scholarly journals From competing motor plans to a single action within a single trial on the human motor periphery

2019 ◽  
Author(s):  
Chao Gu ◽  
Brian D. Corneil ◽  
W. Pieter Medendorp ◽  
Luc P.J. Selen
Keyword(s):  
Strategic Behavior ◽  
Saccadic Eye Movements ◽  
Motor Command ◽  
Task Demands ◽  
Target Onset ◽  
Single Trial ◽  
Single Action ◽  
Motor Commands ◽  
Visual Targets ◽  
Reach Movements

ABSTRACTContemporary theories of motor control have suggested that multiple motor commands compete for action selection. While most of these competitions are completed prior to movement onset, averaged saccadic eye movements that land at an intermediate location between two visual targets are thought to arise when a movement is initiated prior to the resolution of the competition. In contrast, while averaged reach movements have been reported, there is still debate on whether averaged reach movements are the result of a resolved competition between two potential actions or a strategic behavior that optimally incorporates the current task demands. Here, we use a reach version of the paradigm that has previously shown to elicit saccadic averaging to examine whether similar averaging occurs based on neuromuscular activity of an upper limb muscle. On a single trial basis, we observed a temporal evolution of the two competing motor commands during a free-choice reach task to one of two visual targets. The initial wave of directionally-tuned muscle activity (∼100 ms after target onset) was an averaged of the two motor commands which then transformed into a single goal-directed motor command at the onset of the voluntary reach (∼200-300 ms after target onset). The transition from an early motor command to a single goal-direct command resembled the fact that saccadic averaging was most prominent for short-latency saccades. Further, the idiosyncratic choice made on a given trial was correlated with the biases in the averaged motor command.

Sound-Localization Performance in the Cat: The Effect of Restraining the Head

2005 ◽  
Vol 93 (3) ◽  
pp. 1223-1234 ◽  
Author(s):  
Daniel J. Tollin ◽  
Luis C. Populin ◽  
Jordan M. Moore ◽  
Janet L. Ruhland ◽  
Tom C. T. Yin
Keyword(s):  
Short Duration ◽  
Saccadic Eye Movements ◽  
Head Movements ◽  
Gaze Shifts ◽  
Localization Accuracy ◽  
Head Restraint ◽  
The Gaze ◽  
Long Duration ◽  
Localization Performance ◽  
Visual Targets

In oculomotor research, there are two common methods by which the apparent location of visual and/or auditory targets are measured, saccadic eye movements with the head restrained and gaze shifts (combined saccades and head movements) with the head unrestrained. Because cats have a small oculomotor range (approximately ±25°), head movements are necessary when orienting to targets at the extremes of or outside this range. Here we tested the hypothesis that the accuracy of localizing auditory and visual targets using more ethologically natural head-unrestrained gaze shifts would be superior to head-restrained eye saccades. The effect of stimulus duration on localization accuracy was also investigated. Three cats were trained using operant conditioning with their heads initially restrained to indicate the location of auditory and visual targets via eye position. Long-duration visual targets were localized accurately with little error, but the locations of short-duration visual and both long- and short-duration auditory targets were markedly underestimated. With the head unrestrained, localization accuracy improved substantially for all stimuli and all durations. While the improvement for long-duration stimuli with the head unrestrained might be expected given that dynamic sensory cues were available during the gaze shifts and the lack of a memory component, surprisingly, the improvement was greatest for the auditory and visual stimuli with the shortest durations, where the stimuli were extinguished prior to the onset of the eye or head movement. The underestimation of auditory targets with the head restrained is explained in terms of the unnatural sensorimotor conditions that likely result during head restraint.

scholarly journals Apparent Position of Visual Targets during Real and Simulated Saccadic Eye Movements

1997 ◽  
Vol 17 (20) ◽  
pp. 7941-7953 ◽  
Author(s):  
M. Concetta Morrone ◽  
John Ross ◽  
David C. Burr
Keyword(s):  
Eye Movements ◽  
Saccadic Eye Movements ◽  
Apparent Position ◽  
Visual Targets

scholarly journals Target modality determines eye-head coordination in nonhuman primates: implications for gaze control

2011 ◽  
Vol 106 (4) ◽  
pp. 2000-2011 ◽  
Author(s):  
Luis C. Populin ◽  
Abigail Z. Rajala
Keyword(s):  
Nonhuman Primates ◽  
Saccadic Eye Movements ◽  
Head Movements ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
The Gaze ◽  
Midbrain Structure ◽  
The Subject ◽  
Visual Targets ◽  
Time Of Presentation

We have studied eye-head coordination in nonhuman primates with acoustic targets after finding that they are unable to make accurate saccadic eye movements to targets of this type with the head restrained. Three male macaque monkeys with experience in localizing sounds for rewards by pointing their gaze to the perceived location of sources served as subjects. Visual targets were used as controls. The experimental sessions were configured to minimize the chances that the subject would be able to predict the modality of the target as well as its location and time of presentation. The data show that eye and head movements are coordinated differently to generate gaze shifts to acoustic targets. Chiefly, the head invariably started to move before the eye and contributed more to the gaze shift. These differences were more striking for gaze shifts of <20–25° in amplitude, to which the head contributes very little or not at all when the target is visual. Thus acoustic and visual targets trigger gaze shifts with different eye-head coordination. This, coupled to the fact that anatomic evidence involves the superior colliculus as the link between auditory spatial processing and the motor system, suggests that separate signals are likely generated within this midbrain structure.

