Theories of spatial cognition are derived from many sources. Psychologists are concerned with determining the features of the mind which, in combination with external inputs, produce our spatialized experience. A review of philosophical and other approaches has convinced us that the brain must come equipped to impose a three-dimensional Euclidean framework on experience – our analysis suggests that object re-identification may require such a framework. We identify this absolute, nonegocentric, spatial framework with a specific neural system centered in the hippocampus.A (...) consideration of the kinds of behaviours in which such a spatial mapping system would be important is followed by an analysis of the anatomy and physiology of this system, with special emphasis on the place-coded neurons recorded in the hippocampus of freely moving rats. A tentative physiological model for the hippocampal cognitive map is proposed. A review of lesion studies, in tasks as diverse as discrimination learning, avoidance, and extinction, shows that the cognitive map notion can adequately explain much of the data.The model is extended to humans by the assumption that spatial maps are built in one hemisphere, semantic maps in the other. The latter provide a semantic deep structure within which discourse comprehension and production can be achieved. Evidence from the study of amnesic patients, briefly reviewed, is consistent with this extension. (shrink)
Since Freud, clinicians have understood that disturbing memories contribute to psychopathology and that new emotional experiences contribute to therapeutic change. Yet, controversy remains about what is truly essential to bring about psychotherapeutic change. Mounting evidence from empirical studies suggests that emotional arousal is a key ingredient in therapeutic change in many modalities. In addition, memory seems to play an important role but there is a lack of consensus on the role of understanding what happened in the past in bringing about (...) therapeutic change. The core idea of this paper is that therapeutic change in a variety of modalities, including behavioral therapy, cognitive-behavioral therapy, emotion-focused therapy, and psychodynamic psychotherapy, results from the updating of prior emotional memories through a process of reconsolidation that incorporates new emotional experiences. We present an integrated memory model with three interactive components – autobiographical memories, semantic structures, and emotional responses – supported by emerging evidence from cognitive neuroscience on implicit and explicit emotion, implicit and explicit memory, emotion-memory interactions, memory reconsolidation, and the relationship between autobiographical and semantic memory. We propose that the essential ingredients of therapeutic change include: reactivating old memories; engaging in new emotional experiences that are incorporated into these reactivated memories via the process of reconsolidation; and reinforcing the integrated memory structure by practicing a new way of behaving and experiencing the world in a variety of contexts. The implications of this new, neurobiologically grounded synthesis for research, clinical practice, and teaching are discussed. (shrink)
Although the biological bases of forgetting remain obscure, the consensus among cognitive psychologists emphasizes interference processes, rejecting decay in accounting for memory loss. In contrast to this view, recent advances in understanding the neurobiology of long-term memory maintenance lead us to propose that a brain-wide well-regulated decay process, occurring mostly during sleep, systematically removes selected memories. Down-regulation of this decay process can increase the life expectancy of a memory and may eventually prevent its loss. Memory interference usually occurs during certain (...) active processing phases, such as encoding and retrieval, and will be stronger in brain areas with minimal sensory integration and less pattern separation. In areas with efficient pattern separation, such as the hippocampus, interference-driven forgetting will be minimal, and, consequently, decay will cause most forgetting. (shrink)
We all seem to think that we do the acts we do because we consciously choose to do them. This commonsense view is thrown into dispute by Benjamin Libet's eyebrow-raising experiments, which seem to suggest that conscious will occurs not before but after the start of brain activity that produces physical action.
How well does memory work, how accurate is it, and can we tell when someone is reporting an accurate memory? Can we distinguish a true memory from a false one? Can memories be selectively enhanced, or erased? Are memories altered by emotion, by stress, by drugs? These questions and more are addressed by Memory and Law, which aims to present the current state of knowledge among cognitive and neural scientists about memory as applied to legal settings.
Aggleton & Brown rightly point out the shortcomings of the medial temporal lobe hypothesis as an approach to anterograde amnesia. Their broader perspective is a necessary corrective, and one hopes it will be taken very seriously. Although they correctly note the dangers of conflating recognition and recall, they themselves make a similar mistake in discussing familiarity; we suggest an alternative approach. We also discuss implications of their view for an analysis of retrograde amnesia. The notion that there are two routes (...) by which the hippocampus can reactivate neuronal ensembles in the neocortex could help us understand some currently puzzling facts about the dynamics of memory consolidation. (shrink)
In this response to commentaries on our target article, we highlight and clarify a variety of issues and respond to several comments, challenges, and misconceptions. Topics covered include the mechanisms of enduring change, the nature of memory, the conditions in which memories are updated, the role of emotional arousal in change, and current limitations in our understanding of the neural basis of change in psychotherapy. It is our hope that through research stimulated by this exchange the latter may be advanced.
We consider Walker's thorough review in the context of thinking about future research on the relation between sleep and memory. We first address methodological issues including type of memory and sleep-stage dependency. We suggest a broader investigation of potential signaling molecules that may be critical to sleep-related consolidation. A brief review of the importance of the stress hormone cortisol illustrates this point.