Localization of cortical areas activated by thinking.

Area of Science:

• Neuroscience
• Cognitive Science

Background:

• Mental activity, or thinking, is understood as internal information processing.
• Previous research indicates a link between brain metabolism and cerebral blood flow.

Purpose of the Study:

• To demonstrate that thinking increases cerebral blood flow.
• To investigate how different types of thinking affect regional cerebral blood flow (rCBF) in specific cortical areas.

Main Methods:

• Measured rCBF in 254 cortical regions of 11 subjects using the intracarotid 133Xe injection technique.
• Compared rCBF during rest with three distinct mental tasks: 50-3 subtraction, jingle thinking, and route-finding.
• Defined thinking as internal information operations performed by awake subjects.

Main Results:

• Thinking increased rCBF in homotypical cortical areas, with no observed decreases.
• The superior prefrontal cortex showed equivalent rCBF increases across all tasks, likely related to thought organization.
• Specific cortical areas, including the angular cortex, midtemporal cortex, and visual association areas, showed distinct rCBF increases depending on the type of cognitive task.

Conclusions:

• Pure mental activity demonstrably increases cerebral blood flow.
• Different cognitive tasks engage distinct regional brain networks, highlighting the specialized nature of cortical activation during thinking.
• The findings provide insights into the neural correlates of specific cognitive processes.