scholarly journals Saccade selection and inhibition: motor and attentional components

2019 ◽  
Vol 121 (4) ◽  
pp. 1368-1380 ◽  
Author(s):  
Donatas Jonikaitis ◽  
Saurabh Dhawan ◽  
Heiner Deubel
Keyword(s):  
Action Selection ◽  
Oculomotor System ◽  
Attentional Processing ◽  
New Approach ◽  
Neural Organization ◽  
Attentional System ◽  
Human Participants ◽  
The Look ◽  
Inhibitory Motor Control ◽  
Action Inhibition

Motor responses are fundamentally spatial in their function and neural organization. However, studies of inhibitory motor control, focused on global stopping of all actions, have ignored whether inhibitory control can be exercised selectively for specific actions. We used a new approach to elicit and measure motor inhibition by asking human participants to either look at (select) or avoid looking at (inhibit) a location in space. We found that instructing a location to be avoided resulted in an inhibitory bias specific to that location. When compared with the facilitatory bias observed in the Look task, it differed significantly in both its spatiotemporal dynamics and its modulation of attentional processing. While action selection was evident in oculomotor system and interacted with attentional processing, action inhibition was evident mainly in the oculomotor system. Our findings suggest that action inhibition is implemented by spatially specific mechanisms that are separate from action selection. NEW & NOTEWORTHY We show that cognitive control of saccadic responses evokes separable action selection and inhibition processes. Both action selection and inhibition are represented in the saccadic system, but only action selection interacts with the attentional system.

scholarly journals Rewards interact with explicit knowledge to enhance skilled motor performance

2019 ◽  
Author(s):  
Sean P. Anderson ◽  
Tyler J. Adkins ◽  
Bradley S. Gary ◽  
Taraz G. Lee
Keyword(s):  
Motor Skills ◽  
Motor Performance ◽  
Explicit Knowledge ◽  
Motor Planning ◽  
Action Selection ◽  
The Other ◽  
Monetary Incentives ◽  
Sequential Movements ◽  
Human Participants ◽  
Sequencing Task

AbstractFrom typing on a keyboard to playing the piano, many everyday skills require the ability to quickly and accurately perform sequential movements. It is well-known that the availability of rewards leads to increases in motivational vigor whereby people enhance both the speed and force of their movements. However, in the context of motor skills, it is unclear whether rewards also lead to more effective motor planning and action selection. Here, we trained human participants to perform four separate sequences in a skilled motor sequencing task. Two of these sequences were trained explicitly and performed with pre-cues that allow for the planning of movements, while the other two were trained implicitly. Immediately following the introduction of performance-contingent monetary incentives, participants improved their performance on all sequences consistent with enhancements in motivational vigor. However, there was a much larger performance boost for explicitly trained sequences. We replicated these results in a second, pre-registered experiment with an independent sample. We conclude from these experiments that rewards enhance both the planning of movements as well as motivational vigor.

ERP Responses to Facial Affect and Temperament Types in Eysenckian and Strelauvian Theories

2012 ◽  
Vol 33 (4) ◽  
pp. 212-226 ◽  
Author(s):  
Małgorzata Fajkowska ◽  
Anna Zagórska ◽  
Jan Strelau ◽  
Piotr Jaśkowski
Keyword(s):  
Facial Expression ◽  
Facial Affect ◽  
Attentional Processing ◽  
Temporal Characteristics ◽  
Behavioral Level ◽  
Effective Functioning ◽  
Cortical Level ◽  
Facial Stimuli ◽  
Attentional System ◽  
Attentional Mechanisms

Eysenck’s PEN and Strelau’s RTT theories are considered interrelated on the level of traits and translatable on the level of four ancient temperament types. However, they refer to different ways of regulation stimulation, by content (emotional and social) and by the formal (energetic and temporal) characteristics of activity, respectively. Thus, by indexing behavioral and cortical patterns of response, it was predicted that PEN- and RTT-relevant pairs of temperaments would be associated with specific attentional mechanisms. One week after administration of the FCB-TI and EPQ-R, subjects (260) performed the Emotional Go/No Go task while a 32-channel EEG was being recorded. They were instructed to respond to threatening, sad, or friendly faces, respectively, but not to any other facial expression. A range of ERP components responsive to facial stimuli were investigated. According to behavioral and cortical patterns of response, it was shown that PEN- and RTT-related pairs of temperament types were connected with effective functioning of the anterior and posterior attentional system, respectively. On the behavioral level, significant differences in attentional processing of facial affect were registered in PEN sanguines versus RTT sanguines and PEN melancholics versus RTT melancholics, while on the cortical level significant differences were registered in PEN melancholics versus RTT melancholics and PEN phlegmatics versus RTT phlegmatics. Given these results, the theoretical relations between the PEN and RTT – with particular respect to cognitive and cortical mechanisms underlying temperament types – are discussed.

