scholarly journals Similar prevalence and magnitude of auditory-evoked and visually evoked activity in the frontal eye fields: implications for multisensory motor control

2016 ◽  
Vol 115 (6) ◽  
pp. 3162-3173 ◽  
Author(s):  
Valeria C. Caruso ◽  
Daniel S. Pages ◽  
Marc A. Sommer ◽  
Jennifer M. Groh
Keyword(s):  
Target Location ◽  
Saccadic Eye Movements ◽  
Motor Output ◽  
Visual Signals ◽  
Frontal Eye Fields ◽  
Activity Levels ◽  
Population Activity ◽  
Movement Vector ◽  
Saccade Onset ◽  
Evoked Activity

Saccadic eye movements can be elicited by more than one type of sensory stimulus. This implies substantial transformations of signals originating in different sense organs as they reach a common motor output pathway. In this study, we compared the prevalence and magnitude of auditory- and visually evoked activity in a structure implicated in oculomotor processing, the primate frontal eye fields (FEF). We recorded from 324 single neurons while 2 monkeys performed delayed saccades to visual or auditory targets. We found that 64% of FEF neurons were active on presentation of auditory targets and 87% were active during auditory-guided saccades, compared with 75 and 84% for visual targets and saccades. As saccade onset approached, the average level of population activity in the FEF became indistinguishable on visual and auditory trials. FEF activity was better correlated with the movement vector than with the target location for both modalities. In summary, the large proportion of auditory-responsive neurons in the FEF, the similarity between visual and auditory activity levels at the time of the saccade, and the strong correlation between the activity and the saccade vector suggest that auditory signals undergo tailoring to match roughly the strength of visual signals present in the FEF, facilitating accessing of a common motor output pathway.

Perisaccadic Mislocalization of Visual Targets by Head-Free Gaze Shifts: Visual or Motor?

2008 ◽  
Vol 100 (4) ◽  
pp. 1848-1867 ◽  
Author(s):  
Sigrid M. C. I. van Wetter ◽  
A. John van Opstal
Keyword(s):  
Target Location ◽  
Saccadic Eye Movements ◽  
Open Loop ◽  
Spatial Updating ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
The Gaze ◽  
Visual Probe ◽  
Saccade Onset ◽  
Saccade Direction

Such perisaccadic mislocalization is maximal in the direction of the saccade and varies systematically with the target-saccade onset delay. We have recently shown that under head-fixed conditions perisaccadic errors do not follow the quantitative predictions of current visuomotor models that explain these mislocalizations in terms of spatial updating. These models all assume sluggish eye-movement feedback and therefore predict that errors should vary systematically with the amplitude and kinematics of the intervening saccade. Instead, we reported that errors depend only weakly on the saccade amplitude. An alternative explanation for the data is that around the saccade the perceived target location undergoes a uniform transient shift in the saccade direction, but that the oculomotor feedback is, on average, accurate. This “ visual shift” hypothesis predicts that errors will also remain insensitive to kinematic variability within much larger head-free gaze shifts. Here we test this prediction by presenting a brief visual probe near the onset of gaze saccades between 40 and 70° amplitude. According to models with inaccurate gaze-motor feedback, the expected perisaccadic errors for such gaze shifts should be as large as 30° and depend heavily on the kinematics of the gaze shift. In contrast, we found that the actual peak errors were similar to those reported for much smaller saccadic eye movements, i.e., on average about 10°, and that neither gaze-shift amplitude nor kinematics plays a systematic role. Our data further corroborate the visual origin of perisaccadic mislocalization under open-loop conditions and strengthen the idea that efferent feedback signals in the gaze-control system are fast and accurate.

Visual Remapping by Vector Subtraction: Analysis of Multiplicative Gain Field Models

2007 ◽  
Vol 19 (9) ◽  
pp. 2353-2386 ◽  
Author(s):  
Carlos R. Cassanello ◽  
Vincent P. Ferrera
Keyword(s):  
Target Location ◽  
Target Position ◽  
Saccadic Eye Movements ◽  
Neural Mechanism ◽  
Spatial Modulation ◽  
Eye Position ◽  
Retinal Position ◽  
Population Activity ◽  
Firing Rates ◽  
The Brain

Saccadic eye movements remain spatially accurate even when the target becomes invisible and the initial eye position is perturbed. The brain accomplishes this in part by remapping the remembered target location in retinal coordinates. The computation that underlies this visual remapping is approximated by vector subtraction: the original saccade vector is updated by subtracting the vector corresponding to the intervening eye movement. The neural mechanism by which vector subtraction is implemented is not fully understood. Here, we investigate vector subtraction within a framework in which eye position and retinal target position signals interact multiplicatively (gain field). When the eyes move, they induce a spatial modulation of the firing rates across a retinotopic map of neurons. The updated saccade metric can be read from the shift of the peak of the population activity across the map. This model uses a quasi-linear (half-rectified) dependence on the eye position and requires the slope of the eye position input to be negatively proportional to the preferred retinal position of each neuron. We derive analytically this constraint and study its range of validity. We discuss how this mechanism relates to experimental results reported in the frontal eye fields of macaque monkeys.

