Hot answers tagged

8

My knowledge of the neurobiology of pleasure (aka, hedonia, hedonic happiness, happiness, "liking", reward, etc.) is admittedly lacking, but I'd contend that this is mostly true because we actually know very little about how pleasure is instantiated in the brain. So the answer to your question is that we don't know! First of all, mesolimbic dopamine seems ...


7

This will be a long post. FYI. To my knowledge, there is no evidence for back propagation in the brain. If you're interested specifically in that topic, Geoffrey Hinton (Dept. of CS @ UofT) has written about it. I'll try to focus on the biology. Some basic neurophysiology first. Neurons have a slightly negative electrical resting potential ...


7

Yes – electricity does pass through synapses if the link between the neurons in question is constituted by an electrical synapse. There are two different types of synapses, chemical synapses and electrical synapses. At a chemical synapse, an arriving pre-synaptic action potential indeed causes the release of neurotransmitters which carry the signal across ...


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

Generally spoken, synesthesia is unidirectional. For example, grapheme–color synesthesia (i.e., letter–color and digit–color synesthesia) is the most prevalent type of synesthesia. The presentation of a grapheme leads to an additional synesthetic color percept. Although grapheme–color synesthetes are strongly influenced by the synesthetic color perception ...


6

The corpus callosum is a massive horizontal white matter tract (commissure) that connects the two hemispheres and it is considered the most important route of communication between the hemispheres. However, there are five additional commissures that cross the midline, namely: Anterior commissure, connecting the two olfactory bulbs and the temporal ...


6

You are right that active adult neurogenesis is generally considered to be restricted to the dentate gyrus of the hippocampus, and the subventricular zone of the lateral ventricles. The latter generates neurons that subsequently migrate through the rostral migratory stream to the olfactory bulb to become interneurons (Ming & Song, 2011). Although the ...


6

Psychophysiology is totally outside of my wheelhouse, but here it goes… Those feelings in your chest, face, arms, etc. aren't an illusion. Indeed, it's long been argued that physiological arousal (in your body) is a core component of emotional experience (e.g., James, 1884; Russell, 1980)--alongside feelings of pleasure and displeasure. Moreover, that ...


6

20 Watts. Watson mentioned this in 2011: "The human brain only requires 20 watts of power to operate ... Watson? About 20,000 watts." An interview with John Kelly (an IBM senior vice president and director of IBM Research) also puts the brain at "about 20 watts" (but puts the machine at 85 kW; the inconsistency doesn't matter for this question). Popular ...


6

I found that dF/F0 stands for the relative difference in fluorescence at a certain wavelength.


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The textbook convention is that neurons release only one type of chemical from their synaptic terminals. This is known as Dale's Principle (https://en.wikipedia.org/wiki/Dale%27s_principle), and would exclude the possibility that neurons can release both inhibitory and excitatory neurotransmitters. Examples have been found of neurons which co-release two ...


6

As far as I know, it is not possible for a neuron to change which type of neurotransmitter it releases. However, it is the case that the neurotransmitter GABA changes from excitatory to inhibitory over the course of development. This is occurs because GABA activates Cl- (chloride) channels. The chloride concentration gradient across the cell membrane ...


5

Short answer Neurons can increase or decrease the amplitude of their response. A neuron's response strength can be regulated by adjustment of the cell-surface expression of excitatory receptors. Background First off, this question is very broad. To narrow it down I will focus on learning processes in the hippocampus involving long-term potentiation (LTP). ...


5

It is generally accepted that all activity having to do with conscious experience is mediated by spiking in the cortex. Sub-threshold activity, such as excitatory postsynaptic potentials (EPSPs) are not carried forward in the nervous system and will 'fade' before having an effect. It all revolves around action potentials. Quoting from Kandel et al. (2000): ...


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

There is a good article on Wikipedia on the Neuroscience of Free Will, with far too much content to adequately summarize here. Since your question is focused on long-term prediction of behaviour, I'll just mention about that. Using newer fMRI technology, Soon et al (2008) used a learning algorithm to predict "free will" decisions from brain activity about ...


