scholarly journals Humanoid Eyes: Perspective & Challenges

2019 ◽  
Author(s):  
Ahmad Yousef
Keyword(s):  
Prefrontal Cortex ◽  
Eye Movements ◽  
Brain Imaging ◽  
Saccadic Eye Movements ◽  
Essential Elements ◽  
Human Vision ◽  
Human Eye ◽  
Cortical Areas ◽  
The Continuum

This proposal offers perspective and challenges aiming to optimize and socialize the humanoid eyes. The main purpose of this proposal is to bring the readers’ attention to the importance and the sophistication of the human eye and its four dynamics continuum, namely, the continuum that may include saccadic eye movements, pupil variations, blinks along with duchenne markers. We suggested that the robotics’ designers to work collaboratively with neuroscientists to mathematically estimate the aforementioned continuum, and therefore, humanoid eyes/cameras can be perfectly invented; invention that we try to register its essential elements in the present study. The aforementioned collaboration will be very beneficial for an additional purpose, namely, because human vision indeed activates very many cortical areas that extended to the prefrontal cortex; the collaboration may effectively flourish the eye trackers to be good replacements of the expensive brain imaging in certain circumstances.

Effects of unilateral deactivations of dorsolateral prefrontal cortex and anterior cingulate cortex on saccadic eye movements

2014 ◽  
Vol 111 (4) ◽  
pp. 787-803 ◽  
Author(s):  
Michael J. Koval ◽  
R. Matthew Hutchison ◽  
Stephen G. Lomber ◽  
Stefan Everling
Keyword(s):  
Prefrontal Cortex ◽  
Eye Movements ◽  
Functional Connectivity ◽  
Anterior Cingulate Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Saccadic Eye Movements ◽  
Cingulate Cortex ◽  
Anterior Cingulate ◽  
Dorsolateral Prefrontal ◽  
Single Neuron Recording

The dorsolateral prefrontal cortex (dlPFC) and anterior cingulate cortex (ACC) have both been implicated in the cognitive control of saccadic eye movements by single neuron recording studies in nonhuman primates and functional imaging studies in humans, but their relative roles remain unclear. Here, we reversibly deactivated either dlPFC or ACC subregions in macaque monkeys while the animals performed randomly interleaved pro- and antisaccades. In addition, we explored the whole-brain functional connectivity of these two regions by applying a seed-based resting-state functional MRI analysis in a separate cohort of monkeys. We found that unilateral dlPFC deactivation had stronger behavioral effects on saccades than unilateral ACC deactivation, and that the dlPFC displayed stronger functional connectivity with frontoparietal areas than the ACC. We suggest that the dlPFC plays a more prominent role in the preparation of pro- and antisaccades than the ACC.

Role of the Basal Ganglia in the Control of Purposive Saccadic Eye Movements

2000 ◽  
Vol 80 (3) ◽  
pp. 953-978 ◽  
Author(s):  
Okihide Hikosaka ◽  
Yoriko Takikawa ◽  
Reiko Kawagoe
Keyword(s):  
Eye Movements ◽  
Basal Ganglia ◽  
Saccadic Eye Movements ◽  
Behavioral Adaptation ◽  
Inhibitory Input ◽  
Behavioral Context ◽  
Critical Determinant ◽  
Cortical Areas ◽  
Cortical Inputs

In addition to their well-known role in skeletal movements, the basal ganglia control saccadic eye movements (saccades) by means of their connection to the superior colliculus (SC). The SC receives convergent inputs from cerebral cortical areas and the basal ganglia. To make a saccade to an object purposefully, appropriate signals must be selected out of the cortical inputs, in which the basal ganglia play a crucial role. This is done by the sustained inhibitory input from the substantia nigra pars reticulata (SNr) to the SC. This inhibition can be removed by another inhibition from the caudate nucleus (CD) to the SNr, which results in a disinhibition of the SC. The basal ganglia have another mechanism, involving the external segment of the globus pallidus and the subthalamic nucleus, with which the SNr-SC inhibition can further be enhanced. The sensorimotor signals carried by the basal ganglia neurons are strongly modulated depending on the behavioral context, which reflects working memory, expectation, and attention. Expectation of reward is a critical determinant in that the saccade that has been rewarded is facilitated subsequently. The interaction between cortical and dopaminergic inputs to CD neurons may underlie the behavioral adaptation toward purposeful saccades.

scholarly journals Comparison of Cortico-Cortical and Cortico-Collicular Signals for the Generation of Saccadic Eye Movements

2002 ◽  
Vol 87 (2) ◽  
pp. 845-858 ◽  
Author(s):  
Stefano Ferraina ◽  
Martin Paré ◽  
Robert H. Wurtz
Keyword(s):  
Cerebral Cortex ◽  
Eye Movements ◽  
Visual Processing ◽  
Full Range ◽  
Saccadic Eye Movements ◽  
Projection Neurons ◽  
Visual Response ◽  
Antidromic Activation ◽  
Cortical Areas ◽  
Saccade Task