Modeling Strategic Behavior in Human-Automation Interaction: Why an "Aid" Can (and Should) Go Unused

1993 ◽  
Vol 35 (2) ◽  
pp. 221-242 ◽  
Author(s):  
Alex Kirlik
Keyword(s):  
Sensitivity Analysis ◽  
System Performance ◽  
Strategic Behavior ◽  
Task Demands ◽  
Design Parameters ◽  
Task Context ◽  
Effective Operator ◽  
Effective Strategies ◽  
Potential Benefits ◽  
Intelligent Assistant

Task-offload aids (e.g., an autopilot, an "intelligent" assistant) can be selectively engaged by the human operator to dynamically delegate tasks to automation. Introducing such aids eliminates some task demands but creates new ones associated with programming, engaging, and disengaging the aiding device via an interface. The burdens associated with managing automation can sometimes outweigh the potential benefits of automation to improved system performance. Aid design parameters and features of the overall multitask context combine to determine whether or not a task-offload aid will effectively support the operator. A modeling and sensitivity analysis approach is presented that identifies effective strategies for human-automation interaction as a function of three task-context parameters and three aid design parameters. The analysis and modeling approaches provide resources for predicting how a well-adapted operator will use a given task-offload aid, and for specifying aid design features that ensure that automation will provide effective operator support in a multitask environment.

Effects of caudate microstimulation on spontaneous and purposive saccades

2013 ◽  
Vol 110 (2) ◽  
pp. 334-343 ◽  
Author(s):  
Masayuki Watanabe ◽  
Douglas P. Munoz
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Basal Ganglia ◽  
Saccadic Eye Movements ◽  
Task Demands ◽  
Behavioral Symptoms ◽  
Intrinsic Signals ◽  
Clinical Disorders ◽  
Behavioral Paradigm ◽  
The Impact

Electrical stimulation has been delivered to the basal ganglia (BG) to treat intractable symptoms of a variety of clinical disorders. However, it is still unknown how such treatments improve behavioral symptoms. A difficulty of this problem is that artificial signals created by electrical stimulation interact with intrinsic signals before influencing behavior, thereby making it important to understand how such interactions between artificial and intrinsic signals occur. We addressed this issue by analyzing the effects of electrical stimulation under the following two behavioral conditions that induce different states of intrinsic signals: 1) subjects behave spontaneously without task demands; and 2) subjects perform a behavioral paradigm purposefully. We analyzed saccadic eye movements in monkeys while delivering microstimulation to the head and body of the caudate nucleus, a major input stage of the oculomotor BG. When monkeys generated spontaneous saccades, caudate microstimulation biased saccade vector endpoints toward the contralateral direction of stimulation sites. However, when caudate microstimulation was delivered during a purposive prosaccade (look toward a visual stimulus) or an antisaccade (look away from a stimulus) paradigm, it created overall ipsilateral biases by suppressing contralateral saccades more strongly than ipsilateral saccades. These results suggest that the impact of BG electrical stimulation changes dynamically depending on the state of intrinsic signals that vary under a variety of behavioral demands in everyday life.

scholarly journals Visual Attention Through Uncertainty Minimization in Recurrent Generative Models

2020 ◽  
Author(s):  
Kai Standvoss ◽  
Silvan C. Quax ◽  
Marcel A.J. van Gerven
Keyword(s):  
Eye Movements ◽  
Visual Attention ◽  
Intelligent Agents ◽  
Saccadic Eye Movements ◽  
Generative Models ◽  
Task Demands ◽  
Relevant Stimulus ◽  
Predictive Uncertainty ◽  
Proposed Model ◽  
Uncertainty Minimization

AbstractAllocating visual attention through saccadic eye movements is a key ability of intelligent agents. Attention is both influenced through bottom-up stimulus properties as well as top-down task demands. The interaction of these two attention mechanisms is not yet fully understood. A parsimonious reconciliation posits that both processes serve the minimization of predictive uncertainty. We propose a recurrent generative neural network model that predicts a visual scene based on foveated glimpses. The model shifts its attention in order to minimize the uncertainty in its predictions. We show that the proposed model produces naturalistic eye movements focusing on informative stimulus regions. Introducing additional tasks modulates the saccade patterns towards task-relevant stimulus regions. The model’s saccade characteristics correspond well with previous experimental data in humans, providing evidence that uncertainty minimization could be a fundamental mechanisms for the allocation of visual attention.

