In comparing the compensation following horizontal and vertical first saccades, we found that the CD of horizontal saccades is more accurate than that for vertical ( Figures 4 and 5). Though there were differences in the amount of compensation for upward and downward saccades within a given subject, these differences were not consistent across subjects and compensation for vertical first saccades tended to be worse than horizontal first saccades made to reach the same endpoint. While there is no obvious correlate of this in the neuronal circuitry related to either saccade generation or the CD, one possible explanation for this finding is the representation of these vertical saccades on the movement map in the superior colliculus, which is the source of the corollary discharge pathway to frontal cortex in the monkey (Sommer & Wurtz, 2004a). A vertical first saccade should activate movement fields along the vertical meridian that are represented in both superior colliculi in contrast to a ...
We propose that the velocity information used to compensate for the displacement of the target during catch-up saccades both in head-restrained and head-unrestrained conditions corresponds to the signal used to control pursuit. Because Ron and Robinson (1973) reported that stimulations of lobulus simplex and crus I and II of the cerebellar cortex produces saccades and smooth pursuit, those sites could be candidates for neural areas in which both velocity and position signals are mixed to correct catch-up saccade amplitude. However, it is clear that further studies should be conducted to define clearly which neural areas are needed to control catch-up saccades amplitude. The same signal could be used for the head-restrained one-dimensional step-ramp paradigm (de Brouwer, Missal et al., 2002; de Brouwer et al., 2001; de Brouwer, Yuksel et al., 2002), orthogonal position and velocity steps paradigm (Fleuriet & Goffart, 2012; Fleuriet et al., 2011), head-unrestrained step-ramp paradigm (Ackerley & ...
A video oculography system for calculation and display of Corrective Secondary Saccades Analysis is disclosed. A method for Objective Diagnostics of at least one of traumatic brain injury, Internuclear Opthalmopligia, Ocular Lateral Pulsion, Progressive Supernuclear Palsy And Glissades comprises the steps of using a VOG system to calculate corrective saccades. The video oculography based system for the subject is configured to collect eye images of the patient in excess of 60 hz and configured to resolve eye movements smaller than at least 3 degrees of motion. The video oculography based system collects eye movement data wherein at least one fixation target is presented to the subject in a defined position configured to yield a voluntary saccadic eye response from at least one eye of the patient. The latency, amplitude, accuracy and velocity of each respective corrective saccade and totals latency and accuracy is calculated.
TY - JOUR. T1 - Slowed saccades in the acquired immunodeficiency syndrome. AU - Nguyen, Ngoc. AU - Rimmer, Steve. AU - Katz, Barrett. PY - 1989/4/15. Y1 - 1989/4/15. N2 - We recorded eye movements using infrared oculography in ten patients with the acquired immunodeficiency syndrome (AIDS) and ten control subjects of similar age. Peak saccadic velocity for the AIDS group was significantly lower than that of the control group for both adducting and abducting saccades (P , .001). Saccadic duration for the AIDS group was significantly greater than that of the controls for both adducting and abducting saccades (P , .02 for adduction and P , .01 for abduction). There was no difference in saccadic latencies between the two groups. We add slowed saccades to the ocular motility manifestations of AIDS. Our study indicated that analysis of ocular motility may be of value in providing early detection of neurologic dysfunction, and may also be an important quantitative measure of the responsiveness of ...
Severely slowed saccades in ,I,spinocerebellar ataxia,/I, have previously been shown to be at least partially closed-loop in nature: their long duration means that they can be modified in-flight in response to intrasaccadic target movements. In this study, a woman with these pathologically slowed saccades could modify them in-flight in response to target movements, even when saccadic suppression of displacement prevented conscious awareness of those movements. Thus saccadic suppression of displacement is not complete, in that it provides perceptual information that is sub-threshold to consciousness but which can still be effectively utilised by the oculomotor system. ...
The cortical area called frontal eye field (FEF) plays an important role in the control of visual attention and eye movements.[3] Electrical stimulation in the FEF elicits saccadic eye movements. The FEF have a topographic structure and represents saccade targets in retinotopic coordinates.[4]. The frontal eye field is reported to be activated during the initiation of eye movements, such as voluntary saccades[5] and pursuit eye movements.[6] There is also evidence that it plays a role in purely sensory processing and that it belongs to a "fast brain" system through a superior colliculus - medial dorsal nucleus - FEF ascending pathway.[7]. In humans, its earliest activations in regard to visual stimuli occur at 45 ms with activations related to changes in visual stimuli within 45-60 ms (these are comparable with response times in the primary visual cortex).[7] This fast brain pathway also provides auditory input at even shorter times starting at 24 ms and being affected by auditory ...
