Hot answers tagged theoretical-neuroscience
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It is not meaningful to talk about your brain processing something as 'right-side up"' or 'upside-down'. The 'images' in your brain are just collections of neural activations, and not actual pictures. Thus they cannot have an orientation. The only meaningful way to test your question is to try flipping the input the brain receives and seeing if it can cope.
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13
When performing certain tasks, people’s inferences approximate Bayesian inference to a remarkable degree. For example, when people receive both haptic and visual information about the size of an object, they combine this information in a manner that very closely resembles Bayesian inference, taking account of the uncertainties associated with the visual and ...
10
There is a huge body of literature on axon growth cone guidance which will give you some insights into how the biology works. Unfortunately, incorporating it all into a model is probably going to make it unwieldy unless your express purpose is to model the physiology, which doesn't seem like the case.
Here are some references:
Hong K, Nishiyama M. ...
9
It's a local rule. All that it means is that the connection between two neurons gets stronger if you use that specific connection more. The specific connection (the synapse) must be used though; it doesn't apply to two random neurons that aren't connected that happen to fire at the same time.
Hebbian learning is generic term for outcome; there are ...
9
In my experience, the term "semantic knowledge" (or semantic memory or conceptual knowledge) is generally used to refer to knowledge of objects, word meanings, facts and people, without connection to any particular time or place. The neural basis of this kind of knowledge is more or less agreed to depend on a distributed network of cortical brain regions ...
8
The standard complexity metric in theoretical computer science and machine learning, in particular in statistical learning theory, is the Vapnik–Chervonenkis (VC) dimension. It is of interest because it gives us a very good tool to measure the learning ability of a neural network (or any other statistical learner, in general).
A good introduction to the use ...
8
I think part of what makes this question confusing is the use of expressions like "what the eye sees", "what the brain sees" and "what the frog's eye tells the frog's brain". Nobody sees anything except the experiencing subject. When one stops thinking that the brain (or some visual-system part of the brain) observes the image on the retina, then the ...
8
The major neural models of consciousness at the moment roughly fall into two camps: cognitive and phenomenological. They are defined by controversy surrounding what types of experience qualify as concious.
Cognitive models
On the one hand there are strong cognitive models of consciousness, such as the one proposed by Stanislas Dehaene, where consciousness ...
8
I'd like to add to Chuck's excellent answer; the computational approach is very well-represented in neuroscience, and actually involves a large number of very heterogeneous methods. Thus, a very different set of neuroscientists and examples have sprung to mind for me.
To my mind, the best single example of the utility of a computational approach to ...
8
There are many neuroscientists who use the techniques of advanced mathematics and statistics to analyze actual neural data for patterns.
George Gerstein, who is now retired, has been a pioneer in applying "particle" methods in analyzing neuronal interactions. The originator of the Gravity transform, he used this tool to untangle some of the stochastic ...
7
Answering the question in the manner that you are asking for would require quite an exhaustive list. However, a fundamental concept in all of this is having a "leak" channel.
NALCN is the only nonselective channel found in the 24-TM channel family and is equally permeable to Na+, K+, and Cs+. [1]
The majority of the ions transported by the channel are ...
7
I don't know of any NN algorithms that match your definition entirely, and I have looked for them (previously and recently). Here are some papers that I think are close or in the direction that you are exploring.
Using theoretical models to analyze neural development (review)
An Instruction Language for Self-Construction in the Context of Neural Networks
...
6
Fernando et al. (2008) proposed a neuronal mechanism to copy network topologies from one region of the brain to another which is based on Spike Timing Dependent Placticity (STDP) and argue that the mechanism of neuronal copying is a neuronal implementation of causal inference.
Fernando C, Karishma KK, Szathmáry E. (2008) Copying and evolution of neuronal ...
6
There are several such models in the field of auditory perception. For example Patterson 1996 [1] suggests a model that starts with a simulation of the cochlea and the neural activity and reaches up to perception; Winkler 2006 [2] reviews the process of auditory perception, again from the cochlea up to perception.
Somewhat old and does not mention a ...
6
This is a complicated and loaded question. As Neuroskeptic noted, our understanding of consciousness is very poor (in fact, we don't know how to define it most of the time). To see some of the best current definitions, take a look at:
What are current neuronal explanations and models of 'consciousness'?
We definitely can't infer arbitrary properties of ...
