The identification of memory engrams remains a methodological obstacle in neuroscience if they are to play the explanatory role ascribed to them by engram theory. I tackle the problem of specificity, namely the extent to which engrams can be identified, tracked, and distinguished from other engram and non-engram vehicles. I propose that adopting causal specificity from the interventionist framework of causation allows us to describe how engrams are specific to the memories and behaviors they generate. Drawing on (...) recent work using information-theoretic measures to describe causal specificity, I illustrate how this approach can be used to model the reduction of uncertainty about retrieved memories following optogenetic interventions on engram cells. (shrink)

Engrams—physical memory traces resulting from specific experiences—are the central posits of modern memory science. In this paper, I examine engrams through the lens of the theory of mental files. Integrating evidence from a variety of research programs, I argue that engrams exhibit the core functional properties of mental files. I characterize them as discrete informational structures, formed upon individual experiences of events and causally involved in their subsequent recall. Engrams are plausibly structurally complex in a file-like way, consisting of a (...) stable hippocampal index, which may function as an atomic pointer-like component, and a distributed cortical representation of an event’s properties. As such, they afford transmission of content and referential stability during potential content change. Their deployment is constitutive of the capacity for singular reference in episodically remembering particular previously experienced events. This emerging picture of engrams should engender reasonable optimism about the prospects of causal-representational theories of memory. (shrink)

The idea that remembering involves an engram, becoming stable and permanent via consolidation, has guided the neuroscience of memory since its inception. The shift to thinking of memory as continuo...

This article focuses on two indices from Geschlecht III session XIII: (1) an apparently insignificant reference to Stiegler and (2) the recourse to the concept of the engram as a trope of other grammatological figures that are more frequent in Derrida's work. By interweaving these indexes together, the article suggests that Derrida's text can be read as a noteworthy stage in his ongoing dialogue with Bernard Stiegler surrounding the question posed by human evolution to any accounts of the history (...) of life. Along this path, the article inscribes Derrida's (en-)grammatological history of life within the line of thought that goes from Richard Semon's engram theory to Simona Ginsburg and Eva Jablonka's contemporary re-elaboration of this theory. In doing so, it argues that, although for Stiegler Derrida's grammatology aligns with biological reductionism, the latter may provide the theoretical framework for current evolutionary accounts of life as plasticity. (shrink)

The advent of novel technologies has bolstered the idea of extended memory, where memory processes extend beyond the human body or brain. However, investigations of extended memory, and extended cognition more generally, do not address how biological componentry might be externalized from the body and into artifacts. In the paper, I introduce and explore a case where human engrams are externalized into exograms, stored via organic data memory technologies, and reimplanted later. This case involves the same medium of memory storage (...) in internal and external systems, which I call a _biological memory extension_. Further, it creates a concern about a blur between where agent ends and artifact begins, highlighting a potentially inconsistent consideration of the boundary between the two. These concerns reflect the need for us to answer a fundamental question: for extended memory, must the artifact merely extend beyond our bodies, or must it extend beyond our biology? (shrink)

The discovery of the engram, the physical substrate of memory, is a central challenge for the sciences of memory. Following the application of optogenetics to the neurobiological study of memory, scientists and philosophers claim that the engram has been found. In this paper, I evaluate the implications of applying optogenetic tools to the localization of the engram. I argue that conceptions of engram localization need to be revised to be made consistent with optogenetic studies of the (...) engram. I distinguish between challenges to vehicle and content localization. First, I consider the silent engram hypothesis. According to this hypothesis, optogenetic studies indicate that synaptic efficacy, the traditional engram-bearing vehicle, is important merely for retrieval. I argue that this interpretation rests upon a misunderstanding of accessibility. Second, I argue that optogenetic-based strategies and findings conflict with preservationist and constructivist views on memory storage. There is an enduring trace, but stored content may change over time and experience, resulting in doubt about what constitutes a single engram. (shrink)

Optogenetics makes possible the control of neural activity with light. In this article, I explore how the development of this experimental tool has brought about methodological and theoretical advances in the neurobiological study of memory. I begin with Semon’s distinction between the engram and the ecphory, explaining how these concepts present a methodological challenge to investigating memory. Optogenetics provides a way to intervene into the engram without the ecphory that, in turn, opens up new means for testing theories (...) of memory error. I focus on a series of experiments where optogenetics is used to study false memory and forgetting. (shrink)