scholarly journals A test of spatial temporal decoding mechanisms in the superior colliculus

2012 ◽  
Vol 107 (9) ◽  
pp. 2442-2452 ◽  
Author(s):  
Husam A. Katnani ◽  
A. J. Van Opstal ◽  
Neeraj J. Gandhi
Keyword(s):  
Nervous System ◽  
Motor Control ◽  
Eye Movements ◽  
Superior Colliculus ◽  
Motor Behavior ◽  
Saccadic Eye Movements ◽  
Population Coding ◽  
Population Activity ◽  
Low Levels

Population coding is a ubiquitous principle in the nervous system for the proper control of motor behavior. A significant amount of research is dedicated to studying population activity in the superior colliculus (SC) to investigate the motor control of saccadic eye movements. Vector summation with saturation (VSS) has been proposed as a mechanism for how population activity in the SC can be decoded to generate saccades. Interestingly, the model produces different predictions when decoding two simultaneous populations at high vs. low levels of activity. We tested these predictions by generating two simultaneous populations in the SC with high or low levels of dual microstimulation. We also combined varying levels of stimulation with visually induced activity. We found that our results did not perfectly conform to the predictions of the VSS scheme and conclude that the simplest implementation of the model is incomplete. We propose that additional parameters to the model might account for the results of this investigation.

Saccadic Gain Modification: Visual Error Drives Motor Adaptation

1998 ◽  
Vol 80 (5) ◽  
pp. 2405-2416 ◽  
Author(s):  
Josh Wallman ◽  
Albert F. Fuchs
Keyword(s):  
Target Location ◽  
Rhesus Macaques ◽  
Motor Adaptation ◽  
Saccadic Eye Movements ◽  
Target Distance ◽  
Error Signal ◽  
Gain Adaptation ◽  
Horizontal Saccade ◽  
Corrective Saccades ◽  
Visual Error

Wallman, Josh and Albert F. Fuchs. Saccadic gain modification: visual error drives motor adaptation. J. Neurophysiol. 80: 2405–2416, 1998. The brain maintains the accuracy of saccadic eye movements by adjusting saccadic amplitude relative to the target distance (i.e., saccade gain) on the basis of the performance of recent saccades. If an experimenter surreptitiously moves the target backward during each saccade, thereby causing the eyes to land beyond their targets, saccades undergo a gradual gain reduction. The error signal driving this conventional saccadic gain adaptation could be either visual (the postsaccadic distance of the target from the fovea) or motoric (the direction and size of the corrective saccade that brings the eye onto the back-stepped target). Similarly, the adaptation itself might be a motor adjustment (change in the size of saccade for a given perceived target distance) or a visual remapping (change in the perceived target distance). We studied these possibilities in experiments both with rhesus macaques and with humans. To test whether the error signal is motoric, we used a paradigm devised by Heiner Deubel. The Deubel paradigm differed from the conventional adaptation paradigm in that the backward step that occurred during the saccade was brief, and the target then returned to its original displaced location. This ploy replaced most of the usual backward corrective saccades with forward ones. Nevertheless, saccadic gain gradually decreased over hundreds of trials. Therefore, we conclude that the direction of saccadic gain adaptation is not determined by the direction of corrective saccades. To test whether gain adaptation is a manifestation of a static visual remapping, we decreased the gain of 10° horizontal saccades by conventional adaptation and then tested the gain to targets appearing at retinal locations unused during adaptation. To make the target appear in such “virgin territory,” we had it jump first vertically and then 10° horizontally; both jumps were completed and the target spot extinguished before saccades were made sequentially to the remembered target locations. Conventional adaptation decreased the gain of the second, horizontal saccade even though the target was in a nonadapted retinal location. In contrast, the horizontal component of oblique saccades made directly to the same virgin location showed much less gain decrease, suggesting that the adaptation is specific to saccade direction rather than to target location. Thus visual remapping cannot account for the entire reduction of saccadic gain. We conclude that saccadic gain adaptation involves an error signal that is primarily visual, not motor, but that the adaptation itself is primarily motor, not visual.

scholarly journals Temporal Interactions of Air-Puff–Evoked Blinks and Saccadic Eye Movements: Insights Into Motor Preparation

