scholarly journals Biologically plausible mechanisms underlying motor response correction during reward-based decision-making

2017 ◽  
Author(s):  
Jung Hoon Lee
Keyword(s):  
Motor Response ◽  
Behavioral Responses ◽  
Anterior Cingulate ◽  
Adaptive Behaviors ◽  
Optimal Outcome ◽  
Motor Responses ◽  
Response Correction ◽  
Simulation Results ◽  
Experimental Findings ◽  
Goal Directed Behavior

AbstractOur propensity to acclimate to new surroundings and choose a goal-directed behavior for a maximal reward (i.e., optimal outcome) is natural, for it affects our survival. A line of studies suggested that anterior cingulate cortex (ACC) could be a potential hub for adaptive behaviors. For instance, an experimental study noted ACC’s contribution to selecting motor responses for maximal rewards; it found 1) that ACC neurons were selectively activated when the reward was reduced and 2) that suppression of ACC activity impaired monkeys’ ability to change motor responses to obtain the maximal reward. To probe ACC functions in adaptive behaviors, we sought biologically-plausible mechanisms to account for the experimental findings mentioned above by utilizing a computational model. Our simulation results raise the possibility that ACC can correct behavioral responses by reading out and updating the motor plans (guiding future motor responses) stored in prefrontal cortex (PFC).

The Effect of Distraction on Schizophrenic Performance (2) Psychomotor Ability

1965 ◽  
Vol 111 (474) ◽  
pp. 391-398 ◽  
Author(s):  
Andrew McGhie ◽  
James Chapman ◽  
J. S. Lawson
Keyword(s):  
Present Report ◽  
Sensory Modality ◽  
Preceding Paper ◽  
Auditory Distraction ◽  
Psychomotor Tests ◽  
Motor Responses ◽  
Wide Range ◽  
Schizophrenic Patients ◽  
Psychomotor Ability ◽  
Experimental Findings

In the preceding paper the effect of experimental distraction was examined and the findings discussed. The present report is concerned with a similar study of the effect of distraction on tests which involve another aspect of schizophrenic performance, that of psychomotor ability. Earlier studies (Chapman and McGhie, 1961, 1962) produced both clinical and experimental evidence that auditory distraction disrupted the motor responses of some schizophrenic patients. As the previous experimental findings were based on two tests involving only very limited areas of psychomotor performance, it was necessary to examine patients on a wide range of psychomotor tests. A second aim of the present investigation was to assess any differential effects due to variation in the sensory modality of the distracting stimuli.

On the Utility of Crystal Plasticity Modeling to Uncover the Individual Roles of Microdeformation Mechanisms on the Work Hardening Response of Fe-23Mn-0.5C TWIP Steel in the Presence of Hydrogen

2018 ◽  
Vol 140 (3) ◽  
Author(s):  
B. Bal ◽  
M. Koyama ◽  
D. Canadinc ◽  
G. Gerstein ◽  
H. J. Maier ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Embrittlement ◽  
Twip Steel ◽  
Strain Response ◽  
Deformation Response ◽  
Self Consistent ◽  
Twip Steels ◽  
Simulation Results ◽  
The Individual ◽  
Experimental Findings

This paper presents a combined experimental and theoretical analysis focusing on the individual roles of microdeformation mechanisms that are simultaneously active during the deformation of twinning-induced plasticity (TWIP) steels in the presence of hydrogen. Deformation responses of hydrogen-free and hydrogen-charged TWIP steels were examined with the aid of thorough electron microscopy. Specifically, hydrogen charging promoted twinning over slip–twin interactions and reduced ductility. Based on the experimental findings, a mechanism-based microscale fracture model was proposed, and incorporated into a visco-plastic self-consistent (VPSC) model to account for the stress–strain response in the presence of hydrogen. In addition, slip-twin and slip–grain boundary interactions in TWIP steels were also incorporated into VPSC, in order to capture the deformation response of the material in the presence of hydrogen. The simulation results not only verify the success of the proposed hydrogen embrittlement (HE) mechanism for TWIP steels, but also open a venue for the utility of these superior materials in the presence of hydrogen.