The standard way of construing representation in neuroscience thinks of neural activities as encoding information. The activity then contributes to the function of the system by communicating that information to its outputs. We argue that this way of thinking is in tension with a number of well-established facts about neural activities. In general, neural activities do not correspond to one particular environmental or experimental variable. They show mixed selectivity and mixed variance; they are multiplexed and context-sensitive. This suggests that no (...) specific message is encoded in their activity. We articulate this critique and argue that it should motivate alternative ways of thinking about representation. Our preferred alternative is to think in terms of the latent structure of brain systems. These include attractors, subspaces, and manifolds, and are the result of learned synaptic and neuromodulatory connections between neurons in a population. On our view, representations are due to the interaction of the latent structure of a brain system with its environment. We explain the differences between this view and the encoding view, and flesh out our proposal by describing research into prefrontal physiology and engrams. We conclude by arguing that the latent-structure-based view posits genuine representations. (shrink)

Whether neurons represent or play a mere causal role is a foundational issue in philosophy of neuroscience. Evidence that neurons perform a representational role is weakened by the possibility of explaining experimental results by appeal to brute causal processes alone. Despite this, neuroscientists ascribe representational content to patterns of neural activity to explain experimental results. An important problem with this practice is determining which content to ascribe to the neural representation. One view is that researchers are only warranted in ascribing (...) the content determined by particular experimental results. An alternative view is that researchers are warranted in appealing to the broader research domain to determine the content of a putative neural representation. In this paper, I argue that both are warranted; either alone is insufficient. Using optogenetics research on memory engrams as a case study, I show how researchers ascribe content to neural representations and justify their approach. Whether a particular content ascription is warranted depends on particular experimental results, the broader research domain that is appealed to, and how results from various animal models, probes, and experimental paradigms are generalized. (shrink)

The recent emergence of reprogramming technologies to convert brain cell types or epigenetically alter neurons and neural progenitors in vivo and in situ hold significant promises in brain repair and neuronal aging reversal. However, given the significant epigenetic and transcriptomic changes to components of the existing neuronal cells and network, we question if these reprogramming technology might inadvertently alter or erase memory engrams, conceivably resulting in changes in narrative identity or personality. We suggest that the nature of these alterations might (...) be less predictable compared to memory and personality changes known to be associated with diseases, drugs or brain stimulation therapies. While research in applying reprogramming technologies to neurological ailments and aging should continue, more targeted analyses should be put in place in animal experiments to gauge the severity and degree of memory alterations, and appropriate risk and benefit analyses should be conducted before these technologies move into human trials. (shrink)

Neuroscientists are searching for the engram within the conceptual framework established by John Locke's theory of mind. This framework was elaborated before the development of information theory, before the development of information processing machines and the science of computation, before the discovery that molecules carry hereditary information, before the discovery of the codon code and the molecular machinery for editing the messages written in this code and translating it into transcription factors that mark abstract features of organic structure such (...) as anterior and distal. The search for the engram needs to abandon Locke's conceptual framework and work within a framework informed by these developments. The engram is the medium by which information extracted from past experience is transmitted to the computations that inform future behavior. The information-conveying symbols in the engram are rapidly generated in the course of computations, which implies that they are molecules. (shrink)

This paper consists of two parts. In Part I, an attempt to get around certain well-known criticisms of the trace theory of memory is discussed. Part II consists of an account of the so-called "logical" notion of a memory trace. Trace theories are sometimes thought to be empirical hypotheses about the functioning of memory. That this is not the case, that trace theories are in fact philosophical theories, is shown, I believe, in the arguments which follow. If this is so, (...) one may well wonder about psychologists' insistence that any empirical theory of memory must involve the postulation of traces (or trace-like entities: engrams, schemata, etc.). (shrink)

