Related Experiment Videos
Neural basis of endogenous and exogenous spatial orienting. A functional MRI study
A C Rosen1, S M Rao, P Caffarra
1Medical College of Wisconsin, 9200 West Wisconsin Avenue, Milwaukee, WI 53226, USA.
Journal of Cognitive Neuroscience
|April 10, 1999
Summary
This study used functional MRI to investigate how the brain shifts attention. Both internal and external cues activate similar brain regions, but voluntary attention involves working memory.
Area of Science:
- Cognitive Neuroscience
- Neuroimaging
Background:
- Understanding the neural mechanisms of attention is crucial for cognitive science.
- Distinguishing between internally-driven (endogenous) and externally-driven (exogenous) attention is key to understanding attentional control.
Purpose of the Study:
- To examine the neural substrates underlying endogenous and exogenous covert attention shifts.
- To compare the brain activation patterns associated with voluntary versus reflexive attention.
Main Methods:
- Whole-brain functional magnetic resonance imaging (fMRI) was employed.
- Thirteen healthy subjects performed endogenous and exogenous attention orienting tasks.
- Behavioral data (reaction times) and brain activation were analyzed.
Main Results:
- Faster reaction times for valid trials in endogenous attention, and slower in exogenous (inhibition of return).
- Greater spatial extent and intensity of brain activation for endogenous attention, suggesting it is more effortful.
- Both attention types activated bilateral parietal and dorsal premotor regions, including frontal eye fields; right dorsolateral prefrontal cortex (BA 46) was selectively activated by endogenous attention.
Conclusions:
- Parietal and premotor regions play a role in preparatory responses to peripheral stimuli for both attention types.
- Voluntary, but not reflexive, attention shifts engage working memory systems, indicated by right dorsolateral prefrontal cortex activation.