Optokinetic Memory in the Crab, Carcinus

1966 ◽  
Vol 44 (2) ◽  
pp. 233-245
Author(s):  
G. A. HORRIDGE
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Visual Feedback ◽  
Opposite Direction ◽  
Feedback Loop ◽  
Closed Loop ◽  
Dark Period ◽  
Eye Position ◽  
Movement Perception ◽  
Memory Experiment

1. A crab is held at the centre of an illuminated stationary striped drum or any visual field with strong contrasts. After a time all lights are turned off and the drum is moved in the dark. The light is restored when the drum is stationary in its new position. The animal responds by a movement of the eyes. 2. Stimuli of 0.5° over a dark period of 2 min. or 1° over 15 min. give a response. The response depends on the angle of the drum movement, and is slower in performance and less in total amount for longer periods of darkness. 3. On re-illumination the movement of the eye relative to the stationary drum is such that the visual field moves across the eye in the opposite direction to the eye's movement, but nevertheless the perception of small drum oscillations is not impaired. 4. When the visual feedback loop is opened by clamping the seeing eye and painting over the moving one, eye movements can be greater than drum movements, as in movement perception. Comparison of calculated with experimental closed-loop conditions shows that in the memory experiment there is no attenuation or amplification in the visual feedback loop. 5. Perception of very slow movements and stabilization of eye position could, but do not necessarily, depend on this accurate but short-lived directional memory.

scholarly journals Local Feedback Signals Are Not Distorted By Prior Eye Movements: Evidence From Visually Evoked Double Saccades

1997 ◽  
Vol 78 (1) ◽  
pp. 533-538 ◽  
Author(s):  
H.H.L.M. Goossens ◽  
A. J. Van Opstal
Keyword(s):  
Eye Movements ◽  
Feedback Control ◽  
Time Constant ◽  
Feedback Loop ◽  
Eye Position ◽  
Visually Guided ◽  
Double Step ◽  
Local Feedback ◽  
Reset Time ◽  
Saccadic Responses

Goossens, H.H.L.M. and A. J. Van Opstal. Local feedback signals are not distorted by prior eye movements: evidence from visually evoked double saccades. J. Neurophysiol. 78: 533–538, 1997. Recent experiments have shown that the amplitude and direction of saccades evoked by microstimulation of the monkey superior colliculus depend systematically on the amplitude and direction of preceding visually guided saccades as well as on the postsaccade stimulation interval. The data are consistent with the hypothesis that an eye displacement integrator in the local feedback loop of the saccadic burst generator is gradually reset with a time constant of ∼45 ms. If this is true, similar effects should occur during naturally evoked saccade sequences, causing systematic interval-dependent errors. To test this prediction in humans, saccades toward visual single- and double-step stimuli were elicited, and the properties of the second saccades were investigated as a function of the intersaccadic interval (ISI). In 15–20% of the saccadic responses, ISIs fell well below 100 ms. The errors of the second saccades were not systematically affected by the preceding primary saccade, irrespective of the ISI. Only a slight increase in the endpoint variability of second saccades was observed for the shortest ISIs. These results are at odds with the hypothesis that the putative eye displacement integrator has a reset time constant >10 ms. Instead, it is concluded that the signals involved in the internal feedback control of the saccadic burst generator reflect eye position and/or eye displacement accurately, irrespective of preceding eye movements.

scholarly journals Mice Make Targeted Saccades

2021 ◽  
Author(s):  
Sebastian H. Zahler ◽  
David E. Taylor ◽  
Julia M. Adams ◽  
Evan H. Feinberg
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Visual System ◽  
Neural Circuit ◽  
Saccadic Eye Movements ◽  
Eye Position ◽  
Innate Behavior ◽  
High Acuity ◽  
Early Origin ◽  
Innate Ability

AbstractHumans read text, recognize faces, and process emotions using targeted saccadic eye movements. In the textbook model, this innate ability to make targeted saccades evolved in species with foveae or similar high-acuity retinal specializations that enable scrutiny of salient stimuli. According to the model, saccades made by species without retinal specializations (such as mice) are never targeted and serve only to reset the eyes after gaze-stabilizing movements. Here we show that mice innately make touch-evoked targeted saccades. Optogenetic manipulations revealed the neural circuit mechanisms underlying targeted saccades are conserved. Saccade probability is a U-shaped function of current eye position relative to the target, mirroring the simulated relationship between an object’s location within the visual field and the probability its next movement carries it out of view. Thus, a cardinal sophistication of our visual system may have had an unexpectedly early origin as an innate behavior that keeps stimuli in view.

