Functional magnetic resonance imaging of human prefrontal cortex activation during a spatial working memory task

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neuroimaging

Background:

• Understanding the neural basis of spatial working memory is crucial for cognitive neuroscience.
• Previous research in nonhuman primates has identified specific brain regions involved in spatial memory.
• Investigating human prefrontal cortex activation during spatial working memory tasks can elucidate shared neural mechanisms.

Purpose of the Study:

• To detect and localize human prefrontal cortex activation during a spatial working memory task.
• To compare brain activation patterns between spatial working memory and control tasks.
• To support the compartmentalization of working memory functions and compare human and nonhuman primate spatial memory localization.

Main Methods:

• High-speed magnetic resonance (MR) imaging was employed to monitor brain activity.
• A spatial working memory task involving location-based judgments was administered.
• Control tasks included color detection and dot detection to isolate spatial working memory processes.

Main Results:

• Significant MR signal increase was observed in the middle frontal gyrus (Brodmann's area 46) during the spatial working memory task.
• Right hemisphere activation was more pronounced and consistent than left hemisphere activation.
• MR signal changes were greater during the working memory task compared to control tasks, with activation onset and decline within 6-9 seconds.

Conclusions:

• Spatial working memory function is localized to a specific area of the human middle frontal gyrus.
• These findings support the compartmentalization of working memory functions within the human prefrontal cortex.
• The results suggest comparable localization of spatial memory processes in humans and nonhuman primates.