What is a disadvantage of functional magnetic resonance imaging?

There are certain disadvantages of fMRI which include, It is expensive compared to other scans. The patient has to stay still to capture clear images. Patient’s movements can affect the quality of images.

What are some limitations in using the MRI and fMRI?

Yet fMRI also has its disadvantages. First, it’s expensive. Second, it can only capture a clear image if the person being scanned stays completely still. And third, researchers still don’t completely understand how it works.

Why does functional magnetic resonance imaging fMRI have sluggish temporal resolution?

fMRI’s temporal resolution is limited by hemodynamic response time; typically the BOLD response has a width of ~3s and a peak occurring ~5–6s after the onset of a brief neural stimulus. This is much slower than the underlying neural processes, and temporal information is thereby heavily blurred.

What does a functional magnetic resonance imaging fMRI machine capture?

Functional magnetic resonance imaging or functional MRI (fMRI) measures brain activity by detecting changes associated with blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area of the brain is in use, blood flow to that region also increases.

What is a major weakness of current functional neuroimaging techniques?

The fMRI signal is probably insensitive to many critical aspects of neural activity or computation—it just cannot detect all relevant neural changes that are associated with a mental state of interest.

Why is poor temporal resolution bad?

The real problem is that the response is extended over time. Temporal smoothing makes it difficult to pinpoint the precise moment of activity. Therefore, the image actually reflects an average over many seconds.

Why is low temporal resolution bad?

This is a disadvantage, since we have no signal of what happened between that time interval. It also means that at the end of the experiment we will only have a relatively few number of volumes. For example, if you scan a person for 5 minutes, you will get less than 300 time points.

Why does fMRI have good spatial resolution?

Greater spatial resolution allows psychologists to discriminate between different brain regions with greater accuracy. fMRI scans have a spatial resolution of approximately 1-2 mm which is significantly greater than the other techniques (EEG, ERP, etc.)

Which of the following would not be considered a structure that is part of the limbic system?

The hippocampus is the first area where is affected by Alzheimer’s disease. So the correct answer is option is D. Corpus Striatum. Note: The corpus striatum is present in the forebrain part but is not a part of the limbic system.

What are the advantages and disadvantages of using EEG ERP?

One of the biggest advantages to EEG/ERP is the ability to see brain activity as it unfolds in real time, at the level of milliseconds (thousandths of a second). One of the big disadvantages of EEG/ERP is that it’s hard to figure out where in the brain the electrical activity is coming from.

What limits the temporal resolution of fMRI?

In fMRI, images can be collected in a very short time; therefore, high temporal resolution is possible in principle. However, the temporal resolution is limited by a blurred intrinsic hemodynamic response and a finite signal-to-noise ratio.

What are the challenges of applying fMRI in practice?

Technical developments have solved most of the challenges of applying fMRI in practice. These challenges include low contrast to noise ratio of BOLD signals, image distortion, and signal dropout.

What is the resolution of an fMRI scan?

Generally, most fMRI is performed using an Echo Planar Imaging (EPI) method, which can collect data for a two dimensional image in approximately 60 ms at typical resolutions (3.4 × 3.4 × 4 mm 3 voxel size). Typically, whole brain scans with ~ 32 2D slices are acquired with a repetition time (TR) of 2s/volume.

What is an fMRI and how does it work?

fMRI is of course based on MRI, which in turn uses Nuclear Magnetic Resonance coupled with gradients in magnetic field to create images that can incorporate many different types of contrast such as T1 weighting, T2 weighting, susceptibility, flow, etc.

How does fMRI determine cortical activation?

Functional magnetic resonance imaging (fMRI) determines cortical activation by measuring changes in the local concentration of paramagnetic deoxyhemoglobin. Functional magnetic resonance imaging (fMRI) maps the spatiotemporal distribution of neural activity in the brain under varying cognitive conditions.