A-Z of Memory

This book compiles and explains the key terms and core concepts related to memory in an easy-to-navigate A-Z format. The quest to understand how memory works and how it fails remains a cornerstone of both Psychology and Neuroscience; however, defining memory is not easy. At a higher level, memory is sometimes seen as a psychological function for the preservation of information, while other definitions focus on remembering. In this innovative book, John P. Aggleton delves into the many definitions and attributes that constitute memory and guides the reader through over 160 entries ranging from Aging to Repression; Dementia to Working Memory. Each entry explores the various psychological and biological elements of memory and includes recommended further reading and cross-referencing. This guide will serve as an overview and introductory resource for students and scholars involved in memory studies and memory research, as well as practitioners working with sufferers of memory disorders. It will also be of great interest to anyone interested in the utterly remarkable memory skills we all possess.

John Aggleton is a world-wide recognised researcher and author. He has published over 300 papers, principally on brain systems devoted to different forms of memory. His contribution to the field was recognised by the Royal Society in 2012 when he was elected as a Fellow. He has also served as President of the British Neuroscience Association and of the European Brain and Behaviour Society. He is currently Emeritus Professor of Cognitive Neuroscience at Cardiff University.

Introduction A) Absent-minded - being forgetful, often from a failure to pay attention to one's actions Adaptive memory - that our learning and memory skills are tuned to solving fitness-based problems, reflecting how our memory evolved Aging - the impact of time on an organism once maturity is reached Alcohol - a chemical (ethanol) with psychoactive effects that is globally used as a recreational drug Alzheimer's disease (AD) - the commonest form of dementia characterised by the presence of brain atrophy, amyloid plaques, and neurofibrillary tangles, along with pronounced cognitive decline Amnesia - the loss of memory despite the sparing of other cognitive abilities Amygdala - a limbic brain structure in the anterior part of the medial temporal lobes Anaesthetics - see Unconscious learning Anterograde amnesia - the failure to encode, consolidate, or retrieve new information that would normally reside in explicit long-term memory Associative learning - the ability of organisms to make connections between related events in their environment Autobiographical memory - individual personal episodes along with more general life information that concerns the same individual Autonoesis - see Episodic memory, Remember Availability heuristic - see Heuristics B) Bartlett - on the contributions of Sir Frederick Bartlett (1886-1969) Bias - how our memories are shaped by learnt expectations and prejudices Binding - the bringing together of different elements in space and time to create a cohesive entity, be it a sensory percept or a mnemonic representation Blocking - 1) The ability of a previously acquired association to block further associative learning about the same contingency, 2) The ability of an initial (incorrect) recalled item to block the recall of other potential solutions Bottom-up processing - see Top-down processing C) Caffeine - a widely used stimulant with some positive effects on cognition (see also Nootropics) Central executive - a core component of working memory that helps to regulate attention, make decisions, and guide the brief holding of information Change blindness - see Illusions of memory Childhood amnesia (also called Infantile amnesia) - the inability to recall or recognise personal events from our earliest years Classical conditioning -the associative learning of how one stimulus predicts another Cognitive control - see Executive functions Cognitive enhancers - see Nootropics Comprehension and learning - see Understanding and learning Concept learning - see Grandmother cells, Hub and Spoke model, Semantic memory Conditioned taste aversion - the long-lasting, deep dislike of a taste that had been associated with feeling nauseous Confabulation - the fabrication of narratives and other information, often to fill in memory gaps Confirmation bias - see Bias Consolidation - the progressive stabilization of information post encoding Constructivism in memory - the belief that memories reflect our personal understanding of an event, rather than an objective representation Context and memory - how the same contextual cues at learning and recall can benefit retrieval while changed contextual cues can disrupt retrieval Cross-sectional study - see Longitudinal study Curiosity - an intrinsic motivation to seek novel information and so reduce uncertainty D) Declarative memory - explicit long-term memory that incorporates both semantic and episodic memory Deese-Roediger-McDermott paradigm (DRM) - using related words or images to create false memories of a never-presented, but closely related item Default mode network - the network of brain areas that increases coordinated activity in between tasks, typically when self-reflecting or mind wandering Demand characteristics - the array of cues that convey an experimental hypothesis to the participant Dementia - an umbrella term that covers numerous neurological conditions that progressively disrupt brain function and cause the breakdown of multiple cognitive functions Depression and memory - the impact of major depression on memory Depth of processing - see Levels of processing Developmental amnesia - a syndrome of memory loss and memory preservation seen after bilateral hippocampal damage in childhood Diencephalon - a core brain area largely consisting of the thalamus, subthalamus, and hypothalamus Digit span - see Memory span Dissociative amnesia - see Psychogenic