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12 votes
Accepted

What does fMRI measure exactly

As a slight modification of your statement: blood flow increases wherever activity in the brain increases. The type of fMRI that uses this principle is blood-oxygenation-level-dependent fMRI or ...
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7 votes

How does glial cell activity influence fMRI, EEG signals?

I'm only going to attempt to answer a small part of your question: how does glial activation affect the blood oxygen level-dependent (BOLD) response measured by fMRI? Schulz et al. (2012) were able ...
6 votes

Are there any studies (fMRI scans, etc) showing why some people (supposedly) are more open to hypnotism?

Overall, while there are developing cognitive neuroscience theories of how hypnotic states are produced, there does not appear to be any known cognitive neuroscience basis for individual differences ...
5 votes
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How to analyze event-related fMRI data with missing fMRI trigger in logfile?

I can see one case in which you still might analyze the data. This only works under three conditions: your paradigm has no variable durations of either stimulus presentations or breaks or others (or ...
5 votes
Accepted

What do NaNs represent in an SPM β-map?

Apparently, this can happen when your ROI is near the edge of the brain as reported here. The thread is pretty old though so this might have been fixed by today and there is another reason in your ...
5 votes

Have the effects of MRIs and other electromagnetic devices on human psychology been studied?

Yes, the effects of electromagnetic fields on the brain have been studied extensively, especially with respect to cellphone, WiFi, and other small devices that emit such fields. The results are ...
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5 votes

How to get anatomical masks?

I'm a TMS, but not an fMRI, researcher but I have experience using anatomical masks. I can guide you through the steps to make an anatomical mask, but unfortunately I don't have any code to offer you. ...
5 votes
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Can fMRI and EEG signals be generated from NEF models?

Replicating fMRI signal was first used in the Tower of Hanoi task as seen in section 5.8 of "How to Build a Brain": There is strong evidence that dendritic processing, driven by neurotransmitter ...
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5 votes

Can we identify specific emotions on the basis of fMRI scans?

From meta-analyses that include musical emotion inductions, there is not much evidence that we can reliably distinguish between emotions in the brain, independent of the emotion induction procedure or ...
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4 votes
Accepted

Is there a good entry-level tutorial for SPM?

The best way to learn is probably not by reading, but by doing. The SPM website contains a number of useful datasets with tutorials for various tasks. I also find PowerPoint slides from lectures and ...
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4 votes
Accepted

Reference request for creator of heuristic for processing fMRI data (T.Nichols)

I know very little about fmri, but as @strongbad points out, surely it is Professor Thomas Nichols at Warwick. I'm not sure what the authoritative reference is, but Luo and Nichols (2003) might be ...
4 votes
Accepted

Can memory access be detected via fMRI?

In theory, yes, because there are now many theories, supported by evidence, which map different memory processes onto different regions and patterns of activity in the brain. In practice, there are ...
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3 votes
Accepted

How was fMRI performed before EPI became available?

Short answer Older image collection techniques like GRASS and FLASH are slower than EPI, but still fast enough to operate within the time span of the neurovascular delay. Background The speed of ...
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3 votes

Activation of brain reasoning areas during dreaming

I cannot answer from fMRI's, but this theory conflicts with other anecdotal evidence from medicine. In sensory deprivation, or under psychotomimetic substances, you can be awake and unimpaired ...
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3 votes
Accepted

Why is my SPM batch job printing a warning repeatedly?

Below is a corrected version of the script. SPM seems to be quite finicky about the structure of the data passed to ...
3 votes

Why "fractional" anisotropy?

Like lea's comment indicated, FA is called "fractional" anisotropy simply because it's the degree of anisotropic diffusion, i.e., a ratio (Soares, Marques, Alves and Sousa, 2013). Fractional ...
3 votes
Accepted

Finding consciousness through EEG

I don't know any such group in Italy but there is a group in Liege, Belgium which is called Coma Science Group. It consists of scientists of various disciplines and their main interest is ...
3 votes
Accepted

Neurophysiological indications of focus and motivation

Focus and motives are very different cognitive processes. Essentially focus would be attention, while motivation is a complex neurocognitive process, such as hunger or thirst, which drives attentional ...
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3 votes
Accepted

Slices and aquisition of fMRI

I will focus on question #1: Analysis of MRI scans is typically done using voxels (Fig. 1). Voxels have a volume defined by three dimensions (length, width and depth). Voxel analysis. Source: ...
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3 votes

where can i find preprocessed fmri data set for alzheimer's disease

See https://www.reddit.com/r/neuro/comments/5y4pta/does_anyone_know_where_i_can_find_a_repository_of/ for a similar question. Websites that were posted there include http://www.humanconnectome.org/...
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3 votes
Accepted

In fMRI analyses, what is the t-test actually comparing?

The coefficient is the measure of how strongly the given factor predicts the dependent variable, or in other words how much of the variance in the dependent variable can be explained by that factor. ...
3 votes
Accepted

Does only the time-series data of fMRI matter or does spatial distribution of the signal values also matter?

Usually, but not always, fMRI timeseries are used to compute functional connectivity by calculating Pearson correlations among voxels or ROIs. The equation for the Pearson correlation can be written ...
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2 votes

fMRI images: In-plane resolution, slice thickness

The information you seek is contained in the header of the image file. Matlab has open source tools for reading the header information. e.g., http://www.mathworks.com/matlabcentral/fileexchange/29344-...
2 votes

Why superimposing PET data on MRI scan images instead of doing fMRI scans?

They used MRI to compare asymmetry in hemispheric volumes across the groups. Hemispheric volume is not something that is changing over time, and so it doesn't require the use of functional ...
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2 votes
Accepted

Are there any fMRI decoding papers examining the relationship between attentional cueing and activity in V1?

Ha, I was going to mention the Kok Neuron paper :) The Cerebral Cortex one does not use decoding however. This one may also be of interest to you: Vetter, P., Smith, F. W., & Muckli, L. (2014). ...
  • 2,553
2 votes

MRI images upside-down in FSLVIEW

Simply fslreorient2std will orient the images as you would expect. From https://fsl.fmrib.ox.ac.uk/fsl/fslwiki/Orientation%20Explained: fslreorient2std - this ...
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2 votes

Open fMRI data?

There was recently an issue about repositories for neuroimaging data. I just copied the table listing all of them from this paper. (Feel free to add links, I will do so when I have more time.) Title, ...
2 votes

Open access 7T resting-state fMRI dataset

The Nighres project has released some 7T MRI datasets and tools to run them. You can read the paper on the tools here, and download the datasets from NITRC here.
2 votes

Generate fMRI from neurotransmitter consumption

It is not clear what neurotransmitter you are interested in, but one model that relates the PET ligand affinity to the cerebral blood volume (CBV) from fMRI looks like this: Source: Neurovascular ...
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