OBJECTIVES: Magical ideation refers to belief in forms of causation that by conventional standards are invalid, and is considered to be one of prodromal psychotic symptoms in schizophrenia. This study aimed to investigate the relationship between magical ideation and eye gaze pattern in patients with schizophrenia. METHODS: Eye gaze data were recorded in 23 patients with schizophrenia and 23 healthy controls while performing the reality evaluation task, in which participants should judge the realness of real or unreal pictures. RESULTS: Compared to healthy controls, patients with schizophrenia showed decreased fixation, saccade and area of interest (AOI) fixation counts, and reduced scanpath length. Magical Ideation Scale score in patients with schizophrenia showed negative correlation with the scanpath length in the real condition and the AOI fixation count in the unreal condition. CONCLUSION: These findings suggest that patients with schizophrenia show restricted visual scanning during reality evaluation, and their restricted visual scanning may play an important role in the magical ideation.
Humans ; Magic ; Saccades ; Schizophrenia

BACKGROUND AND OBJECTIVES:Convergence-retraction oscillations are rhythmic or arrhythmic jerks of dysjunctive eye movements associated with backward displacement of the eyeballs during the convergence phase. Oscillations in convergence-retraction oscillations have been proposed to be consisted of opposed adducting saccades immediately followed by slow abducting glissades without latency. However, dynamic characteristics of convergence oscillations accompanying retraction have not been studied, and pathomechanism of these eye movements remains to be elucidated. This study was to get insights on the pathomechanisms of convergence-retraction oscillations by using 3-dimensional recording of eye movements. In particular, we intended to clarify whether the nystagmus originates from instability of vergence eye movement or of saccades. MATERIALS AND METHOD:Seven consecutive patients with convergence-retraction oscillations were recruited. All the patients received full neurological and neuro-ophthalmological evaluation by the senior author. Some of the patients underwent 3-dimensional recordings of convergence-retraction oscillations with video-oculography or magnetic search coil technique. RESULTS:Wave forms of convergence-retraction oscillations were varied. The onset of convergent eye movements was either synchronous or asynchronous between both eyes. The initial directions of eye movement was same (conjugate) or opposite (disjunctive). In some, vergence eye movements occurred only in one eye (unilateral). Convergence phase of one eye was commonly consisted of multiple steps while the other eye attained final position with a single step. The following divergent eye movements commonly overshoot the orbital midposition and were followed by correcting convergent eye movements. The velocity-amplitude relationship of convergent eye movements, which was analyzed in typical pairs of vergence oscillations, did not differ between both eyes. Divergent eye movements are slower than convergent eye movements. The both convergent and divergent eye movements were slower than the microsaccades of similar amplitudes. CONCLUSION:Quantitative analyses of convergence-retraction oscillations revealed various patterns of wave forms. The amplitude-velocity relationships of the disjunctive eye movements suggest that the slowed saccades may be due to co-contraction of the agonist and antagonist, or due to enhanced vergence eye movements by the accompanying saccades.
Eye Movements ; Humans ; Orbit ; Saccades

This study aims to ascertain the human saccadic visual tracking characteristics by measuring the eye movement to the double-step stimuli. Responses to simple step and double-step target motions were measured where the target mode and stimulus durations were randomized. To measure the eye movement the Photo-electric Eye Monitor was constructed based on limbus tracking. The results indicate that observers represented two kind of responses (A-or B-type) depending upon the stimulus duration. The percentage of occurrances increased as the stimulus duration increased from 50 to 200 msec. When the subject responded to both target motions, the reaction time of the second saccade was shorter than that of the first. The successive visual information is to change continuously the reaction time or cancel the initial saccade. Our results revealed that parallel data processing characteristics of the visual tracking systems and the saccadic decision-makings are influenced by the temporal relationships.
Eye Movements ; Humans* ; Reaction Time ; Saccades

Saccades are rapid eye movements that shift the line of sight between successive points of fixation. The cerebellum calibrates saccadic amplitude (dorsal vermis and fastigial nucleus) and the saccadic pulse-step match (flocculus) for optimal visuo-ocular motor behavior. Based on electrophysiology and the pharmacological inactivation studies, early activity in one fastigial nucleus could be important for accelerating the eyes at the beginning of a saccade, and the later activity in the other fastigial nucleus could be critical for stopping the eye on target, which is controlled by inhibitory projection from the dorsal vermis. The cerebellum could monitor a corollary discharge of the saccadic command and terminate the eye movement when it is calculated to be on target. The fastigial nucleus and dorsal vermis also participate in the adaptive control of saccadic accuracy.
Cerebellum ; Electrophysiology ; Eye Movements ; Saccades* ; Sleep, REM

This study is concerned with human vertical saccadic systam to various visual stimulus. A system is described fer the recording and analysis of corrective movements and the angular velocities asscciated with 10 degrees and 20degrees vertical saccades. Recordings wsre made with photoelectric IR reflection method and the saccades were induced by a target system which operates on non-predictable manner. Statistical results for average peak veIomnes of right eye are given for a group of 4 normal subjects and compared with horizontal saccades. Most of corrective movements were categorized to saccadic and glissadic and magnitude of corrective errors were within 1 degree and 2 degrees and showed 20% production rate. The peak velccity statistics showed as 280 and 440 deg/s associated with 10 degrees and 20 degrees vertical movement and downward values were slightly faster than upward movements. Our results were compared with horizontal saccades and discussed the possibility of research and clinical tool that could be used on a large number and variety of patients.
Eye Movements* ; Humans ; Ocular Motility Disorders* ; Saccades

