including a small number of samples and lack of functional study, our results suggest that genetic variants of CHGB may be associated with SPEM abnormality and provide useful preliminary information for further study.
Chromogranin B* ; Endophenotypes ; Eye Movements* ; Genetic Variation* ; Genotype ; Humans ; Logistic Models ; Male ; Polymorphism, Single Nucleotide ; Pursuit, Smooth* ; Schizophrenia*

BACKGROUND: Saccade test, smooth pursuit test, and optokinetic nystagmus test are clinically useful tests to accurately diagnose vertigo. However, there have only been a few studies regarding a correlation between the anatomical site of the lesion and the abnormality of eyeball movement in patients with vertigo. METHODS: The medical records of 97 patients with vertigo between January 2006 and June 2008 were reviewed retrospectively. We classified many kinds of abnormalities regarding the saccade test, smooth pursuit test and optokinetic nystagmus test into several categories and analyzed the localizing lesion of vertigo. RESULTS: According to the saccade test, both total saccade abnormality (S-total) and slow velocity of saccade (S-type 3) were shown to be significantly higher in the central lesion of vertigo. According to the smooth pursuit test, symmetrical unidirectional smooth pursuit abnormality (SP-type 2) was observed to be significantly higher in the peripheral lesion over vertigo. Moreover, according to the optokinetic nystagmus test, total optokinetic nystagmus abnormalities (OKN-total) were shown to be significantly useful findings in the diagnosis of the central lesion of vertigo. The coexisting abnormalities of all three tests (S+SP+OKN abnormalities) were shown to be significantly higher in the central lesion of vertigo. CONCLUSION: These results suggest that all these tests, saccade test, smooth pursuit test, and optokinetic nystagmus test, are very useful to distinguish between the central lesion and the peripheral lesion of vertigo. However, these tests are not beneficial in localizing the central lesion of vertigo.
Diagnosis ; Humans ; Medical Records ; Nystagmus, Optokinetic* ; Pursuit, Smooth* ; Retrospective Studies ; Saccades* ; Vertigo

BACKGROUND: Saccade test, smooth pursuit test, and optokinetic nystagmus test are clinically useful tests to accurately diagnose vertigo. However, there have only been a few studies regarding a correlation between the anatomical site of the lesion and the abnormality of eyeball movement in patients with vertigo.METHODS: The medical records of 97 patients with vertigo between January 2006 and June 2008 were reviewed retrospectively. We classified many kinds of abnormalities regarding the saccade test, smooth pursuit test and optokinetic nystagmus test into several categories and analyzed the localizing lesion of vertigo.RESULTS: According to the saccade test, both total saccade abnormality (S-total) and slow velocity of saccade (S-type 3) were shown to be significantly higher in the central lesion of vertigo. According to the smooth pursuit test, symmetrical unidirectional smooth pursuit abnormality (SP-type 2) was observed to be significantly higher in the peripheral lesion over vertigo. Moreover, according to the optokinetic nystagmus test, total optokinetic nystagmus abnormalities (OKN-total) were shown to be significantly useful findings in the diagnosis of the central lesion of vertigo. The coexisting abnormalities of all three tests (S+SP+OKN abnormalities) were shown to be significantly higher in the central lesion of vertigo.CONCLUSION: These results suggest that all these tests, saccade test, smooth pursuit test, and optokinetic nystagmus test, are very useful to distinguish between the central lesion and the peripheral lesion of vertigo. However, these tests are not beneficial in localizing the central lesion of vertigo.
Diagnosis ; Humans ; Medical Records ; Nystagmus, Optokinetic ; Pursuit, Smooth ; Retrospective Studies ; Saccades ; Vertigo