In this reflection article, we present a new theoretical perspective, which we term integrative neurobiology and cultural context (INCC) theory. Traditionally, social scientists have viewed the human brain as a “black box” of behavior. At the same time, advancements in neuroscience tempt us to perceive behavior as a linear extension of brain processes. We advocate for an alternative research structure that explores the integrative dynamics of cultural context, neuroplasticity, learning, memory, neurotransmitters, and emotions as critical components to explicating the multidimensionality (...) of cross-cultural human behavior. Integrative neurobiology and cultural context (INCC) theory specifically challenges contemporary accounts that map organismal behavior in a linear fashion onto genetic makeup as well as molecular or physicochemical brain processes. This essay addresses a fundamental question: how can we link culture, individual experience, neurobiological processes, and inheritance systems? To achieve this goal, we have developed a new conceptual perspective, which we term cultural neurobiological inheritance systems (CNIS), the foundational concept of integrative neurobiology and cultural context (INCC) theory. The significance of this contribution is that it resolves a critical limitation in current cultural and evolutionary theory. Even though existing models, including gene–culture coevolution, dual inheritance, and niche construction theory, have profoundly illuminated the processes of behavioral transmission and environmental modification, none have specified the neurobiological mechanisms by which these effects become stabilized and transmitted across generations. CNIS is inherited vertically and horizontally, and the strength of transference and fidelity is dependent on the intensity of cultural learning and its simultaneous effects on neuroplasticity, neurotransmitters, and the development of emotional systems. We argue that memory and related neurobiological processes shaped by experience are anchored in discrete, physiological substrates of the human brain. In short, CNIS represents the physical trace of memory in the neural architecture, providing an interface between human experience and the functional neurobiological basis of cognition. Recent empirical research into engram and engram assemblage formation, studies of survivors of the Holocaust and their descendants, and theory of mind research provide direct support for proof of concept for integrative neurobiology and cultural context theory and CNIS. (shrink)

Based on theoretical considerations of Aurell (1979) and Block (1995), we argue that object recognition awareness is distinct from purely sensory awareness and that the former is mediated by neuronal activities in areas that are separate and distinct from cortical sensory areas. We propose that two of the principal functions of neuronal activities in sensory cortex, which are to provide sensory awareness and to effect the computations that are necessary for object recognition, are dissociated. We provide examples of how this (...) dissociation might be achieved and argue that the components of the neuronal activities which carry the computations do not directly enter the awareness of the subject. The results of these computations are sparse representations (i.e., vector or distributed codes) which are activated by the presentation of particular sensory objects and are essentially engrams for the recognition of objects. These final representations occur in the highest order areas of sensory cortex; in the visual analyzer, the areas include the anterior part of the inferior temporal cortex and the perirhinal cortex. We propose, based on lesion and connectional data, that the two areas in which activities provide recognition awareness are the temporopolar cortex and the medial orbitofrontal cortex. Activities in the temporopolar cortex provide the recognition awareness of objects learned in the remote past (consolidated object recognition), and those in the medial orbitofrontal cortex provide the recognition awareness of objects learned in the recent past. The activation of the sparse representation for a particular sensory object in turn activates neurons in one or both of these regions of cortex, and it is the activities of these neurons that provide the awareness of recognition of the object in question. The neural circuitry involved in the activation of these representations is discussed. (shrink)

The problem of biological memory led Russell to propose the existence of mnemic causation, a mechanism by which past experience influences current thought directly, that is, without the need for a material intermediary in the form of a neural "memory trace." Russell appears to have been inspired by German biologist Richard Semon's concept of mnemic homophony, which conveys memory to consciousness on the basis of similarity between current and past circumstances. Semon, however, in no way denied a role for stable (...) neural structures or "engrams" in the memory process. In contrast to Russell, contemporary biologist Rupert Sheldrake provides a viable theory of memory by remaining true to Semon's original idea and expanding it beyond personal memory to the collective memory of species, encompassing not only mental but developmental memory. (shrink)

The very idea of a retinal pattern-sensation that can be impressed on the neural tissue of the brain is a misconception, for the neural pattern never even existed in the retinal mosaic. There can be no anatomical engram in the brain if there was no anatomical image in the retina. The retina jerks about. It has a rapid tremor. It even has a gap in it (the blind spot). It is a scintillation, not an image. An engram impressed (...) on the brain would have to be divided into two changing parts in the two halves of the brain, which is impossible. The whole idea stems from the persistent myth that there has to be something in the brain that is visible, and from Johannes Mueller's assumption that the nerves telegraph messages to the brain. (shrink)

