Autism Spectrum Disorder and Memory

  Autism Spectrum Disorder and Memory Seema Nath

  Supervisor: Dr. Claire Hughes June 15 th , 2012 Total words: 11, 079

  Dissertation submitted in partial fulfilment for the degree of Master of Philosophy in Social and Developmental Psychology

  Division of Social and Developmental Psychology Faculty of Human, Social and Political Science

  University of Cambridge © Seema Nath, 2012. All Rights Reserved

  Abstract

  A number of risk factors indicate that children with Autism Spectrum Disorder (ASD) are represented in the criminal justice system as witnesses and victims of crime. The present study attempts to understand the memory capabilities and quantity of recall in children with Autism Spectrum Disorder (ASD) when compared with typically developing children specifically in terms of episodic and semantic memory systems. The study employed a personal interview and a words list paradigm respectively to study the episodic memory and the semantic memory under free and cued recall conditions. In addition, the study examines the effect of the severity of ASD on memory. The results show that children with ASD perform worse than typically developing children in the episodic memory task while the children with ASD perform on par with the typically developing children in the semantic memory task under both free and cued recall conditions. Severity of the symptoms of ASD has a negative effect on the performance in both the episodic and semantic memory task. The results imply that the severity of the ASD should be assessed before deciding on the suitability of a child to be presented as a witness.

  

Acknowledgements

  I would like to express my heartfelt gratitude to Dr. Claire Hughes whose able guidance made this thesis possible. Thank you for cautioning me about the challenges of recruitment and yet supporting me throughout my research. I would also like to thank Dr. Napoleon Katsos for lending me the TROG-2 which was an integral part of the research.

  I would also like to take this opportunity to thank all the schools in India who took part in the study. I am very grateful for the support from the Director, Principal, staff and students at Tamana School, the School of Hope, Prerona School, Carmel School, Springdale School and Don Bosco School.

  I owe my deepest gratitude to the Cambridge Commonwealth Trust for providing me with a scholarship that helped me undertake this MPhil in Social and Developmental Psychology.

  I am very thankful to my colleagues; Katherine, Laura, Nik, Divya and Amanda for keeping the study sessions interesting and all their encouragement. It is my great pleasure to thank my friends who made my time at the University of Cambridge so much fun, thank you Ashley, Lisa, Karishma, Rebecca and Lydia.

  Last but not the least; I would like to thank my parents and sister for their constant support and encouragement.

  Table of Contents

  Abstract ..................................................................................................................... 2 Acknowledgements ................................................................................................... 3 Table of Contents ...................................................................................................... 4 List of Figures ........................................................................................................... 5 Introduction ............................................................................................................... 6 Autism Spectrum Disorder ........................................................................................ 6 Cognitive theories of autism ..................................................................................... 8 General overview of memory deficits in children with ASD .................................. 11 Free and cued recall in children with ASD ............................................................. 15 Implication of memory in child witness testimony in children with ASD .............. 17 Relevance of the study ............................................................................................ 19 Research Questions and Hypothesis ....................................................................... 20 Method - Participants .............................................................................................. 21 Method - Measures .................................................................................................. 23 Method - Procedure ................................................................................................. 26 Results ..................................................................................................................... 28 Discussion ............................................................................................................... 37 Bibliography ............................................................................................................ 44 Appendix 1 - Life Events Questionnaire ................................................................. 50 Appendix 2

• – Semantic Memory Lists .................................................................... 54

  List of Figures

  Figure 1: Performance of children with ASD assessed as mild or moderate by CAR in the episodic memory task- Life Events Questionnaire (LEQ)………………………………………………………………………………………..35 Figure 2 : Performance of children with ASD assessed as mild or moderate by CAR in the semantic memory task under free recall condition………………………………………………………………………………………36 Figure 3. Performance of children with ASD assessed as mild or moderate by CAR in the semantic memory task under cued recall condition……………………………………………………………………………………….36

  

Memory in children with Autism Spectrum Disorder: Memory capabilities and quality of recall

in child witness testimony

  The present study attempts to understand the memory capabilities and quantity of recall in children with Autism Spectrum Disorder (ASD) when compared with typically developing children. This study examines two aspects of memory; episodic memory and semantic memory under free recall and cued recall conditions using a personal interview and a words list paradigm respectively. In addition, the study examines the effect of the ASD severity on memory.

