scholarly journals Illusions, Delusions, and Your Backwards Bayesian Brain: A Biased Visual Perspective

2021 ◽  
pp. 1-14
Author(s):  
Richard T. Born ◽  
Gianluca M. Bencomo
Keyword(s):  
Bayesian Inference ◽  
Visual System ◽  
Retinal Image ◽  
General Framework ◽  
Neural Circuits ◽  
Visual Perspective ◽  
Bayesian Brain ◽  
Sensory Data ◽  
Hierarchical Bayesian Inference

The retinal image is insufficient for determining what is “out there,” because many different real-world geometries could produce any given retinal image. Thus, the visual system must infer which external cause is most likely, given both the sensory data and prior knowledge that is either innate or learned via interactions with the environment. We will describe a general framework of “hierarchical Bayesian inference” that we and others have used to explore the role of cortico-cortical feedback in the visual system, and we will further argue that this approach to “seeing” makes our visual systems prone to perceptual errors in a variety of different ways. In this deliberately provocative and biased perspective, we argue that the neuromodulator, dopamine, may be a crucial link between neural circuits performing Bayesian inference and the perceptual idiosyncrasies of people with schizophrenia.

‘Generic-View Principle’ for Three-Dimensional-Motion Perception: Optics and Inverse Optics of a Moving Straight Bar

Perception ◽  
1996 ◽  
Vol 25 (7) ◽  
pp. 797-814 ◽  
Author(s):  
Michiteru Kitazaki ◽  
Shinsuke Shimojo
Keyword(s):  
Visual System ◽  
Motion Perception ◽  
Retinal Image ◽  
General Framework ◽  
Three Dimensional ◽  
Image Motion ◽  
Optical Process ◽  
Retinal Image Motion ◽  
The Subject ◽  
Three Components

The generic-view principle (GVP) states that given a 2-D image the visual system interprets it as a generic view of a 3-D scene when possible. The GVP was applied to 3-D-motion perception to show how the visual system decomposes retinal image motion into three components of 3-D motion: stretch/shrinkage, rotation, and translation. First, the optical process of retinal image motion was analyzed, and predictions were made based on the GVP in the inverse-optical process. Then experiments were conducted in which the subject judged perception of stretch/shrinkage, rotation in depth, and translation in depth for a moving bar stimulus. Retinal-image parameters—2-D stretch/shrinkage, 2-D rotation, and 2-D translation—were manipulated categorically and exhaustively. The results were highly consistent with the predictions. The GVP seems to offer a broad and general framework for understanding the ambiguity-solving process in motion perception. Its relationship to other constraints such as that of rigidity is discussed.

scholarly journals Corticostriatal control of defense behavior in mice induced by auditory looming cues

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhong Li ◽  
Jin-Xing Wei ◽  
Guang-Wei Zhang ◽  
Junxiang J. Huang ◽  
Brian Zingg ◽  
...  
Keyword(s):  
Essential Role ◽  
Neural Circuits ◽  
Temporal Dynamics ◽  
Defense Behavior ◽  
Innate Defense ◽  
Sensory Inputs ◽  
Corticostriatal Projections ◽  
Behavioral Transition ◽  
Auditory Looming

AbstractAnimals exhibit innate defense behaviors in response to approaching threats cued by the dynamics of sensory inputs of various modalities. The underlying neural circuits have been mostly studied in the visual system, but remain unclear for other modalities. Here, by utilizing sounds with increasing (vs. decreasing) loudness to mimic looming (vs. receding) objects, we find that looming sounds elicit stereotypical sequential defensive reactions: freezing followed by flight. Both behaviors require the activity of auditory cortex, in particular the sustained type of responses, but are differentially mediated by corticostriatal projections primarily innervating D2 neurons in the tail of the striatum and corticocollicular projections to the superior colliculus, respectively. The behavioral transition from freezing to flight can be attributed to the differential temporal dynamics of the striatal and collicular neurons in their responses to looming sound stimuli. Our results reveal an essential role of the striatum in the innate defense control.

scholarly journals Beyond feasibility—the role of motivation to implement measures to enhance resilience