The advent of cinema brought with it a different kind of image montage, to which Warburg’s iconological project was strangely oblivious. Are we meant to believe, then, that the cinema does not produce icons? Is iconology destined to be only a science of classical culture, or can it also evolve to integrate into its own study new forms of kinematic art? We would like to ask the question of organogenesis of iconology here, that is to say, the invention of an (...) iconological science for temporal objects by means of appropriate instruments for this new medium. The instrument is both conceived as a means of acting upon the real, and as a means of activating noetic capacities. The aim of our study will be to first outline the iconographic and iconological consequences stemming from animation and flux that have governed images since the birth of cinema, precipitating a crisis in classical iconology. Secondly, through the analysis of the noetic function of animated GIFs in digital streams, we will introduce the notion of ‘temporal gesture’ – as a tertiarized retentional technology, which can be reused for imagining an iconology of temporal suspension and insistence. This will be presented in the third part of this work to reflect on an iconological device for temporal objects by the grammatization and the engramming of ‘temporal gesture’, as an art of delay and repetition. This thinking will be based on the video artwork produced in collaboration with Gregory Dassié titled Iconologie pour objet temporel. (shrink)

Consolidation of long-term memory is a highly and precisely regulated multistep process. The transcription regulator cAMP response element-binding protein (CREB) plays a key role in initiating memory consolidation. With time processing, first the cofactors are changed and, secondly, CREB gets dispensable. This ultimately changes the expressed gene program to genes required to maintain the memory. Regulation of memory consolidation also requires epigenetic mechanisms and control at the RNA level. At the neuronal circuit level, oscillation in the activity of CREB and (...) downstream factor define engram cells. Together the combination of all regulation mechanisms allows correct memory processing while keeping the process dynamic and flexible to adjust to different contexts. Also see the video abstract here https://youtu.be/BhSCSmorpEc. (shrink)

Long‐term modification of synaptic strength is thought to be the basic mechanism underlying the activity‐dependent refinement of neural circuits and the formation of memories engrammed on them. Studies ranging from cell culture preparations to humans subjects indicate that the decision of whether a synapse will undergo strengthening or weakening critically depends on the temporal order of presynaptic and postsynaptic activity. At many synapses, potentiation will be induced only when the presynaptic neuron fires an action potential within milliseconds before the postsynaptic (...) neuron fires, whereas weakening will occur when it is the postsynaptic neuron that fires first. Such processes might be important for the remodeling of neural circuits by activity during development and for network functions such as sequence learning and prediction. Ultimately, this synaptic property might also be fundamental for the cognitive process by which we structure our experience through cause and effect relations. BioEssays 24:212–222, 2002. © 2002 Wiley Periodicals, Inc.; DOI 10.1002/bies.10060. (shrink)

Jean-Pierre Changeux's Neuronal Man attempts to define mental activity, that is thought, with respect to the neurophysiology of the brain.*Since antiquity, the historical account of these problems has undergone the examination of classical notions: what is a mental image, a concept, a representation? Changeux, who accepts these traditional points of departure, as well as the notion of signification, aims to clarify the physical, neurophysiological counterparts of these notions, in order to arrive at less simplistic terms: image de memoire “memory image,” (...) later - objet mental “mental object,” and still later - objet de mémoire “memory object.” Behind these terms lies transition to neurophysiology, with the notion of engram, and finally with the notion of trace, a notion which is precise but very general, since the substantive reality of these traces, their anatomy and physiology in the brain has yet to be determined. (shrink)

After defining various aspects of memory, this paper has sought to outline the phenomenology of memory developed by Erwin Straus and his effort to refute the trace or engram theory of memory storage. We found Straus proposing some major insights : that human experience has its own structure of lived time, that this experience transcends the realm of physical events, and that the suchness of past experiences is preserved, and can be reactivated, in lived time. Straus's approach repudiates the (...) conventional reductionistic wisdom about memory. That wisdom has some powerful support, both ideological and experimental. However, other evidence taken from physiological, neurological, clinical and psychological observations lends weight to Straus's views. The final answer is not in, but it seems plausible that Straus was on the right track toward a framework for human memory. We concluded with a brief broadening out of the Straus framework into the whole realm of lived time or temporality. (shrink)

From _atavistic_ to _folie a deux_, from _engram_ to _Weltschmerz_ and _Seashore test_, this edition of _The Concise Dictionary of Psychology_ contains more than 1,300 references to words, phrases and eminent pioneers in psychology. Updated to take account of recent developments, each definition is clear, instructive and concise. A lean and efficient source of information, written in a straightforward and readable manner, this book will be an indispensable reference tool for students of psychology, for professionals and for people in the (...) health and caring professions. (shrink)