Early Coding of Reaching in the Parietooccipital Cortex

2000 ◽  
Vol 83 (4) ◽  
pp. 2374-2391 ◽  
Author(s):  
Alexandra Battaglia-Mayer ◽  
Stefano Ferraina ◽  
Takashi Mitsuda ◽  
Barbara Marconi ◽  
Aldo Genovesio ◽  
...  
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Neural Activity ◽  
Movement Time ◽  
Hand Movement ◽  
Cell Activity ◽  
Arm Movement ◽  
Saccadic Eye Movements ◽  
Target Cells ◽  
Eye Position

Neural activity was recorded in the parietooccipital cortex while monkeys performed different tasks aimed at investigating visuomotor interactions of retinal, eye, and arm-related signals on neural activity. The tasks were arm reaching 1) to foveated targets; 2) to extrafoveal targets, with constant eye position; 3) within an instructed-delayed paradigm, under both light and darkness; 4) saccadic eye movements toward, and static eye holding on peripheral targets; and 5) visual fixation and stimulation. The activity of many cells was modulated during arm reaction (68%) and movement time (58%), and during static holding of the arm in space (64%), when eye position was kept constant. Eye position influenced the activity of many cells during hand reaction (45%) and movement time (51%) and holding of hand static position (69%). Many cells (56%) were also modulated during preparation for hand movement, in the delayed reach task. Modulation was present also in the dark in 59% of cells during this epoch, 51% during reaction and movement time, and 48% during eye/hand holding on the target. Cells (50%) displaying light-dark differences of activity were considered as related to the sight and monitoring of hand motion and/or position in the visual field. Saccadic eye movements modulated a smaller percentage (25%) of cells than eye position (68%). Visual receptive fields were mapped in 44% of the cells studied. They were generally large and extended to the periphery of the tested (30°) visual field. Sixty-six percent of cells were motion sensitive. Therefore the activity of many neurons in this area reflects the combined influence of visual, eye, and arm movement–related signals. For most neurons, the orientation of the preferred directions computed across different epochs and tasks, therefore expression of all different eye- and hand-related activity types, clustered within a limited sector of space, the field of global tuning. These spatial fields might be an ideal frame to combine eye and hand signals, thanks to the congruence of their tuning properties. The relationships between cell activity and oculomotor and visuomanual behavior were task dependent. During saccades, most cells were recruited when the eye moved to a spatial location that was also target for hand movement, whereas during hand movement most cells fired depending on whether or not the animal had prior knowledge about the location of the visual targets.

Mislocalisation of Chromatic and Achromatic Stimuli during Saccadic Eye Movements

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 137-137
Author(s):  
M Sato ◽  
K Uchikawa
Keyword(s):  
Eye Movements ◽  
Opposite Direction ◽  
Visual Target ◽  
Saccadic Eye Movements ◽  
Eye Position ◽  
Stationary Target ◽  
Actual Position ◽  
Chromatic Stimulus ◽  
Position Signal ◽  
Retinal Information

It is well known that a brief flash of a small stationary target presented during saccades appears to be shifted from the actual position. The perceptual location of a visual target should be determined by the retinal information and the eye position signal. This mislocalisation seems to indicate that the change of the eye position signal is more sluggish than the actual eye movements. Delay of transmission of the retinal information may be a factor of mislocalisation. Here, we measured the perceptual location of chromatic stimuli which had different temporal characteristics from achromatic stimuli. The chromatic stimulus was a small red spot which replaced the green field for 10 ms. The green field subtended 5 deg × 24 deg and its luminance was 78.6 cd m−2. The luminance of the chromatic stimulus was adjusted to be the same as the green field by the minimum flicker method. The luminance of the achromatic stimulus was 234 cd m−2. Our results show that the chromatic and the achromatic stimuli presented at the beginning of saccades are mislocalised in the same direction as the saccades. We also found that the mislocalisation of the chromatic stimulus began slightly earlier than the achromatic stimulus. Also the chromatic stimulus presented during saccades was mislocalised in the opposite direction to the saccades whereas the achromatic stimulus was localised approximately at the actual position. These results suggest that the chromatic response is transmitted more slowly before saccades but faster during saccades than the achromatic response.

