scholarly journals Multifaceted adaptation of the neural decision process with prior knowledge of time constraints and stimulus probability

2019 ◽  
Author(s):  
Simon P. Kelly ◽  
Elaine A. Corbett ◽  
Redmond G. O’Connell

AbstractWhen selecting actions in response to noisy sensory stimuli, the brain can exploit prior knowledge of time constraints, stimulus discriminability and stimulus probability to hone the decision process. Although behavioral models typically explain such effects through adjustments to decision criteria only, the full range of underlying neural process adjustments remains to be established. Here, we draw on human neurophysiological signals reflecting decision formation to construct and constrain a multi-tiered model of prior-informed motion discrimination, in which a motor-independent representation of cumulative evidence feeds build-to-threshold motor signals that receive additional dynamic urgency and bias signal components. The neurally-informed model not only provides a superior quantitative fit to prior-biased behavior across three distinct task regimes (easy, time-pressured and weak evidence), but also reveals adjustments to evidence accumulation rate, urgency rate, and the timing of accumulation onset and motor execution which go undetected or are discrepant in more standard diffusion-model analysis of behavior.

Author(s):  
Yongbiao Gao ◽  
Yu Zhang ◽  
Xin Geng

Label distribution learning (LDL) is a novel machine learning paradigm that gives a description degree of each label to an instance. However, most of training datasets only contain simple logical labels rather than label distributions due to the difficulty of obtaining the label distributions directly. We propose to use the prior knowledge to recover the label distributions. The process of recovering the label distributions from the logical labels is called label enhancement. In this paper, we formulate the label enhancement as a dynamic decision process. Thus, the label distribution is adjusted by a series of actions conducted by a reinforcement learning agent according to sequential state representations. The target state is defined by the prior knowledge. Experimental results show that the proposed approach outperforms the state-of-the-art methods in both age estimation and image emotion recognition.


2003 ◽  
Vol 90 (3) ◽  
pp. 1392-1407 ◽  
Author(s):  
Roger Ratcliff ◽  
Anil Cherian ◽  
Mark Segraves

Recently, models in psychology have been shown capable of accounting for the full range of behavioral data from simple two-choice decision tasks: mean reaction times for correct and error responses, accuracy, and the reaction time distributions for correct and error responses. At the same time, recent data from neural recordings have allowed investigation of the neural systems that implement such decisions. In the experiment presented here, neural recordings were obtained from superior colliculus prelude/buildup cells in two monkeys while they performed a two-choice task that has been used in humans for testing psychological models of the decision process. The best-developed psychological model, the diffusion model, and a competing model, the Poisson counter model, were explicitly fit to the behavioral data. The pattern of activity shown in the prelude/buildup cells, including the point at which response choices were discriminated, was matched by the evidence accumulation process predicted from the diffusion model using the parameters from the fits to the behavioral data but not by the Poisson counter model. These results suggest that prelude/buildup cells in the superior colliculus, or cells in circuits in which the superior colliculus cells participate, implement a diffusion decision process or a variant of the diffusion process.


Author(s):  
Richard E. Chandler

This paper presents and analyses a statistical framework for combining projections of future climate from different climate simulators. The framework recognizes explicitly that all currently available simulators are imperfect; that they do not span the full range of possible decisions on the part of the climate modelling community; and that individual simulators have strengths and weaknesses. Information from individual simulators is automatically weighted, alongside that from historical observations and from prior knowledge. The weights for a simulator depend on its internal variability, its expected consensus with other simulators, the internal variability of the real climate and the propensity of simulators collectively to deviate from reality. The framework demonstrates, moreover, that some subjective judgements are inevitable when interpreting multiple climate change projections: by clarifying precisely what those judgements are, it provides increased transparency in the ensuing analyses. Although the framework is straightforward to apply in practice by a user with some understanding of Bayesian methods, the emphasis here is on conceptual aspects illustrated with a simplified artificial example. A ‘poor man's version’ is also presented, which can be implemented straightforwardly in simple situations.


