The Identity Function of Autobiographical Memory
One of the most curious aspects of cognitive psychology is its almost-complete disconnect with philosophy of mind, an academic discipline that has developed since Aristotle and, in modern times, since Descartes. This neglect is a two-way street; just as cognitive psychology ignores philosophy of mind, so philosophy of mind ignores cognitive psychology, even as they purport to deal with the same mental phenomena. Wilson and Ross (2003) is a good illustration of this problem. It discusses the complex issue of personal identity, a topic that has traditionally vexed philosophers, even more so than psychologists.
Wilson and Ross (2003) rely on a construct they designate as “autobiographical memory.” Autobiographical memory is one’s recollection of one’s past. Autobiographical memory is a form of episodic memory. Episodic memory is one’s memory of one’s personal experiences. It is one of two types of declarative memory, the other being semantic memory, which is memory of facts. Declarative memory is distinguished from non-declarative or implicit memory, which includes procedural memory (memory of skills and how to do things), and emotional memory. The Harvard psychologist Daniel Schacter (2001) refines these concepts further:
“Episodic memory supports remembering of personal experiences that occurred in a particular time and place; recollections of the surprise birthday party you attended last week, or of the Broadway play you saw on your first visit to New York as a child. Semantic memory allows the acquisition and retrieval of general knowledge and facts: knowing that John Adams and Thomas Jefferson were principal architects of the Declaration of Independence, or that Yankee Stadium is the House That Ruth Built (p. 27).”
Wilson and Ross (2003) attempt to situate autobiographical memory somewhere within the continuum of episodic memory. Their central thesis is that there exists what might be described as a negative feedback loop between one’s autobiographical memory and one’s concept of one’s own personal identity. Each affects the other reciprocally at various stages in one’s life. Thus, for example, the way one recalls event p at time x will be different than the way one recalls event p at time y. One’s recollection at time y will be affected by events intervening between time x and time y. This perspectival shift in autobiographical memory in turn affects one’s current concept of self. Memories that are pleasant enhance life satisfaction, while distressing ones reduce it.
Autobiographical memory is vulnerable to a number of biases. People seek consistency and are “motivated to seek evidence from the past that implies a constant self-identity through time” (Wilson & Ross, 2003, p. 138). People seek self-enhancement and are “motivated to view their current self favorably” (Wilson & Ross, 2003, p. 139). People are have a subjective experience of time and are “more inclined to criticise distant than close former selves” (Wilson & Ross, 2003, p. 139). This effect also motivates people “to feel farther from past failings than from achievements, even when calendar time does not differ” (Wilson & Ross, 2003, p. 141). People adopt a first person perspective and “perceive memories through their own eyes” (Wilson & Ross, 2003, p. 144). People who adopt a third person perspective, on the other hand, “view their memories from the vantage point of an observer,” as a result of which they “can see themselves in the recollection” (Wilson & Ross, 2003, p. 144). This effect tends to suppress unpleasant memories because third-person memories are “older and less vivid” than first-person ones (Wilson & Ross, 2003, p. 144). Wilson and Ross conclude by observing that, regardless of these biases, “Personal memory plays an important role in identity construction because it provides pertinent and plentiful information” (Wilson & Ross, 2003, p. 147).
There are three problems with Wilson and Ross’ (2003) approach. First, there is no place in the brain where any of the classic memory structures assumed or hypothesized by Wilson and Ross (2003) actually exist. One can search authoritative works such as In Search of Memory by Eric Kandel (2006) in vain for references to autobiographical memory, or any of its related constructs. Even the nature of fuzzy concepts such as “working memory” is elusive because of disagreements over what exactly it stores, what is its capacity and how it represents information to conscious awareness (Zhang & Luck, 2008). This suggests that distinctions of the sort that Wilson and Ross make may lack construct validity.
Second, Wilson and Ross (2003) assume one’s personal identity primarily results from the interaction between various memory stages over time. They fail to consider the significant body of research to the effect that one’s concept of self also is a social construct, not solely a cognitive one (Baumeister, 2005; Taylor, 1989). Furthermore, this developmental process has neuroanatomical implications. Research has shown that as one’s concept of self develops during critical periods of social development (such as adolescence), the neuroanatomy of the brain changes in parallel. Regions of the brain such as the medial prefrontal cortex and the superior temporal sulcus undergo significant structural modification and synaptic reorganization (Blakemore, 2008). Wilson and Ross acknowledge that memories may be subject to social reconstruction when they conflict with the recollection of others. For example, a transgressor may attribute misconduct to an “old me” and “claim that he or she has improved since the episode” (Wilson & Ross, 2003, p. 146). Transgressors even may try to keep their pasts secret because “they are not confident that others will agree with their view of a changed self” (Wilson & Ross, 2003, p. 146). Anomalous, counterfactual cases such as these, however, do not acknowledge the historical, linguistic, anthropological and cultural factors molding personal identity. They also do not account for the reciprocal, interactive role that social context and construction play in one’s development of a concept of self, or the resulting neuroanatomical implications.
Third, given the indeterminacy and vague boundary parameters of concepts like “autobiographical memory,” it seems inevitable the issue of personal identity will remain primarily a philosophical one, rather than an empirical one. Personal identity was one of the central focus problems for British empiricists since the 17th century, such as John Locke (1690/1959) and David Hume (1739/1968). In the 18th century, the Scottish philosopher Thomas Reid (1785/2002) famously devised the thought experiment of the Brave Officer, who was flogged when a boy at school. He became a soldier and captured the enemy’s flag in his first battle. He later became a general. When he captured his opponent’s standard, he remembered having been whipped. When he was a general, he remembered having captured the flag, but no longer remembered the flogging. All of the Brave Officer’s memories interact and determine his personal identity at any moment in time. For example, when the general remembered capturing the flag, he may have remembered then having remembered the flogging. His interpretation of the first event was attenuated by a lifetime of intervening experiences. Memory is not linear. It is interactive and constructed from multiple feedback loops of just this sort. In principle Reid’s theory is no different than that advanced by the authors, yet Reid wrote two centuries before the concepts of autobiographical memory and synaptic transmission of information ever existed. More recently, Derek Parfit (1971) has advanced a cogent and sophisticated theory of personal identity based on the pervasiveness of causal links between memories that endure after one’s physical demise. The authors are pervasively uninformed of any of this work.
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