An imaginary fruit that makes its eaters forget their way home

The Lotophagi (lotus eaters in Greek) were encountered by Odysseus and his sailors on an island in the troubled sea, shortly before facing the Cyclope (Homer, Odyssey IX 83-104). Whoever tasted the honey-sweet fruit of the flowering lotus, forgot the way home and desired to stay in lotus land. The fabulous lotus, never identified, is hence the ancient counterpart of modern amnestic drugs. Actually, lotus was not the only potion renown in ancient times for its alleged amnestic powers. Drinking...

A set of historical narratives beliefs and customs shared by a social group over generations

When the 'star of England', Henry V, set out to boost the spirit of his few troops before the battle of Agincourt, he recruited future history (Shakespeare 1600) Harry the king, Bedford and Exeter, Warwick and Talbot, Salisbury and Gloucester, Be in their flowing cups freshly remember'd This story shall the good man teach his son And Crispin Crispian shall ne'er go by, From this day to the ending of the world, But we in it shall be remembered We few, we happy few, we band of brothers And as the...

The process by which cells manufacture protein molecules from amino acids on the basis of the genetic information that

The genetic code is decoded in all living cells in two major phases. First it is transcribed from the DNA into a specific messenger RNA (mRNA) molecule. This process is termed 'transcription'. The code is then read from the mRNA molecule to produce the copy of the corresponding protein. This process, which takes place in a complex cellular factory called ribosome, is termed 'translation'. In practice, a group of ribosomes ('polyri-bosome') performs the task on each mRNA. There are many complex...

The brain state required to attempt or attain 1 and 2 above

Until fairly recently, retrieval was an uncharted terrain in the neurobiology of memory. This was particularly striking when compared with the rich contribution of experimental psychology and modelling to the phenomenology and theory of retrieval (Semon 1904 Shiffrin and Artkinson 1969 Anderson 1983 Tulving 1983). This situation was also in sharp contrast to the signal role of retrieval in behavioural assays of memory, for, at the end of the test, even if the intention is to study acquisition,...

The plasticity of neural plasticity

Metaplasticity is the modulation by experience of neuronal plasticity. It is a family of adaptive processes that have probably evolved to form a dynamic balance among the need for change (*plasticity), the need to resist too much change (*homeostasis, *memory, *persistence), and the metabolic price of both, at various periods in the life of the organism (*development). Metaplasticity is commonly referred to as the plasticity of *synaptic plasticity (Abraham and Bear 1996 Abraham and Tate,...

A type of learning in which a stimulus or action become associated with fear

'Show me a man who is not a slave one is a slave to lust, another to greed, another to ambition, and all men are slaves to fear' (Seneca 63-65). Fear drives fundamental responses to the world in individuals and societies alike (Durkheim 1895 Freud 1908). James (1890), influenced by Darwin (1872), considered fear merely as an instinct. He even thought that the need to exercise this instinct had diminished in evolution, and in a somewhat naive burst of trust in the virtues of human kind, remarked...

Classical conditioning

Types of associative learning in which the subject learns that one stimulus predicts another. 2. Types of training procedures in which two stimuli, the conditioned stimulus (CS) and the unconditioned stimulus (US), are paired with each other, so that the CS comes to evoke a conditioned response (CR), which is similar to the unconditioned response (UR) elicited by the US. Pavlov and his dogs are probably the first association that comes to mind in most people when prompted to contemplate...

Limbic system

A disputed concept, referring to an interconnected collection of cortical and subcortical structures in the medial parts of the mammalian brain that are implicated in autonomic, emotional, and cognitive functions. Limbus is rim or border in Latin. Already in 1664, Willis described the brain area that surrounds the brainstem as 'the limbus' (cited in Witter et al. 1989). He was followed by Broca, who termed more or less the same part of the brain as the 'great limbic lobe' (Broca 1878 see also...

The surroundings and circumstances in which an event takes place

Events always occur in some context (from Latin contextus, 'joined together', 'woven together'). The dissociation between a memorized 'target' event and its context is not trivial. This is beautifully illustrated by Locke (1690) ' a young gentleman, who, having learnt to dance, and that to great perfection, there happened to stand an old trunk in the room where he learnt. The idea of this remarkable piece of household stuff had so mixed itself with the turns and steps of all his dances, that...