Many neurons in the frontal eye field (FEF) and lateral intraparietal (LIP) areas of cerebral cortex are active during the visual-motor events preceding the initiation of saccadic eye movements: they respond to visual targets, increase their activity before saccades, and maintain their activity during intervening delay periods. Previous experiments have shown that the output neurons from both LIP and FEF convey the full range of these activities to the superior colliculus (SC) in the brain stem. These areas of cerebral cortex also have strong interconnections, but what signals they convey remains unknown. To determine what these cortico-cortical signals are, we identified the LIP neurons that project to FEF by antidromic activation, and we studied their activity during a delayed-saccade task. We then compared these cortico-cortical signals to those sent subcortically by also identifying the LIP neurons that project to the intermediate layers of the SC. Of 329 FEF projection neurons and 120 SC projection neurons, none were co-activated by both FEF and SC stimulation. FEF projection neurons were encountered more superficially in LIP than SC projection neurons, which is consistent with the anatomical projection of many cortical layer III neurons to other cortical areas and of layer V neurons to subcortical structures. The estimated conduction velocities of FEF projection neurons (16.7 m/s) were significantly slower that those of SC projection neurons (21.7 m/s), indicating that FEF projection neurons have smaller axons. We identified three main differences in the discharge properties of FEF and SC projection neurons: only 44% of the FEF projection neurons changed their activity during the delayed-saccade task compared with 69% of the SC projection neurons; only 17% of the task-related FEF projection neurons showed saccadic activity, whereas 42% of the SC projection neurons showed such increases; 78% of the FEF projection neurons had a visual response but no saccadic activity, whereas only 55% of the SC projection neurons had similar activity. The FEF and SC projection neurons had three similarities: both had visual, delay, and saccadic activity, both had stronger delay and saccadic activity with visually guided than with memory-guided saccades, and both had broadly tuned responses for disparity stimuli, suggesting that their visual receptive fields have a three-dimensional configuration. These observations indicate that the activity carried between parietal and frontal cortical areas conveys a spectrum of signals but that the preponderance of activity conveyed might be more closely related to earlier visual processing than to the later saccadic stages that are directed to the SC.

Prefrontal Cortex Neurons Reflecting Reports of a Visual Illusion

2001 ◽  
Vol 85 (4) ◽  
pp. 1395-1411 ◽  
Author(s):  
Mikhail A. Lebedev ◽  
Diana K. Douglass ◽  
Sohie Lee Moody ◽  
Steven P. Wise
Keyword(s):  
Prefrontal Cortex ◽  
Eye Movements ◽  
Eye Movement ◽  
Spatial Perception ◽  
Human Subjects ◽  
Saccadic Eye Movements ◽  
Directional Selectivity ◽  
Frame Shift ◽  
The Right ◽  
New Location

When a small, focally attended visual stimulus and a larger background frame shift location at the same time, the frame's new location can affect spatial perception. For horizontal displacements on the order of 1–2°, when the frame moves more than the attended stimulus, human subjects may perceive that the attended stimulus has shifted to the right or left when it has not done so. However, that misapprehension does not disable accurate eye movements to the same stimulus. We trained a rhesus monkey to report the direction that an attended stimulus had shifted by making an eye movement to one of the two report targets. Then, using conditions that induce displacement illusions in human subjects, we tested the hypothesis that neuronal activity in the prefrontal cortex (PF) would reflect the displacement directions reported by the monkey, even when they conflicted with the actual displacement, if any, of the attended stimulus. We also predicted that these cells would have directional selectivity for movements used to make those reports, but not for similar eye movements made to fixate the attended stimulus. A population of PF neurons showed the predicted properties, which could not be accounted for on the basis of either eye-movement or frame-shift parameters. This activity, termed report-related, began approximately 150 ms before the onset of the reporting saccade. Another population of PF neurons showed greater directional selectivity for saccadic eye movements made to fixate the attended stimulus than for similar saccades made to report its displacement. In view of the evidence that PF functions to integrate inputs and actions occurring at different times and places, the present findings support the idea that such integration involves movements to acquire response targets, directly, as well as actions guided by less direct response rules, such as perceptual reports.

scholarly journals Neuronal activity related to saccadic eye movements in the monkey's dorsolateral prefrontal cortex

1991 ◽  
Vol 65 (6) ◽  
pp. 1464-1483 ◽  
Author(s):  
S. Funahashi ◽  
C. J. Bruce ◽  
P. S. Goldman-Rakic
Keyword(s):  
Prefrontal Cortex ◽  
Eye Movements ◽  
Visual Field ◽  
Tuning Curve ◽  
Saccadic Eye Movements ◽  
Neuron Activity ◽  
Delayed Response ◽  
Visually Guided ◽  
Related Activity ◽  
Vertical Meridian

