A New Era in Attention Assessments

ADHD is now defined as attention deficit hyperactive disorder. Attention span varies between children and adults. While children between the ages of 3-6 can focus for a maximum of 8 minutes, this number increases up to 20 minutes for adults. This period varies for the individual and the child with ADHD and may reach a level where they experience difficulties in daily life. Methods used to measure this rate include various neuropsychological tests, computer-based evaluation systems and observational methods. One of the computer-based evaluation systems is Electroencephalography (EEG). So what is this EEG?

Electroencephalography (EEG) is a test that records and measures electrical activity in the brain. The human brain has a complex structure, and it is possible to examine in detail the electrical waves created by nerve cells that produce low electrical currents.

By recording these waves, the EEG device plays an important role in determining possible functional disorders in the brain and their locations. The test is performed by placing electrodes made of silver or gold-containing alloys on the head with the help of thin wires and gel. Thanks to EEG, the effectiveness of communication regions in the brain can be monitored and its functionality can be determined.

Continuing with the definitions, let's look at "What is different in the brain of an individual with ADHD?" and "How can we detect this difference with EEG?"

The electrical activity profiles in the brains of individuals with ADHD (Attention Deficit Hyperactivity Disorder) have marked differences. Electroencephalography (EEG) recordings show that in children with ADHD at rest, the amplitude of theta waves, which represent slow wave activity, is higher, while the amplitude of beta waves, which are fast waves, tends to be lower.

This is expressed as an increase in the theta/beta ratio in the ADHD group and has been observed in many ADHD studies over many years. While a high theta wave level indicates that the brain is generally at a low level of arousal, meaning the individual is in a calm or sleepy state; The relatively low beta waves mean that focus and active cognitive processing abilities may be limited. Therefore, children with ADHD may have difficulty paying attention while performing tasks because their brains are not "awake" enough.

Increased theta/beta ratio was evaluated as a potential biological diagnostic method for ADHD for a while, and this measurement was effective in the approval of a device as an auxiliary diagnostic tool in the USA.

In today's conditions, it is not possible to make a diagnosis with a single brain imaging scan. Although certain differences are observed in the brains of individuals with ADHD compared to other individuals, this person cannot be diagnosed with ADHD with a personal brain printout. Although advances in brain imaging technologies enable the detection of certain structural and functional differences associated with ADHD, these findings are not sufficient to support the diagnosis.

Although EEG alone is not considered sufficient for the diagnosis of ADHD, brain wave tests using EEG serve as an aid in distinguishing subtypes of ADHD. It can help diagnose whether symptoms in adolescence are mostly attention deficit or hyperactivity and impulsivity. In addition to clinical observations made with questionnaires, tests with EEG can provide us with neurophysiological evidence of brain activity. Looking at the function of the EEG also gives us clues for developing treatments that address fundamental processing differences between ADHD subtypes. EEG has also been investigated as part of the treatment and diagnosis of children with ADHD. A recent study found that combining EEG feedback with drug therapy improved outcomes. In addition, neurofeedback therapy, which helps regulate individuals' brain waves, is also one of the functions of EEG. Knowing that EEG feedback alone has an effectiveness rate “as high as 60-70%” and “leads to stable long-term improvement in emotional, behavioral, and academic performance, and improved cognition and performance in daily activities,” scientists conducted a randomized trial in which EEG feedback was used in combination with the stimulant methylphenidate (brand name Ritalin in the US).

EEG has significant potential as a useful complementary tool in ADHD assessments. However, it must be used in conjunction with psychological evaluations, clinical observations and neuropsychological tests to obtain reliable results. Although it is insufficient to diagnose ADHD on its own, it can support the diagnosis and help guide the treatment process.

Resources:

• https://www.memorial.com.tr/tani-ve-testler/eeg-nedir-eeg-testi-nasil-yapilir
• https://psikologgulnurcelik.com/dehb-beyin-yapisi/
• https://www.medicalnewstoday.com/articles/267246