Stimulus Processing during Apparent Unconsciousness in Anesthetized Volunteers

1986 ◽  
Vol 62 (2) ◽  
pp. 587-591 ◽  
Author(s):  
Benno Bonke ◽  
Jože Rupreht ◽  
John H. M. Van Eijndhoven
Keyword(s):  
Nitrous Oxide ◽  
General Anesthesia ◽  
Motor Response ◽  
Effective Concentration ◽  
Healthy Male ◽  
Unconscious Perception ◽  
Stimulus Processing ◽  
Motor Responses ◽  
Minimal Effective Concentration ◽  
Period Return

Return of motor-responses upon request as an indicator of stimulus processing during apparent unconsciousness in general anesthesia was studied in 8 healthy, male volunteers during prolonged inhalation of nitrous oxide. First the minimal effective concentration of nitrous oxide was established for each volunteer, based upon continued absence of motor-responses to repeated verbal commands. One week later this concentration of nitrous oxide was administered for a 3-hr. period; return of motor-responses after at least 30 min. of absence was considered a sign of so-called unconscious perception. Four volunteers showed return of motor-response within the 3 hr. of exposure, but two of these had been rather restless throughout the session. Results indicate that unexpected processing of information by patients may occur during presumed unconsciousness after a prolonged inhalation of nitrous oxide in general anesthesia.

scholarly journals Corticoinsular circuits encode subjective value expectation and violation for effortful goal-directed behavior

2018 ◽  
Vol 115 (22) ◽  
pp. E5233-E5242 ◽  
Author(s):  
Amanda R. Arulpragasam ◽  
Jessica A. Cooper ◽  
Makiah R. Nuutinen ◽  
Michael T. Treadway
Keyword(s):  
Decision Making ◽  
Relevant Information ◽  
Neural Mechanisms ◽  
Anterior Cingulate ◽  
Error Signal ◽  
Value Prediction ◽  
Subjective Value ◽  
Effort Discounting ◽  
Trial History ◽  
Goal Directed Behavior

We are presented with choices each day about how to invest our effort to achieve our goals. Critically, these decisions must frequently be made under conditions of incomplete information, where either the effort required or possible reward to be gained is uncertain. Such choices therefore require the development of potential value estimates to guide effortful goal-directed behavior. To date, however, the neural mechanisms for this expectation process are unknown. Here, we used computational fMRI during an effort-based decision-making task where trial-wise information about effort costs and reward magnitudes was presented separately over time, thereby allowing us to model distinct effort/reward computations as choice-relevant information unfolded. We found that ventromedial prefrontal cortex (vmPFC) encoded expected subjective value. Further, activity in dorsal anterior cingulate (dACC) and anterior insula (aI) reflected both effort discounting as well as a subjective value prediction error signal derived from trial history. While prior studies have identified these regions as being involved in effort-based decision making, these data demonstrate their specific role in the formation and maintenance of subjective value estimates as relevant information becomes available.

scholarly journals Stabilizing stretch reflexes are modulated independently from the rapid release of perturbation-triggered motor plans

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hyunglae Lee ◽  
Eric J. Perreault
Keyword(s):  
Motor Response ◽  
Spinal Reflexes ◽  
Reflex Response ◽  
Voluntary Activity ◽  
Motor Responses ◽  
Triggered Reaction ◽  
Triggered Reactions ◽  
Long Latency ◽  
Target Effect ◽  
Long Latency Reflex