Priming

The nonconscious modulation of the processing, retrieval or production of a mental item by prior exposure to specific information on that item or on items associated with it. 2. The presentation of a stimulus or the induction of a change that prepares the system for functioning. 'Priming' in the current memory literature almost always refers to a specific protocol or type of memory (definition 1) rather than to the more general concept (definition 2). This contemporary use was introduced by...

A procedure or technique for the analysis of a phenomenon process or mechanism a test

Assays (from exagiere, Latin for 'to weigh out') are not merely research tools. They play a decisive part in the development and workings of scientific disciplines. They are also important in shaping the feasibility, progression, and outcome of particular research programmes. Sometimes they even play a decisive part in moulding the fate of individual academic careers. Scientific assays are the nuts and bolts of scientific methods and paradigms. In experimental science, they are the end...

The memory phases during which this stabilization takes place

It took the Muses, daughters of Memory, a single encounter with Hesiod on Mount Helicon to breathe into the poet divine voice and knowledge (Hesiod 8thC bc). Yet for most of us, who are not granted the privilege to mingle with the immortals, learning is often a much more lengthy, complicated, and frustrating process. Even if we do devote to training sufficient effort, memory may still betray us (false memory, forgetting). And as if the burden of confusion and forgetfulness stemming from the...

Learning set

A learned tendency to follow a particular cognitive strategy in response to a particular type of *stimulus. 3. Progressive improvement in the rate of learning of successive object discrimination problems of a given type, culminating in single-trial learning of novel problems of that type. The roots of 'learning set' can be traced back to the beginning of the twentieth century, to a group of psychologists at Wurzburg University, Germany, known collectively as 'The Wurzburg School'. They...

Recognition testA test situation in which the subject judges the familiarity or recency of a stimulus

Similarly to recall, recognition (re-cognoscere, Latin for to get to know again) refers to a type of memory (definition 1, Mandler 1980), a brain process (definition 2), and a memory test (definition 3). To judge that something has occurred previously may mean different things, ranging from the detection of familiarity or recency to the identification of the specific attributes of the target in its proper context. Imagine entering a classroom and detecting a new student in the front row. Her...

The gradual diminution of the response to a stimulus following the repeated presentation of the same or a similar

Habituation is commonly classified as a type of nonassociative learning (taxonomy). This is because it is assumed to be governed solely by the parameters of the habituated, unconditioned stimulus, in the absence of associations with other stimuli. This assumption may be wrong. It is questionable whether any type of learning is indeed purely nonassociative. In habituation, associations are formed with the context (Wagner 1979 Marlin and Miller 1981 Rankin 2000), and possibly also with...

Abrupt improvement in the performance on a task

Some types of learning, such as the acquisition of skill, progress gradually, through numerous repetitions. This is termed 'incremental learning', or 'rote learning' (Hebb 1949). In contrast, other types of learning, both in real-life and in laboratory setting, occur abruptly, following a step function. Two examples are flashbulb memory and conditioned taste aversion. There is, however, a type of abrupt learning that differs from these examples. It cannot be described as fast acquisition of...

The phenomenon in which information learned in one state of the organism is retrieved best if a similar state is

The 'state' in state-dependent learning is taken to imply the internal, physiological, and mental milieu, but its reinstatement often requires elements of the original external milieu (context). The phenomenon is also termed 'dissociated learning'. The more general term 'state-dependent learning' is, however, to be preferred, as 'dissociation' connotes clinical meanings that are not intended.1 The terms 'state-dependent retrieval', 'state-dependent recall', and 'state-dependent memory' are also...

The memory system that subserves the above

The term 'declarative memory', depending on the context of the discussion, refers to a faculty and experience of memory (definition 1), the material stored and retrieved (definition 2), and the relevant brain system(s) (definition 3). That part of our memory is directly accessible to conscious recollection but part is not, was first explicitly stated by philosophers (e.g. de Biran 1804 Bergson 1908).1 Ryle (1949) formulated it as the distinction between 'knowing that' and 'knowing how'....