Introduction to sensory psychology, by C. Mueller.--Some reflections on brain and mind, by R. Brain.--In search of the engram, by K. Lashly.--Cerebral organization and behavior, by R. W. Sperry.--Relations between the central nervous system and the peripheral organs, by E. von Holst.--Effects of the Gestalt revolution, by J. E. Hochberg.--Seeing in depth, by R. L. Gregory.--The stimulus variables for visual depth perception, by J. J. Gibson.--The elaboration of the universe, by J. Piaget.--Visual perception approached by the method of stabilized (...) images, by R. M. Pritchard, W. Heron, and D. O. Hebb.--Philosophy as rigorous science, by E. Husserl.--The "sensation" as a unit of experience, by M. Merleau-Ponty.--The phenomenology of perception: perceptual implications, by A. Gurwitsch.--The expression of thinking, by E. W. Straus.--The concept of group and the theory of perception, by E. Cassirer.--Norm and pathology of I-world relations, by E. W. Straus.--The metaphysical in man, by M. Merleau-Ponty.--Cultural differences in the perception of geometric illusions, by M. H. Segall, D. T. Campbell, and M. J. Herskovits.--The interpretive cortex, by W. Penfield.--Recovery from early blindness: a case study, by R. L. Gregory and J. G. Wallace.--Visual disturbances after perceptual isolation, by W. Heron, B. K. Doane, and T. H. Scott. (shrink)

This chapter reviews the idea of the memory trace, capturing appeals to it over time and across different intellectual traditions. Though this idea has a long history and remains popular amongst philosophers and scientists, there is both debate over what these traces are and what explanatory need, if any, they serve. I address three approaches to the idea of the memory trace: as a metaphor, as an explanatory posit, and as an empirical target. I discuss how these approaches can complement (...) one another. I also address two outstanding questions investigations of these approaches reveal. These outstanding questions are (1) what we aim to explain with traces, and (2) when appeal to traces might be counterproductive. (shrink)

One of the most important debates in the philosophy of memory is the causalism versus post-causalism debate. On the one hand, causalists defend the thesis that remembering requires a causal link via memory traces to a past experience. On the other hand, post-causalists deny that such causal link is necessary for remembering. Recently, some philosophers have suggested that Simulationism, particularly its anti-causalist thesis, is inconsistent with empirical findings about memory traces. In this paper, I analyze these findings and argue that (...) although many of them favor Causalism and seem inconsistent with Simulationism, memory traces also provide data that are inconsistent with Causalism. For this reason, I defend that it is premature to dismiss any of these theories in light of the current evidence on memory traces. (shrink)

What role does the concept of representation play in the contexts of experimentation and explanation in cognitive neurobiology? In this article, a distinction is drawn between minimal and substantive roles for representation. It is argued by appeal to a case study that representation currently plays a role in cognitive neurobiology somewhere in between minimal and substantive and that this is problematic given the ultimate explanatory goals of cognitive neurobiological research. It is suggested that what is needed is for representation to (...) instead play a more substantive role. (shrink)

The notion of affective memory was first introduced by Théodule Ribot (1894), giving rise to a debate about its existence at the beginning of the 20th century. Although Vernon Lee did not directly take part in this discussion, she conceptualized this notion in a quite precise way, mainly in her book Music and Its Lovers (1932), clarifying the sometimes obscure formulations made by previous authors. In this short encyclopedic entry, I present Lee's characterization of affective memory.

In recent years there has been a wealth of studies investigating how memories are allocated in the hippocampus. Some of those studies showed that it is possible to manipulate the identity of neurons recruited to represent a given memory without affecting the memory's behavioral expression. Those findings raised questions about how the hippocampus represents memories, with some researchers arguing that hippocampal neurons do not represent fixed stimuli. Herein, an alternative hypothesis is argued. Neurons in high‐order brain regions can be tuned (...) to multiple dimensions, forming complex, abstract representations. It is argued that such complex receptive fields allow those neurons to show some flexibility in their responses while still representing relatively fixed sets of stimuli. Moreover, it is pointed out that changes induced by artificial manipulation of cell assemblies are not completely redundant—the observed behavioral redundancy does not imply cognitive redundancy, as different, but similar, memories may induce the same behavior. (shrink)

У статті розглядається специфіка віровчення та основних методів культової та позакультової діяльності прихильників однієї з найвідоміших нетрадиційних синкретичних релігій - саєнтології. Культова практика саєнтологів носить допоміжний характер, а головним для них є надання різноманітних платних послуг. Саєнтологи підтримують соціальні програми: антинаркотичні, антиалкогольні, захист прав людини та ін. Соціальні програми адептів Церкви саєнтології є переважно прикриттям для виконання їхніх місіонерських завдань.