  The nature of memory function in individuals with ASD has been under study for decades. While memory deficits have been found in children with ASD, the characterization of the status of the memory abilities in children is still inadequate due to the developmental differences that exist in autism (Williams, Golstein & Minshew, 2006). This is of consequence in the area of child witness testimony as a number of risk factors indicate that individuals with ASD are particularly likely to become victims or witnesses of crime (Maras & Bowler, 2012).

  The first section provides an overview of ASD and the various causal theories, followed by an account of memory and specifically episodic and semantic memory. This is followed by a detailed review of memory functions in individuals with ASD and their implications for child witness testimony together with a summary of the purpose and goal of the current investigation.

  Autism Spectrum Disorder

  The term ‘autism’ was coined by Eugen Bleuler (1916) to describe individuals with schizophrenia who had trouble connecting with the social world. Leo Kanner (1943) in his seminal paper ‘Autistic Disturbances of Affective Contact’ published his observations of eleven children whose condition he termed as ‘early infantile disorder’. A year later, Hans Asperger (1944) published his independent work based on his behavioural observation of four boys, which he termed ‘autistic psychopathy’. Both Kanner and Asperger believed that the behaviour was present from birth and had essential biological origins. Over the years research in autism has progressed and it has come to include a family of disorders under Autism Spectrum Disorder (ASD), which includes autism, Asperger’s Syndrome, Rett Syndrome, Childhood Disintegrative Disorder and Pervasive Developmental Disorder – Not otherwise specified.

  , ‘The essential features of Autistic Disorder are the presence of markedly abnormal or impaired development in social interaction and communication and a markedly restricted repertoire of activity and interests. Manifestations of the disorder vary greatly depending on the developmental level and chronological age of the individual. ’ Frith (2004) has called it a ‘disorder of development’ (p.1). Autism is characterized by impairments in three domains: reciprocal social interaction, communication, and restricted and repetitive repertoire of behaviour and interests.

  According to the WHO (2003), the prevalence of autism varies in the population from 0.7 to 21.1 per 10,000 children while the prevalence of autism spectrum disorders is estimated from 1 to 6 per 1000. They used the standard diagnostic handbooks and the Autism Diagnostic Interview scores to determine the criteria for autism in the population. The incidence of reported cases of autism has increased in recent years but this is attributed to increased awareness and the use of wider criteria for diagnosing autism (Happe, 2004). A review of epidemiological studies in different countries by Wing and Potter (2003) established that autism is not limited to a particular geographical area nor is it limited to any specific social class.

  Many causal factors for autism have been proposed including organic causes (Coleman & Gillberg, 1985; Schopler & Mesibov, 1987 and C. Gillberg, 1991), and genetic causes (Rutter,

  2000). The high incidence of epilepsy, ranging between 5% to 8.3 % ( Tuchman, Rapin & Shinnar, 1991; Mouridsen, Rich, Isager, 1999; Steffenburg, Gillberg & Steffenburg, 1996; Rossi, et. al., 1995; Wong, 1993; Tuchman & Rapin, 1997; Olsson, Steffenburg & Gillberg, 1988; Volkmar & Nelson, 1990 and Giovanardi- Rossi, Posar & Parmeggiani, 2000) in children with autism indicates brain damage to be a root cause of autism (Olsson et. al., 1988). Mental handicap accompanies autism in around three quarters of people with autism, which is another indication that autism has organic causal factors (Smalley et. al., 1988). Twin studies and sibling studies have provided evidence for the presence of genetic causal factors in autism (Folstein & Rutter, 1977 and Smalley, et. al., 1988). The sibling studies found that the incidence of autism is 50 times higher in siblings of people with autism than in the general population. Dizygotic twins were found to have a lower incidence of both twins having autism than monozygotic twins in the studies conducted by Folstein and Rutter (1977). The exact role of the genes in causing autism is still not clear (Rutter, 2000).

  Cognitive theories of autism

  At the cognitive level, various theories provide an interface between the brain and behaviour in explaining autism.

  Autistic children are claimed to have impairment in the intuitive understanding of mental states and experience a lack in attributing mental states to themselves and to others. This attribution of mental states to themselves comes easily to other typically developing children. This theory was tested by Baron-Cohen et. al., (1985) and is referred to as mind blindness. Children and adults with autism have been shown to have deficits in theory of mind, which involves mental states rather than false beliefs (Hill & Frith, 2003). Children and adults with autism therefore experience deficits in understanding pretence, irony, non- literal language and deception.

