Neural efficiency as a function of task demands.

Area of Science:

• Cognitive Neuroscience
• Neuroscience
• Intelligence Research

Background:

• The neural efficiency hypothesis posits that higher intelligence correlates with lower neural activation during cognitive tasks.
• Previous research often used tasks of equal objective difficulty, potentially confounding results.

Purpose of the Study:

• To investigate if the neural efficiency hypothesis holds when task difficulty is person-specific.
• To examine the relationship between intelligence and brain activation under controlled task demands.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activation in 58 participants.
• Participants were categorized into lower and higher intelligence groups.
• Participants completed inductive reasoning tasks with varying person-specific and sample-based difficulties.

Main Results:

• Differences in brain activation and task performance were observed only when tasks shared the same sample-based difficulty.
• No significant differences were found when comparing tasks with matched person-specific difficulty.
• Lower intelligence individuals performed similarly to higher intelligence individuals on tasks of matched person-specific difficulty.

Conclusions:

• Neural efficiency appears to be an adaptive response of brain activation to task demands, dependent on individual ability.
• The findings challenge a simplistic view of neural efficiency and highlight the importance of task difficulty normalization.