Functional magnetic resonance imaging adaptation (FMRIa) is a method of
functional magnetic resonance imaging
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 o ...
that reads the brain changes occurring in response to long exposure to evocative stimulus.
[{{Cite journal, last=Grill-Spector, first=Kalanit, last2=Malach, first2=Rafael, date=2001, title=fMR-adaptation: a tool for studying the functional properties of human cortical neurons, journal=Acta Psychologica, language=en, volume=107, issue=1–3, pages=293–321, doi=10.1016/S0001-6918(01)00019-1, pmid=11388140] If Stimulus 1 (S
1) excites a certain neuronal population, repeated exposure to S
1 will result in subsequently attenuated responses. This
adaptation
In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the po ...
may be due to neural fatigue or coupled hemodynamic processes. However, when S
1 is followed by a unique stimulus, S
2, the response amplitudes should not be attenuated as a fresh sub-population of neurons is excited. Using this technique can allow researchers to determine if the same or unique neuronal groups are involved in processing two stimuli.
[Krekelberg, B, Boynton, G.M., & van Wezel, R.J.A. (2006). Adaptation: from single cells to BOLD signals. ''Trends in Neurosciences''.]
Usage
This technique has been used successfully in examination of the visual system, particularly orientation, motion, and face recognition.
See also
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Adaptive system
An adaptive system is a set of interacting or interdependent entities, real or abstract, forming an integrated whole that together are able to respond to environmental changes or changes in the interacting parts, in a way analogous to either conti ...
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Functional magnetic resonance imaging
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 o ...
*
Neural adaptation
Neural adaptation or sensory adaptation is a gradual decrease over time in the responsiveness of the sensory system to a constant stimulus. It is usually experienced as a change in the stimulus. For example, if a hand is rested on a table, the tabl ...
References
Magnetic resonance imaging