Memory and Imagination: Epistemological Perspectives from British Empiricists to Neuroscience

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URI: http://hdl.handle.net/10900/72415
http://nbn-resolving.de/urn:nbn:de:bsz:21-dspace-724157
http://dx.doi.org/10.15496/publikation-13826
Dokumentart: Dissertation
Date: 2016-10-12
Language: English
Faculty: 5 Philosophische Fakultät
5 Philosophische Fakultät
Department: Philosophie
Advisor: Wertheimer, Jürgen (Prof. Dr.)
Day of Oral Examination: 2014-05-09
DDC Classifikation: 100 - Philosophy
Keywords: Gedächtnis , Imagination
Other Keywords:
Memory
Imagination
License: Publishing license including print on demand
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Abstract:

The dissertation studies the epistemology of memory and whether we can distinguish memory from imagination. I argue that the neuroscience of memory undermines the traditional view that memory is a source of factual truth and challenges our ability to distinguish it from imagination. The paper is divided into three parts. The first part reviews and challenges criteria philosophers have provided to distinguish between memory and imagination. The second part deals with how current neuroscience describes the constructive process of memory formation and imagination. Then the last part demonstrates why the constructive nature of memory formation defies the distinction between memory and imagination. According to common perceptions, memory is a source of knowledge, a reliable reference to our past. We believe that memories are in general trustworthy, that a remembered event probably took place. The trust we place in memory has important ethical implications. We rely on the truth of our memories to form an authentic personal identity, to give testimony at courts, and to create trustworthy personal accounts of historical events. When memory exhibits forgetfulness, errors, or inaccuracy, it is perceived as dysfunction, deficiency, and failure. Imagination, on the other hand, is associated with the unreal and fantastic. We are not obligated to verify its realness or truthfulness and therefore there is no reason to doubt its epistemological status. Not only does imagination not refer to a real past, it need not necessarily refer to anything that really exists. Imagination can represent anything, at any time. However, the opposition between memory and imagination disregards the complexity of cognition. It is true that imagination contains states that do not represent anything in factual reality. Yet, imagination is not constrained to be fictional; it has various manifestations. For, example, imaginings can also be actual and compatible with factual reality as they can also coincide with representations of past occurrences. Alternatively, imagination can deceive us into believing that its representations are true memories rather than products of the imagination. Memories, on the other hand, can be inaccurate, or false, or they can stem from imagination. We often mistakenly designate memories as products of the imagination and vice versa. False memories, which are actually imaginative re-presentations characterized by belief, are the most convincing evidence of the close relationship between imagination and recollection. There are many instances in which remembering and imagining interact, creating vivid details and memories of events that never happened. We use imagination, for example, to fill gaps, to cope with our memories, to imagine what we should have done differently in order to plan how we should react in the future. However, the extent to which imagination is involved in memory exceeds our awareness; often counterfactual representations are integrated in memories themselves that we are sure correspond accurately to the past. Every time we are confronted with inconsistent information, external counter-evidence, or a reality that is incompatible with other memories, we add or modify information to complement the event, reconciling the gaps and providing a coherent story. Absences and gaps in memories are filled automatically and without our awareness, making our conscious experiences comprehensible and palatable. We are sure that we saw or experienced the additional details rather than imagined them. We create an outline of proceedings and then fit in false events and descriptions that corroborate with the general outline. Memory cannot provide us with all necessary details and, in many cases, we have only a fragmented picture of complex events. To provide a coherent story, we then add details to complement the event. These details can be taken from external sources or from our own imagination, and they can lead to a new interpretation of the remembered experience. However, imagination does not only involve in supplementing missing information, but also can produce entirely false autobiographical memories. Indeed, studies show that people can develop both a belief in and a memory of an event that definitely did not happen simply by imagining its occurrence and as a result inducing a false autobiographical memory. Thus, if memory and imagination interact, can represent the same experience, can coincide or overlap, how can we distinguish between the representations of memory from those of imagination? The past is not a presence; it is an absence. Certainly, there is a difference between the reality of the past and the unreality of the imaginary. But the fact remains that the past is no longer present and therefore no longer real. Hence an old problem surfaces: how is it possible to know what is no longer present? How is it possible to distinguish what is no longer present from what was never present? It is the great enigma of memory, the enigma of the past. An awareness of the complex associations of imagination and memory has led philosophers to try to provide criteria for distinguishing between them. However Attempts to distinguish between imagination and memory often disregard the complexity of these two mechanisms. They also do not take into account the complex and interrelated processes and functions of memory and imagination. As Gregory Currie and Ian Ravenscroft write (although in a different context) we can have several factive attitudes towards our mental content. Memory is not necessarily the only mental process to contain a factive attitude, for imaginings can contain a factive attitude just as memories can be false. Attempts to distinguish between remembering and imagining by referring to various criteria—their resemblance or lack of resemblance to actuality, commitment or lack of commitment to truth, intention, belief, circumstances, context, familiarity, vividness, link to the past, etc.