Abstract Responses elicited after the shortest latency spinal reflexes but prior to the onset of voluntary activity can display sophistication beyond a stereotypical reflex. Two distinct behaviors have been identified for these rapid motor responses, often called long-latency reflexes. The first is to maintain limb stability by opposing external perturbations. The second is to quickly release motor actions planned prior to the disturbance, often called a triggered reaction. This study investigated their interaction when motor tasks involve both limb stabilization and motor planning. We used a robotic manipulator to change the stability of the haptic environment during 2D arm reaching tasks, and to apply perturbations that could elicit rapid motor responses. Stabilizing reflexes were modulated by the orientation of the haptic environment (field effect) whereas triggered reactions were modulated by the target to which subjects were instructed to reach (target effect). We observed that there were no significant interactions between the target and field effects in the early (50–75 ms) portion of the long-latency reflex, indicating that these components of the rapid motor response are initially controlled independently. There were small but significant interactions for two of the six relevant muscles in the later portion (75–100 ms) of the reflex response. In addition, the target effect was influenced by the direction of the perturbation used to elicit the motor response, indicating a later feedback correction in addition to the early component of the triggered reaction. Together, these results demonstrate how distinct components of the long-latency reflex can work independently and together to generate sophisticated rapid motor responses that integrate planning with reaction to uncertain conditions.

Motor reflexes of stomach elicited by phenyldiguanide in the rat

1980 ◽  
Vol 58 (4) ◽  
pp. 352-359 ◽  
Author(s):  
K. S. Rao
Keyword(s):  
Motor Activity ◽  
Motor Response ◽  
Sympathetic Nerves ◽  
Vagal Afferents ◽  
Intragastric Pressure ◽  
Motor Responses ◽  
Efferent System ◽  
Efferent Pathway ◽  
Cervical Vagotomy ◽  
Stimulation Of

Intragastric pressure (IGP) as an index of gastric motor activity was used to investigate gastric motor responses elicited by phenyldiguanide (PDG) in rats under pentobarbitone anaesthesia. Phenyldiguanide injected into the atrium produced an inhibitory gastric motor response whereas an aortic injection resulted in an increase in IGP. Intracarotid injections were without effect. Atropine reduced the response to atrial PDG but not to aortic PDG. Cervical vagotomy abolished the response to both atrial and aortic PDG. Guanethidine and spinal transection abolished the response to atrial PDG only. It is concluded that PDG acts by stimulation of nonmedullated vagal afferents. The efferent pathway for PDG-evoked gastric relaxation is through sympathetic nerves and the efferent system for gastric contraction involves a noncholinergic, nonadrenergic excitatory mechanism.

scholarly journals Prefrontal neurons encode context-based response execution and inhibition in reward seeking and extinction

2015 ◽  
Vol 112 (30) ◽  
pp. 9472-9477 ◽  
Author(s):  
David E. Moorman ◽  
Gary Aston-Jones
Keyword(s):  
Single Neuron ◽  
Lever Press ◽  
Contextual Information ◽  
Behavioral Responses ◽  
Conservation Of Energy ◽  
Reward Seeking ◽  
Cocaine Seeking ◽  
Medial Pfc ◽  
Evoked Activity ◽  
Goal Directed Behavior

The prefrontal cortex (PFC) guides execution and inhibition of behavior based on contextual demands. In rodents, the dorsal/prelimbic (PL) medial PFC (mPFC) is frequently considered essential for execution of goal-directed behavior (“go”) whereas ventral/infralimbic (IL) mPFC is thought to control behavioral suppression (“stop”). This dichotomy is commonly seen for fear-related behaviors, and for some behaviors related to cocaine seeking. Overall, however, data for reward-directed behaviors are ambiguous, and few recordings of PL/IL activity have been performed to demonstrate single-neuron correlates. We recorded neuronal activity in PL and IL during discriminative stimulus driven sucrose seeking followed by multiple days of extinction of the reward-predicting stimulus. Contrary to a generalized PL-go/IL-stop hypothesis, we found cue-evoked activity in PL and IL during reward seeking and extinction. Upon analyzing this activity based on resultant behavior (lever press or withhold), we found that neurons in both areas encoded contextually appropriate behavioral initiation (during reward seeking) and withholding (during extinction), where context was dictated by response–outcome contingencies. Our results demonstrate that PL and IL signal contextual information for regulation of behavior, irrespective of whether that involves initiation or suppression of behavioral responses, rather than topographically encoding go vs. stop behaviors. The use of context to optimize behavior likely plays an important role in maximizing utility-promoting exertion of activity when behaviors are rewarded and conservation of energy when not.