A biogenic amine that functions as a Neurotransmitter and a hormone

Noradrenaline (NA, alias norepinephrine, 2-amino-1-(3,4-dihydroxyphenyl)ethanol) belongs to a family of compounds called catecholamines (see also *dopamine). It is synthesized from dopamine in the brain, sympathetic nerve, adrenal medulla, and heart by the enzyme dopamine-P-hydroxylase (DBH Cooper et al. 1996). Noradrenaline fulfils multiple roles in *development, physiology, and behaviour (Mason 1984 Thomas et al. 1995 Thomas and Palmiter 1997a). A related catecholamine, adrenaline (AD, alias...

B How do items in memory persist in the brain over time in the absence of continual actualization

If we only abandon highly simplistic metaphors of memory storage, such as 'cabinet files' or 'computer disks', 'persistence' (per- + sistere, Latin for 'to stand') becomes a prominent enigma of memory research. As memory is the retention of acquired information over time, persistence is clearly its central attribute. Generally speaking, there is a family of'persistence problems'. The classic philosophical problem (definition 2 above) is also known in metaphysics as 'The Ship of Theseus' the...

The maxim that entities are not to be multiplied beyond necessity

The Franciscan theologian William of Ockham (also spelled Occam 1285-1347), later of Oxford, was a most influential medieval scholastic (Adams McCord 1987 Colish 1997). In his analysis of the Universe and human ability to perceive it, Ockham proposed that phenomena should be better explained in terms of the simplest causes rather than the more complex ones. Admittedly, he was not the first to suggest such a principle of parsimony. Even more so, his principle was rather qualified 'No plurality...

The attribution of human attributes to mythical creatures inanimate objects or nonhuman organisms

The term is derived from Greek anthropos human being, morphe form. Anthropomorphism owes much to anthropocentricity, i.e. our a priori inclination to regard ourselves as the centre of the universe and see the world through our biased eyes. By doing so we probably hope to gain some illusory control over reality. Anthropomorphism is intensively and recurrently exemplified in ancient myths, literature, and art (e.g. Burkert 1985). Occasionally, it had also infiltrated other social activities...

The outer layer of the cerebral hemispheres of the brain

The cerebral cortex (Latin for bark, rind, shell) is a mul-tilayered, convoluted sheet of tissue overlaying the cerebral hemispheres. In humans it is 3-4 mm thick, covering -2600 cm2. It contains at least 1010 neurons and about the same number of glia cells. From a phylogenetic perspective, three types of cortices are discerned archicortex (hippocampal formation), paleocortex (olfactory, enthorhinal, and periamyg-daloid cortex), and neocortex. The neocortex forms the bulk of the mammalian...

Synapse

A specialized junction between neurons, or between neurons and other types of excitable cells, capable of transmitting, processing, and retaining neural information. The term 'synapse' (Greek for syn-haptein, 'to make contact') is commonly attributed to Sherrington (Foster and Sherrington 1897). It was actually proposed by Verrall, an expert on classical drama, to replace syndesm (Greek for 'chained together'), which was Sherrington's first choice (Shepherd and Erulkar 1997). 'Synapse' was...

The alert state required for the above

So prominent is the position of attention in the scientific discourse on behaviour, that Titchner (1908) regarded it as 'the nerve of the whole psychological system', and added that 'as men judge of it, so shall they be judged before the general tribunal of psychology'. James (1890) was convinced that 'everybody knows what attention is' and described it as ' the taking possession by the mind in clear and vivid form of one of what seem several simultaneous objects or trains of thought'. James...

A figure of speech in which one entity is described in terms of another

Metaphora is 'a transfer' in Greek, the transference consisting 'in giving the thing a name that belongs to something else' (Aristotle, Poetics 1457b7-8). In a more formal notation, metaphors can be described as statements in figurative language, composed of two juxtaposed elements, the 'tenor' and the 'vehicle', which are presented as sharing common attributes or 'ground' (Richards 1936). The tenor is the subject of the metaphor, while the vehicle is the means by which the subject is referred...

