Using Computational Modelling to Understand Cognition in the Ventral Visual-Perirhinal Pathway

Author(s):  
Rosemary A. Cowell ◽  
Timothy J. Bussey ◽  
Lisa M. Saksida

The authors present a series of studies in which computational models are used as a tool to examine the organization and function of the ventral visual-perirhinal stream in the brain. The prevailing theoretical view in this area of cognitive neuroscience holds that the object-processing pathway has a modular organization, in which visual perception and visual memory are carried out independently. They use computational simulations to demonstrate that the effects of brain damage on both visual discrimination and object recognition memory may not be due to an impairment in a specific function such as memory or perception, but are more likely due to compromised object representations in a hierarchical and continuous representational system. The authors argue that examining the nature of stimulus representations and their processing in cortex is a more fruitful approach than attempting to map cognition onto functional modules.

Author(s):  
Patricia L Lockwood ◽  
Miriam C Klein-Flügge

Abstract Social neuroscience aims to describe the neural systems that underpin social cognition and behaviour. Over the past decade, researchers have begun to combine computational models with neuroimaging to link social computations to the brain. Inspired by approaches from reinforcement learning theory, which describes how decisions are driven by the unexpectedness of outcomes, accounts of the neural basis of prosocial learning, observational learning, mentalizing and impression formation have been developed. Here we provide an introduction for researchers who wish to use these models in their studies. We consider both theoretical and practical issues related to their implementation, with a focus on specific examples from the field.


2000 ◽  
Vol 23 (4) ◽  
pp. 534-535
Author(s):  
Roman Borisyuk

Arbib et al. describe mathematical and computational models in neuroscience as well as neuroanatomy and neurophysiology of several important brain structures. This is a useful guide to mathematical and computational modelling of the structure and function of nervous system. The book highlights the need to develop a theory of brain functioning, and it offers some useful approaches and concepts.


Author(s):  
Alberto Antonietti ◽  
Claudia Casellato ◽  
Egidio D’Angelo ◽  
Alessandra Pedrocchi

AbstractNowadays, clinicians have multiple tools that they can use to stimulate the brain, by means of electric or magnetic fields that can interfere with the bio-electrical behaviour of neurons. However, it is still unclear which are the neural mechanisms that are involved and how the external stimulation changes the neural responses at network-level. In this paper, we have exploited the simulations carried out using a spiking neural network model, which reconstructed the cerebellar system, to shed light on the underlying mechanisms of cerebellar Transcranial Magnetic Stimulation affecting specific task behaviour. Namely, two computational studies have been merged and compared. The two studies employed a very similar experimental protocol: a first session of Pavlovian associative conditioning, the administration of the TMS (effective or sham), a washout period, and a second session of Pavlovian associative conditioning. In one study, the washout period between the two sessions was long (1 week), while the other study foresaw a very short washout (15 min). Computational models suggested a mechanistic explanation for the TMS effect on the cerebellum. In this work, we have found that the duration of the washout strongly changes the modification of plasticity mechanisms in the cerebellar network, then reflected in the learning behaviour.


2016 ◽  
Vol 6 (2) ◽  
pp. 20150083 ◽  
Author(s):  
Radomir Chabiniok ◽  
Vicky Y. Wang ◽  
Myrianthi Hadjicharalambous ◽  
Liya Asner ◽  
Jack Lee ◽  
...  

With heart and cardiovascular diseases continually challenging healthcare systems worldwide, translating basic research on cardiac (patho)physiology into clinical care is essential. Exacerbating this already extensive challenge is the complexity of the heart, relying on its hierarchical structure and function to maintain cardiovascular flow. Computational modelling has been proposed and actively pursued as a tool for accelerating research and translation. Allowing exploration of the relationships between physics, multiscale mechanisms and function, computational modelling provides a platform for improving our understanding of the heart. Further integration of experimental and clinical data through data assimilation and parameter estimation techniques is bringing computational models closer to use in routine clinical practice. This article reviews developments in computational cardiac modelling and how their integration with medical imaging data is providing new pathways for translational cardiac modelling.


2019 ◽  
Author(s):  
Patricia Lockwood ◽  
Miriam Klein-Flugge

Social neuroscience aims to describe the neural systems that underpin social cognition and behaviour. Over the past decade, researchers have begun to combine computational models with neuroimaging to link social computations to the brain. Inspired by approaches from reinforcement learning theory, which describes how decisions are driven by the unexpectedness of outcomes, accounts of the neural basis of prosocial learning, observational learning, mentalising and impression formation have been developed. Here we provide an introduction for researchers who wish to use these models in their studies. We consider both theoretical and practical issues related to their implementation, with a focus on specific examples from the field.


2021 ◽  
Author(s):  
Mikail Khona ◽  
Sarthak Chandra ◽  
Ila Fiete

Modular structures in the brain play a central role in compositionality and intelligence, however the general mechanisms driving module emergence have remained elusive. Studying entorhinal grid cells as paradigmatic examples of modular architecture and function, we demonstrate the spontaneous emergence of a small number of discrete spatial and functional modules from an interplay between continuously varying lateral interactions generated by smooth cortical gradients. We derive a comprehensive analytic theory of modularization, revealing that the process is highly generic with its robustness deriving from topological origins. The theory generates universal predictions for the sequence of grid period ratios, furnishing the most accurate explanation of grid cell data to date. Altogether, this work reveals novel principles by which simple bottom-up dynamical interactions lead to macroscopic modular organization.