scholarly journals Operant Conditioning of Primate Prefrontal Neurons

2010 ◽  
Vol 103 (4) ◽  
pp. 1843-1855 ◽  
Author(s):  
Shunsuke Kobayashi ◽  
Wolfram Schultz ◽  
Masamichi Sakagami
Keyword(s):  
Motor Response ◽  
Single Neuron ◽  
Operant Response ◽  
Neuron Activity ◽  
Optimal Outcome ◽  
Control Task ◽  
Response Data ◽  
Voluntary Behavior ◽  
Single Neuron Activity ◽  
Spiking Activity

An operant is a behavioral act that has an impact on the environment to produce an outcome, constituting an important component of voluntary behavior. Because the environment can be volatile, the same action may cause different consequences. Thus to obtain an optimal outcome, it is crucial to detect action–outcome relationships and adapt the behavior accordingly. Although prefrontal neurons are known to change activity depending on expected reward, it remains unknown whether prefrontal activity contributes to obtaining reward. We investigated this issue by setting variable relationships between levels of single-neuron activity and rewarding outcomes. Lateral prefrontal neurons changed their spiking activity according to the specific requirements for gaining reward, without the animals making a motor response. Thus spiking activity constituted an operant response. Data from a control task suggested that these changes were unlikely to reflect simple reward predictions. These data demonstrate a remarkable capacity of prefrontal neurons to adapt to specific operant requirements at the single-neuron level.

scholarly journals Inhibition of Eye Movements Disrupts Spatial Sequence Learning

2021 ◽  
Vol 68 (4) ◽  
pp. 221-228
Author(s):  
Srdan Medimorec ◽  
Petar Milin ◽  
Dagmar Divjak
Keyword(s):  
Eye Movements ◽  
Reaction Time ◽  
Sequence Learning ◽  
Motor Response ◽  
Implicit Sequence Learning ◽  
Restricted Movement ◽  
Motor Responses ◽  
Motor Processes ◽  
Relative Contribution ◽  
Serial Reaction

Abstract. Implicit sequence learning is an integral part of human experience, yet the nature of the mechanisms underlying this type of learning remains a matter of debate. In the current study, we provide a test for two accounts of implicit sequence learning, that is, one that highlights sequence learning in the absence of any motor responses (with suppressed eye movements) and one that highlights the relative contribution of the motor processes (i.e., eye movements) to learning. To adjudicate between these accounts and determine whether a motor response is a requisite process in sequence learning, we used anticipation measures to compare performance on the standard oculomotor serial reaction time (SRT) task and on a version of the SRT task where the eye movements were restricted during the learning phase. our results demonstrated an increased proportion of correct anticipations in the standard SRT task compared to the restricted-movement task.

Research on the Propagation Characteristics of Fatigue Cracks on Rail Surfaces

2021 ◽  
pp. 2050121
Author(s):  
Ruipeng Gao ◽  
Shanshan Fan
Keyword(s):  
Crack Growth ◽  
Fatigue Cracks ◽  
Three Dimensional ◽  
Cyclic Loads ◽  
Propagation Characteristics ◽  
Ansys Software ◽  
Expansion Curve ◽  
Simulation Results ◽  
The Law ◽  
Experimental Findings

To solve the problem of rail crack propagation, inadequate studies mainly use a two-dimensional (2D) model for macroscopic crack analysis owing to the failure of accurately reflecting the contact status between the wheel and rail. In this work, we use ANSYS software to establish a three-dimensional (3D) wheel–rail contact model to clarify the microcracks on the rail tread. The influence of the number of horizontal and vertical cyclic loads during the rail’s fatigue crack growth is analyzed. The results suggest that as the number of vertical and tangential cyclic loads increases, the length of the rail crack increases. Using experiments to verify the law between the number of cyclic loads and rail crack growth length, the experimental findings proved that the law of crack growth is basically consistent with the aforementioned simulation results and the outcome of the Paris expansion curve, verifying the validity of the simulation results.

Sign in / Sign up

Export Citation Format

Share Document