In internuclear opthalmoplegia, for horizontal movements, the adducting eye is slowed while the abducting eye typically has normal velocity and has a nystagmus. This is covered in much more detail below under the heading of asymmetrical saccadic slowing. For vertical eye movements, the MLF appears to primarily carry posterior canal signals and anterior canal derived eye movements are spared (Cremer et al, 1999). Breaks in binocular fusion may occur in patients with INO (Mills et al, 2008).. Ocular myasthenia may cause weakness of all ocular muscles, or be restricted to individual muscles. Thus, the horizontal-vertical distinction does not help in the diagnosis. Rather, the diagnosis is usually made via observation of fluctuation of ocular alignment from minute to minute, restriction of eye movement to the central range, and post-saccadic drift (see following section on post-saccadic drift for an example). Myasthenics may also develop a progressive slowing of saccades over time, due to fatigue ...
This study analyzed how an unexpected, transient, passive movement of the head during saccades that were initiated while the head was fixed, affects the trajectory of saccades. We showed that the accuracy of the saccade was not altered by the head perturbation. A system based on separate eye and head controllers would not maintain accuracy, because the eye controller would have no way to assess the amount of the gaze trajectory that had been affected by a perturbation with a VOR gain ,1. Thus, our results imply that the brain combines the action of the VOR (whatever its gain) and a feedback mechanism for gaze. We also showed that the saccade trajectory is affected more by the perturbation for larger saccade amplitudes, and when the onset of the head perturbation was close to the onset of the saccade. Finally, we showed that the modulation of the saccade trajectory was insensitive to the latency of the saccade with respect to the target presentation.. In our experiment, we created a passive ...
The location of the human cortical substrate underlying simple horizontal saccadic eye movements was investigated using echoplanar functional magnetic resonance imaging (fMRI) in young healthy volunteers. Echoplanar imaging with signal targeting and alternating radiofrequency (EPISTAR), a novel perfusion technique, measured signal intensity changes in one to four contiguous 10-mm slices centered to include both striate cortex and putative frontal eye fields during horizontal saccade and fixation conditions. Subtraction images of self-paced visually guided saccadic versus fixation conditions showed bilateral marked and statistically significant localized signal increases in the precentral region (Brodmann areas 4, 6) and peristriate cortex (areas 17, 18, 19) and qualitative increases in the superior medial frontal region, as identified by a Talairach-Tournoux generalized template in the brain slices that were scanned. Additional parietal activation occurred during a target-guided saccade task. Our data
Saccade adaptation induced by visual error is known to have a gradual, approximately exponential course, its magnitude and rate being highly variable (Straube et al., 1997; Scudder et al., 1998; Robinson et al., 2003). We quantified the size of gain changes elicited in stimulation-coupled saccades in the two monkeys. The total gain changes observed in individual experiments had a mean of −0.295 ± 0.111 (range of −0.106 to −0.438; n = 8) and 0.267 ± 0.062 (range of 0.210-0.367; n = 6) for gain decreases and increases, respectively. The total number of stimulation-coupled saccades ranged from 345 to 1419 (885 ± 289; n = 14). The gain was clearly far from reaching the steady state in the majority of experiments. Therefore, it was difficult to estimate reliable rate constants using exponential fit. Instead, we calculated the gain changes that occurred for the first 400 and 950 stimulation-coupled saccades. The gain change elicited for the 400 saccades was −0.217 ± 0.133 for gain decrease ...
Our patient had several ocular motor abnormalities: saccades were asymmetric and had increased peak velocity, a dynamic overshoot, an asymmetrical postsaccadic centripetal drift and saccade-induced oscillations.. To account for these observations, we focused on a neuromimetic model of saccadic control with a detailed representation of the brainstem. A key point while designing a model is that several theoretical control structures could be built to reproduce our patients behavior. However, the pathophysiological consequences linked to a modification of the model make sense only if the model structure relates closely to the actual neural circuitry. With that point in mind, we built a model that is constrained by the current knowledge of the anatomy (connections between neural structures) and the neurophysiology (average discharge of the neural structures). Once the model architecture was defined, we tuned the model parameters to reproduce the saccadic behavior of healthy human subjects. Then we ...