2019 ◽  
Vol 21 (12) ◽  
Author(s):  
Kathleen B. Miller ◽  
Virginia M. Miller ◽  
Jill N. Barnes

Abstract Purpose of Review Risks for developing cardiovascular disease and cognitive decline increase with age. In women, these risks may be influenced by pregnancy history. This review provides an integrated evaluation of associations of pregnancy history with hypertension, brain atrophy, and cognitive decline in postmenopausal women. Recent Findings Atrophy in the occipital lobes of the brain was evident in women who had current hypertension and a history of preeclampsia. Deficits in visual memory in women with a history of preeclampsia are consistent with these brain structural changes. The blood velocity response to chemical and sympathoexcitatory stimuli were altered in women with a history of preeclampsia linking impairments in cerebrovascular regulation to the structural and functional changes in the brain. Summary Having a history of preeclampsia should require close monitoring of blood pressure and initiation of anti-hypertensive treatment in perimenopausal women. Mechanisms by which preeclampsia affects cerebrovascular structure and function require additional study.


2010 ◽  
Vol 22 (11) ◽  
pp. 2460-2479 ◽  
Author(s):  
Rosemary A. Cowell ◽  
Timothy J. Bussey ◽  
Lisa M. Saksida

We examined the organization and function of the ventral object processing pathway. The prevailing theoretical approach in this field holds that the ventral object processing stream has a modular organization, in which visual perception is carried out in posterior regions and visual memory is carried out, independently, in the anterior temporal lobe. In contrast, recent work has argued against this modular framework, favoring instead a continuous, hierarchical account of cognitive processing in these regions. We join the latter group and illustrate our view with simulations from a computational model that extends the perceptual-mnemonic feature-conjunction model of visual discrimination proposed by Bussey and Saksida [Bussey, T. J., & Saksida, L. M. The organization of visual object representations: A connectionist model of effects of lesions in perirhinal cortex. European Journal of Neuroscience, 15, 355–364, 2002]. We use the extended model to revisit early data from Iwai and Mishkin [Iwai, E., & Mishkin, M. Two visual foci in the temporal lobe of monkeys. In N. Yoshii & N. Buchwald (Eds.), Neurophysiological basis of learning and behavior (pp. 1–11). Japan: Osaka University Press, 1968]; this seminal study was interpreted as evidence for the modularity of visual perception and visual memory. The model accounts for a double dissociation in monkeys' visual discrimination performance following lesions to different regions of the ventral visual stream. This double dissociation is frequently cited as evidence for separate systems for perception and memory. However, the model provides a parsimonious, mechanistic, single-system account of the double dissociation data. We propose that the effects of lesions in ventral visual stream on visual discrimination are due to compromised representations within a hierarchical representational continuum rather than impairment in a specific type of learning, memory, or perception. We argue that consideration of the nature of stimulus representations and their processing in cortex is a more fruitful approach than attempting to map cognition onto functional modules.


Author(s):  
Caroline A. Miller ◽  
Laura L. Bruce

The first visual cortical axons arrive in the cat superior colliculus by the time of birth. Adultlike receptive fields develop slowly over several weeks following birth. The developing cortical axons go through a sequence of changes before acquiring their adultlike morphology and function. To determine how these axons interact with neurons in the colliculus, cortico-collicular axons were labeled with biocytin (an anterograde neuronal tracer) and studied with electron microscopy.Deeply anesthetized animals received 200-500 nl injections of biocytin (Sigma; 5% in phosphate buffer) in the lateral suprasylvian visual cortical area. After a 24 hr survival time, the animals were deeply anesthetized and perfused with 0.9% phosphate buffered saline followed by fixation with a solution of 1.25% glutaraldehyde and 1.0% paraformaldehyde in 0.1M phosphate buffer. The brain was sectioned transversely on a vibratome at 50 μm. The tissue was processed immediately to visualize the biocytin.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rossana Mastrandrea ◽  
Fabrizio Piras ◽  
Andrea Gabrielli ◽  
Nerisa Banaj ◽  
Guido Caldarelli ◽  
...  

AbstractNetwork neuroscience shed some light on the functional and structural modifications occurring to the brain associated with the phenomenology of schizophrenia. In particular, resting-state functional networks have helped our understanding of the illness by highlighting the global and local alterations within the cerebral organization. We investigated the robustness of the brain functional architecture in 44 medicated schizophrenic patients and 40 healthy comparators through an advanced network analysis of resting-state functional magnetic resonance imaging data. The networks in patients showed more resistance to disconnection than in healthy controls, with an evident discrepancy between the two groups in the node degree distribution computed along a percolation process. Despite a substantial similarity of the basal functional organization between the two groups, the expected hierarchy of healthy brains' modular organization is crumbled in schizophrenia, showing a peculiar arrangement of the functional connections, characterized by several topologically equivalent backbones. Thus, the manifold nature of the functional organization’s basal scheme, together with its altered hierarchical modularity, may be crucial in the pathogenesis of schizophrenia. This result fits the disconnection hypothesis that describes schizophrenia as a brain disorder characterized by an abnormal functional integration among brain regions.


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