ADD Science: Part I

I am an English major. The class that I did the worst in during college was biology. But I got an A+ in high school in biology so, armed with the need to know, I dove into David Freides' Developmental Disorders: A Neuropsychological Approach to try to figure out what is going on in my brain. I've found the book surprisingly easy to understand and interesting. I am not going to quote from it here. Instead, I am going to try to give some paragraphs about my initial findings. As best as I can, I will give page numbers to Freides. He quotes a huge number of studies that I will try to outline separately in a different post.

Inattention has been described in two ways: 1. A failure to remain alert due to a failure of outside attention-grabbers to grab attention. This is called the underarousal hypothesis, and it has been widely questioned. 2. A failure to sort through attention grabbers to react to the ones that demand focus, or "an impaired ability to modulate arousal or alertness to meet situational demands." (Douglas, 1984 as quoted on page 175).

Right now, I do not fully understand the science of the former. It has something to do with the fact that people react to all attention-grabbers but learn to screen certain ones out over time. The first theory says that people with ADHD do not react at the same level to anything that might demand attention, and compares the hyperactive subtype to someone trying to keep himself awake. The hyperactive person with ADHD is trying to keep himself stimulated.

The latter one seems to be more rooted in actual places in the brain. To that end, I included two diagrams of the brain lifted off the Internet and some definitions:

This one show the lobes of the outer layer of grey mass: the cerebral cortex. The frontal lobe is in blue. That is the one that comes into play here, but just for reference, the other lobes are Temporal (green) Occipital (pink) and Parietal (yellow).

The frontal lobes, according to wikipedia, "have been found to play a part in impulse control, judgment, language production, working memory, motor function, problem solving, sexual behavior, socialization and spontaneity."

Also, at play here are the Basal ganglia, which are a group of transit points for electrical signals in the brain. They join all the lobes. The second diagram here indicates where they are.



O.K. Now that we got all of that down, we can look at this hypothesis of what is actually going on in the brain.

A study of hyperactive children in 1989 showed that subjects with ADD had increased blood flow to the sensory parts of the brain (that's all the lobes except for the frontal, with the most emphasis on the Parietal) and insufficient blood flow to the basal ganglia where inhibition and regulation of behavior and control comes from (page 175).

Now, to quote directly from Freides, "the more activity, the more blood is required" (175). So, in other words, there was not enough activity in the place that controls action and too much in the place that processes sensory input (all of those attention grabbers). Again to quote directly, "When there is inadequate Basal ganglia activity, the subjects sensory system is overactive, responding to every input" (175).

In English, with not enough activity in the part of the brain that transmits signals telling the rest of the of the brain what to notice and what to ignore, the brain pays attention to everything.

This is the biology of the theory that someone with ADD pays attention to TOO MUCH (i.e. everything) not too little (i.e. has no attention at all).

Stimulant drugs like Ritalin and Adderall were found to even out the activity in the two areas, giving the person with ADD a boost in sorting through life's sensory material.

It is really late at night (or I guess early in the morning) so I am going to call it quits here for now. But soon I am going to post on the next section of the book which focuses primarily on adult ADD and lack of executive function, which is more specifically my problems (i.e. organization, tidiness, time-management).