—provide us with several necessary criteria for distinguishing memory from imagination which, however, are not sufficient to distinguish between them. Thus, even though these criteria are pertinent, they are not absolute, but a matter of degree. Not only are these criteria not sufficient to distinguish between memory and imagination but the neuroscience of memory challenges these philosophical criteria and, in fact, undermines all existing ways to distinguish between these two cognitive acts. Two central theories explain the constructive nature of memory, the Multiple Trace Theory (MTT) and the Reconsolidation Theory (RT). MTT assumes that no single location contains the entire representation of a specific memory. Instead, the features of a memory are spread out and distributed over many locations. Retrieval of a past experience involves a process of assembling scattered memory features from different neuronal locations. However, this assemblage is not a simple process in which all the pertinent features ‘obey’ at the time of retrieval and join to form an exact representation of past occurrence. It is rather a process in which features from the original memory are omitted or lost, and features from other, associated memories are attached to the retrieved memory. Thus, the retrieval of information does not just mean finding a stored object or pulling a past experience out from storage in a particular place, but an active reformation and reconstruction of it. The revision that neuroscientists have made to consolidation theory also emphasizes the elastic and constructive formation of memory. In the past, researchers claimed that memory consolidation (the process of memory stabilization) takes place only once. According to such accounts, a new memory is initially labile and becomes stabilized over time through the process of consolidation. This process converts an unstable short-term memory into a stable long-term memory. These researchers believed that after consolidation, memories were stable and resilient to disruption. However contemporary neuroscientists, who study neural processes and mechanisms of memory persistence (e.g. synaptic strength and plasticity), show that consolidation takes place not only after new learning (encoding), but also after every recall (memory retrieval). During retrieval, consolidated memories enter a transient state where they become labile once again, and require another phase of consolidation (known as “reconsolidation”) to persist. The current hypothesis infers that the labile phase of reconsolidation allows for new information to be associated with established and reactivated memories. Memory traces are modified and reconstructed to update and adjust them to new circumstances. Every time we recall, new perceptions, expectations, attitudes, perspectives are fused into the original memory trace, thereby constructing a new memory, a new meaning. Reconsolidation is a natural process where the memory trace of an event undergoes various modifications. These modifications cannot necessarily be considered errors or fabrication, but rather, are normal brain activity. In other words, memory distortion is characteristic of normal rather than pathological or abnormal remembering. Thus, multiple trace theory and reconsolidation theory bear out the idea that a memory is not a literal reproduction of the past, but instead a constant constructive process. The constructive nature of episodic memory is probably also the mechanism underlying imagination’s general constructive and generative ability. This insight has been supported by studies which examine patients with deficits in episodic memory and have found that deficits in recall abilities impair the ability such patients to imagine new experiences. Other studies have provided insights into the extensive overlap in the brain regions that support true and false memories showing that both false and true memories depend on the same neural processes and regions, and that brain activity is similar in both of them. Thus, memory distortions stem from many of the same neural processes as true memory. Due to repeated misinformation, false memories may be equally likely to ignite the sensory apparatus of the brain as true memories and, as a result, once false memories are implanted, it is often hard to rid them from memory. These findings have led neuroscientists to conclude that memory imperfections reflect the operation of a constructive and even creative process. Although memory errors may seem dysfunctional, they actually reflect normal memory functioning. This neurobiological characterization of memory provides a framework for rethinking memory. If it is true that stored memories are continually being revived and revised through normal brain activity, this finding changes traditional concepts of memory representation. It challenges the notion that memory is a source of factual truth and, as a result, transforms the way we understand memory and remembering. Furthermore, the current neuroscientific accounts of memory not only cast doubt on the authority of memory, but in fact undermine the very distinction between memory and imagination. Describing memory as a generative reconstructive process is not different from the way we define imagination. Moreover, neuroscientific findings show that memory and imagination share similar functions, and depend on each other—that imagination is involved in remembering the past and remembering the past involves and enables imagining. Their mutual involvement is present in almost every cognitive act. The intuitive distinction between memory as a true representation of the past and imagination as independent from the real does not reflect the real, complex functions of each cognitive process and the interaction of both on each other. Both imagination and memory are cognitive capacities, which alter, compound, dissociate, and reconstruct content. They are not separate cognitive acts responsible for disengaged processes, but, rather, are fused in various types of representation, reflection, simulation, and introspection. This, then, raises the question whether we can distinguish imagination and memory if, as neuroscience shows, we are unaware of the process of construction and adjustment and therefore our belief in the validity of memory is oft unwarranted. Thus, I claim that we must conceive of memory and imagination as a hybrid function that blends fact and fiction. The difference between these two cognitive capacities derives only from different levels of awareness. That is, while in imagination we are aware that we construct and modify reality, in memory we modify and construct without being aware of the process.

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