Movements of the Retinae of Jumping Spiders (Salticidae: Dendryphantinae) in Response to Visual Stimuli

1969 ◽  
Vol 51 (2) ◽  
pp. 471-493 ◽  
Author(s):  
M. F. LAND
Keyword(s):  
Eye Movements ◽  
Spontaneous Activity ◽  
Visual Axis ◽  
Retinal Surface ◽  
Jumping Spiders ◽  
Spatial Alignment ◽  
Edge Detectors ◽  
Central Regions ◽  
Stimulation Of ◽  
Central Fixation

1. Movements made by the principal eyes of jumping spiders (Phidippus and Metaphidippus spp.) have been investigated using an ophthalmoscopic technique which permits simultaneous observation and stimulation of the retinal surface. 2. The eye-movements are produced by six muscles. Four are attached to the carapace, and displace each retina latero-medially and dorso-ventrally. The remaining pair are thin bands of muscle which encircle the eye-tube. These twist the eye-tube, rotating the retina about the visual axis (torsion). 3. The nerve supplying these muscles contains only six axons. Each axon terminates in one of the six muscles. 4. Four types of eye-movements are observed. These are spontaneous activity, saccades, tracking and scanning. All movements are usually conjugate. 5. Spontaneous activity consists of a very variable, periodic side-to-side motion of the retinae. It is associated with states of high excitability, and occurs whether or not there is any structure in the field of view. 6. Saccades occur when a small stimulus (e.g. a dark dot) is presented to, or moved upon, the retinae of either the principal eyes or the antero-lateral eyes. In a saccade the retinae move towards the image of the target so that they come to rest with their central regions fixated on the target. 7. If the target moves the retinae track it, maintaining central fixation. 8. Scanning normally follows a saccade. It consists of an oscillatory, side-to-side movement of the retinae across the stimulus, with a period of 1-2 sec., and a simultaneous torsional movement in which the retinae partially rotate about the visual axes, through an angle of approximately 50° and with a period of 5-15 sec. 9. Jumping spiders distinguish other jumping spiders from potential prey by the geometry of their legs. It is suggested that scanning is a pattern-recognition procedure in which the torsional movements are concerned with the spatial alignment of line or edge detectors, and the horizontal component with providing relative motion between these detectors and the stationary stimulus.

Motor intention activity in the macaque's lateral intraparietal area. I. Dissociation of motor plan from sensory memory

1996 ◽  
Vol 76 (3) ◽  
pp. 1439-1456 ◽  
Author(s):  
P. Mazzoni ◽  
R. M. Bracewell ◽  
S. Barash ◽  
R. A. Andersen
Keyword(s):  
Eye Movements ◽  
Visual Stimulus ◽  
Visual Stimuli ◽  
Saccadic Eye Movements ◽  
Stimulus Location ◽  
Sensory Memory ◽  
Lateral Intraparietal Area ◽  
Preferred Direction ◽  
Motor Plan ◽  
Stimulation Of