A fundamental task performed by many visual systems is to distinguish apparent motion caused by eye movements from real motion occurring within the environment. During saccadic eye movements, this task is achieved by inhibitory signals of central and retinal origin that suppress the output of motion-detecting neurons. To investigate the retinally-generated component of this suppression, we used a computational model of a locust looming-detecting pathway that experiences saccadic suppression. This model received input from the camera of a mobile robot that performed simple saccade-like movements, allowing the models response to simplified real stimuli to be tested. Retinally-generated saccadic suppression resulted from two inhibitory mechanisms within the looming-detectors input architecture. One mechanism fed inhibition forward through the network, inhibiting the looming-detectors initial response to movement. The second spread inhibition laterally within the network, suppressing the ...
Visual neglect of left space following right parietal damage in humans involves a lateral bias in attention, apparent in many search tasks. We hypothesized that parietal neglect may also involve a failure to remember which locations have already been examined during visual search: an impairment in retaining searched locations across saccades. Using a new paradigm, we monitored gaze during search, while simultaneously probing whether observers judged they had found a new target, or judged instead that they were re-fixating a previously examined target. A patient with left neglect following focal right parietal infarction repeatedly re-fixated right locations. Critically, he often failed to remember that these locations had already been searched, treating old targets as new discoveries at an abnormal rate. In comparison, healthy age-matched control subjects rarely re-fixated targets, and mistook old targets as new targets even more rarely. The frequency of such mistakes in the parietal patient, for
Crawford, T J and Broerse, A and den Boer, J A (2001) Parsing Cognition in Schizophrenia Using Saccadic Eye Movements. Neuropsychologia, 39. pp. 742-756. ISSN 0028-3932. Full text not available from this repository ...
The panoramic film above shows the results of a surgery that replaced both of the temperomandibular joints. The prosthetic joints consist of a vertical component including a ball which rotates in a horizontal component, a prosthetic socket. The vertical component replaces a part of the lower jaw called the condyle, and the horizontal component is called the fossa. The fossa is a somewhat complex structure since the condyle does not merely rotate within the socket. It must also slide forward (translate) onto the condylar eminence which is located in front of the socket itself. Below is a diagram of a dried skull with the parts of a natural joint drawn and labeled, for comparison. If you look carefully, you can see that both condyles were removed in their entirety, and the portion of the skull containing the natural fossa was modified to receive the titanium fossa implant. For more on the mechanics of the joint, including an explanation of the rotational and translational components of jaw ...
Anstis, S., Dykmans, N., Kaneko, S., & Cavanagh, P. (2016). Orbiting black/white rays produce an illusory gray disk. Perception, in press. pdf. Born, S. Krger, H. M., Zimmermann, E., & Cavanagh, P. (2016). Compression of space for low visibility probes. Frontiers in Systems Neuroscience, 10(21), 1-13. pdf. Eymond, C., Collins, T., & Cavanagh, P. (2016). Feature-based attention across saccades and immediate post-saccadic selection. Attention, Perception, & Performance, 78(5), 1293-1301.pdf. Knapen, T., Swisher, J. D., Tong, F., & Cavanagh, P. (2016). Oculomotor remapping of visual information to foveal retinotopic cortex. Frontiers in System Neuroscience, 10(51), 1-12. pdf. Krger, H. M., Collins, T., Englitz, B., & Cavanagh, P. (2016) Saccades create similar mislocalizations in visual and auditory space. Journal of Neurophysiology, 115(4), 2237-2245. doi: 10.1152/jn.00853.2014. pdf. Szinte, M., Jonikaitis, D., Rolfs, M., Cavanagh, P., & Deubel, H. (2016). Pre-saccadic motion integration between ...
In a study published last week, researchers looked at the visual tracking of people with and without ASD as they followed a target on a computer screen. Key differences were found between the groups based on their saccades. What are saccades? They are the very rapid shifts both eyes make as they shift gaze and attention. You rely on them every waking moment as they help you navigate, socialize and appreciate beauty in your environment.. The precision of saccades and visual tracking is orchestrated by the cerebellum. In people with ASD, the reduced visual tracking ability may identify poor functioning of the cerebellum, and may also explain the difficulties with communication and social interaction that some people with ASD experience. This connection becomes clearer when you understand that the cerebellum is massively connected not only to motor areas of the brain, but also to areas involved in attention, language, planning and even emotion.. In a recent The Doctor is In article, Dr. Ron talked ...
