Online research in philosophy

The belief that memory is essential to the self is common. Extreme amnesia, e.g., Korsakoff Syndrome, is held to dissolve the afflicted person’s self. This belief is a misconception that rests on a confusion of epistemic with ontological relevance. Epistemically, memory is relevant to the self: a subject’s self-knowledge partly depends on memories of past experiences. However, it is not by virtue of these memories that the subject is a self: ontologically, memory is irrelevant to that status. The fact that an individuals conception of herself as existing through time is wanting does not prevent that individual from being a self at a given point in time. As the past is there whether or not it is remembered, so the self is there whether or not it remembers. If instead we define the self as awareness of being a subject of experience, the self may survive even the most extreme forms of amnesia. Being a self is an important social value, a prerequisite of numerous legal or moral rights. This in itself is questionable, like the social exclusion it may entail. Denying an amnesic person a self is therefore more than a logical mistake: it is a social exclusion that can also be questioned on ethical grounds.

This paper defends the claim that, in order to have a concept of time, subjects must have memories of particular events they once witnessed. Some patients with severe amnesia arguably still have a concept of time. Two possible explanations of their grasp of this concept are discussed. They take as their respective starting points abilities preserved in the patients in question: (1) the ability to retain factual information over time despite being unable to recall the past event or situation that information stems from, and (2) the ability to remember at least some past events or situations themselves (typically because retrograde amnesia is not complete). It is argued that a satisfactory explanation of what it is for subjects to have a concept of time must make reference to their having episodic memories such as those mentioned under (2). It is also shown how the question as to whether subjects have such memories, and thus whether they possess a concept of time, enters into our explanation of their actions.

A review of the patterns of brain activation observed in implicit and explicit memory tasks indicates that during conscious retrieval studied items are first retrieved nonconsciously and are retained in a buffer at the extrastriate cortex. It also indicates that the awareness of the retrieved item is made possible by the activation of a reentrant signaling loop between the extrastriate and left prefrontal cortices.

Memory researchers have discussed the relationship between consciousness and memory frequently in the last few decades. Beginning with research by Warrington and Weiskrantz (1968; 1970), memory has been shown to influence task performance even without awareness of retrieval. Data from amnesic patients show that a study episode influences task performance despite their lack of conscious memory for the study session. More recently, issues of intentionality, awareness, and the relationship between conscious and unconscious forms of memory have come to the forefront. Conscious memory has sometimes been defined by intention to retrieve and sometimes by awareness of retrieval. This distinction has been debated as measurement methodologies have developed. In addition, the functional relationship between conscious and automatic forms of memory has implications for measurement of memory processes and the development of models of memory task performance. Several measurement techniques for conscious and automatic memory are reviewed. The current state of these issues is also discussed.

Aggleton & Brown have built a convincing case that hippocampus-related circuits may be involved in thalamic amnesia. It remains to be established, however, that their model represents a distinct neurological system, that the distinction between recall and familiarity captures the roles of these pathways in episodic memory, or that there are no other systems that contribute to the signs of amnesia associated with thalamic disease.

Dienes & Perner's analysis provides a clear theoretical justification for using a demonstration of volitional control as a criterion for conscious awareness. However, in memory tasks, the converse does not hold: A phenomenological awareness of a memory episode can arise involuntarily, even when the task does not require retrieval of the episode. The varying amounts of volitional retrieval required by different memory tasks need to be recognized.