1. The lateral intraparietal area (area LIP) of the monkey's posterior parietal cortex (PPC) contains neurons that are active during saccadic eye movements. These neurons' activity includes visual and saccade-related components. These responses are spatially tuned and the location of a neuron's visual receptive field (RF) relative to the fovea generally overlaps its preferred saccade amplitude and direction (i.e., its motor field, MF). When a delay is imposed between the presentation of a visual stimulus and a saccade made to its location (memory saccade task), many LIP neurons maintain elevated activity during the delay (memory activity, M), which appears to encode the metrics of the next intended saccadic eye movements. Recent studies have alternatively suggested that LIP neurons encode the locations of visual stimuli regardless of where the animal intends to look. We examined whether the M activity of LIP neurons specifically encodes movement intention or the locations of recent visual stimuli, or a combination of both. In the accompanying study, we investigated whether the intended-movement activity reflects changes in motor plan. 2. We trained monkeys (Macaca mulatta) to memorize the locations of two visual stimuli and plan a sequence of two saccades, one to each remembered target, as we recorded the activity of single LIP neurons. Two targets were flashed briefly while the monkey maintained fixation; after a delay the fixation point was extinguished, and the monkey made two saccades in sequence to each target's remembered location, in the order in which the targets were presented. This "delayed double saccade" (DDS) paradigm allowed us to dissociate the location of visual stimulation from the direction of the planned saccade and thus distinguish neuronal activity related to the target's location from activity related to the saccade plan. By imposing a delay, we eliminated the confounding effect of any phasic responses coincident with the appearance of the stimulus and with the saccade. 3. We arranged the two visual stimuli so that in one set of conditions at least the first one was in the neuron's visual RF, and thus the first saccade was in the neuron's motor field (MF). M activity should be high in these conditions according to both the sensory memory and motor plan hypotheses. In another set of conditions, the second stimulus appeared in the RF but the first one was presented outside the RF, instructing the monkey to plan the first saccade away from the neuron's MF. If the M activity encodes the motor plan, it should be low in these conditions, reflecting the plan for the first saccade (away from the MF). If it is a sensory trace of the stimulus' location, it should be high, reflecting stimulation of the RF by the second target. 4. We tested 49 LIP neurons (in 3 hemispheres of 2 monkeys) with M activity on the DDS task. Of these, 38 (77%) had M activity related to the next intended saccade. They were active in the delay period, as expected, if the first saccade was in their preferred direction. They were less active or silent if the next saccade was not in their preferred direction, even when the second stimulus appeared in their RF. 5. The M activity of 8 (16%) of the remaining neurons specifically encoded the location of the most recent visual stimulus. Their firing rate during the delay reflected stimulation of the RF independently of the saccade being planned. The remaining 3 neurons had M activity that did not consistently encode either the next saccade or the stimulus' location. 6. We also recorded the activity of a subset of neurons (n = 38) in a condition in which no stimulus appeared in a neuron's RF, but the second saccade was in the neuron's MF. In this case the majority of neurons tested (23/38, 60%) became active in the period between the first and second saccade, even if neither stimulus had appeared in their RF. Moreover, this activity appeared only after the first saccade had started in all but two of

Vestibular-related eye movements in the rat following selective electrical stimulation of the vestibular sensors

2018 ◽  
Vol 204 (9-10) ◽  
pp. 835-847 ◽  
Author(s):  
Martin Hitier ◽  
Go Sato ◽  
Yan-Feng Zhang ◽  
Yiwen Zheng ◽  
Stephane Besnard ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Stimulation Of

scholarly journals Electrical Stimulation of the Frontal Eye Field in a Monkey Produces Combined Eye and Head Movements

2000 ◽  
Vol 84 (2) ◽  
pp. 1103-1106 ◽  
Author(s):  
Tyson A. Tu ◽  
E. Gregory Keating
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Head Movements ◽  
Frontal Eye Field ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
Eye Field ◽  
A Site ◽  
Head Rotations ◽  
Stimulation Of

The frontal eye field (FEF), an area in the primate frontal lobe, has long been considered important for the production of eye movements. Past studies have evoked saccade-like movements from the FEF using electrical stimulation in animals that were not allowed to move their heads. Using electrical stimulation in two monkeys that were free to move their heads, we have found that the FEF produces gaze shifts that are composed of both eye and head movements. Repeated stimulation at a site evoked gaze shifts of roughly constant amplitude. However, that gaze shift could be accomplished with varied amounts of head and eye movements, depending on their (head and eye) respective starting positions. This evidence suggests that the FEF controls visually orienting movements using both eye and head rotations rather than just shifting the eyes as previously thought.