scholarly journals Study on Zero-Doppler Centroid Control for GEO SAR Ground Observation

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yicheng Jiang ◽  
Bin Hu ◽  
Yun Zhang ◽  
Meng Lian ◽  
Zhuoqun Wang
Keyword(s):  
Control Method ◽  
Elliptical Orbit ◽  
Earth Orbit ◽  
New Approach ◽  
Orbital Parameters ◽  
Ground Observation ◽  
The Earth ◽  
Satellite Platform ◽  
Simulation Results ◽  
The Look

In geosynchronous Earth orbit SAR (GEO SAR), Doppler centroid compensation is a key step for imaging process, which could be performed by the attitude steering of a satellite platform. However, this zero-Doppler centroid control method does not work well when the look angle of radar is out of an expected range. This paper primarily analyzes the Doppler properties of GEO SAR in the Earth rectangular coordinate. Then, according to the actual conditions of the GEO SAR ground observation, the effective range is presented by the minimum and maximum possible look angles which are directly related to the orbital parameters. Based on the vector analysis, a new approach for zero-Doppler centroid control in GEO SAR, performing the attitude steering by a combination of pitch and roll rotation, is put forward. This approach, considering the Earth’s rotation and elliptical orbit effects, can accurately reduce the residual Doppler centroid. All the simulation results verify the correctness of the range of look angle and the proposed steering method.

scholarly journals Metacognitive Awareness of Difficulty in Action Selection: The Role of the Cingulo-opercular Network

2021 ◽  
pp. 1-11
Author(s):  
Kobe Desender ◽  
Martyn Teuchies ◽  
Carlos Gonzalez Garcia ◽  
Wouter De Baene ◽  
Jelle Demanet ◽  
...  
Keyword(s):  
Action Selection ◽  
Metacognitive Awareness ◽  
Direct Access ◽  
Response Priming ◽  
Metacognitive Judgment ◽  
Cognitive States ◽  
Priming Paradigm ◽  
Human Participants ◽  
Metacognitive Experience

Abstract The question whether and how we are able to monitor our own cognitive states (metacognition) has been a matter of debate for decades. Do we have direct access to our cognitive processes, or can we only infer them indirectly based on their consequences? In the current study, we wanted to investigate the brain circuits that underlie the metacognitive experience of fluency in action selection. To manipulate action-selection fluency, we used a subliminal response priming paradigm. On each trial, both male and female human participants additionally engaged in the metacognitive process of rating how hard they felt it was to respond to the target stimulus. Despite having no conscious awareness of the prime, results showed that participants rated incompatible trials (during which subliminal primes interfered with the required response) to be more difficult than compatible trials (where primes facilitated the required response), reflecting metacognitive awareness of difficulty. This increased sense of subjective difficulty was mirrored by increased activity in the rostral cingulate zone and the anterior insula, two regions that are functionally closely connected. Importantly, this reflected activations that were unique to subjective difficulty ratings and were not explained by RTs or prime–response compatibility. We interpret these findings in light of a possible grounding of the metacognitive judgment of fluency in action selection in interoceptive signals resulting from increased effort.

Neural Organization From the Superior Colliculus to Motoneurons in the Horizontal Oculomotor System of the Cat

1999 ◽  
Vol 81 (6) ◽  
pp. 2597-2611 ◽  
Author(s):  
Y. Izawa ◽  
Y. Sugiuchi ◽  
Y. Shinoda
Keyword(s):  
Superior Colliculus ◽  
Reticular Formation ◽  
Wheat Germ ◽  
Abducens Nerve ◽  
Vestibular Nuclei ◽  
Oculomotor System ◽  
Abducens Nucleus ◽  
Axon Terminals ◽  
Neural Organization ◽  
Premotor Neurons

