Clinical EEG

Question 1

ADHD

Answer 1

Abnormal theta/beta and theta/alpha ratio(usually high). Associated with high frontal theta, increased posterior delta, and decreased alpha and beta activity. (Clarke et al., 2001)

In cluster analysis, Clarke et al. found 3 distinct groups; high frontal theta low delta and beta (cortical hypoarousal they think), increased theta and delta decreased beta, high beta low delta and alpha (cortical hyperarousal).

Question 2

ADHD - ERN

Answer 2

Summary: No sig difference at level of (f)ERN but see different levels of task engagement at different times as indicated by the (f)ERN in the two groups as a function of reward salience (presumably).

Holroyd et al. (2008) found that (f)ERNs for controls were not significantly different from those with ADHD. However, within their task they found that ERNs for controls decreased as their T-maze task progressed and those for ADHD kids increased, indicated increases in task engagement for the latter and vice versa. Seems to be dependent on the giving of reward at the midpoint, which makes the task related reward more salient for children with ADHD.