Parabrachial area and nucleus raphe magnus-induced modulation of nociceptive and nonnociceptive trigeminal subnucleus caudalis neurons activated by cutaneous or deep inputs

1994 ◽  
Vol 71 (6) ◽  
pp. 2430-2445 ◽  
Author(s):  
C. Y. Chiang ◽  
J. W. Hu ◽  
B. J. Sessle
Keyword(s):  
Spontaneous Activity ◽  
Inhibitory Effects ◽  
Conditioning Stimulation ◽  
Nucleus Raphe Magnus ◽  
Nociceptive Neurons ◽  
Nociceptive Responses ◽  
Significant Difference ◽  
Raphe Magnus ◽  
Trigeminal Subnucleus Caudalis ◽  
Stimulation Of

1. The aim of this study was to test whether parabrachial area (PBA) stimulation exerts inhibitory influences on the spontaneous activity and responses evoked by skin and deep afferent inputs in trigeminal subnucleus caudalis (Vc) neurons, and to compare these effects with those of nucleus raphe magnus (NRM) stimulation. A total of 92 nonnociceptive and nociceptive Vc neurons was recorded in urethan/alpha-chloralose-anesthetized rats. Each neuron was functionally classified as low-threshold mechanoceptive (LTM), wide dynamic range (WDR), nociceptive-specific (NS), nociceptive convergent with both skin and deep inputs (S+D), or deep nociceptive (D); the LTM neurons could be subdivided as rapidly adapting (RA) or slowly adapting (SA). Conditioning stimulation was applied to histologically verified sites in PBA and NRM. 2. The spontaneous or evoked activity of all classes of neurons could be inhibited by PBA as well as by NRM stimulation, but generally the incidence and magnitude of inhibition were lower for the LTM neurons. Occasionally, facilitation of neuronal activity was also produced by PBA and NRM stimulation. 3. The spontaneous activity of 11 LTM neurons (6 RA, 5 SA), 13 nociceptive neurons (6 WDR, 7 NS), and 5 D neurons was tested with stimulation of PBA or NRM or both. LTM spontaneous activity was more significantly inhibited by NRM stimulation than by PBA stimulation, whereas both NRM and PBA stimulation had similar and significant inhibitory effects on NS, WDR, and D neurons. 4. The evoked nonnociceptive responses of 28 LTM neurons (16 RA, 12 SA) and of 6 WDR neurons were also tested with stimulation of PBA or NRM or both. The magnitudes of inhibition of the responses produced by PBA conditioning stimulation were statistically significantly less than those induced by NRM conditioning stimulation. 5. The cutaneous and deep nociceptive responses of cutaneous nociceptive neurons (9 NS, 19 WDR) and seven D neurons, respectively, were also tested with PBA and NRM stimulation. There was a significant difference in potency between PBA- and NRM-induced inhibition, but no difference in the magnitude of inhibitory effects among NS, WDR, and D neurons. For both PBA and NRM conditioning stimulation, graded increases in intensities of stimulation produced linear increases in inhibitory effects on nociceptive responses; an increase in stimulation frequency from 5 to 400 Hz also produced increases in inhibition of the nociceptive responses. 6. In five S+D nociceptive convergent neurons, the responses elicited by deep inputs were more powerfully inhibited by PBA stimulation than those elicited by cutaneous inputs.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Attention Combines Similarly in Covert and Overt Conditions

Vision ◽  
2019 ◽  
Vol 3 (2) ◽  
pp. 16
Author(s):  
Blair ◽  
Ristic
Keyword(s):  
Eye Movements ◽  
Human Behavior ◽  
Combined Effect ◽  
Combined Effects ◽  
Unexpected Events ◽  
Do So ◽  
Central Fixation

Attention is classically classified according to mode of engagement into voluntary and reflexive, and type of operation into covert and overt. The first distinguishes whether attention is elicited intentionally or by unexpected events; the second, whether attention is directed with or without eye movements. Recently, this taxonomy has been expanded to include automated orienting engaged by overlearned symbols and combined attention engaged by a combination of several modes of function. However, so far, combined effects were demonstrated in covert conditions only, and, thus, here we examined if attentional modes combined in overt responses as well. To do so, we elicited automated, voluntary, and combined orienting in covert, i.e., when participants responded manually and maintained central fixation, and overt cases, i.e., when they responded by looking. The data indicated typical effects for automated and voluntary conditions in both covert and overt data, with the magnitudes of the combined effect larger than the magnitude of each mode alone as well as their additive sum. No differences in the combined effects emerged across covert and overt conditions. As such, these results show that attentional systems combine similarly in covert and overt responses and highlight attention’s dynamic flexibility in facilitating human behavior.

