scholarly journals Sources of noise during accumulation of evidence in unrestrained and voluntarily head-restrained rats

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Benjamin B Scott ◽  
Christine M Constantinople ◽  
Jeffrey C Erlich ◽  
David W Tank ◽  
Carlos D Brody
Keyword(s):  
Signal Detection Theory ◽  
Numerical Cognition ◽  
Diffusion Modeling ◽  
Drift Diffusion ◽  
Future Studies ◽  
Head Restraint ◽  
Resolution Imaging ◽  
Left And Right ◽  
Decision Making Behavior ◽  
Visual Hemifields

Decision-making behavior is often characterized by substantial variability, but its source remains unclear. We developed a visual accumulation of evidence task designed to quantify sources of noise and to be performed during voluntary head restraint, enabling cellular resolution imaging in future studies. Rats accumulated discrete numbers of flashes presented to the left and right visual hemifields and indicated the side that had the greater number of flashes. Using a signal-detection theory-based model, we found that the standard deviation in their internal estimate of flash number scaled linearly with the number of flashes. This indicates a major source of noise that, surprisingly, is not consistent with the widely used 'drift-diffusion modeling' (DDM) approach but is instead closely related to proposed models of numerical cognition and counting. We speculate that this form of noise could be important in accumulation of evidence tasks generally.

scholarly journals The neural computation of human goal-directed behaviors in complex motivational states

2019 ◽  
Author(s):  
Anne Saulin ◽  
Ulrike Horn ◽  
Martin Lotze ◽  
Jochen Kaiser ◽  
Grit Hein
Keyword(s):  
Prosocial Behavior ◽  
Dorsal Striatum ◽  
Neural Computation ◽  
Diffusion Modeling ◽  
Neural Responses ◽  
Drift Diffusion ◽  
Social Motives ◽  
Behavioral Choice ◽  
Motivational States ◽  
Choice Option

AbstractBecause the motives behind goal-directed behaviors are often complex, most behaviors result from the interplay between different motives. However, it is unclear how this interplay between multiple motives affects the neural computation of goal-directed behaviors. Using a combination of drift-diffusion modeling and fMRI, we show that the interplay between different social motives changes initial preferences for prosocial behavior before a person makes a behavioral choice. This increase in preferences for the prosocial choice option was tracked by neural responses in the bilateral dorsal striatum, which in turn lowered the amount of information necessary for choosing prosocial behavior. We obtained these results using a paradigm in which each participant performed the same behavior based on different, simultaneously activated motives, or based on each of the motives separately. Thus, our findings provide a model of behavioral choice computation in complex motivational states, i.e., the motivational setting that drives most goal-directed human behaviors.

Analytical drift-diffusion modeling of GaAs solar cells incorporating a back mirror

2013 ◽  
Author(s):  
Matthew P. Lumb ◽  
Christopher G. Bailey ◽  
Jessica G. J. Adams ◽  
Glen Hillier ◽  
Francis Tuminello ◽  
...  
Keyword(s):  
Solar Cells ◽  
Diffusion Modeling ◽  
Drift Diffusion

scholarly journals Understanding the impact of C60 at the interface of perovskite solar cells via drift-diffusion modeling

AIP Advances ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 035026 ◽  
Author(s):  
Timofey Golubev ◽  
Dianyi Liu ◽  
Richard Lunt ◽  
Phillip Duxbury
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Diffusion Modeling ◽  
Drift Diffusion ◽  
The Impact

scholarly journals Reward Enhances Pain Discrimination in Humans

2020 ◽  
Vol 31 (9) ◽  
pp. 1191-1199
Author(s):  
Susanne Becker ◽  
Martin Löffler ◽  
Ben Seymour
Keyword(s):  
Information Processing ◽  
Sensory Input ◽  
Signal Strength ◽  
Diffusion Modeling ◽  
Drift Diffusion ◽  
Discriminative Ability ◽  
Discriminative Performance ◽  
Decision Bias ◽  
Sensory Signal ◽  
Human Volunteers

The notion that reward inhibits pain is a well-supported observation in both humans and animals, allowing suppression of pain reflexes to acquired rewarding stimuli. However, a blanket inhibition of pain by reward would also impair pain discrimination. In contrast, early counterconditioning experiments implied that reward might actually spare pain discrimination. To test this hypothesis, we investigated whether discriminative performance was enhanced or inhibited by reward. We found in adult human volunteers ( N = 25) that pain-based discriminative ability is actually enhanced by reward, especially when reward is directly contingent on discriminative performance. Drift-diffusion modeling shows that this relates to an augmentation of the underlying sensory signal strength and is not merely an effect of decision bias. This enhancement of sensory-discriminative pain-information processing suggests that whereas reward can promote reward-acquiring behavior by inhibition of pain in some circumstances, it can also facilitate important discriminative information of the sensory input when necessary.

Alpha Oscillations Correlate with the Successful Inhibition of Unattended Stimuli

2011 ◽  
Vol 23 (9) ◽  
pp. 2494-2502 ◽  
Author(s):  
Barbara F. Händel ◽  
Thomas Haarmeier ◽  
Ole Jensen
Keyword(s):  
Visual System ◽  
Alpha Activity ◽  
Coherent Motion ◽  
Motion Processing ◽  
Alpha Power ◽  
Motion Direction ◽  
Alpha Oscillations ◽  
Visual Hemifield ◽  
Left And Right ◽  
Visual Hemifields

Because the human visual system is continually being bombarded with inputs, it is necessary to have effective mechanisms for filtering out irrelevant information. This is partly achieved by the allocation of attention, allowing the visual system to process relevant input while blocking out irrelevant input. What is the physiological substrate of attentional allocation? It has been proposed that alpha activity reflects functional inhibition. Here we asked if inhibition by alpha oscillations has behavioral consequences for suppressing the perception of unattended input. To this end, we investigated the influence of alpha activity on motion processing in two attentional conditions using magneto-encephalography. The visual stimuli used consisted of two random-dot kinematograms presented simultaneously to the left and right visual hemifields. Subjects were cued to covertly attend the left or right kinematogram. After 1.5 sec, a second cue tested whether subjects could report the direction of coherent motion in the attended (80%) or unattended hemifield (20%). Occipital alpha power was higher contralateral to the unattended side than to the attended side, thus suggesting inhibition of the unattended hemifield. Our key finding is that this alpha lateralization in the 20% invalidly cued trials did correlate with the perception of motion direction: Subjects with pronounced alpha lateralization were worse at detecting motion direction in the unattended hemifield. In contrast, lateralization did not correlate with visual discrimination in the attended visual hemifield. Our findings emphasize the suppressive nature of alpha oscillations and suggest that processing of inputs outside the field of attention is weakened by means of increased alpha activity.

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