Internal Models and Contextual Cues: Encoding Serial Order and Direction of Movement

2005 ◽  
Vol 93 (2) ◽  
pp. 786-800 ◽  
Author(s):  
Stephanie K. Wainscott ◽  
Opher Donchin ◽  
Reza Shadmehr
Keyword(s):  
Internal Model ◽  
Serial Order ◽  
Internal Models ◽  
General Mechanism ◽  
Sources Of Information ◽  
Contextual Cues ◽  
Reaching Task ◽  
Motor Commands ◽  
Preferred Direction ◽  
Direction Of Movement

During reaching, the brain may rely on internal models to transform desired sensory outcomes into motor commands. This transformation depends on both the state of the limb and the cues that can identify the context of the movement. How are contextual cues and information about state of the limb combined in the computations of internal models? We considered a reaching task where forces on the hand depended on both the direction of movement (state of the limb) and order of that movement in a predefined sequence (contextual cue). When the cue was available, the motor system formed an internal model that used both serial order and target direction to program motor commands. Assuming that the internal model was formed by a population code through a combination of unknown basis elements, the sensitivity of the bases with respect to state of the limb and contextual cue should dictate how error in one type of movement affected all other movement types. Using a state-space theory, we estimated this generalization function and identified the adaptive system from trial-by-trial changes in performance. The results implied that the basis elements were tuned to direction of movement but output of each basis at its preferred direction was multiplicatively modulated by a weak tuning with respect to the contextual cue. Activity fields that multiplicatively encode diverse sources of information may serve as a general mechanism for a single network to produce context-dependent motor output.

scholarly journals Internal models for interpreting neural population activity during sensorimotor control

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Matthew D Golub ◽  
Byron M Yu ◽  
Steven M Chase
Keyword(s):  
Internal Model ◽  
Sensory Information ◽  
Internal Models ◽  
Neural Population ◽  
Prior Beliefs ◽  
Population Activity ◽  
Motor Commands ◽  
Machine Interface ◽  
The Brain ◽  
Neural Population Activity

To successfully guide limb movements, the brain takes in sensory information about the limb, internally tracks the state of the limb, and produces appropriate motor commands. It is widely believed that this process uses an internal model, which describes our prior beliefs about how the limb responds to motor commands. Here, we leveraged a brain-machine interface (BMI) paradigm in rhesus monkeys and novel statistical analyses of neural population activity to gain insight into moment-by-moment internal model computations. We discovered that a mismatch between subjects’ internal models and the actual BMI explains roughly 65% of movement errors, as well as long-standing deficiencies in BMI speed control. We then used the internal models to characterize how the neural population activity changes during BMI learning. More broadly, this work provides an approach for interpreting neural population activity in the context of how prior beliefs guide the transformation of sensory input to motor output.

scholarly journals Contextual cuing contributes to the independent modification of multiple internal models for vocal control

2011 ◽  
Vol 105 (5) ◽  
pp. 2448-2456 ◽  
Author(s):  
Dwayne Keough ◽  
Jeffery A. Jones
Keyword(s):  
Auditory Feedback ◽  
Internal Model ◽  
Sensory Feedback ◽  
Motor Command ◽  
Internal Models ◽  
Motor Commands ◽  
Arm Reaching ◽  
Vocal Control ◽  
Vocal Productions ◽  
The Brain

Research on the control of visually guided limb movements indicates that the brain learns and continuously updates an internal model that maps the relationship between motor commands and sensory feedback. A growing body of work suggests that an internal model that relates motor commands to sensory feedback also supports vocal control. There is evidence from arm-reaching studies that shows that when provided with a contextual cue, the motor system can acquire multiple internal models, which allows an animal to adapt to different perturbations in diverse contexts. In this study we show that trained singers can rapidly acquire multiple internal models regarding voice fundamental frequency ( F0). These models accommodate different perturbations to ongoing auditory feedback. Participants heard three musical notes and reproduced each one in succession. The musical targets could serve as a contextual cue to indicate which direction (up or down) feedback would be altered on each trial; however, participants were not explicitly instructed to use this strategy. When participants were gradually exposed to altered feedback adaptation was observed immediately following vocal onset. Aftereffects were target specific and did not influence vocal productions on subsequent trials. When target notes were no longer a contextual cue, adaptation occurred during altered feedback trials and evidence for trial-by-trial adaptation was found. These findings indicate that the brain is exceptionally sensitive to the deviations between auditory feedback and the predicted consequence of a motor command during vocalization. Moreover, these results indicate that, with contextual cues, the vocal control system may maintain multiple internal models that are capable of independent modification during different tasks or environments.

