Short-term memory

The idea of separate memories for short-term and long-term storage originated in the 19th century. A model of memory developed in the 1960s assumed that all memories are formed in one store and transfer to others store after a small period of time. This model is referred to as the "modal model", most famously detailed by Shiffrin.^[2] The model states that memory is first stored in sensory memory, which has a large capacity but can only maintain information for milliseconds.^[3] A representation of that rapidly decaying memory is moved to short-term memory. Short-term memory does not have a large capacity like sensory memory, but holds information for seconds or minutes. The final storage is long-term memory, which has a very large capacity and is capable of holding information possibly for a lifetime.

The exact mechanisms by which this transfer takes place, whether all or only some memories are retained permanently, and even to have the existence of a genuine distinction between stores, remain controversial.

Evidence

Anterograde amnesia

One form of evidence cited in favor of the existence of a short-term store comes from anterograde amnesia, the inability to learn new facts and episodes. Patients with this form of amnesia have an intact ability to retain small amounts of information over short time scales (up to 30 seconds) but have little ability to form longer-term memories (illustrated by patient HM). This is interpreted as showing that the short-term store is spared from damage and diseases.^[4]

Distraction tasks

Other evidence comes from experimental studies showing that some manipulations impair memory for the 3 to 5 most recently learned words of a list (it is presumed that they are held in short-term memory). Recall for words from earlier in the list (it is presumed, stored in long-term memory) are unaffected. Other manipulations (e.g., semantic similarity of the words) affect only memory for earlier list words,^[5] but do not affect memory for the most recent few words. These results show that different factors affect short-term recall (disruption of rehearsal) and long-term recall (semantic similarity). Together, these findings show that long-term memory and short-term memory can vary independently of each other.

Models

Unitary model

Not all researchers agree that short- and long-term memory are separate systems. The alternative Unitary Model proposes that short-term memory consists of temporary activations of long term representations (that there is one memory that behaves variously over all time scales, from milliseconds to years).^[6][7] It has been difficult to identify a sharp boundary between short-term and long-term memory. For instance, Tarnow reported that the recall probability vs. latency curve is a straight line from 6 to 600 seconds, with the probability of failure to recall only saturating after 600 seconds.^[8] If two different stores were operating in this time domain, it is reasonable to expect a discontinuity in this curve. Other research has shown that the detailed pattern of recall errors looks remarkably similar to recall of a list immediately after learning (it is presumed, from short-term memory) and recall after 24 hours (necessarily from long-term memory).^[9]

Further evidence for a unified store comes from experiments involving continual distractor tasks. In 1974, Bjork and Whitten presented subjects with word pairs to remember; before and after each word pair, subjects performed a simple multiplication task for 12 seconds. After the final word-pair, subjects performed the multiplication distractor task for 20 seconds. They reported that the recency effect (the increased probability of recall of the last items studied) and the primacy effect (the increased probability of recall of the first few items) was sustained. These results are incompatible with a separate short-term memory as the distractor items should have displaced some of the word-pairs in the buffer, thereby weakening the associated strength of the items in long-term memory.^[10]

Tzeng (1973) reported an instance where the recency effect in free recall did not seem to result from a short-term memory store. Subjects were presented with four study-test periods of 10 word lists, with a continual distractor task (20-second period of counting-backward). At the end of each list, participants had to free-recall as many words as possible. After recall of the fourth list, participants were asked to recall items from all four lists. Both the initial and final recall showed a recency effect. These results violated the predictions of a short-term memory model, where no recency effect would be expected.^[11]

Koppenaal and Glanzer (1990) attempted to explain these phenomena as a result of the subjects' adaptation to the distractor task, which allowed them to preserve at least some short-term memory capabilities. In their experiment the long-term recency effect disappeared when the distractor after the last item differed from the distractors that preceded and followed the other items (e.g., arithmetic distractor task and word reading distractor task). Thapar and Greene challenged this theory. In one of their experiments, participants were given a different distractor task after every study item. According to Koppenaal and Glanzer's theory, no recency effect would be expected as subjects would not have had time to adapt to the distractor; yet such a recency effect remained in place in the experiment.^[12]

Another explanation

One proposed explanation for recency in a continual distractor condition, and its disappearance in an end-only distractor task is the influence of contextual and distinctive processes.^[13] According to this model, recency is a result of the similarity of the final items' processing context to the processing context of the other items and the distinctive position of the final items versus intermediate items. In the end distractor task, the processing context of the final items is no longer similar to that of the other list items. At the same time, retrieval cues for these items are no longer as effective as without the distractor. Therefore, recency recedes or vanishes. However, when distractor tasks are placed before and after each item, recency returns, because all the list items have similar processing context.^[13]

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Richard Shiffrin

Richard Shiffrin

Richard Shiffrin is an American psychologist, professor of cognitive science in the Department of Psychological and Brain Sciences at Indiana University, Bloomington. Shiffrin has contributed a number of theories of attention and memory to the field of psychology. He co-authored the Atkinson–Shiffrin model of memory in 1968 with Richard Atkinson, who was his academic adviser at the time. In 1977, he published a theory of attention with Walter Schneider. With Jeroen G.W. Raaijmakers in 1980, Shiffrin published the Search of Associative Memory (SAM) model, which has served as the standard model of recall for cognitive psychologists well into the 2000s. He extended the SAM model with the Retrieving Effectively From Memory (REM) model in 1997 with Mark Steyvers.