scholarly journals Eye and head movements are complementary in visual selection

2017 ◽  
Vol 4 (1) ◽  
pp. 160569 ◽  
Author(s):  
Grayden J. F. Solman ◽  
Tom Foulsham ◽  
Alan Kingstone
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Visual Selection ◽  
Head Movements ◽  
Eye Position ◽  
Vertical Slot ◽  
New Information ◽  
Complementary Pattern ◽  
Selection For ◽  
Nested System

In the natural environment, visual selection is accomplished by a system of nested effectors, moving the head and body within space and the eyes within the visual field. However, it is not yet known if the principles of selection for these different effectors are the same or different. We used a novel gaze-contingent display in which an asymmetric window of visibility (a horizontal or vertical slot) was yoked to either head or eye position. Participants showed highly systematic changes in behaviour, revealing clear differences in the principles underlying selection by eye and head. Eye movements were more likely to move in the direction of visible information—horizontally when viewing with a horizontal slot, and vertically with a vertical slot. Head movements showed the opposite and complementary pattern, moving to reveal new information (e.g. vertically with a horizontal slot and vice versa). These results are consistent with a nested system in which the head favours exploration of unknown regions, while the eye exploits what can be seen with finer-scale saccades.

scholarly journals Reversible Inactivation of Monkey Superior Colliculus. I. Curvature of Saccadic Trajectory

1998 ◽  
Vol 79 (4) ◽  
pp. 2082-2096 ◽  
Author(s):  
Hiroshi Aizawa ◽  
Robert H. Wurtz
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Superior Colliculus ◽  
Saccadic Eye Movements ◽  
Cell Types ◽  
Neuron Activity ◽  
Eye Position ◽  
Two Dimensional ◽  
Reversible Inactivation ◽  
Intermediate Layers

Aizawa, Hiroshi and Robert H. Wurtz. Reversible inactivation of monkey superior colliculus. I. Curvature of saccadic trajectory. J. Neurophysiol. 79: 2082–2096, 1998. The neurons in the intermediate layers of the monkey superior colliculus (SC) that discharge before saccadic eye movements can be divided into at least two types, burst and buildup neurons, and the differences in their characteristics are compatible with different functional contributions of the two cell types. It has been suggested that a spread of activity across the population of the buildup neurons during saccade generation may contribute to the control of saccadic eye movements. The influence of any such spread should be on both the horizontal and vertical components of the saccade because the map of the movement fields on the SC is a two-dimensional one; it should affect the trajectory of saccade. The present experiments used muscimol injections to inactivate areas within the SC to determine the functional contribution of such a spread of activity on the trajectory of the saccades. The analysis concentrated on saccades made to areas of the visual field that should be affected primarily by alteration of buildup neuron activity. Muscimol injections produced saccades with altered trajectories; they became consistently curved after the injection, and successive saccades to the same targets had similar curvatures. The curved saccades showed changes in their direction and speed at the very beginning of the saccade, and for those saccades that reached the target, the direction of the saccade was altered near the end to compensate for the initially incorrect direction. Postinjection saccades had lower peak speeds, longer durations, and longer latencies for initiation. The changes in saccadic trajectories resulting from muscimol injections, along with the previous observations on changes in speed of saccades with such injections, indicate that the SC is involved in influencing the eye position during the saccade as well as at the end of the saccade. The changes in trajectory when injections were made more rostral in the SC than the most active burst neurons also are consistent with a contribution of the buildup neurons to the control of the eye trajectory. The results do not, however, support the hypothesis that the buildup neurons in the SC act as a spatial integrator.

Visual Tracking Neurons in Primate Area MST Are Activated by Smooth-Pursuit Eye Movements of an “Imaginary” Target

2003 ◽  
Vol 90 (3) ◽  
pp. 1489-1502 ◽  
Author(s):  
Uwe J. Ilg ◽  
Peter Thier
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Eye Movement ◽  
Visual Tracking ◽  
Smooth Pursuit ◽  
Rhesus Monkeys ◽  
Image Motion ◽  
Eye Position ◽  
Smooth Pursuit Eye Movements ◽  
Pursuit Eye Movements