amnesia Distributed practice - see Spaced training Directed forgetting - see Motivated forgetting E) Ebbinghaus - Hermann Ebbinghaus (1850-1909) is principally famous for his systematic studies of rates of learning and rates of forgetting Echoic memory - the brief sensory store for auditory information, including words Ecological validity - a term typically used when considering how well a set of experimental findings can be generalized to real-world settings Ecphory - when a cue helps trigger the memory of a past event Eidetic memory - an unusually vivid form of visual memory that is highly accurate Elaborative rehearsal - the process of considering the meaning of a stimulus and its implications, processes that create additional connections and enhance recall Embodied cognition - the notion that the way we think is shaped by our bodily perceptions and experiences Emotion and memory - the interplay between affect and the elements of memory Encoding specificity principle - see Context-dependent memory and Ecphory Engram - the enduring trace that records a memory and is potentially available for retrieval Epigenetics - how cellular experiences may modify gene expression without altering the underlying (DNA) genetic code Episodic buffer - a subsystem within working memory that provides a two-way bridge with episodic memory and other aspects of long-term memory Episodic foresight (Episodic future thinking) - see Future memory Episodic memory - our long-term memory for individual events located in a particular time and place (an episode) Errorless learning - a method of teaching in which people are prevented as far as possible from making errors whilst learning a new skill or new information Event segmentation - how a continuous stream of activity is broken down into meaningful units Executive functions - an umbrella term for a set of related cognitive skills that help planning, problem solving, and adapting to new situations Expert knowledge - the superior ability to acquire and retain new information within one's domain of expertise Explicit (declarative) memory - the division of long-term memory that holds information over which we have conscious access and awareness Extinction - the reduction in frequency or intensity of a conditioned response following the removal of reinforcement Eyewitness memory - the study of how and when the remembrance of witnessed events may differ from reality F) False memory (syndrome) - personal narratives for events that never occurred Familiarity principle - see Mere-exposure effect Fear conditioning - learning in which a stimulus or context becomes associated with fear Feeling of knowing - a sense of familiarity indicating the presence of a memory that cannot be fully retrieved Flashbulb memory - a vivid, detailed memory of a surprising, emotional event that often includes what the observer was doing when the event occurred Forgetting - the absence or error in a memory, whether by inadequate encoding, alteration, erasure, or retrieval failure Forgetting curve - the decline in memory over time Free recall - the recollection of information as it comes to mind without explicit cues or prompts Fugue - a temporary loss of personal identity that appears unaccompanied by physical brain damage Future memory (episodic future thinking) - our ability to imagine or simulate future autobiographical events Fuzzy trace theory - see Gist G) Generation Effect - how self-generated information is remembered better than information that you have read or heard Gist - that some memories only capture the essence of an experience, its gist Grandmother cell - a neuron that only responds to a highly specific, complex stimulus (such as one's grandmother) Grid cells - spatial neurons whose firing fields are organized in a horizontal lattice that covers the environment, with each firing field being equally spaced (forming a grid) H) Habit - a behaviour that can be performed without conscious control or a behaviour that is gradually acquired over many repetitive trials Habituation - the gradual lessening of a reaction to a stimulus after the repeated presentation of the same or similar stimulus Head-direction cells - neurons that selectively fire when facing a particular direction ('the brain's compass') Hebb - Donald O. Hebb (1904-1985), a Canadian psychologist best known for his pioneering work on neural networks and learning Heuristic - a cognitive shortcut (rule-of-thumb) that aids rapid decision making Highly Superior Autobiographical Memory (HSAM) (also known as Hyperthymesia) - the ability to retain past autobiographical memories at exceptional levels of detail Hippocampal formation (Hippocampus) - a medial temporal lobe structure that critically contributes to a range of memory functions, including those required for episodic memory and spatial navigation Hippocampal replay - see Memory replay H.M. - Henry Molaison (1926-2008) is the best-known and most studied case of amnesia Homunculus - i) the seductive fallacy of a little human solving problems inside our head, ii) the outline of a human body across our motor and somatosensory cortices Hub and Spoke model of semantic memory - a model of how we represent semantic information Hyperthymesia - see Highly Superior Autobiographical Memory Hypnosis and memory - on whether hypnosis can aid the retrieval of memories or disrupt aspects of memory I) Iconic memory - a brief visual store thought to combine two forms of visual persistence Illusions of memory - when our recall or recognition of a past event markedly deviates from the real experience Imagery and memory - how a mental pictorial representation impacts on memory Imagination inflation (see also False memories) - how imagining events that did not occur increases the likelihood of believing in their reality Imitation (Imitative learning) - social learning that involves copying the actions of others Implicit memory (Nondeclarative memory) - that component of long-term