BOLD Correlates of Trial-by-Trial Reaction Time Variability in Gray and White Matter: A Multi-Study fMRI Analysis
2009

Brain Activation and Reaction Time: A Study Using fMRI

Sample size: 252 publication 10 minutes Evidence: high

Author Information

Author(s): Yarkoni Tal, Barch Deanna M., Gray Jeremy R., Conturo Thomas E., Braver Todd S.

Primary Institution: Washington University, Saint Louis, Missouri, United States of America

Hypothesis

Are there brain regions that show a general relationship between trial-by-trial reaction time variability and activation across a range of cognitive tasks?

Conclusion

The study found that reaction time variability is associated with brain activation in both gray and white matter regions.

Supporting Evidence

  • Activation was delayed on trials with long reaction times relative to short reaction times.
  • Activation in frontal regions increased linearly as a function of reaction time.
  • Reaction time variability modulated the BOLD signal in both gray and white matter.

Takeaway

The study looked at how the time it takes people to react to things is connected to how their brains work, finding that both gray and white matter in the brain are involved.

Methodology

The study analyzed five different fMRI datasets to model the relationship between reaction time and brain activation.

Potential Biases

Potential confounding factors such as response accuracy and trial difficulty were controlled for, but residual biases may still exist.

Limitations

The study's findings may not generalize to all populations or tasks, and the nature of white matter activation remains unclear.

Participant Demographics

Healthy young adults, with specific samples varying in size from 26 to 102 participants.

Statistical Information

P-Value

p<0.0015

Statistical Significance

p<0.05

Digital Object Identifier (DOI)

10.1371/journal.pone.0004257

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