Anterograde amnesia

Anterograde amnesia

In neurology, anterograde amnesia is the inability to create new memories after the event that caused amnesia, leading to a partial or complete inability to recall the recent past, while long-term memories from before the event remain intact. This is in contrast to retrograde amnesia, where memories created prior to the event are lost while new memories can still be created. Both can occur together in the same patient. To a large degree, anterograde amnesia remains a mysterious ailment because the precise mechanism of storing memories is not yet well understood, although it is known that the regions of the brain involved are certain sites in the temporal cortex, especially in the hippocampus and nearby subcortical regions.

Amnesia

Amnesia

Amnesia is a deficit in memory caused by brain damage or disease, but it can also be caused temporarily by the use of various sedatives and hypnotic drugs. The memory can be either wholly or partially lost due to the extent of damage that was caused. There are two main types of amnesia: retrograde amnesia and anterograde amnesia. Retrograde amnesia is the inability to retrieve information that was acquired before a particular date, usually the date of an accident or operation. In some cases the memory loss can extend back decades, while in others the person may lose only a few months of memory. Anterograde amnesia is the inability to transfer new information from the short-term store into the long-term store. People with anterograde amnesia cannot remember things for long periods of time. These two types are not mutually exclusive; both can occur simultaneously.

Semantics

Semantics

Semantics is the study of reference, meaning, or truth. The term can be used to refer to subfields of several distinct disciplines, including philosophy, linguistics and computer science.

Ovid Tzeng

Ovid Tzeng

Ovid Tzeng is a Taiwanese politician. He was Minister of Education from 2000 to 2002 and Minister of the Council for Cultural Affairs from 2011 to 2012.

Free recall

Free recall

Free recall is a common task in the psychological study of memory. In this task, participants study a list of items on each trial, and then are prompted to recall the items in any order. Items are usually presented one at a time for a short duration, and can be any of a number of nameable materials, although traditionally, words from a larger set are chosen. The recall period typically lasts a few minutes, and can involve spoken or written recall. The standard test involves the recall period starting immediately after the final list item; this can be referred to as immediate free recall (IFR) to distinguish it from delayed free recall (DFR). In delayed free recall, there is a short distraction period between the final list item and the start of the recall period. Both IFR and DFR have been used to test certain effects that appear during recall tests, such as the primacy effect and recency effect.

Various researchers have proposed that stimuli are coded in short-term memory using transmitter depletion.^[14][15] According to this hypothesis, a stimulus activates a spatial pattern of activity across neurons in a brain region. As these neurons fire, the available neurotransmitters are depleted. This depletion pattern represents stimulus information and functions as a memory trace. The memory trace decays over time as a consequence of neurotransmitter reuptake mechanisms that restore neurotransmitters to prior levels.

The relationship between short-term memory and working memory is described by various theories, but the two concepts are generally considered distinct. Neither holds information for long, but short-term memory is a simple store, while working memory allows it to be manipulated.^[16] Short-term memory is part of working memory, but is not the same thing.

Working memory refers to structures and processes used for temporarily storing and manipulating information. Working memory has been termed working attention. Working memory and attention together play a major role in the thought process. Short-term memory in general refers to the short-term storage of information, and it does not encompass memory manipulation or organization. Thus, while short-term memory components appear in working memory models, the concept of short-term memory is distinct from other concepts.

Within Baddeley's influential 1986 model of working memory two short-term storage mechanisms appear: the phonological loop and the visuospatial sketchpad. Most of the above research involves the phonological loop, because most of the work on short-term memory uses verbal material. Since the 1990s, however, research on visual short-term memory^[17] and spatial short-term memory has expanded.^[18]

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Working memory

Working memory

Working memory is a cognitive system with a limited capacity that can hold information temporarily. It is important for reasoning and the guidance of decision-making and behavior. Working memory is often used synonymously with short-term memory, but some theorists consider the two forms of memory distinct, assuming that working memory allows for the manipulation of stored information, whereas short-term memory only refers to the short-term storage of information. Working memory is a theoretical concept central to cognitive psychology, neuropsychology, and neuroscience.