New Mechanism That Accounts for Position Sensitivity of Saccades Evoked in Response to Stimulation of Superior Colliculus

1998 ◽  
Vol 80 (6) ◽  
pp. 3373-3379 ◽  
Author(s):  
A. K. Moschovakis ◽  
Y. Dalezios ◽  
J. Petit ◽  
A. A. Grantyn
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Superior Colliculus ◽  
Short Duration ◽  
High Frequency ◽  
Initial Position ◽  
Characteristic Vector ◽  
Extraocular Motoneurons ◽  
Position Sensitivity ◽  
Stimulation Of

Moschovakis, A. K., Y. Dalezios, J. Petit, and A. A. Grantyn. New mechanism that accounts for position sensitivity of saccades evoked in response to stimulation of superior colliculus. J. Neurophysiol. 80: 3373–3379, 1998. Electrical stimulation of the feline superior colliculus (SC) is known to evoke saccades whose size depends on the site stimulated (the “characteristic vector” of evoked saccades) and the initial position of the eyes. Similar stimuli were recently shown to produce slow drifts that are presumably caused by relatively direct projections of the SC onto extraocular motoneurons. Both slow and fast evoked eye movements are similarly affected by the initial position of the eyes, despite their dissimilar metrics, kinematics, and anatomic substrates. We tested the hypothesis that the position sensitivity of evoked saccades is due to the superposition of largely position-invariant saccades and position-dependent slow drifts. We show that such a mechanism can account for the fact that the position sensitivity of evoked saccades increases together with the size of their characteristic vector. Consistent with it, the position sensitivity of saccades drops considerably when the contribution of slow drifts is minimal as, for example, when there is no overlap between evoked saccades and short-duration trains of high-frequency stimuli.

Saccadic eye movements evoked by microstimulation of the fastigial nucleus of macaque monkeys

1988 ◽  
Vol 60 (3) ◽  
pp. 1036-1052 ◽  
Author(s):  
H. Noda ◽  
S. Murakami ◽  
J. Yamada ◽  
J. Tamada ◽  
Y. Tamaki ◽  
...  
Keyword(s):  
Eye Movements ◽  
White Matter ◽  
Purkinje Cells ◽  
Saccadic Eye Movements ◽  
The Other ◽  
Fastigial Nucleus ◽  
Threshold Region ◽  
Other Hand ◽  
Low Threshold ◽  
Stimulation Of

1. Systematic exploration throughout the deep cerebellar nuclei and white matter disclosed that the region from which saccadic eye movements (saccades) were evoked with weak currents (less than 10 microA) was confined to the fastigial nucleus and the adjacent white matter. 2. When an electrode for stimulation was advanced in the cerebellum, saccades were evoked in the direction of the stimulated side (ipsilateral saccades) as it entered the low-threshold region. In some tracks, particularly when the electrode was advanced in the medial portion of the fastigial nucleus, the direction of the evoked saccades changed from the ipsilateral to the contralateral. 3. The mappings with microstimulation disclosed that the ipsilateral saccades were elicited from a relatively wide region that included almost the full extent of the fastigial nucleus. The low-threshold region continued in the white matter caudally into vermal lobule VII and rostrally into the dorsal aspect of the brachium conjunctivum. On the other hand, the contralateral saccades were evoked from a relatively circumscribed region in the ventromedial portion of the fastigial nucleus. 4. The reversal in the direction of the horizontal component occurred always in a narrow zone in the core of the fastigial nucleus. The caudal part of this zone coincided with an ellipsoidal region where anterogradely labeled axons of the Purkinje cells terminated when HRP was injected into vermal lobule VII. 5. When bicuculline (0.2-1 microgram) was injected in the ellipsoidal region, the ipsilateral saccades evoked from the dorsocaudal aspect of the region were suppressed for several hours. On the other hand, the contralateral saccades evoked from the ventromedial portion of the fastigial nucleus were either unchanged or enhanced. 6. Because the ipsilateral saccades were suppressed by bicuculline, they were most probably evoked by stimulation of the presynaptic component of gamma-amino-butyric acid-(GABA) mediated synapses, namely the axons of Purkinje cells. 7. Because stimulation of the presynaptic component of the inhibitory synapses evoked ipsilateral saccades, activation of the postsynaptic component would evoke contralateral saccades. In fact, the distribution of the fastigial sites yielding contralateral saccades coincided with the course of axons of fastigial neurons arising in the ellipsoidal region. It is most likely, therefore, that the contralateral saccades were evoked by stimulation of fastigial neurons.(ABSTRACT TRUNCATED AT 400 WORDS)