Visual and Saccade-Related Activity in Macaque Posterior Cingulate Cortex

2004 ◽  
Vol 92 (5) ◽  
pp. 3056-3068 ◽  
Author(s):  
Heather L. Dean ◽  
Justin C. Crowley ◽  
Michael L. Platt
Keyword(s):  
Target Location ◽  
Neuronal Response ◽  
Cingulate Cortex ◽  
Posterior Cingulate Cortex ◽  
Saccade Target ◽  
Target Onset ◽  
Fixation Stimulus ◽  
Posterior Cingulate ◽  
Neurophysiological Studies ◽  
Visual Targets

Previous neurophysiological studies have reported that neurons in posterior cingulate cortex (PCC) respond after eye movements, and that these responses may vary with ambient illumination. In monkeys, PCC neurons also respond after the illumination of large visual patterns but not after the illumination of small visual targets on either reflexive saccade tasks or peripheral attention tasks. These observations suggest that neuronal activity in PCC is modulated by behavioral context, which varies with the timing and spatial distribution of visual and oculomotor events. To test this hypothesis, we measured the spatial and temporal response properties of single PCC neurons in monkeys performing saccades in which target location and movement timing varied unpredictably. Specifically, an unsignaled delay between target onset and movement onset permitted us to temporally dissociate changes in PCC activity associated with either event. Response fields constructed from these data demonstrated that many PCC neurons were activated after the illumination of small contralateral visual targets, as well as after the onset of contraversive saccades guided by those targets. In addition, the PCC population maintained selectivity for small contralateral targets during delays of up to 600 ms. Overall, PCC activation was highly variable trial to trial and selective for a broad range of directions and amplitudes. Planar functions described response fields nearly as well as broadly tuned 2-dimensional Gaussian functions. Additionally, the overall responsiveness of PCC neurons decreased during delays when both a fixation stimulus and a saccade target were visible, suggesting a modulation by divided attention. Finally, the strength of the neuronal response after target onset was correlated with saccade accuracy on delayed-saccade trials. Thus PCC neurons may signal salient visual and oculomotor events, consistent with a role in visual orienting and attention.

Human Visuospatial Updating After Noncommutative Rotations

2007 ◽  
Vol 98 (1) ◽  
pp. 537-541 ◽  
Author(s):  
Eliana M. Klier ◽  
Dora E. Angelaki ◽  
Bernhard J. M. Hess
Keyword(s):  
Eye Movements ◽  
Target Location ◽  
Body Orientation ◽  
Whole Body ◽  
Final Position ◽  
Intersubject Variability ◽  
Fixed Target ◽  
Motor Commands ◽  
Visual Targets ◽  
The Brain

As we move our bodies in space, we often undergo head and body rotations about different axes—yaw, pitch, and roll. The order in which we rotate about these axes is an important factor in determining the final position of our bodies in space because rotations, unlike translations, do not commute. Does our brain keep track of the noncommutativity of rotations when computing changes in head and body orientation and then use this information when planning subsequent motor commands? We used a visuospatial updating task to investigate whether saccades to remembered visual targets are accurate after intervening, whole-body rotational sequences. The sequences were reversed, either yaw then roll or roll then yaw, such that the final required eye movements to reach the same space-fixed target were different in each case. While each subject performed consistently irrespective of target location and rotational combination, we found great intersubject variability in their capacity to update. The distance between the noncommutative endpoints was, on average, half of that predicted by perfect noncommutativity. Nevertheless, most subjects did make eye movements to distinct final endpoint locations and not to one unique location in space as predicted by a commutative model. In addition, their noncommutative performance significantly improved when their less than ideal updating performance was taken into account. Thus the brain can produce movements that are consistent with the processing of noncommutative rotations, although it is often poor in using internal estimates of rotation for updating.

Remembering More Than You Can Say: Re-examining “Amnesia” of Attended Attributes

2020 ◽  
Author(s):  
Geoffrey William Harrison ◽  
Melissa Kang ◽  
Daryl E Wilson
Keyword(s):  
Memory Consolidation ◽  
Search Task ◽  
Memory Test ◽  
Trial Data ◽  
Task Demands ◽  
Single Trial ◽  
Weak State ◽  
Task Goal ◽  
Cast Doubt ◽  
Surprise Question

Attribute amnesia (AA) describes a phenomenon whereby observers fail a surprise memory test which asks them to report an attribute they had just attended and used to fulfil a task goal. This finding has cast doubt on the prominent theory that attention results in encoding into working memory (WM), to which two competing explanations have been proposed: (1) task demands dictate whether attended information is encoded into WM, and (2) attended information is encoded in a weak state that does not survive the demands of the surprise memory test. To address this debate our study circumvented the limitations of a surprise memory test by embedding a second search task within a typical color-based AA search task. The search task was modified so that the attended attribute would reappear in the second search as either the target, a distractor, or not at all. Critically, our results support encoding of the attended attribute in WM though to a weaker extent than the attribute that is required for report. A second experiment confirmed that WM encoding only occurs for the attended attribute, though distractor attributes produce a bias consistent with negative priming. Our data provide novel support for a theory of memory consolidation that links the strength of a memory’s representation with expectations for how it will be used in a task. Implications for the utility of this procedure in future investigations previously limited by single trial data (i.e., surprise question methodology) are discussed.

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