  Another cognitive theory to explain the causal basis for autism is the weak central coherence theory. The central coherence refers to a style of information processing in which incoming information is processed in its context. If the central coherence is strong then attention and memory for details will suffer (Happe, 1999 and Frith, 2003). Individuals with autism have a tendency to have a localised rather than global focus. Therefore in certain tests such as the embedded picture task (Witkin et. al., 1971), where participants are required to locate small parts within a global picture, individuals with autism are found to perform better than normal individuals (Shah & Frith, 1983, 1993; Jolliffe & Baron-Cohen, 1997). This superior ability is explained as stemming from the autistic individual’s tendency to be less influenced by the gestalt and finding the local parts of the gestalt more salient. Another extension of this theory says that rather than poor integration of information globally, it is enhanced discrimination of the individual elements (Mottron et. al. 2000 and Plaisted 2001).This also explains savant abilities in individuals with autism, which result from superior developed abilities and obsessive attention to detail.

  Executive dysfunction is another widely accepted theory for explaining some of the behavioural problems in autism. Rigidity and perseverance are problems addressed by this theory and it is explained by the likelihood of being stuck doing a given task set and poor initiation of new actions (Hill & Frith, 2003). Planning, working memory, impulse control, shifting set and the initiation and monitoring action and the inhibition of proponent responses are functions that fall under the umbrella term of executive dysfunction. Deficits in planning have been observed in autistic individuals using various tasks. The Tower of Hanoi and its variant, the Tower of London has been widely used tasks for evaluating executive function. Autistic children have been found to be impaired on such tasks (Ozonoff et. al., 1991; Hughes, et. al., 1994; Ozonoff & McEvoy, 1994 and Ozonoff & Jensen, 1999).

  Memory-Episodic and Semantic

  Memory plays a central part in our life as is evident from both our day-to-day and academic life. Memory is distinguished as explicit (declarative) which refers to memories revealed through intentional retrieval of previous experience (birth of a sibling) and implicit (procedural) which are concerned with memories that are manifested in subsequent behaviour without the direct recollection of a previous event (like riding a bicycle) (Balota et. al., 2000). In this study the focus is on two specific types of explicit memory. Tulving (1972) proposed that explicit memory could be divided into two types, episodic and semantic memory. His original definition of episodic memory stated that it is the memory that focuses on the recall of events from a specific time or place (Tulving, 1972). He later added that it depends on ‘autonoetic’ or self knowing awareness in which information when retrieved successfully is experienced as a part of one’s past and the encoding context is recalled. (Tulving, 2002 and Wheeler, Stuss & Tulving, 1997). Tulving has also included ideas such as self and subjective time to the definition of episodic memory. Semantic memory contains knowledge and facts relating to one’s past and this in clude the knowledge of one’s identity, personal characteristics and historical facts mediated by the awareness that the event has occurred (Levine, 2004). Semantic memory is important for the use of language (Tulving, 1972). It consists of organized knowledge for words and verbal symbols, their meanings and relationships between them. The semantic memory makes retrieval of information not directly stored in it possible and this process of retrieval does not alter the stored information.

  Tulving (1972) gave a taxonomic distinction between episodic and semantic memory primarily for ease of communication rather than based on any structural or functional differences. Subsequently different authors have advocated structural and functional distinction between them and considered them two separate memory systems (Atkinson et. al., 1974; Kintsch, 1975; Lockhart,Craik, & Jacoby, 1976; Tulving, 1976 and Watkins & Tulving, 1975).

  The difference between episodic and semantic memory is that unlike episodic memory, sem antic memory is not dependent on time and does not require mental time travel. Tulving’s later definition incorporated autonoetic or self-awareness of the time events occurred, in which he likened it to mental time travel (Gardiner, 1988; Tulving, 1972, 1983, 1986 and Wheeler, et. al., 1997).

  The semantic memory system is found to be less likely to experience loss of information and less susceptible to involuntary transformation than episodic memory system. (Tulving, 1972).

  

General overview of research relating to the episodic and semantic memory deficits of children

with Autism Spectrum Disorder

  In the theoretical sense, child witness testimony is affected by memory deficits and hence this section reviews the various episodic and semantic memory processes that are known to be impaired in children with ASD.

