Weak working memory is part of the deficit in the “executive functioning” of the brain. The brain’s executive function manages, regulates, and controls many of the brain’s functions, including attention and planning. The working memory holds multiple pieces of information in the mind, to be manipulated. If you have a poor working memory, you will likely have a hard time proving you remember something when you are tested on it. In other words, it may seem that the person has difficulty learning, when in fact the person can learn a lot, but they simply have a hard time demonstrating that knowledge through standard forms of testing.
People on the autism spectrum actually do best when they have an opportunity to demonstrate that knowledge in context. In a conversation, for example, the person will talk about all of the things they know about that given topic. But if you had given that same person a test on the subject instead, they may not be able to recall all of the information in the same way. Especially if demands are being made on working memory, as is often the case with testing. People on the spectrum often have quite good associative memory, verbal working memory, and recognition memory. Recognition memory is what we typically just call “remembering”, also known as recollection memory, and “knowing,” or familiarity memory. Recollection is a slow process, and familiarity is a fast one. Associative learning is learning that takes place in a given context, and is often recalled in a similar context.
In addition to working memory, people on the autism spectrum have problems with temporal order (when things happen in time), source (inability to remember when, where, etc you learned something, while remembering what you learned), and free recall. The latter is, again, central to testing and is not at all indicative of whether or not a child is in fact learning anything. If you require someone to simply recall information in a random way, they can typically do so, unless they are on the spectrum. People on the spectrum typically have to have a stimulus or context in which to remember everything. Then they will spill the beans. And more. There is also a tendency to do better with visual memory and cues than verbal ones. While temporal working memory seems to be impaired, spatial working memory (images, maps, etc) often seems to work better.
Children on the autism spectrum also have to be explicitly taught strategies to recall information, strategies which neurotypical children have naturally. If you want a child to do well on a test, for example, you need to not only teach them information, but teach them how to retrieve the information. People on the spectrum have difficulty with organization and performance skills, but have exceptional abilities to follow rules, so long as the rules are explicitly laid out. You cannot imply the rules or suggest the rules or have unspoken rules—all rules must be explicit, detailed, and clear if you want someone on the spectrum to follow them. And when you do that, they will follow those rules. Also, people on the spectrum have extremely powerful implicit memory. Implicit memory is the ability to remember something or how to do something without conscious awareness of those previous experiences. What this means is that a student, for example, who is on the spectrum and doesn’t seem to be paying attention is in fact learning, gaining information implicitly, which can then be easily recalled later.
The main issue with autism spectrum disorder is the impaired executive functioning, which affects attention, inhibitory control, working memory, cognitive flexibility, reasoning, problem solving, and planning. As you can imagine, these are going to affect school. The autistic student will appear not to be paying attention, will have a hard time inhibiting behaviors and may therefore sometime act inappropriately, will be rigid in her thinking, have difficulty with some kinds of reasoning and problem solving, and have difficulty planning and prioritizing. The child can be taught some of these things and the executive functioning can be developed, but it has to be explicit in the way it’s taught. The more explicit you are about the rules and what you expect from the student, the more the student will learn and behaviors will improve.
Another important element to understand is that the person on the autism spectrum typically has to have things repeated and related to each other to a far greater degree than has to be done for other students. In many ways the autistic brain works in opposite ways from the neurotypical brain. Teaching and testing methods developed for neurotypical students often cannot work well for autistic students. They will show “deficits” where there are really only differences. Teachers need to learn how to teach autistic students, because in many ways everything they are doing is wrong, from the perspective of teaching the autistic brain.
The issue then is that the memory in people on the autism spectrum works and expresses itself differently than it does in other people. The way we test for knowledge and learning, it is not uncommon for us to “find” the student hasn’t learned much of anything or retained much of anything. However, if we test the student in the right way, we will find that they probably have retained far more than the regular student has.