scholarly journals Generalization and transfer of contextual cues in motor learning

2015 ◽  
Vol 114 (3) ◽  
pp. 1565-1576 ◽  
Author(s):  
A. M. E. Sarwary ◽  
D. F. Stegeman ◽  
L. P. J. Selen ◽  
W. P. Medendorp
Keyword(s):  
Force Field ◽  
Internal Model ◽  
Force Fields ◽  
Daily Life ◽  
Angular Separation ◽  
Internal Models ◽  
Reaching Movements ◽  
Contextual Cues ◽  
New Models ◽  
The Individual

We continuously adapt our movements in daily life, forming new internal models whenever necessary and updating existing ones. Recent work has suggested that this flexibility is enabled via sensorimotor cues, serving to access the correct internal model whenever necessary and keeping new models apart from previous ones. While research to date has mainly focused on identifying the nature of such cue representations, here we investigated whether and how these cue representations generalize, interfere, and transfer within and across effector systems. Subjects were trained to make two-stage reaching movements: a premovement that served as a cue, followed by a targeted movement that was perturbed by one of two opposite curl force fields. The direction of the premovement was uniquely coupled to the direction of the ensuing force field, enabling simultaneous learning of the two respective internal models. After training, generalization of the two premovement cues' representations was tested at untrained premovement directions, within both the trained and untrained hand. We show that the individual premovement representations generalize in a Gaussian-like pattern around the trained premovement direction. When the force fields are of unequal strengths, the cue-dependent generalization skews toward the strongest field. Furthermore, generalization patterns transfer to the nontrained hand, in an extrinsic reference frame. We conclude that contextual cues do not serve as discrete switches between multiple internal models. Instead, their generalization suggests a weighted contribution of the associated internal models based on the angular separation from the trained cues to the net motor output.

Receptive-field properties of neurons in middle temporal visual area (MT) of owl monkeys

1984 ◽  
Vol 52 (3) ◽  
pp. 488-513 ◽  
Author(s):  
D. J. Felleman ◽  
J. H. Kaas
Keyword(s):  
Receptive Field ◽  
Stimulus Onset ◽  
Visual Area ◽  
Area Mt ◽  
Stimulus Movement ◽  
Middle Temporal ◽  
Preferred Direction ◽  
Direction Of Movement ◽  
Owl Monkeys ◽  
Visual Area Mt

Response properties of single neurons in the middle temporal visual area (MT) of anesthetized owl monkeys were determined and quantified for flashed and moving bars of light under computer control for position, orientation, direction of movement, and speed. Receptive-field sizes, ranging from 4 to 25 degrees in width, were considerably larger than receptive fields with corresponding eccentricities in the striate cortex. Neurons were highly binocular with most cells equally or nearly equally activated by either eye. Neurons varied in selectivity for axis and direction of moving bars. Some neurons demonstrated little or no selectivity, others were bidirectional on a single axis, while the largest group was highly selective for direction with little or no response to bar movement opposite to the preferred direction. Over 70% of neurons were classified as highly selective and 90% showed some preference for direction and/or axis of stimulus movement. Neurons typically responded to bar movement only over a restricted range of velocities. The majority of neurons responded best to a particular velocity within the 5-60 degrees/s range, with marked attenuation of the response for velocities greater or less than the preferred. Some neurons failed to show significant response attenuation even at the lowest tested velocity, while other neurons preferred velocities of 100 degrees/s or more and failed to attenuate to the highest velocities. Response magnitude varied with stimulus dimensions. Increasing the length of the moving bar typically increased the magnitude of the response slightly until the stimulus exceeded the receptive-field borders. Other neurons responded less to increases in bar length within the excitatory receptive field. Neurons preferred narrow bars less than 1 degree in width, and marked reductions in responses characteristically occurred with wider stimuli. Moving patterns of randomly placed small dots were often as effective as or more effective than single bars in activating neurons. Selectivity for direction of movement remained for the dot pattern. for the dot pattern. Poststimulus time (PST) histograms of responses to bars flashed at a series of 21 different positions across the receptive field, in the "response-plane" format, indicated a spatially and temporally homogeneous receptive-field structure for nearly all neurons. Cells characteristically showed transient excitation at both stimulus onset and offset for all effective stimulus locations. Some cells responded mainly at bright stimulus onset or offset.

