Tag Info

Hot answers tagged

9

It's all about the receptors, really. There are 7 families of serotonin receptors that perform different functions within the brain, and according to Wikipedia 14 different subtypes have been discovered. The article assumes that a blanket level of serotonin would be sufficient to "perk" up the brain, wherein it is much more complicated. Serotonin serves ...


8

For a comprehensive review, see: Berg, D.A., Belnoue, L.,Song,H., Simon A. (2013) Neurotransmitter-mediated control of neurogenesis in the adult vertebrate brain. Development, 140(12), 2548-2561. [DOI]. Briefly, active adult neurogenesis is confined to two distinct locations: the subventricular zone (SVZ) of the lateral ventricles in the ...


7

Like many topics in neuroscience, this is a controversial subject. While dopamine is very popular among the public as a mechanism for pleasure, recent research challenges that view and has started to tease apart pleasure from motivation, finding a distinction in dopamine. John Salamone's opinion: Low levels of dopamine make people and other animals ...


7

One thing worth pointing out as a very terse hint of an answer: we all know that activation of the sympathetic nervous system is often referred to as the "fight-or-flight response," but parasympathetic nervous system (PNS) activation is less commonly known as the "rest-and-digest" response...though this does appear on Wikipedia's PNS page. Eating (or maybe ...


7

There are (at least) two ways epigenetic traits are inherited. The important background in both cases is gene expression: there is a misconception that genes are for this or that, where the reality is that most traits come from an overlap of several genes expressing themselves in different ratios. As a simple example, consider two varieties of bird of the ...


6

The primary difference is two-fold: 1) Methods : Social sciences use mostly qualitative methods and content analysis, psychology and cognitive sciences use quantitative methods and statistical analysis. The one basic standard tool in psychology and cognitive sciences is the laboratory experiment, while social sciences usually collect data in the field. 2) ...


6

Although LTP might be necessary for brain plasticity, I would doubt that it is also sufficient. There is quite a lot of literature about homeostatic plasticity (for a review, see Turrigiano & Nelson, 2004) and synaptic scaling (for another review, see Turrigiano, 2008) which seem to be necessary to keep LTP working in the long run. References ...


6

There are two kinds of neuron-to-neuron connections in the brain. The most well known is the chemical synapse, which is unidirectional. Despite this, two neurons can each synapse on each other with a chemical synapse, and both types of connection are observable in brain networks (unidirectional and bidirectional) The second kind of connection is a ...


6

From Stevens & Galanter (1957) Although an extensive investigation of the subjective scale of brightness is still in progress in this laboratory, enough has been learned to show that, for patches of white light viewed in a dark room, subjective brightness is a power function of luminance. Moreover, the exponent is of the order of one-third ...


6

I think Keegan provides a great set of references, but I just wanted to expand on his answer in a little bit more detail. Penrose and Hameroff's ideas are mentioned a lot on the internet and although they are often debunked, you can never do it enough. I want to discuss (1) what microtubules are and (2) are there quantum effects in them? And, more ...


6

Personality studies are typically investigated via the "big five" traits. Some attempts to legitimize the personality traits through biology have been pursued [1]. Following are some excerpts from a particular study that proposed a hypothesis and searched for confirmation in 116 subjects. Of course, this means we should be wary of confirmation bias when ...


6

The key point is that the brain is not a uniform structure. The outer layer, known as grey matter, is a relatively uniform and flat structure. Underneath the grey matter is white matter. An overly-simple characterization of these two areas is that grey matter performs computations, and white matter lets different areas of grey matter talk to each other. ...


5

The first question is, what is normal human sexual behavior. The answer to this changes over time. For example, a hundred years ago masturbation was thought to cause physical degeneration and be a sin, today it is perceived as healthy, even recommended. Research shows that adolescent girls who masturbate have more and stronger orgasms as adults. So, if anal ...


5

Based on general principles of skill transfer: Reading a book aloud should improve your skills in reading books aloud, and in particular it should improve your skill in reading the particular passages that you are reading. So if you are going to be reading a particular text in a public setting, it makes sense to practice reading that passage of text. ...


5

Research exists on craniopagus twins, maybe most notably Tatiana and Krista, who seem to share sensory input somewhat. I doubt that connective mechanisms such as this abnormal case would suffice to permit "compound cognition" in ways that would enhance cognitive ability similarly to your point about hominid evolution. Your relatively simple proposal for a ...


5

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) ...


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 ...


4

There is little evidence that stress affects structural MRI (reduction in the volume of the hippocampus). The review article (Effects of stress throughout the lifespan on the brain, behaviour and cognition Lupien et al., 2009) synthesizes the current knowledge in the field. Another article might be of interest (MRI measurement of hippocampal volume in ...


4

The phenomenon you describe is called the global precedence effect, and was first studied extensively by David Navon (1977). One way to measure this effect is to create conflict between global and local features. For example, Navon presented observes with letter stimuli that were globally organised into different letters, such as; Observers were ...


4

Michelle Heijblom's (2009) master thesis on Visualising tinnitus with fMRI and EEG mentions the following: Different studies report that tinnitus is characterised by an increase in slow-wave activity (0.5- 4Hz: delta activity) and a decrease in alpha activity (8-12 Hz) at temporal regions. Recently it has been suggested that this loss of alpha ...


4

This is a continuation of Penrose's Quantum Mind. It's not taken seriously by the majority of the neuroscience or quantum community. Here are some references to get you started: Tegmark, M. (2000). Importance of quantum decoherence in brain processes. Physical Review E, 61(4), 4194. Seife, C. (2000). Cold numbers unmake the quantum mind. Science, ...


4

My answer to this question would be pretty straightforward. From a neurobiological standpoint, sex causes the release of various pair-bonding influencing hormones oxytocin, vasopressin and dopamine. These "feel good" hormones promote bonding and basically encourage the couple to stay together. The more the pair have sex, the more these hormones get ...


4

The number one hormonal suspect in infidelity has been testosterone. Partially this has been predicted because testosterone predicts sex drive in both men and women. The problem with testing this one in actual humans though is that most of the things associated with cheating also cause increased testosterone levels (flirting, increased number of sexual ...


4

In adult mouse cortex, synaptic spines can last anywhere from days to months. I'm not sure that any such work has been done on human Broca's area, but keep in mind that many synapses are experience dependent. One study found that fear conditioning and fear extinction lead, respectively, to synapse formation and elimination. So the lifetime of a synapse ...


4

Ahh yes, The Secret. I'd recommend starting with Wikipedia for a critical view of the "law of attraction" and the book as a whole. The former page has some particularly good excerpts to offer (emphasis added; hyperlinks not preserved, though I'd appreciate help editing them back in): Skeptical Inquirer magazine criticized the lack of falsifiability and ...



Only top voted, non community-wiki answers of a minimum length are eligible