The upper limit of this ability

Pondering the capacity of our memory carries with it the risk of being enslaved to the common metaphor of memory as a static storehouse (Roediger 1980). This misconception should be avoided at the outset. Furthermore, in the case of the nervous system, even the definition itself evokes cardinal issues What is the meaning of'store' (definition 1) Are internal representations stored as such, reactivated, or reconstructed anew each time they are retrieved 1 If memory is reconstructed, then the...

A biogenic amine that functions as a Neurotransmitter in the brain and as a regulator of physiological activity in

Dopamine (3,4-dihydroxyphenylethylamine) is the predominant catecholamine neurotransmitter in the mammalian brain. Catecholamines are so called because they are amines (compounds derived by replacing the hydrogen atoms in ammonia with organic groups) that contain the aromatic alcohol catechol. Other catecholamine neurotransmitters and hormones are adrenaline (epinephrine) and noradrenaline (norepinephrine). The catecholamines in the body are synthesized from the amino acid tyrosine. In fact,...

The amnestic syndrome A marked chronic impairment in memory in the absence of other major cognitive deficits

Amnesia is 'forgetfulness' in Greek (mnemonics). The adverse effect of certain types of brain injury and mental trauma on memory was recognized long ago. But the systematic analysis of amnesia started only in the nineteenth century, with Ribot (1882) and Korsakoff (1887). Till the introduction of functional neuroimaging, the study of amnesia has been the only practical approach to the investigation of brain substrates of memory in humans. Some information could be also obtained from electrical...

Working memory

A memory system that holds information in temporary storage during the *planning and execution of a task. 2. The process in which newly perceived information is combined with retrieved information during the planning and execution of a task, to form and maintain short-lived internal representations that guide the behavioural response. 'Working memory' is one of the most important and exciting concepts in modern neuroscience, and rightly so. It refers to a cognitive faculty that is essential for...

The occurrence of a learned response in circumstances that differ from those prevailing during acquisition

Pigeons Key Generalization

The functional counterpart of 'generalization' is 'discrimination', which is the ability to distinguish one stimulus or response from another. This is why it is convenient to treat these faculties together. Discrimination increases the repertoire of fine-tuned perception and response, but places a burden on capacity generalization diminishes the sensitivity to input noise, but limits the degrees of freedom of the behavioural repertoire and could increase the proportion of false-positive...

Human the only extant species of the primate family Hominidae

Humans are a very popular species in memory research. Over the years, far more memory experiments have been published on humans than on monkeys, or on all invertebrate species combined. Only rodents still keep an edge in popularity in labs that specialize in the neurobiology of memory, but this could change, with the widespread availability of functional neuroimaging. And yet, human beings almost always identify themselves with the side of the experimenter, even in situations in which they...

The common fruit fly which is extensively used in the study of genetics developmental biology and neurobiology

There are over 3000 different species of Drosophilidae (Greek for 'dew lovers'), but none is as popular as Drosophila melanogaster, which became the pet organism of geneticists already a century ago (melanogaster is 'black belly' in Greek, referring to the colour of the male's bottom). The term 'fruit fl is a misnomer, because Drosophila are actually after the yeast that flourishes on rotten fruit rather than after the fruit itself. D. melanogaster was one of the first organisms to be adapted...

The phenomena that refer to the report of such items by the subject

'Footfalls echo in the memory Down the passage which we did not take Towards the door we never opened' (Eliot 1963) more often than we tend to concede, memory leads us to passages we never took in reality. Fantasy and facts mix well in poetry, but the charm could become nightmare if they do so in reality. Why does it happen, when and how, are major questions in memory research. These questions have been approached in experimental psychology long ago (Bartlett 1932 Carmichael et al. 1932),...

A device that responds only on receiving a complete set of two or more signals

Many brain faculties depend on the ability to detect and encode associations and correlations among events. Coincidence detectors are essential for this ability. The most straightforward type of coincidence detector senses the occurrence of two events at the same time (definition 1). However, what is meant by 'at the same time' depends on the scientific discipline and on the level of analysis. Simultaneity in particle physics has a different meaning than in physiology and psychology. Hence,...