The superior colliculus (SC), one of the most well-characterized midbrain sensorimotor structures where visual, auditory, and somatosensory information are integrated to initiate motor commands, is highly conserved across vertebrate evolution. Moreover, cell-type-specific SC neurons integrate afferent signals within local networks to generate defined output related to innate and cognitive behaviors. This review focuses on the recent progress in understanding of phenotypic diversity amongst SC neurons and their intrinsic circuits and long-projection targets. We further describe relevant neural circuits and specific cell types in relation to behavioral outputs and cognitive functions. The systematic delineation of SC organization, cell types, and neural connections is further put into context across species as these depend upon laminar architecture. Moreover, we focus on SC neural circuitry involving saccadic eye movement, and cognitive and innate behaviors. Overall, the review provides insight into SC functioning and represents a basis for further understanding of the pathology associated with SC dysfunction.
Superior Colliculi/physiology* ; Saccades ; Neurons/physiology*

A small localized infarction in the dorsal pontine area can cause various eye-movement disturbances, such as abducens palsy, horizontal conjugate gaze palsy, internuclear ophthalmoplegia, and one-and-a-half syndrome. However, complete loss of vertical saccades and pursuit with horizontal gaze palsy has not been reported previously in a patient with a small pontine lesion. We report a 67-year-old man with a small dorsal caudal pontine infarct who exhibited total horizontal gaze palsy as well as loss of vertical saccades and pursuit.
Aged ; Humans ; Infarction* ; Ocular Motility Disorders ; Ophthalmoplegia ; Paralysis* ; Saccades*

This is a study to determine if there is a significant relationship between eye movement and alcohol intake at and below the legal limit of 0.05% blood alcohol concentration [BAC], and to identify the minimal BAC that causes significant change in eye movement. Twenty healthy males were orally given 0.57g/kg alcohol. After the alcohol intake, the BAC was measured at 10 minute intervals along with measurements of saccadic velocity, latency, and gain of pursuit movement of the eye. Linear regression analysis between BAC < or =0.05%and saccadic velocity and latency resulted in correlation coefficients of 0.258 and 0.306 respectively[p<0.005], while gain of pursuit movement had no relation to BAC.The latency at 0.05~0.06%BAC interval increased compared with the values before alcohol intake, with statistical significance [p<0.05 ]. Although there existed variations among subjects, a significant functional change of eye movement developed at 0.05%BAC, the legal limit of alcohol.Eye movement is thought to be a valuable indicator of CNS depression by alcohol and prolonged latency of saccadic eye movement by alcohol may be the explanation for increased risk of traffic accidents after alcohol intake.
Accidents, Traffic ; Depression ; Eye Movements* ; Humans ; Linear Models ; Male ; Saccades

PURPOSE: We evaluated the clinical manifestations of voluntary nystagmus in three patients and verified the efficacy of video-oculography as a diagnostic tool to differentiate voluntary nystagmus from congenital or latent nystagmus. METHODS: Meticulous history taking and neuro-ophthalmologic examination were performed for three patients with voluntary nystagmus. Video-oculography was also performed in one patient. RESULTS: All of the three patients were young men in military service. Neuro-ophthalmologic examination was normal in all three patients, except for shaking of the eyes. Video-oculography in one patient showed 5~6 Hz pendular oscillation with an amplitude of 7~15 degrees and a peak velocity of 345.4 deg/sec, verifying that the oscillatory eye movement was composed of saccades and was not a nystagmus. CONCLUSIONS: In differentiating between voluntary and congenital nystagmus, video-oculography as well as history taking and neuro-ophthalmologic examination were very helpful.
Eye Movements ; Humans ; Male ; Military Personnel ; Nystagmus, Congenital ; Saccades

BACKGROUND AND OBJECTIVES: While it is known that sleep have influence on emergence of rapid eye movements (REMs), namely saccades including fast component of nystagmus, whether spontaneous nystagmus due to vestibular imbalance presents during sleep is still unclear. The purpose of our study was to investigate whether tonic vestibular imbalance appeared as spontaneous nystagmus during the wakeful state could present during REM sleep. MATERIALS AND METHOD: Overnight polysomnography (PSG) was performed in 7 patients with spontaneous nystagmus due to vestibular neuritis (VN) and 7 control patients without dizziness or any nystagmus. The numbers of horizontal saccades were counted, during 3 minutes samples of the alert state before and after the PSG and the first and last REM sleep. RESULTS: All patients with VN showed significantly more saccades (fast phases of spontaneous nystagmus) towards the side contralateral to their vestibular lesion in the awake state before and after the PSG compared with control group. By contrast, during REM sleep the patients with VN showed no preponderance in saccade direction (p<0.05). Some brief nystagmoid jerks showed during REM sleep in both patients and controls equally and also had no preponderance in direction. CONCLUSION: The tonic vestibular imbalance at peripheral level observed during alert state does not appear at the brainstem level during REM sleep. It is suggested that a de-afferentation of the peripheral vestibular input to the REM sleep generating areas may explain an absence of nystagmus during REM sleep in patients with VN.
Brain Stem ; Dizziness ; Humans ; Polysomnography ; Saccades ; Sleep, REM ; Vestibular Neuronitis*