2005 ◽  
Vol 93 (3) ◽  
pp. 1718-1729 ◽  
Author(s):  
Neeraj J. Gandhi ◽  
Desiree K. Bonadonna
Keyword(s):  
Eye Movement ◽  
Target Location ◽  
Low Frequency ◽  
Saccadic Eye Movements ◽  
Stimulus Presentation ◽  
Motor Preparation ◽  
Threshold Level ◽  
Saccade Latency ◽  
Sensory Response ◽  
Temporal Interactions

Following the initial, sensory response to stimulus presentation, activity in many saccade-related burst neurons along the oculomotor neuraxis is observed as a gradually increasing low-frequency discharge hypothesized to encode both timing and metrics of the impending eye movement. When the activity reaches an activation threshold level, these cells discharge a high-frequency burst, inhibit the pontine omnipause neurons (OPNs) and trigger a high-velocity eye movement known as saccade. We tested whether early cessation of OPN activity, prior to when it ordinarily pauses, acts to effectively lower the threshold and prematurely trigger a movement of modified metrics and/or dynamics. Relying on the observation that OPN discharge ceases during not only saccades but also blinks, air-puffs were delivered to one eye to evoke blinks as monkeys performed standard oculomotor tasks. We observed a linear relationship between blink and saccade onsets when the blink occurred shortly after the cue to initiate the movement but before the average reaction time. Blinks that preceded and overlapped with the cue increased saccade latency. Blinks evoked during the overlap period of the delayed saccade task, when target location is known but a saccade cannot be initiated for correct performance, failed to trigger saccades prematurely. Furthermore, when saccade and blink execution coincided temporally, the peak velocity of the eye movement was attenuated, and its initial velocity was correlated with its latency. Despite the perturbations, saccade accuracy was maintained across all blink times and task types. Collectively, these results support the notion that temporal features of the low-frequency activity encode aspects of a premotor command and imply that inhibition of OPNs alone is not sufficient to trigger saccades.

scholarly journals Saccades and smooth pursuit eye movements trigger equivalent gaze-cued orienting effects

2018 ◽  
Vol 71 (9) ◽  
pp. 1860-1872 ◽  
Author(s):  
Stephen RH Langton ◽  
Alex H McIntyre ◽  
Peter JB Hancock ◽  
Helmut Leder
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Target Location ◽  
Eye Gaze ◽  
Saccadic Eye Movements ◽  
Gaze Shift ◽  
The Gaze ◽  
Orienting Effect ◽  
Motion Speed ◽  
Uncued Target

Research has established that a perceived eye gaze produces a concomitant shift in a viewer’s spatial attention in the direction of that gaze. The two experiments reported here investigate the extent to which the nature of the eye movement made by the gazer contributes to this orienting effect. On each trial in these experiments, participants were asked to make a speeded response to a target that could appear in a location toward which a centrally presented face had just gazed (a cued target) or in a location that was not the recipient of a gaze (an uncued target). The gaze cues consisted of either fast saccadic eye movements or slower smooth pursuit movements. Cued targets were responded to faster than uncued targets, and this gaze-cued orienting effect was found to be equivalent for each type of gaze shift both when the gazes were un-predictive of target location (Experiment 1) and counterpredictive of target location (Experiment 2). The results offer no support for the hypothesis that motion speed modulates gaze-cued orienting. However, they do suggest that motion of the eyes per se, regardless of the type of movement, may be sufficient to trigger an orienting effect.

scholarly journals Dynamical Latent State Computation in the Posterior Parietal Cortex

2022 ◽  
Author(s):  
Kaushik J Lakshminarasimhan ◽  
Eric Avila ◽  
Xaq Pitkow ◽  
Dora E Angelaki
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Target Location ◽  
Neural Representation ◽  
World Model ◽  
Population Activity ◽  
The World ◽  
Neural Interactions ◽  
Posterior Parietal ◽  
Hidden States

Success in many real-world tasks depends on our ability to dynamically track hidden states of the world. To understand the underlying neural computations, we recorded brain activity in posterior parietal cortex (PPC) of monkeys navigating by optic flow to a hidden target location within a virtual environment, without explicit position cues. In addition to sequential neural dynamics and strong interneuronal interactions, we found that the hidden state -- monkey's displacement from the goal -- was encoded in single neurons, and could be dynamically decoded from population activity. The decoded estimates predicted navigation performance on individual trials. Task manipulations that perturbed the world model induced substantial changes in neural interactions, and modified the neural representation of the hidden state, while representations of sensory and motor variables remained stable. The findings were recapitulated by a task-optimized recurrent neural network model, suggesting that neural interactions in PPC embody the world model to consolidate information and track task-relevant hidden states.

scholarly journals The role of action intentionality and effector in the subjective expansion of temporal duration after saccadic eye movements