  Distinctive memory profiles have been observed in individuals with autism spectrum disorder (ASD) with crests and troughs in their capabilities (Maras & Bowler, 2012). The role of memory function and the classification of the significance of memory in ASD are still inadequate due to inconsistency of findings till date. These inconsistent findings can be attributed to the different cognitive capabilities and the developmental differences within the autistic population. However, memory has been represented in ASD populations as an essential cognitive domain that is responsible for the clinical manifestations of the disorder and also as secondary to a more generalized cognitive deficit surpassing memory such as executive dysfunction (Williams, Goldstein & Minshew, 2006).The specific difficulties with memory in individuals with ASD have also been argued to be responsible for some of the behavioural characteristics of the disorder (Boucher & Bowler, 2008).

  Empirical research involving the memory of children with autism has found rote memory, cued memory, associative memory, echoic and recognition memory intact in children with autism (Ameli et. al., 1988; Bartak & Rutter,1976; Boucher, 1978; Boucher & Lewis, 1989;

Hermelin & O’Connor, 1970; Minshew & Goldstein, 1993 and Ozonoff et. al., 1991). Children with autism have been found to have impairments in specific areas involving memory such as the

  memory of recent events and the ability to remember faces and auditory and verbal skills (Boucher & Lewis, 1989). Evidence of executive dysfunction has also been found in autism (Bennetto, Pennington & Rogers, 1996; Hughes et al., 1994; Ozonoff et al., 1991). Fein et. al (1996) have reported that young children with autism had less difficulties with digit recall, while sentences were found to be difficult to recall and stories were the hardest to recall. Findings such as these may have implications for eyewitness testimony of children and adolescents with ASD who may be witnesses, victims or perpetrators of crime.

  Boucher (1981) and Boucher and Lewis (1989) found children with autism had difficulties in memory for events they had recently experienced and in free recall of information when they were compared with normal age matched and mentally retarded ability matched counterparts. This led her to conclude that in a complex stimulus, children with autism might encode less information such as in a social interaction or conversation. Millward, Powell, Messer and Jordan (2000), adapted an early study by Boucher and Lewis (1989), which examined memory for events in children with autism and a matched group of typically developing children.

  Their research suggested that the recall of events experienced personally is particularly difficult for children with autism. This study also revealed that children with autism recalled lesser personal events as compared with the typically developing children who were matched controls thus indicating that it was a specific rather than a general difficulty that children with autism faced when required to recall personal events. Consequently it emerges from these studies that the memories of children with autism are somewhat impaired when they have to process information relating to self. A study (Jones, et al., 2010) of individuals with ASD concluded that there are everyday memory deficits, which also include event based prospective memory. It also mentions difficulties in verbal word recall. This study had 94 adolescent participants with ASD and 55 participants without ASD. This study used Rivermead Behavioural Memory Test (RBMT) and the Children’s Auditory Verbal Learning Test – 2 (CAVLT-2) to assess everyday memory and standard word recall tasks respectively. This study provides emphasis on the real world application of memory in children with ASD.

  Another study on the content and structure relating to episodic memory in children with and without Asperge r’s Syndrome (Brown, 2007) suggests that children with Asperger’s syndrome provide less articulate memory narratives than their typically developed peers.Further explaining memory deficits in adults and adolescents with ASD, research have shown that their level of episodic memory can predict Theory of Mind impairments in adults and adolescents with ASD. (Nogaet. al., 2009). Memory has been found connected to executive function ability in children with ASD (Bennetto, Pennington & Rogers, 1996). These findings have been found to reflect the larger arrangement of relationships between the memory functioning and non-verbal reasoning in children with ASD that has not been observed in typically developing counterparts (Toichi & Kamio, 2003).

  The presence of semantic networks in children with autism originates from the research done by O’ Connor and Hermelin (1967) and later by Tager-Flusberg (1991). Both researches however came up with contrasting outcomes. While O’ Connor and Hermelin proposed that children with autism are unable to encode meaningful stimuli, Tager-Flusberg, came to the conclusion that children with autism just had a deficit in using linguistic information thereby hampering their recall of stored information.

  The presence of a semantic network for children with autism has been found with evidence of the children using clustering strategies and category cues just as their typically developed controls (Privett, 1995). Studies of children with autism involving both high functioning and moderate cognitive impairments have found some evidence for the use of memory strategy by children with autism though they tended to use it less than typically developing children (Bebko & Ricciuti, 2000).