Because smooth-pursuit eye movements (SPEM) can be executed only in the presence of a moving target, it has been difficult to attribute the neuronal activity observed during the execution of these eye movements to either sensory processing or to motor preparation or execution. Previously, we showed that rhesus monkeys can be trained to perform SPEM directed toward an “imaginary” target defined by visual cues confined to the periphery of the visual field. The pursuit of an “imaginary” target provides the opportunity to elicit SPEM without stimulating visual receptive fields confined to the center of the visual field. Here, we report that a subset of neurons [85 “ imaginary” visual tracking (iVT)-neurons] in area MST of 3 rhesus monkeys were identically activated during pursuit of a conventional, foveal dot target and the “imaginary” target. Because iVT-neurons did not respond to the presentation of a moving “imaginary” target during fixation of a stationary dot, we are able to exclude that responses to pursuit of the “imaginary” target were artifacts of stimulation of the visual field periphery. Neurons recorded from the representation of the central parts of the visual field in neighboring area MT, usually vigorously discharging during pursuit of foveal targets, in no case responded to pursuit of the “imaginary” target. This dissociation between MT and MST neurons supports the view that pursuit responses of MT neurons are the result of target image motion, whereas those of iVT-neurons in area MST reflect an eye movement–related signal that is nonretinal in origin. iVT-neurons fell into two groups, depending on the properties of the eye movement–related signal. Whereas most of them (71%) encoded eye velocity, a minority showed responses determined by eye position, irrespective of whether eye position was changed by smooth pursuit or by saccades. Only the former group exhibited responses that led the eye movement, which is a prerequisite for a causal role in the generation of SPEM.

The Impact of Visual Feedback Type on the Mastery of Visuo-Motor Transformations

2012 ◽  
Vol 220 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Sandra Sülzenbrück
Keyword(s):  
Empirical Research ◽  
Visual Feedback ◽  
Closed Loop ◽  
Motor Planning ◽  
Visual Input ◽  
Closed Loop Control ◽  
Loop Control ◽  
Feedback Type ◽  
Effective Use ◽  
The Impact

For the effective use of modern tools, the inherent visuo-motor transformation needs to be mastered. The successful adjustment to and learning of these transformations crucially depends on practice conditions, particularly on the type of visual feedback during practice. Here, a review about empirical research exploring the influence of continuous and terminal visual feedback during practice on the mastery of visuo-motor transformations is provided. Two studies investigating the impact of the type of visual feedback on either direction-dependent visuo-motor gains or the complex visuo-motor transformation of a virtual two-sided lever are presented in more detail. The findings of these studies indicate that the continuous availability of visual feedback supports performance when closed-loop control is possible, but impairs performance when visual input is no longer available. Different approaches to explain these performance differences due to the type of visual feedback during practice are considered. For example, these differences could reflect a process of re-optimization of motor planning in a novel environment or represent effects of the specificity of practice. Furthermore, differences in the allocation of attention during movements with terminal and continuous visual feedback could account for the observed differences.

Visual asymmetries during face encoding Increased dwell time and fixations in the upper and left hemifields

2018 ◽  
Author(s):  
Fatima Maria Felisberti
Keyword(s):  
Face Recognition ◽  
Eye Movements ◽  
Visual Field ◽  
Face Processing ◽  
Dwell Time ◽  
The Other ◽  
Environmental Cues ◽  
Reading Habits ◽  
The Right

Visual field asymmetries (VFA) in the encoding of groups rather than individual faces has been rarely investigated. Here, eye movements (dwell time (DT) and fixations (Fix)) were recorded during the encoding of three groups of four faces tagged with cheating, cooperative, or neutral behaviours. Faces in each of the three groups were placed in the upper left (UL), upper right (UR), lower left (LL), or lower right (LR) quadrants. Face recognition was equally high in the three groups. In contrast, the proportion of DT and Fix were higher for faces in the left than the right hemifield and in the upper rather than the lower hemifield. The overall time spent looking at the UL was higher than in the other quadrants. The findings are relevant to the understanding of VFA in face processing, especially groups of faces, and might be linked to environmental cues and/or reading habits.

Visual Field Accuracy and Eye Movement Direction: A Child's Eye View

1980 ◽  
Vol 50 (2) ◽  
pp. 631-636
Author(s):  
Evans Mandes
Keyword(s):  
Eye Movements ◽  
Visual Field ◽  
Eye Movement ◽  
Visual Fields ◽  
Movement Direction

Post-exposural eye movements were studied in 32 adults and 24 7-yr.-old children. Stimuli were binary figures exposed tachistoscopically in both visual fields simultaneously. The data showed significant correlations between direction of eye movement and locus of recognition for both children and adults. No significant differences were found in frequencies of eye movements of children and adults. The data are interpreted in terms of the facilitative effects of post-exposural eye movements upon perception for both groups.

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