This week I have been discussing the basic principles of neuropsychological assessment, and its two foundational assumptions: the ability to reconstruct pre-morbid IQ and the need for “consistent best effort”. Yesterday’s blog dealt with the pre-morbid IQ. Today, we will discuss the issue of “consistent best effort.”
The number side of the neuropsychological assessment is based upon the theory that a neuropsychologist can make certain conclussions about pathology based upon an examination of the pattern of test scores. The process of doing this is called “discrepancy analysis”, meaning that if there is a discrepancy in certain areas, this points to pathology. Two other terms are important: “relative weakness” and “intraindividual comparison”. If while doing the intraindividual comparision (mean comparing the patient, only to his or her own scores versus the population as a whole) a “relative weakness” shows up, then that means something.
In a perfect world, it is a beautiful theory. You chart the scores, the “relative weakness” jumps out at the neuropsychologist, you look to the part of the brain that controls that area of function, and thus, make a diagnosis. The fundamental problem is that you must be able to presume that the test subject was making the same effort during the test where he or she did poorly, as across the entire battery of tests. But can we make that assumption?
I like to quote from depositions I have done to make these type of points, and I will do that again. My apologies to my son for my references to his middle school running career.
12 Q (By Mr. Johnson) Do you still have your Exhibit Number 1
13 before you?
14 A I do.
15 Q Page 6?
16 A Yes.
17 Q Now, as I understand what you’re saying in the first
18 paragraph of Page 6, what you’re saying is that because you
19 cannot be sure that the patient did not give optimum effort,
20 that you can’t reach conclusions based on the data in those
21 testing — in that testing; is that correct?
22 A I can make certain conclusions, but not on her current
23 status, on that date. That’s what I’m — all I’m trying to say
24 is this set of data had serious reservations because of lack of
25 effort.
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1 Q Now, there are any number of things — strike that. Let’s
2 talk about the continuum of effort when you’re giving someone a
3 test; all right? I’ll give you an example.
4 My son, who is a 13 year old, goes out and runs a six-
5 minute mile, and he gave better effort than anyone else in the
6 class if you judge it just based on his performance, because he
7 won the race; okay?
8 A Got you.
9 Q Now, would that be considered best effort?
10 A It was certainly a sufficient effort to be recorded, yes.
11 Q Two months later in a track meet in his conference meet,
12 he’s able to run a five-minute, six-second mile without
13 significant change in this training status. In comparison to
14 the gym class — in comparison to the conference meet time of
15 five minutes and six seconds, did he give best effort in gym
16 class?
17 A There are other variables that have to be considered, and
18 I’d have to know other things. I’m not really following you.
19 Q Okay. Tell me what the variables would be.
20 A Like the environmental conditions, the contingencies if he
21 won or if he didn’t win, the particular mood or attitude that he
22 had on that day, how his physical health was, if he had a cold,
23 if he had some sort of limitation.
24 Q Now, we always have all of those limitations anytime we
25 give someone any type of test; is that correct?
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1 A Exactly right.
2 Q If we were going to pick an example of when we might get
3 the highest percentage of people giving maximal effort or
4 optimal effort, is there a better example than the law school
5 admission test?
6 A Well, I’ve never seen the law school admission test, but if
7 it’s like the test that I took to get to graduate school, then
8 one certainly has to do well, as best as they can, yes.
9 Q And can we — if there ever — can we ever presume a higher
10 likelihood of maximum effort in an academic test than we would
11 in something like a law school or a medical college admissions?
12 A Well, I agree. I mean, one can’t do better than one can
13 do.
14 Q But what’s unique about the law school and the medical
15 school admission test, is people’s whole lives revolve around
16 how they do on this test; correct?
17 A Well, that’s probably their interpretation, but it’s not
18 real. They probably think —
19 Q And that thinking that would convince them at least
20 relative to other variables to give it their best shot?
21 A I would think so, yes.
22 Q Despite that, sometimes people who are testing in high-
23 pressure situations like a law school admissions test or a
24 medical college entrance exam, do not wind up at their optimum
25 performance level; correct?
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1 A I presume that’s correct.
2 Q And what explanations for that would do?
3 A Again, we just went through some of them. They have a
4 cold, they’re worried about money, they have stress at home,
5 they have stress on the job, I mean, there are all kinds of
6 events that could influence particular effort on a particular
7 day.
8 Q Or actually the stress of the test itself?
9 A Well, yes, of course. There’s some people who don’t do
10 well on tests.
11 Q And there are some people who do worse the more the
12 pressure is?
13 A Right. It’s not really the pressure; it’s how the patient
14 manages the pressure that’s the issue.
Now as we consider this long introduction in the context of the search for “relative weaknesses”, what does that mean? What if our test subject was only using the gym class effort level, versus the conference meet effort level? Can we make statistical comparisons then? Or should we compare that performance to how people do in gym class, and not comparing how they do in more stimulating environments?
Neuropsychology is a science, right? They should have control out all of these variables, right? Guess again, not because they don’t want to, but because they are dealing with human beings, and in brain injury evaluations, human beings who prevented from doing what they are presumed to do, based upon the precise disability for which we are evaluating them: brain damage.
Next: The Scope of the Problem for Brain Injured Person in Giving Consistent Best Effort.