Alan Baddeley

Alan Baddeley

Alan David Baddeley CBE FRS is a British psychologist. He is known for his research on memory and for developing the three-component model of working memory. He is a professor of psychology at the University of York.

Baddeley's model of working memory

Baddeley's model of working memory

Baddeley's model of working memory is a model of human memory proposed by Alan Baddeley and Graham Hitch in 1974, in an attempt to present a more accurate model of primary memory. Working memory splits primary memory into multiple components, rather than considering it to be a single, unified construct.

Visual short-term memory

Visual short-term memory

In the study of vision, visual short-term memory (VSTM) is one of three broad memory systems including iconic memory and long-term memory. VSTM is a type of short-term memory, but one limited to information within the visual domain.

The limited duration of short-term memory (~18 seconds without rehearsal)^[19] suggests that its contents spontaneously decay over time.^[20] The decay assumption is part of many theories of short-term memory. The most notable one is Baddeley's model of working memory. The decay assumption is usually paired with the idea of rapid covert rehearsal: to retain information for longer, information must be periodically repeated or rehearsed, either by articulating it out loud or by mental simulation. Another type of rehearsal that can improve short-term memory is attention-based rehearsal. Information is mentally searched in a particular sequence.^[16] Once recalled, the information re-enters short-term memory and is then retained for a further period.

Nairn and Lewandosky et. al. dispute that spontaneous decay plays any significant role in short-term forgetting,^[21][22] and the evidence is not conclusive.^[23]

One alternative asserts that several elements (such as digits, words, or pictures, or logos) are held in short-term memory simultaneously, their representations compete with each other for recall, degrading each other. Thereby, new content gradually replaces older content, unless the older content is actively protected.^[24]

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Memory rehearsal

Memory rehearsal

Memory rehearsal is a term for the role of repetition in the retention of memories. It involves repeating information over and over in order to get the information processed and stored as a memory.

Baddeley's model of working memory

Baddeley's model of working memory

Baddeley's model of working memory is a model of human memory proposed by Alan Baddeley and Graham Hitch in 1974, in an attempt to present a more accurate model of primary memory. Working memory splits primary memory into multiple components, rather than considering it to be a single, unified construct.

Numerical digit

Numerical digit

A numerical digit is a single symbol used alone or in combinations, to represent numbers in a positional numeral system. The name "digit" comes from the fact that the ten digits of the hands correspond to the ten symbols of the common base 10 numeral system, i.e. the decimal digits.

Word

Word

A word is a basic element of language that carries an objective or practical meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of what a word is, there is no consensus among linguists on its definition and numerous attempts to find specific criteria of the concept remain controversial. Different standards have been proposed, depending on the theoretical background and descriptive context; these do not converge on a single definition. Some specific definitions of the term "word" are employed to convey its different meanings at different levels of description, for example based on phonological, grammatical or orthographic basis. Others suggest that the concept is simply a convention used in everyday situations.

Whatever the cause(s) of short-term forgetting, consensus asserts that it limits the amount of retained new information short term. This limit is referred to as the finite capacity of short-term memory. Short-term memory capacity is often called memory span, in reference to a common measurement procedure. In a memory span test, the experimenter presents a list of items (e.g. digits or words) of increasing length. An individual's span is determined as the longest list length that he or she can recall correctly in the given order on half or more trials.

In an early and influential article, "The Magical Number Seven, Plus or Minus Two",^[25] Miller suggested that human short-term memory has a forward memory span of approximately seven plus or minus two items and that that was well known at the time (apparently originating with Wundt). Later research reported that this "magical number seven" is roughly accurate for college students recalling lists of digits, but memory span varies widely across populations and material. For example, the ability to recall words in order depends on characteristics of those words: fewer words can be recalled when the words have longer spoken duration; this is known as the word-length effect,^[26] or when their speech sounds are similar to each other; this is called the phonological similarity effect.^[27] More words can be recalled when the words are highly familiar or occur frequently in speech.^[28] Recall performance is better when all of the words are taken from a single semantic category (such as games) than when the words are chosen randomly.^[29] A later estimate of short-term memory capacity reported that the capacity was about four pieces, or "chunks", of information.^[30] Other notable theories argue against measuring capacity in terms of the number of elements.^[31][32][33]

In the visual domain, several studies report no fixed capacity limit in terms of total number of items that can be retained. Instead, some investigators have argued for a limited resource that can be flexibly shared between items held in short-term memory, with some items (in the focus of attention) being allocated more resource and being recalled with greater fidelity.^[31][32] Many of these experiments have used delayed response tasks that have a continuous, analogue response space, rather than using a binary (correct/incorrect) recall method as is often used in change detection tasks. Instead of asking people to report whether a change occurred between the memory and probe array, delayed reproduction tasks require participants to reproduce the precise quality of a visual feature, e.g. an object’s orientation or colour.^[34][35][36]