2021 ◽  
Vol 26 (5) ◽  
Author(s):  
Luzian Messmer ◽  
Braida Thom ◽  
Pius Kruetli ◽  
Evans Dawoe ◽  
Kebebew Assefa ◽  
...  
Keyword(s):  
Food Security ◽  
Conceptual Framework ◽  
General Framework ◽  
Rural Livelihoods ◽  
Weather Forecast ◽  
Reduced Tillage ◽  
Shade Trees ◽  
The World ◽  
Cocoa Farmers

AbstractMany regions around the world are experiencing an increase in climate-related shocks, such as drought. This poses serious threats to farming activities and has major implications for sustaining rural livelihoods and food security. Farmers’ ability to respond to and withstand the increasing incidence of drought events needs to be strengthened and their resilience enhanced. Implementation of measures to enhance resilience is determined by decisions of farmers and it is important to understand the reasons behind their behavior. We assessed the viability of measures to enhance resilience of farmers to drought, by developing a general framework that covers economic-technical and psychological-cognitive aspects, here summarized under the terms (1) motivation and (2) feasibility. The conceptual framework was applied to cocoa farmers in Ghana and tef farmers in Ethiopia by using questionnaire-based surveys. A portfolio of five specific measures to build resilience (i.e., irrigation, shade trees, fire belts, bookkeeping, mulching, early mature varieties, weather forecast, reduced tillage, improved harvesting) in each country was evaluated with a closed-ended questionnaire that covered the various aspects of motivation and feasibility whereby farmers were asked to (dis)agree on a 5-point Likert scale. The results show that if the motivation mean score is increased by 0.1 units, the probability of implementation increases by 16.9% in Ghana and by 7.7% in Ethiopia. If the feasibility mean score is increased by 0.1 units, the probability of implementation increases by 24.9% in Ghana and by 11.9% in Ethiopia. We can conclude that motivation and feasibility matter, and we improve our understanding of measure implementation if we include both feasibility and motivation into viability assessments.

Introduction

2016 ◽  
Vol 6 (2-3) ◽  
pp. 101-108
Author(s):  
Marc Belissa ◽  
Gary Berton
Keyword(s):  
General Framework ◽  
American English ◽  
Atlantic History ◽  
Thomas Paine ◽  
International Conference ◽  
Opening Up ◽  
Second International

The volume contains six contributions (and an introduction) that have been presented in the Thomas Paine Second International Conference held in Paris Ouest Nanterre in 2014. All scholars involved in the field of research of Atlantic history agree on the fact that the partitioning between ‘national’ historiographies (American, English and French) is detrimental in the understanding of the role of specific transatlantic actors, of which Thomas Paine is one the most spectacular example for the era of the revolutions (1760–1830). This conference gathered American, British and French historians to develop this fruitful approach. The papers presented here participate in the historiographic opening up of studies on Thomas Paine and propose studies, reflexion and specific comments on how Thomas Paine converges within the general framework of Atlantic history and Republicanism history.

Pertinence of Predictive Models as Regards the Behavior of Observed Biological and Artificial Phenomena

2021 ◽  
Vol 8 (3) ◽  
pp. 189-200
Author(s):  
Adel Razek
Keyword(s):  
Link Prediction ◽  
Clinical Observation ◽  
Mutant Virus ◽  
Brain Functioning ◽  
Bayesian Brain ◽  
Digital Twins ◽  
Brain Theory ◽  
Observation Protocol ◽  
Knowledge Uncertainty

