حافظه اپیزودیک در بزرگسالان مبتلا به اختلالات طیف اوتیسم: فراخوان برای رویدادهای خودتجربه ای در مقابل رویدادهای دگرتجربه ای
|کد مقاله||سال انتشار||مقاله انگلیسی||ترجمه فارسی||تعداد کلمات|
|33613||2007||13 صفحه PDF||سفارش دهید||6431 کلمه|
Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)
Journal : Research in Developmental Disabilities, Volume 28, Issue 3, May–June 2007, Pages 317–329
People with autistic spectrum disorders (ASD) have difficulties in recalling recently experienced events, which is dependent upon intact functioning of several aspects of ‘self awareness’. The current study examined impaired episodic recall in ASD and its relationship to specific impairments in aspects of ‘self awareness’. Between-group (participants with learning disabilities with and without autistic spectrum disorder) experimental design examining free and cued recall of table-top activities that were either self-experienced by participants or observed being performed by the experimenter. Participants with ASD did not show superiority of free recall for self-experienced events over observed events, nor for recall of other-experienced events over self-experienced events, but did demonstrate a superiority for cued recall of self-experienced events. The implications for theory and practice are discussed.
Memory involves storage and recall of different forms of information (Tulving, 2000). In addition to the distinction between working, short and long-term memory, ‘semantic memory’ (knowledge about the world) can be distinguished from ‘episodic memory’ (recollection of events from an individual's personal past characterised by the conscious experience of ‘remembering’) (Tulving, 1985). A further distinction is made between the subjective experiences of ‘remembering’ (i.e. mentally returning to an event and re-experiencing it) and ‘knowing’ (i.e. recognition without recall of the original experience). ‘Autonoetic consciousness’ is the conscious awareness of one's own existence and identity “… in subjective time extending from the personal past through the present to the personal future” ( Tulving, 1985). This facilitates ‘mental time-travel’ to past events, which can then be re-experienced ( Gardiner, 2002). The linkage of episodic recall and autonoetic consciousness has implications for understanding of the ‘self’ and the extent to which self concept develops from episodic experiences ( Klein, 2001). Conway (2002) further proposes that the recollective experience associated with episodic memories indicates that the mental image generated is a reflection of a self-experienced event, rather than dreams or fantasy, and that ‘experiences with strong self-reference may receive privileged encoding that render them highly accessible’. If episodic memory is dependent upon autonoetic consciousness, then episodic memory requires a ‘self’ that is continuing through time, with past and present experiences relating to the same ‘self’. Episodic recollection is dependent on recollection of specific events and recognising that the event happened in one's own past. Thus, without reference to the past and self-continuity across time, individuals would exist in a ‘permanent present’ (Baddeley, 1999). Self-continuity through time does not develop until the age of 4 years, when episodic memory is first observed (Perner, 1990 and Welch-Ross, 1995). Klein (2001) argues that impaired self concept leads to impaired memory, rather than vice-versa, and proposes that people with autistic spectrum disorders (ASD) might experience impaired self continuity related to observed autobiographical episodic memory dysfunction (Boucher & Lewis, 1989; Klein, Chan, & Loftus, 1999; Ozonoff, Pennington, & Rogers, 1991). Perner (1990) proposes that episodic memory in typically developing children is dependent on mentalisation abilities. Therefore, people with ASD would be expected to exhibit episodic memory deficits and children with ASD have been found to have difficulties in recalling self-participation in events (Boucher, 1981; Boucher & Lewis, 1989). Powell and Jordan (1993) explain deficits in episodic memory associated with ASD by reference to an impaired ‘experiencing self’ that ‘encodes events as part of a personal dimension’. Without this specialised encoding, spontaneous retrieval is hindered, impairing free recall of personal episodic memories. They further posit a difference between ‘knowing’ that one is engaged in an event and ‘experiencing’ it as happening to oneself, the latter involving evaluating personal feelings about the event and the personal significance of the event. Episodic memories can be recalled by cued recall or by spontaneous free recall, which requires re-experiencing (Conway, 2002). Powell and Jordan (1995) suggest people with ASD will not be impaired on cued recall of personally experienced events, only on free recall, as their ability to deliberately place themselves back in an experience is impaired, which results in events not being encoded as part of a personal dimension. Conway (2002) proposes experiences directly involving the self may receive ‘privileged’ encoding that makes them more easily searched for and retrieved, i.e. events involving the self should be more easily remembered than events observed (Baker-Ward, Hess, & Flannagan, 1990; Conway & Dewhurst, 1995). Therefore, people with ASD who have deficits in processes involving the self should not demonstrate this superiority for self-experienced events. 2. Concepts of ‘self’ in autistic spectrum disorders Although there is limited research into concepts of self in ASD, impaired functions of ‘self’ can be identified, e.g. refer to self in the third person and confusion of personal pronouns ‘I’ and ‘you’ (Lee, Hobson, & Chiat, 1994). Loveland (1993) suggests that pronoun confusion results from difficulties in understanding the differing view-points of others, i.e. ‘you’ and ‘I’ are simultaneously both ‘I’ to oneself and ‘you’ to another person. Powell and Jordan (1995) propose that self-concept comprises both a ‘descriptive element’, referring to factual self-knowledge (i.e. semantic autobiographical) and an ‘evaluative element’ (i.e. ‘interpersonal self’), the latter developing through interaction with others and therefore impaired in ASD (Frith & Happé 1999). Hence, people with ASD can possess knowledge about themselves, but not the ‘experience’ of what it is like to be them. This is supported by the observation that although the ‘interacting self’ may be impaired (Lee & Hobson, 1998), people with ASD can have an intact ‘self knowledge’ (i.e. semantic personal knowledge about the facts of their lives) without recall of events upon which this knowledge is based. Klein (2001) proposes deficits in self awareness lead to deficits in episodic memory, which is dependent on a sense of the self continuing through time and an awareness of having had past experiences that can be re-visited. Klein also suggests that this self-continuity involves self-reflection of thought and actions and a sense of personal agency in events and of personal ownership. Klein cites evidence indicating that people with ASD have impairments in each of these components (Tager-Flusberg, 1992), which would therefore imply impaired episodic memory. In conclusion, there is some evidence that individuals with ASD have specific impairments in their sense of ‘experiencing’ events as happening to themselves (Hobson, 1990), in self-continuity through time (Klein, 2001) and possibly in self-monitoring ability, which appear to be associated with impaired recall of episodic memories. A further study of free versus cued recall by children with ASD was carried out by Millward, Powell, Messer, and Jordon (2000), with children, with and without ASD matched for verbal ability. Following engagement in various activities in the course of a walk, some of which were engaged in solely by the child, some by the researcher and some jointly, participants’ recall of events was elicited through open questions and then prompted through cueing. Three separate recall scores were elicited: personal condition self-experienced (‘Unaccompanied Self’), companion condition self-experienced events (‘Accompanied Self’) and companion condition other-experienced events (‘Accompanied Other’). Participants with ASD performed significantly worse on the ‘Unaccompanied Self’ recall task than on ‘Accompanied Other’ on overall recall, i.e. other-experienced events when with another were recalled than self-experienced events when alone. There was no significant difference between recall on ‘Accompanied Self’ and ‘Accompanied Other’ or ‘Accompanied Self’ and ‘Unaccompanied Self’. No significant differences were found between free and cued recall for any of the recall conditions cued recall between any of the recall conditions (Table 1).