memory which is not consciously accessible Imprinting - whereby an animal learns, during a sensitive period, to confine its preferences to a specific stimulus (typically another individual), class of stimuli, or location Inattentional blindness - see Illusions of memory Incidental learning - learning that occurs without the explicit intention to learn and memorise Infantile amnesia - See Childhood amnesia Instrumental learning (Operant conditioning) - associative learning in which the likelihood or intensity of a response is regulated by its outcome Interference - competition between similar information that can cause memory errors Irrelevant speech (sound) effect - how background speech or word-like sounds can disrupt ongoing memory tasks and comprehension Isolation effect - see von Restorff effect J) Jost's law - see Ebbinghaus, Ribot's law K) Korsakoff's disease (syndrome) - a form of organic amnesia associated with vitamin B1 (thiamine) deficiency, and most often seen in chronic alcoholics L) Latent inhibition - when a familiar stimulus takes longer to acquire a new association than a novel stimulus Learning - at its simplest, learning is commonly defined as behavioral change brought about by experience Learning-set - learning to learn, so that previous similar problems lead to the acquisition of a rule (learning-set) to help solve the same class of problems Learning styles - a teaching vogue which presumes that students learn better when receiving information in their preferred medium (style), e.g., auditory, visual, or kinaesthetic Levels of processing - the concept that the deeper you process information the better it is subsequently remembered Lloyd-Morgan's canon - see Instrumental learning Longitudinal study - repeatedly testing the performance of the same individual over time Long-term memory - a repository of stored information that persists for minutes, days, or even years (sometimes referred to as secondary memory) Long-term depression (LTD) - although the term can refer to a chronic depressive disorder, here it concerns a process that weakens connections between neurons, often acting in the opposite way to long-term potentiation (LTP) Long-term potentiation (LTP) - the lasting strengthening of synaptic efficacy following pulses of stimulation M) Maintenance rehearsal - see Elaborative rehearsal Mammillary bodies - see Diencephalon, Korsakoff's syndrome Massed learning - see Spaced learning Memory - the meaning of memory Memory in sensitive plants and unicellular organisms, including slime moulds - on whether memory exists in organisms that lack neurons Memory replay - the reactivation of sequential activity patterns in neuronal assemblies that replays their prior patterns of activity during learning Memory span - a test of short-term memory in which a series of items are recalled in their order of presentation Mental time travel - see Future memory (Future episodic memory) Mere-exposure effect - how, after repeated exposure, a neutral stimulus acquires positive values Metamemory - the introspective ability to monitor your own memory processes, including its content and capabilities Method of loci - A memory aid (mnemonic) that involves making visual images of items to be remembered, and placing these images in a pre-set sequence of visualised locations Mild cognitive impairment - a condition causing memory or other thinking problems that is often, but not always, a transitional phase leading to dementia Mirror neuron - a neuron that increases its activity when performing an action and when observing that same action Mnemonics - effortful cognitive strategies used to improve memory Mnemonists - individuals who possess exceptional memory abilities, whether seemingly spontaneously or by dint of exhaustive training Mood congruency - see Context-dependent memory Motivated forgetting - an effortful process that helps us to forget unwanted memories Motor learning - see Procedural learning Multiple trace theory (of consolidation and retrieval) - that each retrieval effort creates a new memory trace, as a result of which the hippocampus remains necessary for the consolidation and retrieval of past episodic memories, irrespective of their age N) n-back task - where participants mentally hold a continuous sequence of items while checking for any repeats from a specified number of places (n) back in the sequence Neurogenesis - the creation of new neurons Nicotine - an addictive drug that activates one of the two major types of acetylcholine receptors (nicotinic) and is thought to influence cognition Nondeclarative memory - see Implicit memory Nootropics ('Cognitive enhancers', 'Neuroenhancers', 'Smart drugs') - chemicals and supplements purported to improve cognition, including learning and memory O) Observational learning - social learning based on imitation that makes it possible to acquire new behaviours and knowledge Olfactory memory - memory for smells Operant learning - see Instrumental learning P) Partial reinforcement extinction effect - see Extinction Partial report method - see Iconic memory, Echoic memory Pattern completion and Pattern separation - 'Pattern completion' is the process of retrieving a complete memory representation from a partial or degraded cue; 'Pattern separation' is the process of segregating similar experiences into distinct, dissimilar representations Pavlovian conditioning - see Classical conditioning Penfield (Wilder Penfield, 1891-1976) - see Engram Perceptual learning - see Expert knowledge Phenotype - the observable attributes displayed by an individual Phonological loop - a working memory subsystem for speech-based sounds Place cells - neurons that signal a specific location by increasing their activity Prediction error - the mismatch between a prior expectation and the experienced event Preverbal learning - that period of learning by infants prior to verbal communication, typified by other communication skills such as vocalizations, gestures, and