Falsification of memory in the absence of deceitfulness occurring in clear consciousness in association with amnesia

In Latin confabulari is 'to chat', fabula 'a tale', and fabulae 'nonsense'. The confabulator indeed tells a story, but this story is not complete nonsense. In many cases it is more or less coherent and internally consistent, yet false in the context named (Talland 1965 Moscovitch 1989). Typically, the account concerns the person who tells it, who is unaware of its memory deficit. Confabulation in its broader meaning (definition 1) refers to a wide spectrum of phenomena. Some of these phenomena...

The systematic grouping of entities into categories according to some method of arrangement or distribution

The tendency to categorize the world into 'similar' and 'different' is fundamental to human cognition. It underlies folk knowledge systems in orally-reliant societies as well as sophisticated taxonomies in science (Durkheim 1912 Levi-Strauss 1962 Smith and Medin 1981 Sokal 1985 Berlin 1992). It is shared to some degree even by species far remote from us on the phylo-genetic scale (Giurfa et al. 1996). The term 'taxonomy' itself is, however, a newcomer to language taxinomie,or taxonomie, was...

An amino acid that functions as the primary excitatory neurotransmitter in the vertebrate central nervous system

L-glutamate is present in the mammalian brain at remarkably high concentrations. For a while this observation, coupled with the ability of glutamate to excite neurons all over the brain, cast doubt on its role in neurotransmission for how can such a 'non-specific' agent mediate specific information The case for glutamate as a neurotransmitter in the invertebrate neuromuscular junction was easier to establish (Usherwood 1994 criterion). But with time it became clear that not only is glutamate a...

The formulation of a theory in terms of a more inclusive or basic theory

'Reductionism' is a tenet of modern neuroscience. Only its version and explicitness vary among subdisciplines and their practitioners. Neuroscientists attempt to explain mental faculties by brain faculties, hence mental phenomena by biology. In that they are different, for example, from orthodox behaviourists. Clearly, biology at large has accomplished some of its most impressive triumphs so far by adhering to the radical reductionist approach, epitomized in state-of-the-art molecular and...

Unanticipated contradiction between percepts or thoughts and the predictions of organized knowledge

The trouble with political jokes is that they often get elected. For most if not all the readers, encountering this statement here is a real surprise. This is precisely why it stands a good chance to be remembered. Surprise ('sur'- + 'prendre', Old French, prehendere, 'to seize' in Latin) is a perceptual dimension well known to affect the acquisition of memory in real-life it may lead, for example, to an enduring 'flashbulb memory'. Descartes regarded 'wonder', or 'sudden surprise', as one of...

Cognitive map Mental model of physical or imaginary space

Classical Space

Mappa is a cloth or napkin in Latin yet the first maps were probably drawn not on cloth but rather on clay, by the Babylonians. In the neurosciences, the term is occasionally used in its everyday connotation (definition 2), to denote functional architecture and spatiotemporal activity patterns in discrete brain areas (e.g. in functional neuroimaging), without necessarily making assumptions about the code and the fine properties of the map. This usage needs no further elaboration. But 'map' is...

Birdsong

Complex, stereotyped vocalizations, accompanied by characteristic body postures, produced predominantly by mature male birds during the breeding season. Male birds sing to selected audiences. The male is a landlord and potential warrior, notifying other males that it is ready to defend its territory. It is also a charming troubadour attempting to convince females that it is the best in town. The song occupies such a cardinal role in the male's life that it may even dream about it (Dave and...

A portion of the universe selected for study

'System' (from sunistanai, 'to combine' in Greek) is abundant in colloquial 'scientinglish'. 'Let me tell you about my system' or 'did you try it in your system' are only selected examples of ritualistic utterances of scientific culture. An experimental system well-matched to the research goal is a key to successful research programmes. Prolific systems facilitate the road to academic tenure and fame, and trendy systems increase the probability of acceptance of manuscripts into respectable...