A person walks 12 m across a room a. what is their horizontal component b. what is their vertical component a) horizontal component is 12m b) ve...
abstract = {Observers show a marked tendency to fixate the center of the screen when viewing scenes on computer monitors. This is often assumed to arise because image features tend to be biased toward the center of natural images and fixations are correlated with image features. A common alternative explanation is that experiments typically use a central pre-trial fixation marker, and observers tend to make small amplitude saccades. In the present study, the central bias was explored by dividing images post hoc according to biases in their image feature distributions. Central biases could not be explained by motor biases for making small saccades and were found irrespective of the distribution of image features. When the scene appeared, the initial response was to orient to the center of the screen. Following this, fixation distributions did not vary with image feature distributions when freely viewing scenes. When searching the scenes, fixation distributions shifted slightly toward the ...
Coordinating the movements of different body parts is a challenging process for the central nervous system because of several problems. Four of these main difficulties are: first, moving one part can
Motor adaptation is an important factor in the recovery of function following motor deficits associated with neural damage due to stroke, injury or aging. Such...
We present an approach to measure and model the parameters of human point-of-gaze (PoG) in 3D space. Our model considers the following three parameters: position of the gaze in 3D space, volume encompassed by the gaze and time for the gaze to arrive on the desired target. Extracting the 3D gaze position from binocular gaze data is hindered by three problems. The first problem is the lack of convergence - due to micro saccadic movements the optical lines of both eyes rarely intersect at a point in space. The second problem is resolution - the combination of short observation distance and limited comfort disparity zone typical for a mobile 3D display does not allow the depth of the gaze position to be reliably extracted. The third problem is measurement noise - due to the limited display size, the noise range is close to the range of properly measured data. We have developed a methodology which allows us to suppress most of the measurement noise. This allows us to estimate the typical time which ...
The invention provides a method of determining the orientation of a seismic receiver (4, 6) from seismic data acquired at the receiver (4, 6). The determined orientation can be taken into account in subsequent analysis of the seismic data. This avoids inaccuracies that can occur if the receiver orientation is estimated. In a preferred embodiment the horizontal spatial derivatives of the pressure measured at the receiver are used in the determination of the orientation of the receiver. These may be calculated on either the source side or the receiver side. These are combined with horizontal components of the particle displacement, velocity or acceleration (or a higher time-derivative of the particle displacement). Alternatively, horizontal spatial derivatives of the particle displacement measured at the receiver may be used in place of the horizontal spatial derivatives of the pressure. The invention also provides a seismic receiver (6) having three or more closely-spaced, non-collinear pressure sensors
This unit presents description of four basic clinical paradigms for clinical fMRI of language cmprehension, eye movement (visually guidede saccades), motor cortex (finger‐thumb apposition), and visual cortex
Individual differences of cognitive ability differentiates neural and behavioral strategy during concurrent working memory and oculomotor task. Gusang Kwon [2013 Society for Neuroscience, San Diego, California - Poster- (2013-Nov 9-)]. ...
These transducers allow direct observation of shaft or target displacement for a variety of vibration, position, speed, and timing (i.e., phase) measurements. Various tip diameters and thread sizes/configurations are offered to allow measurement ranges as small as 200 micro inches, as large as 1.1 inch, and everything in between, including the popular 80 mil range used for the majority of machinery measurements.. ...
An important function of the brain is to inhibit irrelevant behaviors. This thesis examines the role of the basal ganglia in response suppression using saccadic eye movements as a model of behavior. We measured the activity ...
MERCATI E COMPETITIVITÀ - Come percepiamo i display incompleti nei punti vendita? ( In questo studio valutiamo lesistenza di un fenomeno di asimmetria percettiva dei consumatori rispetto al grado di incompletezza dei display nei punti vendita. 159 soggetti destrorsi sono stati coinvolti in un esperimento di laboratorio che prevedeva lesposizione ad immagini che, in visione frontale o prospettica, mettevano a confronto due display, uno alla sinistra e laltro alla destra dellosservatore. I partecipanti dovevano individuare di volta in volta, in condizioni di free-viewing, il più rapidamente ed accuratamente possibile, il display più incompleto. Il test ha evidenziato che le persone tendono a percepire come maggiormente incompleto il display alla propria sinistra, benché, nella realtà, le risposte corrette al task fossero equidistribuite tra sinistra e destra. Tale bias verso sinistra è consistente con le predizioni della Teoria della attivazione selettiva dellemisfero cerebrale destro.)