eye contact Primacy effect - the superior recall of the first few items in a sequence Primary memory - see Short-term memory Priming - when exposure to a stimulus (now 'primed') influences our response to a subsequent stimulus Proactive interference - see Interference Procedural memory - the implicit memory for skills, habits, and cognitive actions that are performed automatically and for which we lack conscious awareness of their underlying nature Prospective memory - the cognitive ability to remember to perform an intended action or recall a planned intention at an appropriate future time Psychogenic amnesia (or Dissociative amnesia) - a memory dysfunction, typically involving a loss of personal memories, which arises from psychological stress or trauma yet without detectable brain damage (or damage that could account for the degree of memory loss) Q) Qualia - the subjective conscious experience of a quality or property R) Reality monitoring - see Source monitoring Recall - see Remember Recency effect - the superior recall of information presented at the end of a list over those items presented in the middle Recognition memory - the ability to detect the re-occurrence of a stimulus Reconsolidation (and Reconstruction) - the process whereby the retrieval of a memory renders it unstable and prone to modification Recovered memories - see Repression of memory Rehearsal - the mental repetition of an item to prolong its storage Reinforcement and Reward - terms describing how pleasant or unpleasant stimuli can influence the likelihood of a preceding action Remember (Recall, Retrieve) - to access a memory (or past representation) Remember/Know - see Recognition memory Replication crisis (Reproducibility crisis) - a methodological crisis concerning how many published findings (e.g., in psychology) are difficult or seemingly impossible to reproduce Repression (memory) - the self-removal of a traumatic memory that cannot be accommodated in conscious memory Retrieval - see Remember Retrieval effect (Retrieval practice effect) - see Testing effect Retroactive interference - see Interference Retrograde amnesia - the sudden loss of past memories, typically following a neurological insult Ribot's law (1881) - that in retrograde amnesia, recent memories are more likely to be lost than older memories S) Savants - people who display spectacular feats of memory, the term 'savant syndrome' being largely reserved for those who also face neurodevelopmental challenges Savings - using rates of relearning to assess original levels of learning and retention Schema - an acquired mental framework that guides the interpretation, organization, and recollection of incoming information Scripts - see Schemas Semantic dementia - a subtype of frontotemporal dementia that predominantly affects language skills, in particular, word comprehension and naming Semantic memory - a division of explicit long-term memory that holds general knowledge about the world, including facts, concepts, words, and number meanings Sensitization - when the repeated exposure to a stimulus results in an amplification of responsiveness to that stimulus, and potentially to other stimuli Sensory memory - see Echoic memory, Iconic memory Serial position effect - see Primacy effect, Recency effect Short-term memory - a store holding restricted amounts of information over short time periods Smart drugs - see Nootropics Source monitoring - the cognitive ability to identify the origin of a memory Spaced training (Spaced learning) - how distributed practice results in more effective learning and more durable retention State-dependent learning (State-dependency) - see Context and memory Superstitious learning - the mistaken learning that occurs when an action is coincidentally paired with a reinforcer Synaptic plasticity - see Long-term depression and Long-term potentiation T) Taxi drivers (London) - insights into brain plasticity and spatial learning made possible by the unique training demands on London taxi drivers Testing effect - how taking tests during the learning phase facilitates later retrieval from long-term memory Tip-of-the-tongue (tip-of-the-finger, tip-of-the-eye) - the feeling that you are on the brink of recollecting a word, but the correct word will not come to mind Tobacco smoking - see Nicotine Top-down processing (also Bottom-up processing) - how our prior knowledge and expectations influence perceptual and cognitive decisions Trace decay - that memories get weaker over time, with time being the critical agent of forgetting Transient global amnesia - an anterograde amnesia of sudden origin and brief duration that selectively affects the ability to make or access new memories while sparing other cognitive abilities U) Unconscious learning when anaesthetised - evidence that new implicit learning is possible despite being unconscious Understanding and memory - the relationship between depth of understanding and subsequent memory (also see Constructivism, Elaborative rehearsal, Expert knowledge, Levels of processing, Mnemonics, Schemas) V) Visuospatial sketchpad - a subsystem within the multicomponent model of working memory that holds visual and spatial information von Restorff effect (Isolation effect) - the enhanced memorability of an item that stands-out from the array by being different or unexpected W) White matter plasticity - how experience-induced changes to white matter accompany learning Wisconsin Card Sorting Test - see Learning-set Working memory - a cognitive system with limited capacity and temporary duration that actively holds information making it available for reasoning, decision-making, and planning (a more restricted definition applies to animal working memory) Y) Yerkes-Dodson law - see Emotion and memory Z) Zebra fish - a model vertebrate species that has optically transparent embryonic and young larval stages Zeigarnik effect - that uncompleted or interrupted tasks are remembered better Acknowledgements