Experimental extinction

A decline in the frequency or intensity of a conditioned behaviour following the withdrawal of *reinforcement. 2. The experimental protocol used to obtain the aforementioned phenomenon. 3. A modification in the *internal representation of a conditioned association that leads to suppression of the conditioned response, due to behaviourally meaningful rearrangements in the relationship among previously associated *stimuli or stimuli and *reinforcers. Pavlov noted that once one of his famous dogs...

Selfappreciation monitoring and control of ones own memory

Although some authors consider the study of metamemory a newcomer to the field of memory research, its roots are rather ancient. Already St Augustine (400) referred to 'Memory of memories I have remembered that I have remembered'. Interest in the self-appreciation of one's own knowledge and performance was shared by introspectionists during the early days of experimental psychology, especially the so-called 'Wurzburg school' of 'systematic experimental introspection' (Boring 1950a).1 However,...

Something that diverts attention from the real issue or purpose

A bundle of smelly smoked (red) herrings drawn across a fox's trail confuses the hounds (Cowie et al. 1985). Discovering that a metaphorical red herring had been hiding in one's path is a scientist's nightmare, although not discovering it if it is there is even worse. It possibly tends to materialize more frequently on the fringe of hectic, fast-advancing disciplines that attract risk-takers (scoopophobia). The diversionary data or concepts could pose a real treat to academic careers. Indeed...

Any of various members of the order Primates excluding the anthropoid apes and humans

'This is what I see in my dreams about final exams Two monkeys, chained to the floor, sit on the windowsill The sky behind them flutters, The sea is taking its bath. The exam is History of Mankind. I stammer and hedge. One monkey stares and listens with mocking disdain, the other seems to be dreaming away But when it's clear I don't know what to say He prompts me with a gentle Clinking of his chain' (Szymborska 1995). It is the appreciation that monkeys are our closest phylogenetic relatives...

A learned association of taste with visceral distress

Farmers know, probably from the dawn of farming, that animals tend to avoid poisonous bait if they survive their first encounter with it. The farmers themselves may have probably noticed that foodstuff comes to evoke disgust if consuming it results in nausea and intestinal distress. However, common knowledge does not always penetrate academic barriers it has taken John Garcia and his colleagues several distressful years to convince the referees of respectable scientific journals that...

A neuronally encoded structured version of the world which could potentially guide behaviour

'Representation' and 'internal representation' are used in multiple senses in philosophy, linguistics, and the cognitive sciences. The meaning of'internal representation' as used here deserves, therefore, careful clarification, especially as it is ardently reductionistic. Generally speaking, 'representation' is the expression of things in one language transformed into another. 'Language' is any set of symbols with rules for putting them together (Marr 1982). We are not engaged here, however, in...

The fear of being scooped

Scoopophobia (sometimes manifested as priorityma-nia) is a common occupational hazard in contemporary science. The term stems from 'scoop', which literally means to gather or collect swiftly, and metaphorically, to top or outmanoeuvre a competitor in acquiring and publishing an important news story (it all originated in schope, Old Dutch for 'bucket'). Scoopophobia is a very focused phobia the victim does not fear scoops in general, only those of the competitors. The first signs could become...

The use of mental techniques for assisting improving and expanding memory

Mr Memory, Hitchcock's master of facts, earned his living by performing feats of trivia pursuit in night clubs, while in parallel trusting to memory information for the sake of the notorious spy organization '39 Steps' (Hitchcock 1935). Most mnemonists, both in fiction and in real life, are engaged in much more innocent activities. In modern times mnemonists are either regarded as curiosities or at most as interesting subjects for research. But only a few centuries ago, mnemonists were still...

The visualization of the functional organization of the brain by electromagnetic or optical methods

The search for the engram is a mapping expedition. It requires maps that chart both anatomy and function. Anatomy per se only rarely tells us what specific brain structures do. This is evident, by the way, from some neuroanatomical terms that mean only a fruit or a sea monster (e.g. amygdala, hippocampus). Surely if early anatomists would have known something about what these structures do, they would have called them by other names. Indeed, some idea on function could occasionally be obtained...