1. Single-neuron activity was recorded from the prefrontal cortex of monkeys performing saccadic eye movements in oculomotor delayed-response (ODR) and visually guided saccade (VGS) tasks. In the ODR task the monkey was required to maintain fixation of a central spot throughout the 0.5-s cue and 3.0-s delay before making a saccadic eye movement in the dark to one of four or eight locations where the visual cue had been presented. The same locations were used for targets in the VGS tasks; however, unlike the ODR task, saccades in the VGS tasks were visually guided. 2. Among 434 neurons recorded from prefrontal cortex within and surrounding the principal sulcus (PS), 147 changed their discharge rates in relation to saccadic eye movements in the ODR task. Their response latencies relative to saccade initiation were distributed between -192 and 460-ms, with 22% exhibiting presaccadic activity and 78% exhibiting only postsaccadic activity. Among PS neurons with presaccadic activity, 53% also had postsaccadic activity when the monkey made saccadic eye movements opposite to the directions for which the presaccadic activity was observed. 3. Almost all (97%) PS neurons with presaccadic activity were directionally selective. The best direction and tuning specificity of each neuron were estimated from parameters used to fit a Gaussian tuning curve function. The best direction for 62% of the neurons with presaccadic activity was toward the contralateral visual field, with the remaining neurons having best directions toward the ipsilateral field (23%) or along the vertical meridian (15%). 4. Most postsaccadic activity of PS neurons (92%) was also directionally selective. The best direction for 48% of these neurons was toward the contralateral visual field, with the remaining neurons having best directions toward the ipsilateral field (36%) or along the vertical meridian (16%). Eighteen percent of the neurons with postsaccadic activity showed a reciprocal response pattern: excitatory responses occurred for one set of saccade directions, whereas inhibitory responses occurred for roughly the opposite set of directions. 5. Sixty PS neurons with saccade-related activity in the ODR task were also examined in a VGS task. Forty of these neurons showed highly similar profiles of directional specificity and response magnitude in both tasks, 13 showed saccade-related activity only in the ODR task, and 7 changed their response characteristics between the ODR and VGS tasks.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Reflexive and Intentional Saccadic Eye Movements in Migraineurs

2021 ◽  
Vol 12 ◽  
Author(s):  
Filipp M. Filippopulos ◽  
Christine Goeschy ◽  
Florian Schoeberl ◽  
Ozan E. Eren ◽  
Andreas Straube ◽  
...  
Keyword(s):  
Eye Movements ◽  
Saccadic Eye Movements ◽  
Saccade Latency ◽  
Control Group ◽  
Cortical Networks ◽  
Functional Changes ◽  
Cortical Areas ◽  
Vector Inversion ◽  
Anti Saccades ◽  
Reflexive Saccades

Background: Migraine has been postulated to lead to structural and functional changes of different cortical and subcortical areas, including the frontal lobe, the brainstem, and cerebellum. The (sub-)clinical impact of these changes is a matter of debate. The spectrum of possible clinical differences include domains such as cognition but also coordination. The present study investigated the oculomotor performance of patients with migraine with and without aura compared to control subjects without migraine in reflexive saccades, but also in intentional saccades, which involve cerebellar as well as cortical networks.Methods: In 18 patients with migraine with aura and 21 patients with migraine without aura saccadic eye movements were recorded in two reflexive (gap, overlap) and two intentional (anti, memory) paradigms and compared to 25 controls without migraine.Results: The main finding of the study was an increase of saccade latency in patients with and without aura compared to the control group solely in the anti-task. No deficits were found in the execution of reflexive saccades.Conclusions: Our results suggest a specific deficit in the generation of correct anti-saccades, such as vector inversion. Such processes are considered to need cortical networks to be executed correctly. The parietal cortex has been suggested to be involved in vector inversion processes but is not commonly described to be altered in migraine patients. It could be discussed that the cerebellum, which is recently thought to be involved in the pathophysiology of migraine, might be involved in distinct processes such as spatial re-mapping through known interconnections with parietal and frontal cortical areas.

Human Sleep, Sleep Loss and Behaviour

1993 ◽  
Vol 162 (3) ◽  
pp. 413-419 ◽  
Author(s):  
J. A. Horne
Keyword(s):  
Prefrontal Cortex ◽  
Eye Movements ◽  
Motor Cortex ◽  
Sleep Loss ◽  
Frontal Eye Fields ◽  
Specific Task ◽  
Task Execution ◽  
Cortical Areas ◽  
Human Sleep ◽  
The Senses

The prefrontal cortex (PFC) consists of the cortex lying in front of the primary and secondary motor cortex, and includes the dorsolateral and orbital areas, frontal eye fields, and Broca's area. Not all of the functions of the PFC are known, but key ones are the maintenance of wakefulness and non-specific arousal, and the recruiting of various cortical areas required to deal with tasks in hand (Luria, 1973; Stuss & Benson, 1986; Fuster, 1989). Other roles include (Kolb & Whishaw, 1985) planning, sensory comparisons, discrimination, decisions for action, direction and maintenance of attention at a specific task, execution of associated scanning eye movements, and initiation and production of novel goal-directed behaviour (especially with speech). Of the senses, vision makes a particular demand of the PFC, and this is reflected by the frontal eye fields.

The effect of task set on fixational saccadic eye movements

2013 ◽  
Author(s):  
Sara Spotorno ◽  
Guillaume S. Masson ◽  
Anna Montagnini
Keyword(s):  
Eye Movements ◽  
Saccadic Eye Movements ◽  
Task Set
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