5
The use of neural-networks in the cognitive sciences has been around since Turing. However, many of the networks common in connectionism suffer from a lack of biological plausibility. Of these abstract ones, even the ones that try to capture some properties of biological neural networks only do some metaphorically. See for instance the limitations of cascade ...
5
One of Koch's collaborators, Francis Crick (yes, that Francis Crick, much later in his career), put forth an interesting theory with Koch that while perhaps is a bit far fetched, it's worth mentioning for sake of a slightly different perspective.
Crick and Koch posited the claustrum (see diagram below) as one of the seats of consciousness in the brain.
As ...
5
I am not sure whether the three assumptions on which your question is based are really valid.
(1) Why should a high transformation transfer be linked to a high firing rate? Depending on the role of a single neuron within a group, not firing might carry as much as information as firing.
(2) Energy conservation might not be linked to the behavior of a ...
5
Here's something I dug up for language: a Computer Science Thesis from Boulder:
The Sensorimotor Foundations of Phonology: A Computational Model of Early Childhood Articulatory and Phonetic Development (1994)
it discusses what it calls HABLAR (Hierarchical Articulatory Based Language
Acquisition by Reinforcement learning).
From the reductionist/biology ...
4
For the dentate gyrus, which is probably more closely analogous to a feedforward hidden layer in a memory network, here are some answers:
Axon and dendrite connectivity is essentially local and can probably be assumed to be initially random within that local region. That is, a neuron integrating into the DG at the midpoint (along the long hippocampal ...
4
Many parts of the fetus brain begin showing neural activity before the senses that feed them are sufficiently developed to provide actual sensory information. In other words, it is unlikely that spiking activity in the brain is initiated by the senses. Some of the cells that become sensory organs, however, often fire in very specific patterns similar to the ...
4
Traveling waves are a developmental mechanism to "prime" neural circuits. In a mature adult, certain mechanisms allow the strengthening and weakening of synapses (LTP/LTP, dendritic spine growth, etc...). These same mechanisms are used during development to achieve initial connectivity. For these to work however, spiking activity must be present. Experience ...
4
I think you are begginning to push at the limits of human brain vs computer metaphor.(mildly related link here) I'll list the objections as:
While neurons firing can be translated/compared to 0 or 1 states, am
not convinced it is a valid equivalence. (i.e: simulating 100
billion neurons on a computer would still not be able to match a
human brain). My ...
3
There is a passage in On intelligence about the differences between parallel processing in human versus computers :
From the dawn of the industrial revolution, people have viewed the
brain as some sort of machine. They knew there weren't gears and cogs
in the head, but it was the best metaphor they had. Somehow
information entered the brain and the ...
3
Closely related to random firing:
Neurotransmitter-filled vesicles are released not only en masse when a neuron fires but also individually at random intervals. Nobel laureate Bernard Katz, who studied NMJs, observed:
In the absence of any form of stimulation, the end-plate region of the
muscle fibre is not completely at rest, but displays electric ...
3
Related to this is several works on the integration or non-integration of computational models in general to cognitive science. For instance, the Tractable Cognition Thesis basically says that we can improve cognitive modeling if we limit cognitive models to those tractably implementable on a Turing machine.
Van Rooij, I. 2008. The Tractable Cognition ...
2
Recently Bayesian models of cognitive development have been very successful in at least formulating working hypotheses as to how abstract knowledge "regularizes" and guides learning and reasoning from sparse data. I was thinking for instance of the following paper:
Tenenbaum, J. B., Kemp, C., Griffiths, T. L., and Goodman, N. D. (2011). How to Grow a Mind: ...
2
Maybe I just don't get it, but I see your question as confusing because:
1/ Your brain is capable of running multiple parallel processes. Actualy each one of tasks you've mentioned consists of number of processes that are done at the same time. Lots of your neurons and neuronal networks are being used at the very same moment.
2/ If you can do something ...
2
Well firstly, what are those statements really saying? How do you measure "processing" or "power" as it relates to the brain? For an electrical engineer working in communicatons, it's easy: you just take the square of the amplitude of the signal (signal power) or count the number of instructions per second (processing power). But that's the discipline ...
2
Consider that elimination of such a phenomena is not ideal. It's been proposed that actual neuronal networks exist under the tension of synchronous decoupling.
http://www.sciencedirect.com/science/article/pii/S0896627308001281
To answer your question though, you probably should consider that reciprocal connections might not be between two individual ...
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