scholarly journals An internal model approach for motor behavior

2021 ◽  
Vol 15 (5) ◽  
pp. 356-371
Author(s):  
Cláudio M. F. Leite ◽  
Carlos E. Campos ◽  
Crislaine R. Couto ◽  
Herbert Ugrinowitsch
Keyword(s):  
Motor Skills ◽  
Internal Model ◽  
Motor Behavior ◽  
External World ◽  
Internal Models ◽  
Sensory Inputs ◽  
Theoretical Approaches ◽  
Internal Coherence ◽  
Motor Actions ◽  
Model Approach

Interacting with the environment requires a remarkable ability to control, learn, and adapt motor skills to ever-changing conditions. The intriguing complexity involved in the process of controlling, learning, and adapting motor skills has led to the development of many theoretical approaches to explain and investigate motor behavior. This paper will present a theoretical approach built upon the top-down mode of motor control that shows substantial internal coherence and has a large and growing body of empirical evidence: The Internal Models. The Internal Models are representations of the external world within the CNS, which learn to predict this external world, simulate behaviors based on sensory inputs, and transform these predictions into motor actions. We present the Internal Models’ background based on two main structures, Inverse and Forward models, explain how they work, and present some applicability.

Dynamical Organization of Directional Tuning in the Primate Premotor and Primary Motor Cortex

2003 ◽  
Vol 89 (2) ◽  
pp. 1136-1142 ◽  
Author(s):  
Yoram Ben-Shaul ◽  
Eran Stark ◽  
Itay Asher ◽  
Rotem Drori ◽  
Zoltan Nadasdy ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Hand Movement ◽  
Movement Direction ◽  
Cortical Surface ◽  
Preferred Direction ◽  
Preparation Period ◽  
Direction Of Movement ◽  
The Mean ◽  
Movement Parameters

Although previous studies have shown that activity of neurons in the motor cortex is related to various movement parameters, including the direction of movement, the spatial pattern by which these parameters are represented is still unresolved. The current work was designed to study the pattern of representation of the preferred direction (PD) of hand movement over the cortical surface. By studying pairwise PD differences, and by applying a novel implementation of the circular variance during preparation and movement periods in the context of a center-out task, we demonstrate a nonrandom distribution of PDs over the premotor and motor cortical surface of two monkeys. Our analysis shows that, whereas PDs of units recorded by nonadjacent electrodes are not more similar than expected by chance, PDs of units recorded by adjacent electrodes are. PDs of units recorded by a single electrode display the greatest similarity. Comparison of PD distributions during preparation and movement reveals that PDs of nearby units tend to be more similar during the preparation period. However, even for pairs of units recorded by a single electrode, the mean PD difference is typically large (45° and 75° during preparation and movement, respectively), so that a strictly modular representation of hand movement direction over the cortical surface is not supported by our data.

Modulation of preparatory neuronal activity in dorsal premotor cortex due to stimulus-response compatibility

1994 ◽  
Vol 71 (3) ◽  
pp. 1281-1284 ◽  
Author(s):  
D. J. Crammond ◽  
J. F. Kalaska
Keyword(s):  
Neuronal Activity ◽  
Premotor Cortex ◽  
Spatial Location ◽  
Dorsal Premotor Cortex ◽  
Reaching Task ◽  
Stimulus Response ◽  
Sustained Activity ◽  
Spatial Attributes ◽  
Direction Of Movement ◽  
Selection Of

1. Neuronal activity was recorded in the dorsal premotor cortex (PMd) of two monkeys performing a multidirectional, instructed-delay (ID) reaching task in which visuospatial cues signaled the direction of movement either congruent with the instruction cue ("direct-delay" trials, DD) or redirected 180 degrees opposite to the cue ("redirected-delay" trials, RD). Therefore, this task had two degrees of stimulus-response (S-R) compatibility because in one-half of the trials the spatial attributes of the visual cue were incongruent with those of the intended movement. 2. The majority of PMd cells discharged both at short latency to the RD or DD cues and subsequently with sustained activity during the remaining ID period (IDP). The earliest responses (< 250 ms) in both DD and RD trials covaried with cue location and so could be either a "visuospatial" response or a neuronal correlate of the selection of action with highest S-R compatibility, namely move to the stimulus. In contrast, later IDP activity usually covaried with the direction of movement signaled by the cues, independent of their spatial location, supporting the hypothesis that IDP discharge in PMd ultimately encodes attributes of intended reaching movements.

