The relationship between autism and memory, specifically memory functions in relation to autism spectrum disorder (ASD), is an ongoing topic of research. ASD is a neurodevelopmental disorder characterised by social communication and interaction impairments, along with restricted and repetitive patterns of behavior. In this article, the word autism is used to refer to the whole range of conditions on the autism spectrum, which are not uncommon.
Some of the earliest references to the topic of autism and memory dated back to the 1960s and 1970s, when several studies appeared proposing that autism should be classified as amnesia. What is now diagnosed as autism was formerly diagnosed as developmental amnesia. Although the views of autism as an amnesia of memory have now been rejected, there are still many studies done on the relationship between memory functions and autism.
Autism can affect memory in complex and varied ways, with strengths and challenges depending on the individual. Many autistic people show strong semantic memory, excelling at recalling facts, details, or specific areas of interest, while episodic memory—recalling personal experiences, especially social or emotional ones—may be more difficult. Working memory, which involves holding and manipulating information short-term (Paytin), can also be weaker, particularly for verbal tasks. In contrast, visual and rote memory are often strengths, enabling some individuals to remember patterns, dates, or sequences with high accuracy. Although working memory difficulty is not part of the diagnostic criteria for ASD, it is widely recognized that autistic people commonly exhibit specific types of memory difficulties. These memory differences can influence daily life, learning, and social interactions, but vary widely across the autism spectrum. Further research is needed to get a fuller understanding of the relationship between autism and memory.
Physiological underpinnings
The physical underpinnings of the cause for differences in the memory of autistic people has been studied. Bachevalier suggests a major difference in the brain of an autistic person resides in the neural mechanisms of the structures in the medial temporal lobe (MTL) and perhaps, more specifically the amygdaloid complex. This may have implications in their ability to encode information because of the role the MTL and especially the hippocampal areas play in information processing. DeLong reinforces this by suggesting autism affects hippocampal function. Because the hippocampus is pivotal in memory encoding and modulating memory consolidation, any impairment can drastically affect an autistic person's ability to process (i.e. multi-modal) and retain information. Sumiyoshi, Kawakubo, Suga, Sumiyoshi and Kasai have suggested that it is possible that the attenuated neural activities in parahippocampal regions (including the parahippocampal gyrus) may affect an autistic person's ability to organize information. This region has an implied role in sorting, relating, and sending information to the hippocampus. The authors believe this altered or inhibited activity within the hippocampal regions may explain some of the behavioral differences in autistic people.
Further evidence suggests autistic people have differences in the circuitry responsible for what Brothers calls the neural basis for social intelligence, which involves holistically interpreting people's expressions and intentions. The interaction between the amygdala, the orbitofrontal cortex, and the superior temporal sulcus and gyrus enables processing of social information for personal interaction. For people who are autistic, altered activation in these areas may explain difficulties in remembering social-emotional information.Schumann et al., 2004 Long-term memory There are two types of long-term memory; both of which have been studied in relation to autism. Declarative memory is memory that can be consciously recalled, such as facts and knowledge. Declarative memory includes semantic and episodic memory. Semantic memory involves the recollection of facts, and episodic memory involves the recollection of previous experiences in life. Studies on autistic people have shown impairments in their episodic memory but relative preservation of their semantic memory. The brain regions that play a major role in declarative learning and memory are the hippocampus and regions of the medial temporal lobe.
Autistic people often show mixed long-term memory abilities. While semantic memory, the memory for facts, tends to remain mostly intact, memory related to personal life events, or episodic memory, may be impaired. This particularly affects social or emotional information in an individual.Boucher, 2001 Studies also suggest that high-functioning autistic individuals have intact recognition memory for non-social stimuli while struggling with features such as color or location.Bowler, 2004
Declarative memory Autobiographical memory Autobiographical memory is an example of declarative memory. One aspect of autobiographical memory is the self-reference effect, which means that typically people have a stronger memory for information that is relevant to themselves. It has been theorized that autistic people have diminished psychological self-knowledge but intact physical self-knowledge. As a result, these individuals show impaired autobiographical episodic memory and a reduced self-reference effect (which may each rely on psychological aspects of the self-concept), but do not show specific impairments in memory for their own rather than others' actions (which may rely on physical aspects of the self-concept).
A study by Unveren et al. in 2025 found that autistic people recalled shorter and less detailed autobiographical memories. The researchers compared 4 autistic and 8 non-autistic people using memory tasks and brain imaging. They found that the autistic people recalled shorter, less detailed personal memories. One limitation to this study is that they used a small number of participants.