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I have a question about the worth of this ring on single target after 7.1.5. Since MS does less damage than AS now, is it even worth using the GCD to ...
The Operative is the master of single target damage who specializes in deadly psionic attacks that weaken the target making them easier to kill.. ...
The Operative is the master of single target damage who specializes in deadly psionic attacks that weaken the target making them easier to kill.. ...
Saccadic eye movements are driven by motor commands that are continuously modified so that errors created by eye muscle fatigue, injury, or-in humans-wearing spectacles can be corrected. It is possible to rapidly adapt saccades in the laboratory by introducing a discrepancy between the intended and actual saccadic target. Neurophysiological and lesion studies in the non-human primate as well as neuroimaging and patient studies in humans have demonstrated that the oculomotor vermis (lobules VI and VII of the posterior cerebellum) is critical for saccadic adaptation. We studied the effect of transiently disrupting the function of posterior cerebellum with repetitive transcranial magnetic stimulation (rTMS) on the ability of healthy human subjects to adapt saccadic eye movements. rTMS significantly impaired the adaptation of the amplitude of saccades, without modulating saccadic amplitude or variability in baseline conditions. Moreover, increasing the intensity of rTMS produced a larger impairment in the
Gandhi, N.J.; Keller, E.L., 1999: Activity of the brain stem omnipause neurons during saccades perturbed by stimulation of the primate superior colliculus
NIH Rare Diseases : 52 The following summary is from Orphanet , a European reference portal for information on rare diseases and orphan drugs. Orpha Number: 95434 Definition A rare hereditary ataxia characterized by a progressive cerebellar ataxia associated with disruption of visual fixation by saccadic intrusions (overshooting horizontal saccades with macrosaccadic oscillations and increased velocity of larger saccades). It presents with progressive gait, trunk and limb ataxia with pyramidal tract signs (increased tendon reflexes and Babinski sign), myoclonic jerks, fasciculations, cerebellar dysarthria , sensorimotor axonal neuropathy with impaired joint position, vibration, temperature, pain sensations, pes cavus, and saccadic intrusions with characteristic overshooting horizontal saccades, macrosaccadic oscillations, and increased velocity of larger saccades, without other eye movement disturbances. Visit the Orphanet disease page for more resources ...
Once the data from all the participants were collected, the eye position traces were extracted from Tobii Studio and analyzed offline using custom software written in MATLAB (MathWorks, Natick, MA). The first step was to obtain eye velocity, and this was achieved by differentiating the eye position over time and smoothing it with a three-window moving average filter, to reduce the additional noise that arose from the differentiation process.18 Following this, the adaptive threshold algorithm described by Behrens et al.19 was used to automatically detect saccades during the smooth pursuit. Once the saccades were detected, these were removed from the eye movement traces, and the periods free of saccades were considered smooth pursuit. Further analysis of the smooth pursuit segments followed the procedures described in Vinuela-Navarro et al.16 In brief, linear regressions were performed on each segment of smooth pursuit, and the slope of the fitted equation was defined as the eye velocity for that ...
Recordings of the horizontal component of movements of the eyes were made during monocular and binocular fixation. The variation in the vergence of the eyes over time was found to be of the same order of magnitude as the variation in position of the individual eyes, even though the lateral positions of the two eyes are somewhat correlated. The drift and tremor of the two eyes are not correlated; the over-all correlation is due to the saccadic movements. Saccades in one eye seem to be always accompanied by simultaneous saccades in the other eye which are almost always in the same direction and about the same in size. The maintenance of binocular fixation does not seem to be dependent on a direct response to or sensing of vergence error. Rather, it appears to be dependent on the saccadic responses of the two eyes to their own fixation errors.. © 1960 Optical Society of America. Full Article , PDF Article ...