Neural organization from the superior colliculus to motoneurons in the horizontal oculomotor system of the cat. The neural organization of the superior colliculus (SC) projection to horizontal ocular motoneurons was analyzed in anesthetized cats using intracellular recording and transneuronal labeling. Intracellular responses to SC stimulation were analyzed in lateral rectus (LR) and medial rectus (MR) motoneurons and internuclear neurons in the abducens nucleus (AINs). LR motoneurons and AINs received excitation from the contralateral SC and inhibition from the ipsilateral SC. The shortest excitation (0.9–1.9 ms) and inhibition (1.4–2.4 ms) were mainly disynaptic from the SC and were followed by tri- and polysynaptic responses evoked with increasing stimuli or intensity. All MR motoneurons received excitation from the ipsilateral SC, whereas none of them received any short-latency inhibition from the contralateral SC, but some received excitation. The latency of the ipsilateral excitation in MR motoneurons (1.7–2.8 ms) suggested that this excitation was trisynaptic via contralateral AINs, because conditioning SC stimulation spatially facilitated trisynaptic excitation from the ipsilateral vestibular nerve. To locate interneurons mediating the disynaptic SC inputs to LR motoneurons, last-order premotor neurons were labeled transneuronally after injecting wheat germ agglutinin–conjugated horseradish peroxidase into the abducens nerve, and tectoreticular axon terminals were labeled after injecting dextran-biotin into the ipsilateral or contralateral SC in the same preparations. Transneuronally labeled neurons were mainly distributed ipsilaterally in the paramedian pontine reticular formation (PPRF) rostral to retrogradely labeled LR motoneurons and the vestibular nuclei, and contralaterally in the paramedian pontomedullary reticular formation (PPMRF) caudomedial to the abducens nucleus and the vestibular nuclei. Among the last-order premotor neuron areas, orthogradely labeled tectoreticular axon terminals were observed only in the PPRF and the PPMRF contralateral to the injected SC and seemed to make direct contacts with many of the labeled last-order premotor neurons in the PPRF and the PPMRF. These morphological results confirmed that the main excitatory and inhibitory connections from the SC to LR motoneurons are disynaptic and that the PPRF neurons that receive tectoreticular axon terminals from the contralateral SC terminate on ipsilateral LR motoneurons, whereas the PPMRF neurons that receive tectoreticular axon terminals from the contralateral SC terminate on contralateral LR motoneurons.

scholarly journals Basal Ganglia Control of Reflexive Saccades: A Computational Model Integrating Physiology Anatomy and Behaviour

2017 ◽  
Author(s):  
Alex J. Cope ◽  
Jonathan M. Chambers ◽  
Tony J. Prescott ◽  
Kevin N. Gurney
Keyword(s):  
Basal Ganglia ◽  
Computational Model ◽  
Degrees Of Freedom ◽  
Model Comparison ◽  
Functional Anatomy ◽  
Computational Modelling ◽  
Action Selection ◽  
Oculomotor System ◽  
Model Dynamics ◽  
Reflexive Saccades

AbstractIt is hypothesised that the basal ganglia play a key role in solving the problem of action selection. Here we investigate this hypothesis through computational modelling of the primate saccadic oculomotor system. This system is an excellent target for computational modelling because it is supported by a reasonably well understood functional anatomy, has limited degrees of freedom, and there is a wealth of behavioural and electrophysiological data for model comparison. Here, we describe a computational model of the reflexive saccadic oculomotor system incorporating the basal ganglia, key structures in motor control and competition between possible actions. To restrict the likelihood of overfitting the model it is structured and parameterised by the known anatomy and neurophysiology along with data from a single experimental behavioural paradigm, then validated by testing against several additional behavioural experimental data without modification of the parameters. With this model we reproduce a range of fundamental reflexive saccadic results both qualitatively and quantitatively, comprising: the distribution of saccadic latencies; the effect of eccentricity, luminance and fixation-target interactions on saccadic latencies; and the effect of competing targets on saccadic endpoint. By investigating the model dynamics we are able to provide mechanistic explanations for the sources of these behaviours. Further, because of its accesibility, the oculomotor system has also been used to study general principle of sensorimotor control. We interpret the ability of the basal ganglia to successfully control saccade selection in our model as further evidence for the action selection hypothesis.

scholarly journals Unexpected Sounds Nonselectively Inhibit Active Visual Stimulus Representations

2020 ◽  
Author(s):  
Cheol Soh ◽  
Jan R Wessel
Keyword(s):  
Neural Mechanism ◽  
Stop Signal Task ◽  
Unexpected Events ◽  
Control Signals ◽  
Attentional Engagement ◽  
Memory Representations ◽  
Human Participants ◽  
Scalp Electroencephalogram ◽  
P3 Component ◽  
Inhibitory Motor Control