  There has been work in the area involving both episodic and semantic memory, but this study has involved adult participants (21-61 years) with autism spectrum disorders (Crane & Goddard, 2008). The research consisted of first administering the Weschler’s Abbreviated Scale of Intelligence, then the Children’s Autobiographical Memory Inventory (cited: CAMI: Bekerian et. al., 2001) to the participants with ASD. These measures were used as a basis for an episodic and semantic memory interview. This was followed by an Autobiographical Fluency task (cited: Dritschel et. al., 1992) in which participants had to recall events and people from specific periods of their life. Their findings suggest that individuals with ASD exhibit a deficit when disassociating between the personal episodic and semantic memory measures. Also in contrast to the control group the group of participants diagnosed with ASD showed a separate way of remembering. The number of memories recalled by the ASD group was not affected as a function of time whereas the control group’s memories peaked at the secondary school and the five years post school period. This separate way of remembering is consistent with theories that link autobiographical memory to the formation of self (Conway & Pleydell-Pearce, 2000). The lack of reminiscence has been attributed to difficulties in forming ideas of self in individuals with ASD.

  Another study on the semantic and episodic memory in children with ASD used a task that determined recognition and self-other source memory (Lind and Bowler, 2009). Their research showed recognition memory to have remained unaffected but source memory was significantly reduced in children with ASD.

  Free recall and cued recall in children with ASD

  Retrieval and recall of information from the past is memory and there are mainly three types of recall: free recall, cued recall and serial recall (Tulving, 1972). The present study examines the conditions of free and cued recall. The recall process in which a person is presented with a list of items and then asked to recall them in any order is called free recall (Bower, 2000).

  The recall process in which a person is presented with a list of items that is accompanied with cues to help with the recall of the items is known as cued recall (Bower, 2000). Both free and cued recall has been studied in respect to the memory of children with ASD.

  In a study by Tager-Flusberg (1991), children with autism were found to perform significantly worse than their typically matched counterparts under free recall conditions where they had to recall semantically related words. However they were found comparable to the typically developing group when they had to remember semantically unrelated words under free recall conditions.

  The free recall of pictures, written and spoken words have been found to be impaired in children with ASD when compared with their verbal age matched typically developing counterparts (Boucher and Warrington, 1976).As mentioned earlier, free recall of events experienced by the self were found to be poor in children with autism (Boucher and Lewis, 1989). In the same study when leading questions were used as cues then the performance of the children with autism were found to be at par with their typically developing matched group. Millward, Powell, Messer & Jordan (2000), later adapted these studies and reported similar findings. These studies point to the presence of a decline in the amount of recall under free recall conditions but enriched recall under cued recall conditions. Another study by McCrory, Henry and Happe (2007); (discussed in detail in the later section) found children with

Asperger’s Syndrome when asked to use free recall to report a witnessed event had lower remembrance of the details when compared to their typically developing peers. However their

  overall accuracy and recall under guided recall conditions were found to be complete. Children with ASD have also been reported to recall fewer details and made more errors under free recall conditions than the typically developing counterparts (Maras and Bowler, 2011).

  One explanation for the impaired free recall in individuals with autism has been presented from the weak central coherence theory that gist representation might be impaired while their verbatim memory stays steady (Happe and Frith, 2006). Another explanation put forth by Bowler et. al., (2004) states that the impaired free recall and the intact cued recall may be due to a difference in how the representation of the memory was manipulated at recall.

  Implication of memory in child witness testimony of children with ASD

  Specific memory deficits in children with ASD put them at a disadvantage as a witness as it diminishes their credibility as a witness (Maras & Bowler, 2012). It is therefore of great importance to understand the memory capabilities in children with ASD.

  With respect to specific studies investigating eyewitness testimony in ASD only two studies have included children and adolescents as participants while the rest of the studies involve adults (Maras and Bowler, 2012). Bruck et. al., (2007) investigated the extent to which autistic children’s autobiographical memory can be distorted by suggestion. This study found that children with ASD had difficulties recalling personal events as was reported earlier by Millward, Powell, Messer and Jordan (2000). When compared with typically developing children it was found that children with ASD showed deficits in recalling personal events as well as failed to recall events completely in some instances. With regards to the dimensions of suggestibility their research evidenced that the poor memory in children with ASD was mainly characterized by omission errors rather than commission errors. This means that in comparison to their typically developing counterparts children with ASD were more prone to denying that an event has actually happened but were as prone to claiming that an event had happened when actually it had not. This research concluded that children with ASD had a less recall of events and therefore had poor autobiographical memory, hence bolstering the claim that children with ASD were not more suggestible than typically developing children. The findings suggested that misinformation leading to suggestibility was less likely to assimilate into their memory, as their autobiographical memory was poor.