Krämer, G; Bonetti, C; Mathis, J; Meyer, K; Seeck, M; Seeger, R; Wiest, D (2015). Epilepsie und Führerschein. Swiss Medical Forum, 15(7):157-160.. Schmitt, K U; Seeger, R; Fischer, H; Lanz, C; Muser, M; Walz, F; Schwarz, U (2015). Reply to: Technical Comment on "Saccadic eye movement performance as an indicator of driving ability in elderly drivers". Swiss Medical Weekly, 145:w14195.. Schmitt, K U; Seeger, R; Fischer, H; Lanz, Christian; Muser, M; Walz, Felix; Schwarz, U (2015). Saccadic eye movement performance as an indicator of driving ability in elderly drivers. Swiss Medical Weekly, 2015:w14098.. Seeger, R (2012). Der kriminelle Verkehrsteilnehmer - Alkohol, Drogen und weitere Beeinträchtigungen der Fahrfähigkeit und Fahreignung. In: Schwarzenegger, Christian. 5. Zürcher Präventionsforum : Raser, Risikofahrer und andere kriminelle Verkehrsteilnehmer. Zürich: Schulthess, 161-170.. Mosimann, U P; Bächli-Biétry, J; Boll, J; Bopp-Kistler, I; Donati, F; Kressig, R W; Martensson, B; ...
OBJECTIVE: The authors investigated the structural brain correlates of antisaccade performance. METHOD: Magnetic resonance imaging was used to measure the volumes of the prefrontal, premotor, sensorimotor, and occipitoparietal cortices as well as the caudate, thalamus, cerebellar vermis, and cerebrum in 20 first-episode psychosis patients and 18 healthy comparison subjects. Antisaccades were recorded by using infrared oculography. RESULTS: Groups significantly differed in terms of antisaccade error rate and amplitude gain and tended to differ in terms of latency but not brain region volumes. Premotor cortex volume predicted antisaccade error rate among comparison subjects. In the patient group, caudate volume was related to latency and amplitude gain. Negative symptoms, independent of structural volumes, predicted error rate. CONCLUSIONS: These findings point to altered structure-function relationships in first-episode psychosis.. ...
Initiating an eye movement towards a suddenly appearing visual target is faster when an accessory auditory stimulus occurs in close spatiotemporal vicinity. Such facilitation of saccadic reaction time (SRT) is well-documented, but the exact neural mechanisms underlying the crossmodal effect remain to be elucidated. From EEG/MEG studies it has been hypothesized that coupled oscillatory activity in primary sensory cortices regulates multisensory processing. Specifically, it is assumed that the phase of an ongoing neural oscillation is shifted due to the occurrence of a sensory stimulus so that, across trials, phase values become highly consistent (phase reset). If one can identify the phase an oscillation is reset to, it is possible to predict when temporal windows of high and low excitability will occur. However, in behavioral experiments the pre-stimulus phase will be different on successive repetitions of the experimental trial, and average performance over many trials will show no signs of the
Initiating an eye movement towards a suddenly appearing visual target is faster when an accessory auditory stimulus occurs in close spatiotemporal vicinity. Such facilitation of saccadic reaction time (SRT) is well-documented, but the exact neural mechanisms underlying the crossmodal effect remain to be elucidated. From EEG/MEG studies it has been hypothesized that coupled oscillatory activity in primary sensory cortices regulates multisensory processing. Specifically, it is assumed that the phase of an ongoing neural oscillation is shifted due to the occurrence of a sensory stimulus so that, across trials, phase values become highly consistent (phase reset). If one can identify the phase an oscillation is reset to, it is possible to predict when temporal windows of high and low excitability will occur. However, in behavioral experiments the pre-stimulus phase will be different on successive repetitions of the experimental trial, and average performance over many trials will show no signs of the
The Frontal Eye Fields (FEF) participate in both working memory and sensorimotor transformations for saccades, but their role in integrating these functions through time remains unclear. Here, we tracked FEF spatial codes through time using a novel analytic method applied to the classic memory-delay saccade task. Three-dimensional recordings of head-unrestrained gaze shifts were made in two monkeys trained to make gaze shifts toward briefly flashed targets after a variable delay (450-1500 ms). A preliminary analysis of visual and motor response fields in 74 FEF neurons eliminated most potential models for spatial coding at the neuron population level, as in our previous study (Sajad et al., 2015). We then focused on the spatiotemporal transition from an eye-centered target code (T; preferred in the visual response) to an eye-centered intended gaze position code (G; preferred in the movement response) during the memory delay interval. We treated neural population codes as a continuous ...