In this assessment, we have made an effort of synthesis on the role of theoretical and observational investigations in the analysis of the concepts and functioning of different natural biological and artificial phenomena. In this context, we pursued the objective of examining published works relating to the behavioral prediction of phenomena associated with its observation. We have examined examples from the literature concerning phenomena with known behaviors that associated to knowledge uncertainty as well as cases concerning phenomena with unknown and changing random behaviors linked to random uncertainty. The concerned cases are relative to brain functioning in neuroscience, modern smart industrial devices, and health care predictive endemic protocols. As predictive modeling is very concerned by the problematics relative to uncertainties that depend on the degree of matching in the link prediction-observation, we investigated first how to improve the model to match better the observation. Thus, we considered the case when the observed behavior and its model are contrasting, that implies the development of revised or amended models. Then we studied the case concerning the practice of modeling for the prediction of future behaviors of a phenomenon that is well known, and owning identified behavior. For such case, we illustrated the situation of prediction matched to observation operated in two cases. These are the Bayesian Brain theory in neuroscience and the Digital Twins industrial concept. The last investigated circumstance concerns the use of modeling for the prediction of future behaviors of a phenomenon that is not well known, or owning behavior varying arbitrary. For this situation, we studied contagion infections with an unknown mutant virus where the prediction task is very complicated and would be constrained only to adjust the principal clinical observation protocol. Keywords: prediction, observation, Bayesian, neuroscience, brain functioning, mutant virus

Expression of the BDNF gene in the developing visual system of the chick

Development ◽  
1994 ◽  
Vol 120 (6) ◽  
pp. 1643-1649 ◽  
Author(s):  
K.H. Herzog ◽  
K. Bailey ◽  
Y.A. Barde
Keyword(s):  
Visual System ◽  
Ganglion Cells ◽  
Mrna Levels ◽  
Retinal Ganglion ◽  
Bdnf Gene ◽  
Bdnf Mrna ◽  
Optic Stalk ◽  
Copy Numbers ◽  
Activity Dependent

Using a sensitive and quantitative method, the mRNA levels of brain-derived neurotrophic factor (BDNF) were determined during the development of the chick visual system. Low copy numbers were detected, and BDNF was found to be expressed in the optic tectum already 2 days before the arrival of the first retinal ganglion cell axons, suggesting an early role of BDNF in tectal development. After the beginning of tectal innervation, BDNF mRNA levels markedly increased, and optic stalk transection at day 4 (which prevents subsequent tectal innervation) was found to reduce the contralateral tectal levels of BDNF mRNA. Comparable reductions were obtained after injection of tetrodotoxin into one eye, indicating that, already during the earliest stages of target encounter in the CNS, the degree of BDNF gene expression is influenced by activity-dependent mechanisms. BDNF mRNA was also detected in the retina itself and at levels comparable to those found in the tectum. Together with previous findings indicating that BDNF prevents the death of cultured chick retinal ganglion cells, these results support the idea that the tightly controlled expression of the BDNF gene might be important in the co-ordinated development of the visual system.

The role of vision on postural strategy evaluated in patients affected by congenital nystagmus as an experimental model

1999 ◽  
Vol 9 (6) ◽  
pp. 445-451
Author(s):  
S. Di Girolamo ◽  
W. Di Nardo ◽  
A. Cosenza ◽  
F. Ottaviani ◽  
A. Dickmann ◽  
...  
Keyword(s):  
Visual System ◽  
Postural Control ◽  
Visual Stimulus ◽  
Postural Balance ◽  
Visual Cues ◽  
Normal Subjects ◽  
Congenital Nystagmus ◽  
Dynamic Posturography ◽  
Normal Controls

The role of vision in postural control is crucial and is strictly related to the characteristics of the visual stimulus and to the performance of the visual system. The purpose of this investigation was to evaluate the effects of chronically reduced visual cues upon postural control in patients affected by Congenital Nystagmus (CN). These patients have developed since birth a postural strategy mainly based on vestibular and somatosensorial cues. Fifteen patients affected by CN and 15 normal controls (NC) were enrolled in the study and evaluated by means of dynamic posturography. The overall postural control in CN patients was impaired as demonstrated by the equilibrium score and by the changes of the postural strategy. This impairment was even more enhanced in CN than in NC group when somatosensorial cues were experimentally reduced. An aspecific pattern of visual impairment and a pathological composite score were also present. Our data outline that in patients affected by CN an impairment of the postural balance is present especially when the postural control relies mainly on visual cues. Moreover, a decrease in accuracy of the somatosensory cues has a proportionally greater effect on balance than it has on normal subjects.

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