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
David Melcher ◽  
Devpriya Kumar ◽  
Narayanan Srinivasan
Keyword(s):  
Eye Movements ◽  
Visual Processing ◽  
Saccadic Eye Movements ◽  
Intentional Binding ◽  
Opposite Pattern ◽  
Motor Action ◽  
Saccade Onset ◽  
Backward Shift ◽  
The Moment

Abstract Visual perception is based on periods of stable fixation separated by saccadic eye movements. Although naive perception seems stable (in space) and continuous (in time), laboratory studies have demonstrated that events presented around the time of saccades are misperceived spatially and temporally. Saccadic chronostasis, the “stopped clock illusion”, represents one such temporal distortion in which the movement of the clock hand after the saccade is perceived as lasting longer than usual. Multiple explanations for chronostasis have been proposed including action-backdating, temporal binding of the action towards the moment of its effect (“intentional binding”) and post-saccadic temporal dilation. The current study aimed to resolve this debate by using different types of action (keypress vs saccade) and varying the intentionality of the action. We measured both perceived onset of the motor action and perceived onset of an auditory tone presented at different delays after the keypress/saccade. The results showed intentional binding for the keypress action, with perceived motor onset shifted forwards in time and the time of the tone shifted backwards. Saccades resulted in the opposite pattern, showing temporal expansion rather than compression, especially with cued saccades. The temporal illusion was modulated by intentionality of the movement. Our findings suggest that saccadic chronostasis is not solely dependent on a backward shift in perceived saccade onset, but instead reflects a temporal dilation. This percept of an effectively “longer” period at the beginning of a new fixation may reflect the pattern of suppressed, and then enhanced, visual processing around the time of saccades.

Behavioural responses of the cercariae of Cryptocotyle lingua (Digenea: Heterophyidae) to computer-controlled shadow sequences

Parasitology ◽  
1991 ◽  
Vol 103 (3) ◽  
pp. 471-477 ◽  
Author(s):  
J. G. Rea ◽  
S. W. B. Irwin
Keyword(s):  
Laboratory Experiments ◽  
Muscular Activity ◽  
Finite Energy ◽  
Fish Host ◽  
Activity Levels ◽  
Energy Reserves ◽  
Population Activity ◽  
Behavioural Responses ◽  
Active Life ◽  
Computer Controlled

The cercariae of Cryptocotyle lingua have a brief but active life during which they do not feed. In order to maximize the probability of infection they must respond to a variety of host-related stimuli yet conserve their finite energy reserves by minimizing unnecessary muscular activity. In laboratory experiments, simulated shadows representing the passage of a fish host were found to increase population activity levels. Evidence was also found for a relationship between shadow duration and the duration of subsequent bursts of swimming activity. Adaptation to continuous shadowing was recorded, its onset and magnitude being dependent on both the frequency and duration of shadows delivered. As cercariae aged they became less responsive to shadow stimuli, especially those of short duration.

Differential Involvement of Neurons in the Dorsal and Ventral Premotor Cortex During Processing of Visual Signals for Action Planning

2006 ◽  
Vol 95 (6) ◽  
pp. 3596-3616 ◽  
Author(s):  
Eiji Hoshi ◽  
Jun Tanji
Keyword(s):  
Neuronal Activity ◽  
Visual Information ◽  
Visual Cues ◽  
Target Location ◽  
Premotor Cortex ◽  
Action Planning ◽  
Visual Signals ◽  
Visual Cue ◽  
Ventral Premotor Cortex ◽  
Neuron Response

We examined neuronal activity in the dorsal and ventral premotor cortex (PMd and PMv, respectively) to explore the role of each motor area in processing visual signals for action planning. We recorded neuronal activity while monkeys performed a behavioral task during which two visual instruction cues were given successively with an intervening delay. One cue instructed the location of the target to be reached, and the other indicated which arm was to be used. We found that the properties of neuronal activity in the PMd and PMv differed in many respects. After the first cue was given, PMv neuron response mostly reflected the spatial position of the visual cue. In contrast, PMd neuron response also reflected what the visual cue instructed, such as which arm to be used or which target to be reached. After the second cue was given, PMv neurons initially responded to the cue's visuospatial features and later reflected what the two visual cues instructed, progressively increasing information about the target location. In contrast, the activity of the majority of PMd neurons responded to the second cue with activity reflecting a combination of information supplied by the first and second cues. Such activity, already reflecting a forthcoming action, appeared with short latencies (<400 ms) and persisted throughout the delay period. In addition, both the PMv and PMd showed bilateral representation on visuospatial information and motor-target or effector information. These results further elucidate the functional specialization of the PMd and PMv during the processing of visual information for action planning.

Sign in / Sign up

Export Citation Format

Share Document