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11

Typically 'presynaptic' and 'postsynaptic' are used to indicate two neurons that are connected, as you indicate correctly in your second example. Information flow in the nervous system basically goes one way. If one neuron fires (presynaptic cell) it can chemically activate another cell on which it synapses, as shown in the following figure 1. As an ...


9

Short answer Yes, there is a difference between hearing and understanding sound. Background Acoustic information is processed in different neural centers along the auditory pathway. The auditory system runs from the peripheral end organ in the inner ear (the cochlea) to the cortex. Along the way various processing steps are carried out. For ...


8

As you have already hinted at, the issue is controversial. I could leave it at that and say "no, there is no consensus", and it would be a true answer, but it wouldn't be satisfying, wouldn't it? Instead, I'll briefly define the topic, give a few examples, and then a few recent criticisms. My answer will be weighted somewhat towards "cognition" instead of ...


7

First of all, the human brain is distinctively larger than that of any other primate, mainly due to the great expansion of the cerebral cortex. The underlying structures have remained relatively stable (Toro et al., 2008). As the cortex overlies the rest of the brain, a solution had to be found, because the whole brain did not have to inflate to increase ...


7

Part of the difficulty in studying time perception is that memory is known to be biased by numerous factors including arousal and salience. So while people commonly report time slowing down during specific events, it is difficult to differentiate the effects of retroactive memory bias in encoding and recall from actual increased resolution in the perception ...


7

They are ordered based on when they were discovered/named (as pointed about by Ana's comment). Alpha and beta waves were among the first signals observed in EEG data. From Wikipedia: Alpha waves were discovered by German neurologist Hans Berger, most famous for his invention of the EEG. Alpha waves were among the first waves documented by Berger, along ...


6

There are quite a few stations between cochlea and the brain and I will focus on the auditory nerve. That said, your theories (a) and (b) are both correct, and therefore (d) applies as well. (a) Neurons in the auditory nerve increase their firing rate when sound level is increased (Heil et al, 2011). This can be regarded as the primary mechanism for ...


6

Short answer Yes, continuous exposure to white noise affects neural responses in the auditory system. First, it can alter the tonotopic map in the auditory cortex. Second, it can lead to reduced responsiveness of the auditory thalamus. Background Note: this answer is based on animal experiments using extreme conditions, namely a continuous noise ...


6

Short answer Damage to the inner ear can result in an asymmetric distortion in pitch perception between the two ears. This phenomenon can result in the same tone being perceived as a different pitch by the two ears. Background Damage to the inner ear (the cochlea) can lead to hearing loss. Hearing loss can sometimes lead to changes in perceived pitch. For ...


6

Have you ever seen IBM's Watson? Watson is composed of a cluster of ninety IBM Power 750 servers, each of which uses a 3.5 GHz POWER7 eight core processor, with four threads per core. In total, the system has 2,880 POWER7 processor cores and has 16 terabytes of RAM. It must be kept in a (very) large refrigerated room. Watson is a question answering (QA) ...


6

Interesting question! I performed a fairly extensive search in Google Scholar and Scopus using various keyword searches, including, but not limited to "color blindness and plasticity", "color blind and brain", "dichromates brain", and "monochromates brain". Strikingly, I found nothing. The reason is aptly explained by Solomon & Rosa, 2014 and I quote ...


6

From my undergraduate biology degree, I am only familiar with the second use of the terms which you describe. That is, the terms pre-synaptic and post-synaptic describe a spatial relationship to the synapse, which has directionality, as you know. If the terms are used to describe whole cells, as Chris Stronks covers, and as people often do when describing a ...


6

Visual acuity is highest in the foveal region, namely around 1/60 of a degree, or 1 minute of arc (1 MAR). At about 30 degrees of eccentricity, visual acuity is reduced to anywhere between 1.5 and 10 MAR when determined by a shape recognition task, as shown in Fig. 1 taken from Lie, 1980: A later study (Anderson et al., 1991) shows the following picture: ...


5

This is partially an aspect of the binding problem. Sensory information arrives in parallel as a variety of heterogeneous hints, (shapes, colors, motions, smells and sounds) encoded in partly modular systems. Typically many objects are present at once. The result is an urgent case of what has been labelled the binding problem. We must collect the hints, ...