Abstract The brain’s capacity to process unexpected events is key to cognitive flexibility. The most well-known effect of unexpected events is the interruption of attentional engagement (distraction). We tested whether unexpected events interrupt attentional representations by activating a neural mechanism for inhibitory control. This mechanism is most well characterized within the motor system. However, recent work showed that it is automatically activated by unexpected events and can explain some of their nonmotor effects (e.g., on working memory representations). Here, human participants attended to lateralized flickering visual stimuli, producing steady-state visual evoked potentials (SSVEPs) in the scalp electroencephalogram. After unexpected sounds, the SSVEP was rapidly suppressed. Using a functional localizer (stop-signal) task and independent component analysis, we then identified a fronto-central EEG source whose activity indexes inhibitory motor control. Unexpected sounds in the SSVEP task also activated this source. Using single-trial analyses, we found that subcomponents of this source differentially relate to sound-induced SSVEP changes: While its N2 component predicted the subsequent suppression of the attended-stimulus SSVEP, the P3 component predicted the suppression of the SSVEP to the unattended stimulus. These results shed new light on the processes underlying fronto-central control signals and have implications for phenomena such as distraction and the attentional blink.

scholarly journals Mechanistic determinants of effector-independent motor memory encoding

2020 ◽  
Vol 117 (29) ◽  
pp. 17338-17347 ◽  
Author(s):  
Adarsh Kumar ◽  
Gaurav Panthi ◽  
Rechu Divakar ◽  
Pratik K. Mutha
Keyword(s):  
Performing Arts ◽  
Posterior Parietal Cortex ◽  
Primary Motor Cortex ◽  
Movement Planning ◽  
Motor Memory ◽  
High Definition ◽  
Healthy Human ◽  
Neural Organization ◽  
Human Participants ◽  
Stable Memory

Coordinated, purposeful movements learned with one effector generalize to another effector, a finding that has important implications for tool use, sports, performing arts, and rehabilitation. This occurs because the motor memory acquired through learning comprises representations that are effector-independent. Despite knowing this for decades, the neural mechanisms and substrates that are causally associated with the encoding of effector-independent motor memories remain poorly understood. Here we exploit intereffector generalization, the behavioral signature of effector-independent representations, to address this crucial gap. We first show in healthy human participants that postlearning generalization across effectors is principally predicted by the level of an implicit mechanism that evolves gradually during learning to produce a temporally stable memory. We then demonstrate that interfering with left but not right posterior parietal cortex (PPC) using high-definition cathodal transcranial direct current stimulation impedes learning mediated by this mechanism, thus potentially preventing the encoding of effector-independent memory components. We confirm this in our final experiment in which we show that disrupting left PPC but not primary motor cortex after learning has been allowed to occur blocks intereffector generalization. Collectively, our results reveal the key mechanism that encodes an effector-independent memory trace and uncover a central role for the PPC in its representation. The encoding of such motor memory components outside primary sensorimotor regions likely underlies a parsimonious neural organization that enables more efficient movement planning in the brain, independent of the effector used to act.

scholarly journals Exploration Entropy for Reinforcement Learning

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Bo Xin ◽  
Haixu Yu ◽  
You Qin ◽  
Qing Tang ◽  
Zhangqing Zhu
Keyword(s):  
Reinforcement Learning ◽  
Theoretical Analysis ◽  
Learning Process ◽  
Process Analysis ◽  
Action Selection ◽  
Training Process ◽  
New Approach ◽  
State Entropy ◽  
Key Issues ◽  
New Criterion

The training process analysis and termination condition of the training process of a Reinforcement Learning (RL) system have always been the key issues to train an RL agent. In this paper, a new approach based on State Entropy and Exploration Entropy is proposed to analyse the training process. The concept of State Entropy is used to denote the uncertainty for an RL agent to select the action at every state that the agent will traverse, while the Exploration Entropy denotes the action selection uncertainty of the whole system. Actually, the action selection uncertainty of a certain state or the whole system reflects the degree of exploration and the stage of the learning process for an agent. The Exploration Entropy is a new criterion to analyse and manage the training process of RL. The theoretical analysis and experiment results illustrate that the curve of Exploration Entropy contains more information than the existing analytical methods.

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