The method of vanishing cues has been tested primarily through the use of computers, teaching patients how to use simple computer programs and functions. Glisky and Schacter (1986) developed this procedure.

"Students" work independently on a computer, and are able to work at their own pace. The "lesson" is comprised of a series of incomplete sentences that the student is required to complete (essentially a "fill in the blank" exercise). If the student doesn't know the response, they can press the return key to desplay the first letter of the target word. If he/she still doesn't know, they can ask for another letter, and another and another until they get the right word. These cues "vanish" when the lesson is repeated. When the lesson is performed on subsequent occasions, progressively less cues are required to answer the question, a function of the concept being learned. Amazingly, this learning occurs despite an amnesic's unawareness of ever completing the task before! With sufficient practice, amnesic students can do the lesson with no hints at all, and this learning has been shown to last up to 9 months.

Sample Question using Vanishing Cues

A sequence of characters enclosed in quotation marks is called a ________. (answer: STRING)

• 1st trial hints required: S, T, R, I, N 
• 2nd trial hints required: S, T, R 
• 3rd trial hints required: S, T 
• 4th trial hints required: S 
• 5th trial hints required: none!

How does this work?

"The vanishing cues procedure was designed specifically to tap into patient's preserved abilites to produce recently produced words in the presence of fragment cues, as shown in research on direct priming" (Glisky & Schacter, 1986). 

It is remarkable to observe that individuals thought to have no capacity to learn can do so with accuracy equivalent to unimpaired individuals. But it is important to qualify this by examining HOW amnesics do it. Their learning is not normal- what is mastered by an normal subject can be mastered by an amnesic, but in significantly less time. The knowledge obtained by amnesics is also extremely specific, and not easily transferrable. It can only be accessed if presented in the way it was learned. "They seemed to be relying on a particular stimulus to trigger the appropriate chain of responses."

Evaluating the Method

We know that the method of vanishing cues is effective in teaching complex skills to amnesic patients, but is it the best method? Other methods that have been documented include Errorless learning, spaced retrieval, coping strategies, etc. (These will not be discussed here, but see Thone (1996) for a review.) In one of the only studies comparing vanishing cues with another method, Hunkin and Parkin (1995) compared this against a standard anticipation method. "Contrary to expectations, the memory impaired group showed no significant advantage during training for items learned by the VC method." These are important findings that must be examined in more detail. In summary, despite the demonstrated effectiveness of the method of Vanishing Cues, its superiority as a learning method remains unproven.