5

The short answer is we don't know for sure. Look up "alexia" and "agraphia"; pinpointing the regions of the brain that, if damaged, interfere with reading might give some indication of the cortical regions involved. Visual cortex (back of the brain) is obviously necessary for the general population, but it's clearly possible for blind people to learn to ...


5

I think the major reason is inertia, in the sense that many labs use Matlab, so many Matlab toolboxes are available, so many labs train people in the use of Matlab... However, as a trained software engineer turned Neuroscientist who has been programming in various languages for close to 30 years, there are several reasons why I actually enjoy using Matlab. ...


5

There is data on this question generated by research on the embodiment of spatial cognition. The idea here is that we mentally represent and construct space in relation to our bodies. From this perspective, the differences that you describe (left vs. right more complicated than up vs down) stem from the properties of how we perceive the world in our bodies: ...


5

Nature Neuroscience offers such a possibility. http://www.nature.com/news/nature-journals-offer-double-blind-review-1.16931 See also Does anyone know of any clinical psychology journals that use a double-blind review process?


5

I'm not sure the math checks out in the question (the CPU cycles per second seems awfully high), but I think there are some useful principles to keep in mind regardless of the details of the math. So let's assume that we do have a computer that can perform more operations per second than the combined sum of all action potentials in the brain per second. Is ...


5

I think you should reverse your approach. Rather than trying to find every prerequisite, start reading sections of PNS and as you encounter something you don't understand, look up the background information. It's an exhaustive work (and well worth reading!) but you're going to find different sections require different levels of background. For example, ...


5

The question that you are referring to is worded in a way that I think is leading to the confusion. The question in the title is "Can the mind affect the brain?" but in the question body the final question posed is "Does [a thought producing a tear] not contradict the (physical) law of cause and effect?". The answer is yes to the title question: the mind ...


5

There are other meanings of "potential" than the regular meaning "having or showing the capacity to become or develop into something in the future" (source: Google Translate). In case of "resting potential" it refers to the voltage difference across the cellular membrane. Every cell maintains a voltage difference across the membrane (see a related question ...


5

I will try to answer all of your main and sub questions structurally below: How do neurotransmitters manage to depolarize the inside of the cell? Do they force the cell to give up pumping out Na ions? No, the Na,K-ATPase (the sodium potassium pump) keeps active, also during the action potential (AP). Do the neurotransmitters themselves contain ...


5

It is well documented that people are able to selectively attend to different speakers. The ability to tune-in to a particular speaker and filter out others was dubbed the cocktail party effect, since it is the kind of skill that is required in when trying to have a conversation with another person in a crowded party. A common way of studying this ...


5

You are right to suspect that cognitive control and executive function are essentially interchangeable, at least for most purposes. Among researchers in the area, I would say there is a slight difference, however. Cognitive control refers to the more abstract concept and affords researchers more degrees of freedom in defining what that means operationally ...


4

I completely agree with most the factors you've identified, but before I suggest some additional points, I'd like to correct one of yours: file formats that can only be read in MATLAB Unless you're talking about some obscure format that I'm unaware of (entirely possible!), MATLAB files are readable by non-MATLAB tools. In particular, scipy.io provides ...


4

It is highly variable, depending on the strength and placement of the synapse (which in turn depends on synapse activity and how often the two neurons fire together, among other things). The wikipedia page here is a pretty good place to start, or if you want more detail on how that pulls together in an actual system, this paper is a good place to start.


4

what has always puzzled me is the neurobiological basis that gives rise to the phenomenon that we associate our bodies with ourselves – i.e., why does my brain think of my physical body as "me" and make me care for it? In other words, why is me me at this particular point in time and not some other body living e.g. centuries ago? Why do I not ...


4

Complexity. That is, the fundamental laws governing the behavior isn't terribly difficult to comprehend or model. However, putting it all together and hoping it reproduces the correct behavior is a great challenge. Once you develop a model that has the appropriate underlying mechanisms in it's components, you still have to put them all together and ...



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