The brain’s ability to inhibit unwanted thoughts and actions is crucial for self-control and mental health.
New research provides fascinating insights into how low-frequency alpha brain waves and default mode networks are associated with individual differences in behavioral inhibition.
Key Takeaways:
- The 8-10 Hz low-alpha frequency band, rather than total or high-alpha bands, was most related to behavioral inhibition.
- Individuals with higher low-alpha power had greater behavioral inhibition based on psychological tests.
- Their brains also showed more robust inhibition network properties, including tighter connectivity of the default mode network.
- Low-alpha power and network measures correlated with a personality measure of behavioral inhibition.
- Two frontal brain regions tied to inhibition showed the strongest network connections.
Source: Clinical Psychopharmacology and Neuroscience 2023
The Brain’s Inhibitory Control System
Behavioral inhibition acts like the brain’s brake pedal – it allows us to override impulses and stop ourselves from acting rashly.
Poor inhibition control is linked to disorders like ADHD, addiction, anxiety, and obsessive compulsive disorder.
Researchers are keen to understand how the brain implements this vital self-control mechanism.
New findings reveal that low-frequency alpha brain waves are a key player, along with networked regions of the brain’s default mode network.
The study provides evidence that someone’s level of alpha waves and properties of their inhibition networks are tied to their inherent capacity for behavioral inhibition.
Measuring Individual Differences in Self-Control
The researchers at Inje University in South Korea analyzed data from 104 healthy adults.
To gauge their inhibitory abilities, the participants completed psychological questionnaires about behavioral inhibition traits and an impulse control task.
The questionnaires measured tendencies towards impulsiveness versus cautiousness and anxiety.
For the task, volunteers had to inhibit prepotent responses on a Go/No-Go test, where the aim is to press a button for certain stimuli but avoid responding to others.
The researchers also recorded each participant’s resting state brain activity patterns using electroencephalography (EEG).
Alpha Waves Reflect Inhibition Ability
The EEG analyses focused on alpha wave frequencies.
Alpha waves in the 8-12 Hz range are dominant when we are relaxed yet mentally alert.
They are thought to represent a readiness state for the brain.
The researchers divided the participants into three evenly spaced groups based on the power of their total alpha, low alpha (8-10 Hz) and high alpha (10-12 Hz) bands.
Intriguingly, the groups differed only based on low alpha.
Those with the most low alpha waves scored higher on the behavioral inhibition personality measure and made fewer errors on the response inhibition task.
This suggests that low alpha power, specifically, indexes an individual’s inherent ability to inhibit thoughts and impulses.
Default Mode Network & Alpha Power
The researchers went further by using the EEG data to model functional brain networks. They focused on the default mode network (DMN), comprised of regions that activate during inward-oriented thinking.
The DMN showed heightened connectivity in the low alpha group compared to the others.
Key network measures were also correlated with low alpha power and inhibition scores across all participants.
Two frontal lobe DMN regions had the strongest connections.
These exact areas are known to activate during response inhibition tasks, as shown by fMRI studies.
The analyses indicate that beyond just low alpha power, properties like the coherence of inhibition networks correspond to behavioral inhibition abilities.
Low Alpha and Inhibition Networks Go Hand-In-Hand
By considering both EEG rhythms and modeled brain networks, the researchers present compelling evidence that low-frequency alpha activity provides a window into the brain’s inhibitory control system.
On one hand, individuals with more low alpha activity seem to have a greater inherent capacity to keep their impulses in check.
At the same time, their inhibitory brain networks are more strongly wired together at rest.
These findings advance our understanding of the neurobiology underlying self-discipline.
They also demonstrate the power of measuring not just localized brain activity but also the interconnectedness of brain networks.
The study highlights potential bio-markers of behavioral inhibition that could be relevant for mental health disorders involving executive function deficits.
Furthermore, non-invasive brain monitoring could enable assessing the impacts of treatments, brain stimulation, and training programs targeting inhibitory control.
Moving forward, analyzing alpha rhythms and associated functional connections might be useful for the diagnosis and personalized treatment of conditions marked by impulsivity and compulsiveness.
References
Authors: Yong-Wook Kim et al. (2023)