5

Gap junctions can couple cells directly electrically. Cell types electrically coupled via gap junctions include neurons, the pancreatic islets of Langerhans (Andreu et al, 1997) and cardiac cells (Fig. 1.). In contrast to chemical synapses, information transfer via electrical "synapses" (gap junctions) is nearly instantaneous. In chemical information flow, ...


5

The superior colliculus can be regarded as the center of saccadic eye movement. It contains a topographically organized representation of the visual space in its upper layers, and saccade-related activity in its deeper layers (Van Gisbergen et al., 1987). Ablation of the superior colliculus unilaterally eliminates saccades contralateral to the lesion, and ...


5

I agree with much of AliceD's well-cited answer, but here are a few extras. What part of the brain is actively controlling saccadic movement? It is not clear how you would choose just one area of the brain, given that a whole network of cortical and sub-cortical areas are involved, and what you mean by "actively controlling". The superior ...


5

Here's the only one that's easy to find in google scholar, but there might be more: Page, F., Coleman, G., & Conduit, R. (2006). The effect of transdermal nicotine patches on sleep and dreams. Physiology & Behavior, 88(4), 425-432.


5

My question is: are these all the rules? No. Some things you left out: Plasticity (change) Very-short-term synaptic "plasticity" (changes in synaptic strength); at least a few different forms of this (post-tetanic potentiation, short term synaptic depression, synaptic facilitation). Very-short-term intrinsic "plasticity" (changes in spiking ...


5

Does electricity pass through synapse? No because ... ... when a neuron fires the action potential generated in a cell body reaches only the presynaptic part of the synapse, then triggers the transmitter to pass through the gap, and that transmitter causes the membrane in the postsynaptic part to open ion channels, pumps, etc ..., which ...


5

Although this paper is not grounded in neurobiology "Up speeds you down. Awe-evoking monumental buildings trigger behavioral and perceived freezing" by Joey et al. should be a good starting point for further research into the domain of environmental psychology with a focus on human-made environments. In the paper, subjects are shown to have slower reaction ...


4

Too much dopamine release in the striatum may lead to psychosis, and especially to the positive symptoms associated with this disease (e.g., delusions and hallucinations, as opposed to the negative symptoms such as a flattened affect) (Laruelle et al., 1999). The etiology of psychosis is complex. Many direct and indirect environmental factors are ...


4

Biondi et al. (1998) compared MR images of monozygotic twins and found that while the brains of monozygotic twins are not identical, they are similar. Relevant for understanding the concordance rate of schizophrenia in monozygotic twins, Suddath et al. (1990) examined MR images of monozygotic twins who where discordant for schizophrenia. They found that the ...


4

Part of what makes speech possible is a complex set of interactions between a number of different muscles that control aspects of producing speech sounds like airflow and mouth shape. Humans are unique in the complexity of the sounds that we can produce. Even if we granted the science-fiction that would be necessary to put a human brain into a chimpanzee and ...


4

Short answer A cap of magnets, or state-of-the-art TMS protocols, will not make you smarter. Background First off, TMS uses bursts of magnetic stimulation in the order of milliseconds (Rothkegel et al., 2010). Pulses of magnetic stimulation are used, because permanent magnetic fields will not induce current flow. Hence, wearing a cap of permanent magnets ...


4

Short answer On the basis of a cursory literature review, I conclude that Jospeh's observations were correct, but his conclusions that a callosotomy can result in a dual consciousness were far stretched. Background First off, I'm not an expert on this topic, but I will give my referenced opinion anyway, as there is no answer yet to this question; Below are ...


4

Visual masking has quite a few variations, and the source you've linked is by far the worst explanation I've seen. In forward masking an early stimuli takes hold over consciousness (resulting in top-down activation) that prevents a later stimuli from overshooting the selective attention threshold, thus the latter remains subliminal (limen is threshold in ...


4

Check it: https://en.wikipedia.org/wiki/Long-term_potentiation In other words, yes, the strength of synapses matters. A synapse that has been potentiated means that the postsynaptic neuron will fire more readily as a function of the stimulation from the presynaptic neuron. As for how widely the strengths vary, I have to admit I'm not quite sure how to ...



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