  A study by McCrory, Henry & Happe (2007) explored the eyewitness memory and suggestibility in children with Asperger Syndrome (AS). They used an experimental paradigm that involved a live staged event and they interviewed the children the next day regarding the event. The interviewer used a structured protocol and the children were given a free recall, then they were asked a few general questions followed by specific questions. The interview ended with the interviewer asking leading questions that entailed incorrect assumption. The AS group performed worse than their typically developing counterparts on the free recall. However, no significant differences were found between the AS group and the typically developing group in the general and specific questioning or their performance on the leading questions. In addition, the children were given two executive function tasks, Hayling Sentence Completion Test and Fluency task. The results indicated deficits in response suppression in the AS group while no group differences were found in the Fluency task. Their findings show that free recall underestimates the memory for an event in individuals with AS while general and specific questioning can elicit more information than free recall. In line with the findings of Bruck et. al.

  (2007), this study found that children with AS were found to be no more suggestible than their typically developing counterparts. The correlation found between executive function and memory in AS has been used to explain that individuals with autism rely more on generic cognitive resources during recall due to their weak central coherence.

  Barring these studies involving children with AS and ASD as participants most other studies have included adult participants. The findings by McCrory, Henry & Happe (2007) and Bruck et. al., (2007) that children with ASD were no less suggestible than their typically developing counterparts has been found to hold true in an adult ASD population in a study by North et. al., (2007). In another study Maras and Bowler (2011) found that high functioning individuals with ASD used schemas to aid their memory as much as the typically developing group that led them to report inaccurate details consistent with their schemas. The ASD group was found to recall fewer details and reported to have made more errors than their typically developing counterparts.

  From the work in the field of eyewitness testimony done till date with high functioning individuals with ASD it can be concluded that they are capable of providing reliable eyewitness testimony. However, it must be noted that all the studies have involved high functioning individuals with ASD and hence it may not be generalizable to the entire ASD population. This is discussed in detail in the next section.

  Relevance of the study

  Memory in autism has been under study for decades. The purpose of the current study was to assess the capability and quality of recall in children with Autism Spectrum Disorder (ASD) when compared with typically developing children. As mentioned earlier, almost all the memory studies that have involved individuals with ASD have involved relatively high functioning participants (see review, Maras and Bowler, 2012). Therefore the research needs to be extended to include low functioning individuals with ASD.

  It has been widely accepted that the majority of people who meet the criteria for autism also meet the criteria for mental retardation (APA, 1994 and NRC, 2001). Intellectual disability has further damaging effects on memory (Lifshitz et. al., 2011), and therefore as individuals with ASD with added intellectual disability can have more trouble with remembering details and temporal order of events which as mentioned earlier is very important in case of eye-witness testimony (Maras and Bowler, 2012). Individuals with more severe ASD have also been observed to have delays and impairments in language development (Boucher et. al., 2008) and this may also further add to their difficulty to testify as a witness.

  The present study was carried out in India. The evaluation of previous research on

  

memory and autism presents that while a lot of research involving various aspects of memory in

individuals with autism have been done, most of this research has almost entirely been carried out in Europe and America. As such there is no data on the various memory profiles in autistic

individuals available on this topic from developing countries. A cross-cultural interpretation will

be very useful in analysing the extent of the applicability of common principles across countries

and cultures. Having a dataset from a developing country will enable multi national comparisons

and the opportunity to explore more research options in the future involving cross-cultural

perspective of memory in autistic individuals. It is generally accepted that there is a difference in

the education system and the support network between western countries and developing nations

with regards to children and more specifically where children with disability are concerned, this

might also be a factor in the differences in their memory.

  Research questions and hypothesis

  The present study attempts to answer two questions: what is the quantity of recall in the episodic memory task and semantic memory task under free and cued recall conditions in children with Autism Spectrum Disorder (ASD) as compared with typically developing children? And does severity of the symptoms of ASD have an effect on the recall capabilities of children with ASD? The present study proposes to test the following hypotheses (H): H1: Children with ASD will perform worse on the episodic memory task than typically developing children; furthermore, this difference is predicted to be significant for semantic memory tasks under both free and cued recall conditions.

