Author: Alejandra Guillen
Editor: Theodore Zanto, PhD, Department of Neurology, University of California, San Francisco.
Dr. Zanto is an Associate Professor in Neurology and Director of the Neuroscience Division of Neuroscape at the University of California San Francisco where he studies interventions that may improve cognitive function and overall wellness across the lifespan.
What is EEG?
Electroencephalography (EEG) is a method for recording the brain's electrical activity via electrodes placed on your head. EEG measures voltage fluctuations resulting from the activity of the neurons in the brain, which are typically categorized into frequency bands (such as delta, theta, alpha, beta and gamma) that correspond to different rates (or types) of brain activities.
Traditionally used in clinical and research settings to diagnose conditions like epilepsy and sleep disorders, EEG technology has historically been both bulky and expensive, requiring sophisticated setups with multiple wired electrodes and specialized environments to reduce noise and interference in the signal.
Over the past few years, technology has advanced, which has led to a significant evolution in EEG equipment. Miniaturization of components and improvements in wireless technology have facilitated the development of portable and wearable EEG devices.
This means that EEG can now be used outside traditional laboratory or clinical settings. Modern wearable EEG can be easily used by consumers daily and comfortably at home or anywhere.
There are multiple applications where EEG can provide unique insights into our mind and health like managing stress, improving sleep, and enhancing cognitive performance.
What is brain arousal or mental alertness and why use EEG to measure it?
Mental alertness refers to the brain's level of responsiveness and readiness to engage with external stimuli. It's a state where the brain is active and primed to react to its environment. This concept plays a pivotal role in several cognitive processes, such as attention, learning, and decision-making.
The regulation of mental alertness involves multiple brain systems that are key in managing sleep-wake cycles and facilitating shifts between various states of consciousness.
EEG directly records electrical activity in the brain, which is sensitive to levels of arousal or alertness. By measuring the fluctuations in brain waves, EEG can provide real-time insights into the state of arousal.
Different brain wave patterns—such as alpha, beta, theta, and delta waves—are associated with different levels of alertness and cognitive engagement.
For instance, alpha waves are often linked to states of relaxation, while beta waves are associated with active thinking and alertness. Additionally, EEG provides precise time resolution, meaning that it can detect changes in brain activity almost instantaneously.
Is it a positive or a negative feeling?
Mental alertness isn't inherently positive or negative, its value depends on context and balance. Optimal alertness can enhance cognitive performance, attention, and responsiveness, making it beneficial for learning and effective functioning.
However, excessive alertness can lead to anxiety and stress, while too little may result in sluggishness and reduced cognitive capabilities. The key is finding the right balance to match the demands of a particular situation.
The brain optimizes individual performance across various activities by adjusting the levels of alertness to suit different environmental and task-related requirements.
Why is it important to be aware of your levels of alertness and emotions?
Emotions are subjective, physiological, and behavioral responses to personally meaningful external factors or internal mental states (e.g., memories) that underlie our experience of the world.
Identifying and understanding our emotions is crucial for our physical and mental health. Awareness of our emotions is the first step to learning the causes that trigger them and how to process them in a healthy way.
Permanent states of high alertness and low alertness are detrimental not just to cognitive and emotional well-being but also to physical health.
Managing these states effectively often requires interventions such as behavioral therapies, medication, meditation, lifestyle changes, and potentially professional counseling to address underlying issues.
Which emotions are related to high and low levels of alertness?
The emotions that are typically associated with alertness can be separated into a positive (pleasant) and a negative (unpleasant) dimension. Emotions associated with high levels of alertness include (but not limited to):
Excitement and amusement are associated with higher energy and positive feelings.
Anger, fear or stress are typically associated with overwhelming or frustrating states.
Similarly, emotions associated to low levels of alertness are:
Calmness, contentment and relief relate to mildly positive emotional tones.
Boredom, sadness and depression relate to lower energy and motivation states.
To achieve and maintain an optimal balance in life, it's crucial to incorporate strategies such as regular physical exercise, consistent sleep routines, using stress management techniques such as meditation, and, when necessary, reaching out for therapeutic support.
Central to this, is the monitoring of one's own mental state and alertness. By understanding your mental and emotional needs, you can significantly influence your ability to find balance. This conscious awareness and adjustment not only boosts productivity but is essential for fostering overall well-being, contributing to a healthier, happier life.
References:
Simon M Hofmann, Felix Klotzsche, Alberto Mariola, Vadim Nikulin, Arno Villringer, Michael Gaebler (2021) Decoding subjective emotional arousal from EEG during an immersive virtual reality experience eLife 10:e64812