Are neurons in cat posteromedial lateral suprasylvian visual cortex orientation sensitive? Tests with bars and gratings

1995 ◽  
Vol 12 (1) ◽  
pp. 141-151 ◽  
Author(s):  
Yuri Danilov ◽  
Rodney J. Moore ◽  
Von R. King ◽  
Peter D. Spear
Keyword(s):  
Visual Cortex ◽  
Receptive Fields ◽  
Orientation Tuning ◽  
Orientation Sensitivity ◽  
Tuning Curves ◽  
Preferred Direction ◽  
Response Measures ◽  
Direction Of Movement ◽  
The Difference ◽  
Quantitative Response

AbstractThere is controversy in the literature concerning whether or not neurons in the cat's posteromedial lateral suprasylvian (PMLS) visual cortex are orientation selective. Previous studies that have tested cells with simple bar stimuli have found that few, if any, PMLS cells are orientation selective. Conversely, studies that have used repetitive stimuli such as gratings have found that most or all PMLS cells are orientation selective. It is not known whether this difference in results is due to the stimuli used or the laboratories using them. The present experiments were designed to answer this question by testing individual PMLS neurons for orientation sensitivity with both bar and grating stimuli. Using quantitative response measures, we found that most PMLS neurons respond well enough to stationary flashed stimuli to use such stimuli to test for orientation sensitivity. On the basis of these tests, we found that about 85% of the cells with well-defined receptive fields are orientation sensitive to flashed gratings, and a similar percentage are orientation sensitive to flashed bars. About 80% of the cells were orientation sensitive to both types of stimuli. The preferred orientations typically were similar for the two tests, and they were orthogonal to the preferred direction of movement. The strength of the orientation sensitivity (measured as the ratio of discharge to the preferred and nonpreferred orientations) was similar to both types of stimuli. However, the width of the orientation tuning curves was systematically broader to bars than to gratings. Several hypotheses are considered as to why previous studies using bars failed to find evidence for orientation sensitivity. In addition, a mechanism for the difference in orientation tuning to bars and gratings is suggested.

The Effect of An Internal Model on Subsequent Learning

1983 ◽  
Vol 27 (2) ◽  
pp. 156-160 ◽  
Author(s):  
Ray E. Eberts
Keyword(s):  
System Dynamics ◽  
Internal Model ◽  
Prior Experience ◽  
Internal Models ◽  
The Other ◽  
Learning Performance ◽  
Continuous Control ◽  
Control Task ◽  
Discrete Task ◽  
Previous Training

The purpose of this experiment was to compare the learning performance on a discrete second order control task between an experienced group of subjects, who had generated both accurate and inaccurate internal models through prior experience, to a group of subjects who had little prior experience and no model of the system dynamics. The 48 subjects were divided into six groups of eight subjects each. Three of the groups, the experienced groups, had previous training in a continuous control task and the other three groups, the no experience groups, had only a few trials on the continuous control task. The results showed that all three experienced groups learned the new discrete task faster than the no experience groups; the no experience groups actually got slightly worse with practice. It was concluded that an internal model, even an inaccurate one, provides a reference for subjects which can be used to analyze and improve their performance.

scholarly journals A cerebellar internal model calibrates a feedback controller involved in sensorimotor control

2020 ◽  
Author(s):  
Daniil A. Markov ◽  
Luigi Petrucco ◽  
Andreas M. Kist ◽  
Ruben Portugues
Keyword(s):  
Feedback Control ◽  
Visual Feedback ◽  
Internal Model ◽  
Control Mechanism ◽  
Internal Models ◽  
List Type ◽  
Optomotor Response ◽  
Larval Zebrafish ◽  
Sensory State ◽  
Control Feedback

AbstractAnimals must adapt their behavior to survive in a changing environment. Behavioral adaptations can be evoked by two mechanisms: feedback control and internal-model-based control. Feedback controllers can maintain the sensory state of the animal at a desired level under different environmental conditions. In turn, internal models learn the relationship between behavior and resulting sensory consequences in order to modify the behavior when this relationship changes. Here, we present multiple perturbations in visual feedback to larval zebrafish performing the optomotor response and show that they react to these perturbations through a feedback control mechanism. In contrast, if a perturbation is long-lasting, fish adapt their behavior by updating a cerebellum-dependent internal model. We use modelling and functional imaging to show that neuronal requirements for these mechanisms are met in the larval zebrafish brain. Our results illustrate the role of the cerebellum in encoding internal models and how these can calibrate neuronal circuits involved in reactive behaviors depending on the interactions between animal and environment.HighlightsBehavioral reactions to unexpected changes in visual feedback are implemented by a feedback control mechanismA long-lasting change in visual feedback updates the state of the neuronal controllerThe cerebellar internal model mediates this recalibration

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