  H2: The severity of ASD symptoms as assessed using the Childhood Autism Rating Scale (CARS) will have a negative effect on the performance in the episodic memory task and the semantic memory tasks under free and cued recall conditions.

  

Method

  In order to address the above hypotheses, data analysis was performed on a series of memory tasks performed by a group of children with Autism Spectrum Disorder (ASD) and a control group of typically developing children.

  Participants

  The participants consisted of 20 typically developing children and 19 children with Autism Spectrum Disorder (ASD). In the typically developing group there were 8 males and 12 females and in the ASD group there were 15 males and 4 females. Epidemiological studies have shown that the incidence of autism is higher in males than females. The sex ratio has been found to vary from 2:1 (Ciadella & Mamelle, 1989) to about 3:1 (Steffenburg & Gillberg, 1986). It has been found to vary with respect to ability too, with females more likely to be at the lower end of the autism spectrum while males are more likely to be at the higher end of the spectrum (Lord &

  2 Schopler, 1987).As the sample was collected using convenience sampling the participants were

  not matched for gender. All the 20 typically developing children in the control group were enrolled in Grade 1 to 4 of the Indian primary education system. The 19 children with Autism Spectrum Disorder (ASD) were enrolled in Grade 1 to 4 in special education schools in India. An examination of the school records showed that all the children in the ASD group were given a formal diagnosis by a qualified clinician according to current diagnostic criteria; DSM

• – IV

  (APA, 1994) and ICD- 10 (WHO, 1993). In the ASD group, 2 children were diagnosed with Asperger’s Syndrome, 15 children were diagnosed with Autism and 2 children were diagnosed with Pervasive Developmental Disorder

• – Not Otherwise Specified (PD- NOS). In the ASD group, 18 children were verbal while 1 child was non-verbal. However, the non-verbal children were able to communicate by writing. The same instructions were provided to the non-verbal child as the verbal children and he responded with his answers in writing. In order to avoid comorbidity, children with ASD who received an additional diagnosis of mental retardation from the clinical psychologist were not included. The present study included children with ASD who have received an assessment of mild, moderate or severe ASD symptoms (as assessed by the Childhood Autism Rating Scale).

  The mean age of the participants in the typically developing group was 7.46 years (SD = 1.74). The mean age of the participants in the ASD group was 12.00 years (SD = 2.35). The age range for the typically group was from 5.02 to 10.11 years and the age range for the ASD group was from 7 to 14.11 years. Participants did not differ by gender on age. The two groups of children were closely matched on verbal age as a group. On an individual level, they were relatively matched though not perfectly matched. In the typically developing group, the participant’s mean verbal comprehension age was 7.36 years (S.D = 2.19) and in the ASD group, the participant’s mean verbal comprehension age was 7.37 years (S.D = 1.94). The verbal comprehension age range for the typically group was from 4.11 to 12 years and the age range for the ASD group was from 5.06 to 12 years.

  The participants were recruited through contact with the schools, which in turn contacted the parents. Parental consent was taken for all children. All the participants in the study were Indian. All the 39 children attended English medium schools and therefore the language of instruction for all the children was English. All the children in the study were bilingual and spoke English in addition to their mother tongue.

  Measures

  The present study used four measures. The Test for Reception of Grammar

• – 2 (TROG – 2) was used for both the groups of children. The Childhood Autism Rating Scale (CARS) was administered to the parents of the children with ASD to assess the severity of the autism. Both groups of children were administered the ‘Life Events Questionnaire’ and the semantic memory tasks under free and cued recall conditions. A brief description of all the measures is provided below.

  Test for Reception of Grammar

• – 2 (TROG- 2): Dorothy Bishop first developed The TROG in

  1983. The revised version TROG

• – 2 (2003) is currently in use. The TROG – 2 assesses grammatical ability by measuring the understanding of twenty constructions four times each using different test stimuli. The test is individually administered and is presented in a four picture multiple-choice format consisting of lexical and grammatical foils in English. The test provides a comparison of the child’s comprehension in relation to his or her peer group and also provides a qualitative assessment of specific areas of grammatical difficulty.

  The test is suitable for administration to children in the age group of 4 to 12 years. In addition, it can also be used for older children and adults with specific impairments and for them the norms for children in the 12-year age group are applicable. The total test time varies between

  10 – 20 minutes.