Amygdala

A heterogeneous collection of nuclei and cortical areas in the temporal lobe, considered to subserve emotional and social behaviour, learning, and memory. The amygdala (alias the amygdaloid or amygdalar complex), first described and named by the German anatomist Burdach in the early nineteenth century (Meyer 1971), is so called because in the primate brain its shape resembles an almond (amugdale in Greek). About a dozen different nuclei and specialized cortical areas are currently discerned in...

Observational learning

1.The *acquisition of novel behaviour by observing its *performance by a model. 2. The generation or modification of lasting *internal representations of actions, or actions and their consequences, by observing the behaviour of a model. 'Whatever you see me do, do like-wise', said Gid'on to his selected three hundred men, blew the shofar, waved the torch, and surprised the Midyanites in their camp (Judges 7 17-22). He was a master demonstrator in an observational learning class. A lot of what...

The deterioration of correspondence between the memory retrieved and the memory acquired

Herman Ebbinghaus, the progenitor of quantitative experimental psychology (Gorfein and Hoffman 1987), remarked that 'all sorts of ideas, if left to themselves, are gradually forgotten' (Ebbinghaus 1885). Whether this statement is acceptable by laypersons and scientists alike, depends on what is meant by 'forgotten'. If'forgot-ten' means 'erased from memory', then many, including professional psychologists, tend to believe that everything we learn is never erased (Loftus and Loftus 1980). In...

The physical record of a memory the memory trace

The notion that stimuli produce enduring physical changes in the brain, and that these changes are the basis for memory, has been with us since early times (e.g. see Plato's etched wax tablets of memory, Theaete-tus metaphor). About 100 years ago, a German scholar, Richard Semon, termed the material record engraved by a stimulus in living tissue as the 'engram' (Semon 1904). The etymological roots of the term are Greek, and it means 'something converted into writing'. Semon had in mind a rather...

Achievement on a specific task

In behaving animals, the process or the outcome of learning are measured by monitoring changes in performance. But learning and performance are not equivalent. Learned information may remain latent until the appropriate conditions emerge for its expression as a change in performance ('latent learning' Tolman 1932). Earlier in the twentieth century, orthodox behaviourists attempted to shy away from this common knowledge. They claimed that only overt behavioural acts (definition 3) are legitimate...

The type of knowledge that subserves this proficiency

The first systematic investigation of skill learning involved a skill that is now obsolete. This was the study of the acquisition of the American Morse code by employees of railway and telegraph companies (Bryan and Harter 1897, 1899). On the basis of these studies, Bryan and Harter proposed that the formation of skill is a multi*phase process, which involves the mastery of specific elementary habits that become associated in a hierarchy. The expert is then able to perform the hierarchy of...

Memory for the circumstances in which one first learned of a surprising consequential or emotionally arousing event

In their now classic paper, Brown and Kulik (1977) reported that 79 of 80 US citizens remembered vividly the circumstances in which they had first heard about the assassination of President John F. Kennedy, 14 years earlier. The fact that this type of recall involves mental illumination of a specific scene explains the flashbulb metaphor. Since then, recollections of additional salient events, such as the Challenger disaster (McCloskey et al. 1988 Neisser and Harsch 1992), have been used to...

Learning that depends on the parameters of more than a single stimulus

The notion of'association' is central to both the philosophical and the experimental study of the mind. In philosophy it can be traced back to Aristotle, who proposed that similarity, contrast, and contiguity of images subserve recollection (On memory Sorabji 1972). 'Associationism', the philosophical doctrine that the mind learns and construes the world bottom-up by associating elementary events, has emerged with British empiricism in the seventeenth century (Warren 1921). Hobbes (1651) talks...

Conscious awareness

The mental state in which one experiences, notices, and is directly apprised of one's own percepts, memories, emotions, beliefs, thoughts, and actions. Books on memory tend to shy away from the discussion of consciousness and related issues. This is surprising on the one hand yet understandable on the other. It is surprising because the relation of consciousness to memory is of great importance in memory research amnesia, declarative memory, episodic memory , and conscious awareness is a major...

