scholarly journals Prior expectations evoke stimulus templates in the deep layers of V1

2020 ◽  
Author(s):  
Fraser Aitken ◽  
Georgios Menelaou ◽  
Oliver Warrington ◽  
Renée S. Koolschijn ◽  
Nadège Corbin ◽  
...  
Keyword(s):  
Sensory Processing ◽  
Neural Circuit ◽  
Cortical Layers ◽  
Perceptual Inference ◽  
Connectivity Patterns ◽  
Deep Layers ◽  
Flow Through ◽  
The Brain ◽  
Shed Light ◽  
The Way

AbstractThe way we perceive the world is strongly influenced by our expectations. In line with this, much recent research has revealed that prior expectations strongly modulate sensory processing. However, the neural circuitry through which the brain integrates external sensory inputs with internal expectation signals remains unknown. In order to understand the computational architecture of the cortex, we need to investigate the way these signals flow through the cortical layers. This is crucial because the different cortical layers have distinct intra- and interregional connectivity patterns, and therefore determining which layers are involved in a cortical computation can inform us on the sources and targets of these signals. Here, we used ultra-high field (7T) functional magnetic resonance imaging (fMRI) to reveal that prior expectations evoke stimulus templates selectively in the deep layers of the primary visual cortex. These results shed light on the neural circuit underlying perceptual inference.

scholarly journals Prior expectations evoke stimulus-specific activity in the deep layers of the primary visual cortex

PLoS Biology ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. e3001023
Author(s):  
Fraser Aitken ◽  
Georgios Menelaou ◽  
Oliver Warrington ◽  
Renée S. Koolschijn ◽  
Nadège Corbin ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Specific Activity ◽  
Predictive Processing ◽  
Cortical Layers ◽  
Computational Architecture ◽  
Deep Layers ◽  
Flow Through ◽  
The Brain ◽  
The Way

The way we perceive the world is strongly influenced by our expectations. In line with this, much recent research has revealed that prior expectations strongly modulate sensory processing. However, the neural circuitry through which the brain integrates external sensory inputs with internal expectation signals remains unknown. In order to understand the computational architecture of the cortex, we need to investigate the way these signals flow through the cortical layers. This is crucial because the different cortical layers have distinct intra- and interregional connectivity patterns, and therefore determining which layers are involved in a cortical computation can inform us on the sources and targets of these signals. Here, we used ultra-high field (7T) functional magnetic resonance imaging (fMRI) to reveal that prior expectations evoke stimulus-specific activity selectively in the deep layers of the primary visual cortex (V1). These findings are in line with predictive processing theories proposing that neurons in the deep cortical layers represent perceptual hypotheses and thereby shed light on the computational architecture of cortex.

Targeted Circuit Manipulations in the Modeling of OCD

2017 ◽  
Author(s):  
Susanne E. Ahmari
Keyword(s):  
Neural Circuit ◽  
Brain Network ◽  
Repetitive Behaviors ◽  
Imaging Studies ◽  
Targeted Treatments ◽  
Excessive Grooming ◽  
The Brain ◽  
Shed Light ◽  
Deep Brain

Work in animal models has great potential to shed light on the neural circuit perturbations that lead to OCD-related behaviors. Circuit-specific manipulations allow testing of the causal role of the brain network abnormalities observed in clinical imaging studies, with a precision that is not possible in investigations in humans. In recent years, circuit-specific manipulations in animals using a range of technologies have confirmed that abnormalities in the cortico-striatal circuitry can produce repetitive behaviors, such as excessive grooming. This chapter summarizes these advances. Refining our understanding of the contribution of particular neural circuits to OCD-relevant behaviors can inform the development of anatomically targeted treatments, such as deep brain stimulation.

scholarly journals A Dependency Capturing Code for Robust Object Representation

2019 ◽  
Author(s):  
Rishabh Raj ◽  
Dar Dahlen ◽  
Kyle Duyck ◽  
C. Ron Yu
Keyword(s):  
Sensory Processing ◽  
Object Representation ◽  
Learning Experience ◽  
Receptive Fields ◽  
Efficient Coding ◽  
Sensory Inputs ◽  
Redundant Feature ◽  
Deep Layers ◽  
Robust Face Recognition ◽  
The Brain

AbstractThe brain has a remarkable ability to recognize objects from noisy or corrupted sensory inputs. How this cognitive robustness is achieved computationally remains unknown. We present a coding paradigm, which encodes structural dependence among features of the input and transforms various forms of the same input into the same representation. The paradigm, through dimensionally expanded representation and sparsity constraint, allows redundant feature coding to enhance robustness and is efficient in representing objects. We demonstrate consistent representations of visual and olfactory objects under conditions of occlusion, high noise or with corrupted coding units. Robust face recognition is achievable without deep layers or large training sets. The paradigm produces both complex and simple receptive fields depending on learning experience, thereby offers a unifying framework of sensory processing.One line abstractWe present a framework of efficient coding of objects as a combination of structurally dependent feature groups that is robust against noise and corruption.