Site of interaction between saccade signals and vestibular signals induced by head rotation in the alert cat: functional properties and afferent organization of burster-driving neurons

1995 ◽  
Vol 74 (1) ◽  
pp. 273-287 ◽  
Author(s):  
T. Kitama ◽  
Y. Ohki ◽  
H. Shimazu ◽  
M. Tanaka ◽  
K. Yoshida
Keyword(s):  
Eye Movements ◽  
Superior Colliculus ◽  
Firing Rate ◽  
Regression Line ◽  
Head Rotation ◽  
Eye Position ◽  
Alert Cat ◽  
The Mean ◽  
Horizontal Head ◽  
Stimulation Of

1. Extracellular spikes of burster-driving neurons (BDNs) were recorded within and immediately below the prepositus hypoglossi nucleus in the alert cat. BDNs were characterized by short-latency activation after stimulation of the contralateral vestibular nerve (latency: 1.4-2.7 ms) and the ipsilateral superior colliculus (latency: 1.7-3.5 ms). Convergence of vestibular and collicular inputs was found in all of 85 BDNs tested. Firing of BDNs increased during contralateral horizontal head rotation and decreased during ipsilateral rotation. A burst of spikes was induced in association with contralateral saccades and quick phases of nystagmus. 2. BDNs showed irregular tonic discharges during fixation. There was no significant correlation between the firing rate during fixation and horizontal or vertical eye position in most BDNs. During horizontal sinusoidal head rotation, the change in firing rate was approximately proportional to and in phase with contralateral head velocity. The phase lag of the response relative to head angular velocity was 13.8 +/- 20.1 degrees (mean +/- SD) at 0.5 Hz and 7.2 +/- 13.5 degrees at 0.2 Hz on the average. The gain was 0.88 +/- 0.25 (spikes/s)/(degrees/s) at 0.5 Hz and 1.19 +/- 0.49 (spikes/s)/(degrees/s) at 0.2 Hz. 3. Quantitative analysis of burst activity associated with saccades or quick phases indicated that the ON direction of BDNs was contralateral horizontal. The number of spikes in the burst was linearly related to the amplitude of the contralateral component of rapid eye movements. The slope of regression line was, on the average, 1.14 +/- 0.48 spikes/deg. There was no significant difference between the mean slopes for saccades and quick phases. The number of spikes depended on the difference between initial and final horizontal eye positions and not on the absolute eye position in the orbit. The mean burst firing rate was proportional to the mean velocity of the contralateral component of rapid eye movements. The slope of the regression line was 0.82 +/- 0.34 (spikes/s)/(degrees/s). Significant correlation was also found between intraburst instantaneous firing rate and instantaneous component eye velocity. 4. Objects presented in the contralateral visual field elicited a brief burst of spikes in BDNs independent of any eye movement. Contralateral saccades to the target were preceded by an early response to the visual stimulus and subsequent response associated with eye movement. 5. Excitation of BDNs produced by stimulation of the ipsilateral superior colliculus was facilitated by contralateral horizontal head rotation. Therefore saccadic signals from the superior colliculus to BDNs may be augmented by vestibular signals during head rotation.(ABSTRACT TRUNCATED AT 400 WORDS)

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