1986 ◽  
Vol 4 ◽  
pp. 189-196
Author(s):  
Shogo KAWAKAMI ◽  
Tomohiko ISOBE ◽  
Thdahiro SENGOKU

2017 ◽  
Author(s):  
Kyle Dunovan ◽  
Timothy Verstynen

AbstractGoal-directed behavior requires integrating action selection processes with learning systems that adapt control using environmental feedback. These functions intersect in the basal ganglia (BG), which has at least two targets of plasticity: a dopaminergic modulation of striatal pathways and cortical modulation of the subthalamic nucleus (STN). Dual learning mechanisms suggests that feedback signals have a multifaceted impact on BG-dependent decisions. Using a hybrid of accumulation-to-bound decision models and reinforcement learning, we modeled the performance of humans in a stop-signal task where participants (N=75) learned the prior distribution of the timing of a stop signal through trial-and-error feedback. Changes in the drift-rate of the action execution process were driven by errors in action timing, whereas adaptation in the boundary height served to increase caution following failed stops. These findings highlight two interactive learning mechanisms for adapting the control of goal-directed actions based on dissociable dimensions of feedback error.Author SummaryMany complex behavioral goals rely on one’s ability to regulate the timing of action execution while also maintaining enough control to cancel actions in response to “Stop” cues in the environment. Here we examined how these two fundamental components of behavior become tuned to the control demands of the environment by combining principles of reinforcement learning with accumulator models of decision making. The synthesis of these two theoretical frameworks is motivated by previous work showing that reinforcement learning and control rely on overlapping circuitry in the basal ganglia. Leveraging knowledge about the interaction of learning and control signals in this network, we formulated a computational model in which performance feedback is used to modulate key mechanisms of the decision process to facilitate goal acquisition. Model-based analysis of behavioral data collected on an adaptive stop-signal task revealed two critical learning mechanisms: one that adjusts the accumulation rate of the “Go” signal to errors in action timing and another that exercises caution by raising the height of the execution boundary after a failed Stop trial. We show how these independent learning mechanisms interact over the course of learning, shedding light on the behavioral effects plasticity in different pathways of the basal ganglia.


2001 ◽  
Vol 29 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Noni Richardson Ahlfinger ◽  
James K. Esser

Two hypotheses derived from groupthink theory were tested in a laboratory study which included measures of the full range of symptoms of groupthink, symptoms of a poor decision process, and decision quality. The hypothesis that groups whose leaders promoted their own preferred solutions would be more likely to fall victim to groupthink than groups with nonpromotional leaders received partial support. Groups with promotional leaders produced more symptoms of groupthink, discussed fewer facts, and reached a decision more quickly than groups with nonpromotional leaders. The hypothesis that groups composed of members who were predisposed to conform would be more likely to fall victim to groupthink than groups whose members were not predisposed to conform received no support. It is suggested that groupthink research is hampered by measurement problems.


ASHA Leader ◽  
2013 ◽  
Vol 18 (8) ◽  
pp. 40-45 ◽  
Author(s):  
Judy Rudebusch ◽  
JoAnn Wiechmann

To offer a full range of RTI and IEP services, school-based SLPs can schedule activity blocks rather than go student by student—here's how.


2016 ◽  
Vol 1 (15) ◽  
pp. 79-83
Author(s):  
Ed Bice ◽  
Kristine E. Galek

Dysphagia is common in patients with dementia. Dysphagia occurs as a result of changes in the sensory and motor function of the swallow (Easterling, 2007). It is known that the central nervous system can undergo experience-dependent plasticity, even in those individuals with dementia (Park & Bischof, 2013). The purpose of this study was to explore whether or not the use of neuroplastic principles would improve the swallow motor plan and produce positive outcomes of a patient in severe cognitive decline. The disordered swallow motor plan was manipulated by focusing on a neuroplastic principles of frequency (repetition), velocity of movement (speed of presentation), reversibility (Use it or Lose it), specificity and adaptation, intensity (bolus size), and salience (Crary & Carnaby-Mann, 2008). After five therapeutic sessions, the patient progressed from holding solids in her mouth with decreased swallow initiation to independently consuming a regular diet with full range of liquids with no oral retention and no verbal cues.


2012 ◽  
Vol 26 (4) ◽  
pp. 178-203 ◽  
Author(s):  
Francesco Riganello ◽  
Sergio Garbarino ◽  
Walter G. Sannita

Measures of heart rate variability (HRV) are major indices of the sympathovagal balance in cardiovascular research. These measures are thought to reflect complex patterns of brain activation as well and HRV is now emerging as a descriptor thought to provide information on the nervous system organization of homeostatic responses in accordance with the situational requirements. Current models of integration equate HRV to the affective states as parallel outputs of the central autonomic network, with HRV reflecting its organization of affective, physiological, “cognitive,” and behavioral elements into a homeostatic response. Clinical application is in the study of patients with psychiatric disorders, traumatic brain injury, impaired emotion-specific processing, personality, and communication disorders. HRV responses to highly emotional sensory inputs have been identified in subjects in vegetative state and in healthy or brain injured subjects processing complex sensory stimuli. In this respect, HRV measurements can provide additional information on the brain functional setup in the severely brain damaged and would provide researchers with a suitable approach in the absence of conscious behavior or whenever complex experimental conditions and data collection are impracticable, as it is the case, for example, in intensive care units.


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