Géographie et cartographie fictionnelles dans l’Utopie (1516) de Thomas More

Moreana ◽  
2010 ◽  
Vol 47 (Number 181- (3-4) ◽  
pp. 9-68
Author(s):  
Jean Du Verger
Keyword(s):  
Complex Network ◽  
Narrative Strategies ◽  
Thomas More ◽  
The Third ◽  
Editio Princeps ◽  
Shed Light ◽  
The Way

The philosophical and political aspects of Utopia have often shadowed the geographical and cartographical dimension of More’s work. Thus, I will try to shed light on this aspect of the book in order to lay emphasis on the links fostered between knowledge and space during the Renaissance. I shall try to show how More’s opusculum aureum, which is fraught with cartographical references, reifies what Germain Marc’hadour terms a “fictional archipelago” (“The Catalan World Atlas” (c. 1375) by Abraham Cresques ; Zuane Pizzigano’s portolano chart (1423); Martin Benhaim’s globe (1492); Martin Waldseemüller’s Cosmographiae Introductio (1507); Claudius Ptolemy’s Geographia (1513) ; Benedetto Bordone’s Isolario (1528) ; Diogo Ribeiro’s world map (1529) ; the Grand Insulaire et Pilotage (c.1586) by André Thevet). I will, therefore, uncover the narrative strategies used by Thomas More in a text which lies on a complex network of geographical and cartographical references. Finally, I will examine the way in which the frontispiece of the editio princeps of 1516, as well as the frontispiece of the third edition published by Froben at Basle in 1518, clearly highlight the geographical and cartographical aspect of More’s narrative.

8. Retrospect of Mental Philosophy (Periodical Literature.)

1880 ◽  
Vol 26 (113) ◽  
pp. 119
Author(s):  
B. F. C. Costelloe
Keyword(s):  
Periodical Literature ◽  
Main Interest ◽  
Intended Meaning ◽  
Border Line ◽  
Emotional Language ◽  
Ordinary Power ◽  
The Moment ◽  
The Brain ◽  
The Way

The first number for the year is not remarkable for any paper of striking value. Readers of the Journal will be chiefly attracted by the long and clearly written resumé of Dr. Hughlings Jackson's recent studies “On Affections of Speech from Disease of the Brain,” which is contributed by Mr. James Sully. He remarks on the great value of Dr. Jackson's attempts to classify the different forms of aphasia under the three main heads or stages of—(1) Defect of Speech, in which the patient has a full vocabulary, but confuses words; (2) Loss of Speech, in which the patient is practically speechless, and his pantomimic power is impaired as well; and (3) Loss of Language, in which, besides being speechless, he has altogether lost the power of pantomime, and even his faculty of emotional language is deeply involved in the wreck. All these states or stages again are, properly speaking, to be distinguished altogether from affections of speech in the way of loss of articulation (owing to paralysis of the tongue, &c.), or loss of vocalisation (owing to disease of the larynx); whereas the three degrees or stages of aphasia proper are due to a deep-seated and severe disorganisation of the brain. The main interest of the theory lies in the ingenious and carefully-argued analysis of the symptoms, by which Dr. Jackson arrives at the theory that as the process of destruction goes on, the superior “layers” or strata of speech fail first—those namely which involve the ordinary power of adapting sounds to the circumstances of the moment as they arise; after them fail the “more highly organized utterances” those, namely, which have in any way become automatic, such as “come on,” “wo! wo!” and even “yes” and “no,” which stand on the border-line between emotional and intellectual language; next fails the power of adapting other than vocal signs to convey an intended meaning, which is called, rather clumsily, “pantomimic propositionising;” and last of all dies out the power of uttering sounds or making signs expressive merely of emotion—a power which, of course, is not true speech at all.

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