  

Childhood Autism Rating Scale (CARS): The CARS is a behaviour rating scale intended for use

  in diagnosing the severity of autism (DiLalla and Rogers, 1994). It is used to provide additional information when the diagnosis of ASD has already been made or is highly suspected (Vaughan,

  2011). Eric Schopler, Robert J. Reicher & Barbara R. Renner originally developed the CARS in 1986. The revised version CARS

• – 2 was used in the present study. It retains the original Childhood Autism Rating Scale (renamed CARS
• – 2) and consists of 15 item rating scales to be completed by the practitioner and a parent/care-giver. It also includes an additional rating scale to make it more sensitive to detecting symptoms of ASD in children and adults with high functioning autism and Asperger’s. The 15 items in the CARS – 2 address 15 functional areas (Schopler, Bourgondien, Wellman & Love, 2010).

  4

  from the autobiographical memory questionnaire developed by Bruck et. al., (2007) for their study. The LEQ was used as a measure of episodic memory in both groups of children. This questionnaire has been used previously with both typically developing children and children with ASD to assess autobiographical memory. The questionnaire was pilot tested by Bruck et. al., (2007) before administration on a small group of typically developing and a set of children with ASD and found to be appropriate and was administered to 38 typically developing children and 30 children with ASD for t heir study to assess the children’s autobiographical memory. The

  LEQ was also pilot-tested for the present study in a small group of typically developing children in India to ensure that the vocabulary level and content was appropriate for administration to the children. A few adjustments were made accordingly. For example, questions such as “How old is your mother/father?” were dropped, as around 90% of the children were unable to answer the question. The LEQ consists of three sections; Section 1 asks about Personal Information such as name, age, parent’s information, etc.; Section 2 asks about School Information such as name of school, teacher, classmates, etc., and Section 3 asks the child two open ended questions, what they remember about their first day in school and what was their favourite holiday. Each section measures the child’s recollection of facts about their life and events experienced personally by the child such as a holiday they went for and the amount of details concerning the same. Every correct answer in Section 1 and 2 get a score of 1 and every wrong answer gets scored 0. Section 3 was coded by giving a score of 1 per unique information recalled in both the questions. For example; in the question about their favourite holiday the child was given a score of 1 for answering where they went, and a point each for where they stayed, what they did, what places they visited and so on. The total score were counted and recorded.

  experimental design of Perner and Ruffman (1995). They have used these memory tasks previously in their study to test the free and cued recall in young typically developing children using list of words.

The list of words from Perner and Ruffman’s (1995) study was pilot tested on a sub set of typically developing children in India. Certain objects were changed to adapt

  them to the Indian context. For example: in the musical instruments category, piano was replaced by harmonium to make it more suitable to the Indian context.

  The semantic memory tasks consist of a memory task involving pictures of familiar objects or animals belonging to the same category. The tasks test for both free recall and cued recall. In the first condition, the child was randomly presented with eight pictures belonging to eight unrelated categories and then asked to recall the objects they were just shown. This was for the purpose of assessing the performance under free recall condition. In the second condition, the child was presented with eight pictures that are randomly presented but belonged to certain categories and the instructions clearly mentioned that they would be presented with items belonging to a certain category. This con dition was for the purpose of assessing the child’s performance under the cued recall conditions to distinct categories (for example; modes of transport or type of fruits etc.). The objective of the test was to determine whether children recalled more in the free recall condition or the cued recall condition. A score of 1 was given for each correct recall. The total number of correct recalls were counted and recorded.

  Procedure

  The study had the approval of the University of Cambridge Ethics Committee. Parents of children in both the typically developing group and the Autism Spectrum Disorder (ASD) group were informed of the study through the participating schools. All tests were administered as individual sessions in paper and pen booklets.

  In both groups, the Test for Reception of Grammar

• – II (TROG II) was administered first, followed by the Life Event Questionnaire and the Semantic Memory Task; together these measures took approximately 30
• – 45 minutes to complete. In both the groups, the responses given by the child on the Life Event Questionnaire was verified with the parent. In the ASD group, the Childhood Autism Rating Scale - 2 (CARS 2) was also administered to the parent to assess the severity of the autism symptoms.

  

Results

Variable and Sample Descriptive: The present study had 39 participants of which 19 were in the