Autism

Autism and Memory

Can you guess the memory superpowers of a child with autism?

Posted Apr 02, 2020

Autism is characterized by difficulty recognizing and responding appropriately to social and emotional cues, which causes problems with social interactions. Yes, they have unique strengths that can give them an advantage in certain areas. Watch a clip.

Working Memory and the Brain: From Understanding Working Memory

The brain of a child with autism develops differently from children without it. Recent research has found that the prefrontal cortex (PFC), the home of working memory, is one of the brain regions most affected by autism.

Initial results show that the PFC of a child with autism has a much greater volume of neurons, up to 67 percent more. One possible explanation for this excess growth is that the genes controlling neuron development are overactive, resulting in greater brain volume. Exactly how this is related to autistic behavior is unclear at the moment, but the link between an abnormal PFC and autism suggests that there may be a working memory connection to the behavior (Courchesne & Pierce, 2005).

Children with autism also display less activation in the PFC when they are asked to remember and process information. This pattern seems to be evident regardless of the nature of the task. In one experiment, they were asked to process letters, in another, shapes, and in another, faces. In all instances, the result was the same: There was less activation in the PFC for children with autism than in those without it. The study with faces also found that children with autism tend to analyze facial features like objects, rather than in light of social relationships, which may explain their trouble interpreting social nuances (Koshino et al., 2005; 2008).

Furthermore, when a child with ASD is presented with two tasks and has to focus on one while ignoring the other distracting task, their brain activity reveals that they do not actually shift their attention to the more important information (Luna et al., 2002). They have a difficult time determining what information is important. In the classroom, some students with ASD might appear to struggle with certain memory-heavy activities. However, this may be connected to their difficulty in knowing what they should focus on, rather than a working memory deficit per se.

Working Memory Is Linked to Autism

The working memory profile of the student with ASD depends on whether they are low or high functioning. In some cases, high-functioning students can have an above-average verbal working memory, while low-functioning students perform at the same level as a student with a specific language impairment. In general, low-functioning ASD students also have a poorer working memory than their typically developing peers do.

However, even high-functioning ASD students can display verbal working memory problems. In my own research, I found that the type of material they have to remember provides us with a clue to their working memory profile. They struggle in particular with abstract information, like nonsense words or new vocabulary. Why? One explanation is that when they are presented with abstract ideas that they have to both process and remember, they spend too long trying to comprehend the material and so forget what they need to do.

For example, during a verbal working memory test, Daniel, a 14-year-old with ASD, was presented with the sentence: Dogs can play the guitar. Daniel spent a long time thinking about the sentence before finally answering, “True,” because “you can train a dog.” As a result of the lengthy time spent deliberating the answer, he forgot the final word in the list of sentences (Alloway, Rajendran, & Archibald, 2009).

The strategies they use to remember information can also over-burden them. Studies confirm that when remembering information, high-functioning ASD individuals do not use their long-term memory, visual strategies, or even contextual clues. Instead, they rehearse things over and over again. While this can be useful in remembering short sequences of information, it is ultimately a time-consuming and inefficient strategy to simply keep repeating things. These students are aware of their own memory problems. Alistair, a high-functioning 13-year-old, commented that he had “number overload” when he failed a test that required him to repeat numbers in backward order.

Now, let’s look at their visual-spatial working memory profile. The majority of individuals with ASD do not have deficits in this area. In one task, students are shown a matrix with dots that appear in random locations, and they have to recall their location in a backward sequence. Both my own research, as well as other studies, confirms that students with ASD do as well as their peers without autism. In the classroom, this means they should be able to remember information that is presented visually. 

References

Alloway, T.P., Rajendran, G., & Archibald, L.M. (2009). Working memory profiles of children with developmental disorders. Journal of Learning Difficulties, 42, 372–82.

Courchesne, E.,  & Pierce, K. (2005).  Brain overgrowth in autism during a critical time in development: implications for frontal pyramidal neuron and interneuron development and connectivity. International Journal of Developmental Neuroscience, 23, 153-170.

Koshino, H., et al. (2005). Functional connectivity in an fMRI working memory task in high-functioning autism. Neuroimage, 24, 810–821.

Koshino, H., et al. (2008). fMRI investigation of working memory for faces in autism: visual coding and underconnectivity with frontal areas. Cerebral Cortex, 18, 289-300.

Luna, B., Minshew, N.J., Garver, K.E., Lazar, N.A., Thulborn, K.R., Eddy, W.F., & Sweeney, J. (2002). Neocortical system abnormalities in autism: an fMRI study of spatial working memory. Neurology, 59, 834-840.