Types of training protocols in which reinforcement is made contingent upon performance of the proper behaviour

In classical conditioning the subject learns relations among stimuli in instrumental conditioning also 'instrumental learning' it learns the impact of its actions on the world. The scientific interest in this type of learning can be traced to Bain 1859 , who, impressed by his experience in the Scottish Highlands, noted 'association of movement with the effects produced on outward things' in animals trying to leap over obstacles ' spontaneous impulses of locomotion lead them to make attempts any...

A small mammal of the genus Rattus family Muridea order Rodentia rodents

The contribution of the rat to the behavioural and brain sciences is second only to that of humans, the main difference being that the contribution of the latter is frequently more voluntary. It has all started with the invasion of Europe by the brown rat Rattus norvegi-cus . The brown rat arrived from Asia at the beginning of the eighteenth century, almost 400 years after its cousin, Rattus rattus the black or grey rat , spread the devastating Black Death throughout the Continent. The brown...

The memory of intentions and things to do

The term 'prospective memory' was introduced by Meacham Meacham and Singer 1977 . It contrasts with 'retrospective memory', which is the memory for past events and experiences. A scientific culture trivia will illustrate the distinction. I just got a request from a neuroscience journal to review a manuscript. I glanced through it and decided to read it again thoroughly over the weekend, conclude then whether to recommend acceptance or rejection, because it may not be sufficiently novel...

A task in which response is guided by an internal representation of a stimulus in the absence of that stimulus

Delayed Response Task Monkey

Delay tasks were introduced into experimental psychology by Hunter 1913 , who found that a variety of species can learn to respond to a light stimulus after a delay, which in his hands ranged from a few seconds in rats to about half an hour in children. The procedures were later refined by Yerkes and Yerkes 1928 in their investigation on mnemonic capabilities in the chimpanzee. Since then, a variety of delay tasks have been developed and proven highly useful in the measurement of short-term and...

A behavioural routine as in 1 acquired gradually via repetitive experience

Definition 1 refers to 'habit' irrespective of whether it is innate a priori , acquired, or induced by disease or drugs. Definition 2 restricts 'habit' to a type of learned behaviour it is a special case of definition 1, but is stated separately because this is what 'habit' commonly means in the contemporary learning literature. In the early learning literature, 'habit' was also occasionally used to denote a learned act in general, but this is now unacceptable. Habits comprise a substantial...

The philosophical stand that considers propositions about mental states identical to propositions about behavioural

The tenet of behaviourism is that behaviour rather than mind or brain is the subject matter of psychology, and that only publicly observed behaviour can be used as psychological datum. Although its roots can be traced to earlier materialistic philosophy and physiology, the formal emergence of behaviourism in psychology is associated with a manifesto entitled 'Psychology as the behaviorist views it' Watson 1913 Psychology as the behaviorist views it is a purely objective experimental branch of...

Acknowledgements

Permission granted by authors and publishers to adapt material for the preparation of figures is gratefully acknowledged the particular sources are accredited in the appropriate figure legends. Material copyrighted by the following publishers was used with permission in preparation of the following figures Fig. 1, Oxford University Press Fig. 2, Society for Neuroscience, Washington, DC Fig. 3, Oxford University Press Fig. 6, Wiley-Liss, a subsidiary of John Wiley amp Sons, Inc. Fig. 7,...

The seahare a marine snail

Heterosynaptic

Aplysia, a hind-gilled opistobranch marine snail Kandel 1979 , is one of the heroes of the cellular revolution in the neurosciences. Its external resemblance to the rabbit earned it the name sea-hare. Yet it is the insides of Aplysia that has turned it into such a highly successful system in the cellular analysis of simple memory. Quinn pers. comm. had defined an ideal subject for the neurobio-logical analysis of learning as a creature with 10 large neurons, 10 genes, a generation time of 1...

A phenomenon process or mechanism that does not exist in nature but is believed to exist due to erroneous

Artefact stems from the Latin 'something made with skill', but occasionally, in science, the major skill at stake is how to distinguish an artefact from a natural phenomenon. Artefacts have haunted the experimental sciences since the emergence of the latter, much before the term was introduced into English at the beginning of the nineteenth century. In biology, 'artefact' was first used to denote aberrations produced in histological specimens by the fixation methods used to prepare the tissue...