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In the paper by Thurtell and colleagues,1 two patients with epilepsy are described in whom in one stimulation over the frontal eye field (FEF) resulted in dysconjugate contraversive horizontal eye movements and in the other similar eye movements were observed as a result of focal seizures (see page 683). The neural system controlling eye movements, particularly rapid conjugate versive movements, called saccades, is one of the most thoroughly understood neural circuits in the brain. It contains a number of cortical centres, … ...
An area of visual-motor cortex called the lateral intraparietal area encodes eye position signals that support visually-guided behaviors and image stabilization.
Schaeffer, D. J., Chi, L., Krafft, C. E., Li, Q., Schwarz, N. F., & McDowell, J. E. (2014). Individual differences in working memory moderate the relationship between prosaccade latency and antisaccade error rate. Psychophysiology. Advance online publication. doi: 10.1111/psyp.12380. Pierce, J.E., McCardel, J.B., & McDowell, J.E. (2015). Trial type probability and task switching effects on behavioral response characteristics in a mixed saccade task. Experimental Brain Research, 233(3), 959-69. doi: 10.1007/s00221-014-4170-z. Pierce, J.E., Krafft, C.E., Rodrigue, A.L., Bobilev, A., Lauderdale, J.D., & McDowell, J.E. (2014). Intrinsic functional connectivity networks in individuals with aniridia. Frontiers in Human Neuroscience, 8: 1013. doi: 10.3389/fnhum.2014.01013. Schaeffer, D. J., Krafft, C. E., Schwarz, N. F., Chi, L., Rodrigue, A. L., Pierce, J. E., Allison, J. D., Yanasak, N. E., Liu, T., Davis, C. L., & McDowell, J. E. (2014). The relationship between uncinate fasciculus white matter ...
Mean response accuracy was 92% (SD: 5%) with mean false positive rate 6% (SD: 4%). Mean reaction time was 1579 ms (SD: 235 ms). After excluding 3 frontal EOG clusters comprising 240 ICs, the major (90 ms) lambda response peak in the fixation-onset locked ERPs was dominated by 3 occipital IC clusters (100 ICs, 92% of the peak scalp map accounted for) (Figure 1). ERPs time locked to saccade onsets contained a pre-saccadic spike peaking at -12 ms. Three far frontal clusters dominated this spike (260 ICs, 95% variance accounted) (Figure 2 left). However, after removing all 5 EOG and far frontal clusters (314 ICs) and 1 temporal scalp muscle (EMG) cluster (26 ICs), 4 posterior clusters (114 ICs) contributed 82% of the remaining (positive-going) pre-saccadic spike (Figure 2 right).. ...
This is an upper-level README for the model associated with the paper: Moren J, Shibata T, Doya K (2013) The mechanism of saccade motor pattern generation investigated by a large-scale spiking neuron model of the superior colliculus. PLoS One 8:e57134 A spatial model of the intermediate superior colliculus. It reproduces the collicular saccade-generating output profile from NMDA receptor-driven burst neurons, shaped by integrative inhibitory feedback from spreading buildup neuron activity. The model is consistent with the view that collicular activity directly shapes the temporal profile of saccadic eye movements. We use the Adaptive exponential integrate and fire neuron model, augmented with an NMDA-like membrane potential-dependent receptor. In addition, we use a synthetic spike integrator model as a stand-in for a spike-integrator circuit in the reticular formation. NOTE: We use a couple of custom neuron models, so the supplied model file includes an entire version of NEST. I also include a ...
In the future, operators of complex equipment will spend more time monitoring computer controlled devices rather than having hands-on control of such equipment. The operator intervenes in system operation under unusual conditions or when there is a computer malfunction. The latter occurs relatively seldom. The operators task thus becomes a vigilance task, one requiring attention to monitoring equipment with little need for action. An individuals ability to maintain vigilance is easily compromised, with time-on-task (TOT) a major detractor of performance. The question asked in this research was: Can gaze control measures be used to reflect, and hopefully to predict, periods of impaired vigilance?*PERFORMANCE(HUMAN)
In bottom-up visual perception our eyes quickly move and fixate before processing the information they take in. Some data is pushed to memory. Some isnt.