Explicit memory retrieval and recognition Recognition in HFA (high-functioning autistic) people has been widely studied. Overall, these studies conclude that the majority of HFA people have intact recognition abilities. Non-social stimulus recognition is often superior, or "robustly intact", although there is some evidence suggesting that HFA people have difficulty with complex scenes and color combinations. For example, HFA people exhibit intact recognition of non-social stimuli such as written words, spoken sentences, pictures of common objects, and meaningless patterns or shapes. HFA people showed intact memory for individual features (such as objects, colors, or locations), but impaired memory binding when asked to recognize object-color or object-location combinations. Impaired memory has also been found in the recognition of words encoded self-referentially—that is, words processed in relation to oneself, such as judging whether a word describes one's own personality.
Contrary to the plethora of HFA recognition memory studies, the study of recognition for M-LFA (medium-low functioning autistic) people is considerably lacking. The studies that do exist predominantly point to impaired recognition of pictures, words to name objects, and other non-social stimuli. Four delayed recognition studies reported recognition impairments for M-LFA participants. Additionally, four of the seven primary studies of non-social stimuli recognition revealed significant impairment of non-social stimuli for M-LFA people. The other three studies were less reliable because of their methodology. Boucher, Lewis, and Collis gathered data supporting poor facial recognition, something widely observed for M-LFA people.
Implicit/non-declarative memory
Implicit memory, also known as non-declarative memory, appears to be relatively strong in many autistic people. Procedural memory, priming, and classical conditioning often function normally in higher-performing individuals, especially with therapies, allowing them to learn habits and patterns without conscious awareness.Gidley Larson & Mostofsky, 2008
Implicit memory is memory that relies on past experiences to help recall things without actively thinking of them. Procedural memory, classical conditioning, and priming are all included in implicit memory; for example, procedural skills, such as riding a bike, become so natural over time that one does not have to explicitly think about them. The brain regions that process implicit memory are the basal ganglia and the cerebellum. Research suggests that HFA and M-LFA people show strong implicit memory functions. HFA people display intact implicit memory for non-social stimuli, unimpaired classical conditioning, and performance on other implicit learning tasks. HFA people displayed normal perceptual and conceptual priming. Studies concerning implicit memory in M-LFA people are sparse, and further study is needed.
As mentioned above, there are very few reliable studies of non-declarative memory for M-LFA people. However, there are some speculations. Some consider that the impaired motor skills evident in many cases of M-LFA may suggest impaired procedural learning. Other studies, including Walenski (2006) and Romero-Muguia (2008), also think that ASD behavior is indicative of implicit memory function. For example, many autistic people have exceptional implicit perceptual processing abilities in mathematics, the arts and in musical improvisation. Furthermore, there is speculation that because M-LFA people are often characterised by habit and routine, habit formation is likely unimpaired. Behavioral treatments and therapies used with M-LFA people are usually very helpful, suggesting that implicit knowledge can be acquired and conditioning is intact.
Working memory
Working memory, a cognitive system with limited capacity that retains and manipulates multiple pieces of transient information, has been found to be affected in autistic people. Certain studies have suggested that deficits in working memory performance exist in autistic people, especially when it comes to verbally mediated working memory tasks. One reason for this impairment is due to the working memory which is a part of the executive functions (EF), an umbrella term for cognitive processes that regulate, control, and manage other cognitive processes, for instance planning and attention.
A majority of the research has found that autistic people perform poorly on measures of executive function. A general decrease in working memory (WM) is one of the limitations, although some studies have shown that working memory is not impaired in autistic children relative to controls matched for IQ. However, some evidence suggests that there may be minimal impairment in high-functioning autistic (HFA) people in that they have intact associative learning ability, verbal working memory, and recognition memory. A longitudinal study by Kim and Kasari (2025) found that autistic children continued to improve their working memory over a longer period of time than typically developing peers. This suggests that working memory development in autistic children may extend later into childhood.. In rare cases, there are even instances of individuals possessing extremely good memory in constricted domains which are typically characterized as savants. Bennetto, Pennington and Rogers also suggest that WM deficits and limited EF is likely compounded by the onset of autism where early development yields hindrances in social interaction which typically (i.e. without impairment) improves both WM and EF. However, due to limited ability in interpreting social gestures and an impaired ability to process such information in a holistic and comprehensive manner, autistic people are subject to diminishing and confounding instances of memory functions and performance.