Rehearsal

Rehearsal is the process of repeating information to be retained, ostensibly keeping it in short-term memory. Each repetition reenters the information into short-term memory, thus keeping that information for another 10 to 20 seconds (the average storage time for short-term memory).^[37]

Chunking

Chunking is a technique that allows memory to remember more things. Chunking involves organizing material into meaningful groups. Chunking can greatly increase recall capacity. For example, in recalling a phone number, chunking the digits into three groups (area code, prefix, and extension). This method of remembering phone numbers is far more effective than attempting to remember a string of 10 digits.

Practice and the usage of existing information in long-term memory can lead to additional improvements in chunking. In one testing session, an American cross-country runner was able to recall a string of 79 digits after hearing them only once by chunking them into groups the size of a running time.^[38]

Factors

Diseases that cause neurodegeneration, such as Alzheimer's disease, can damage short-term as well as long-term memory.^[39] Damage to certain sections of the brain due to this disease causes a shrinkage in the cerebral cortex, which impairs the ability to think and recall.^[40]

Short-term memory performance is influenced by diet. More intake of blueberries was reported to improve short-term memory after continuous use whereas alcohol decreases short-term memory performance.^[41]

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Memory span

Memory span

In psychology and neuroscience, memory span is the longest list of items that a person can repeat back in correct order immediately after presentation on 50% of all trials. Items may include words, numbers, or letters. The task is known as digit span when numbers are used. Memory span is a common measure of working memory and short-term memory. It is also a component of cognitive ability tests such as the WAIS. Backward memory span is a more challenging variation which involves recalling items in reverse order.

The Magical Number Seven, Plus or Minus Two

The Magical Number Seven, Plus or Minus Two

"The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information" is one of the most highly cited papers in psychology. It was written by the cognitive psychologist George A. Miller of Harvard University's Department of Psychology and published in 1956 in Psychological Review. It is often interpreted to argue that the number of objects an average human can hold in short-term memory is 7 ± 2. This has occasionally been referred to as Miller's law.

George Armitage Miller

George Armitage Miller

George Armitage Miller was an American psychologist who was one of the founders of cognitive psychology, and more broadly, of cognitive science. He also contributed to the birth of psycholinguistics. Miller wrote several books and directed the development of WordNet, an online word-linkage database usable by computer programs. He authored the paper, "The Magical Number Seven, Plus or Minus Two," in which he observed that many different experimental findings considered together reveal the presence of an average limit of seven for human short-term memory capacity. This paper is frequently cited by psychologists and in the wider culture. Miller won numerous awards, including the National Medal of Science.

Chunking (psychology)

Chunking (psychology)

In cognitive psychology, chunking is a process by which individual pieces of an information set are bound together into a meaningful whole. The chunks, by which the information is grouped, are meant to improve short-term retention of the material, thus bypassing the limited capacity of working memory and allowing the working memory to be more efficient. A chunk is a collection of basic units that have been grouped together and stored in a person's memory. These chunks can be retrieved easily due to their coherent grouping. It is believed that individuals create higher-order cognitive representations of the items within the chunk. The items are more easily remembered as a group than as the individual items themselves. These chunks can be highly subjective because they rely on an individual's perceptions and past experiences, which are linked to the information set. The size of the chunks generally ranges from two to six items but often differs based on language and culture.

Alzheimer's disease

Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems with language, disorientation, mood swings, loss of motivation, self-neglect, and behavioral issues. As a person's condition declines, they often withdraw from family and society. Gradually, bodily functions are lost, ultimately leading to death. Although the speed of progression can vary, the typical life expectancy following diagnosis is three to nine years.

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Age

Memory loss is a natural aging process. Research has reported short-term memory decreases with age. The decline appears to be constant and continuous beginning in the twenties.

One study used data from a previous study that compiled normative French data for three short-term memory tasks (verbal, visual and spatial). They found impairments in participants between the ages of 55 and 85 years of age.^[42]

Advanced age is also associated with decrements in episodic memory. The associated deficit is that differences in recognition memory reflect difficulty in binding components of a memory episode and bound units.^[43] A previous study used mixed and blocked test designs and reported an associative deficit for older adults.^[44]

Even absent neurological diseases and disorders, progressive and gradual loss of some intellectual functions become evident in later years. Several tests assess the psychophysical characteristics of the elderly, such as the functional reach (FR) test and the mini–mental state examination (MMSE). FR is an index of the aptitude to maintain balance in an upright position, while the MMSE test is a global index of cognitive abilities. These tests were used by Costarella et al.^[45] to evaluate the psychophysical characteristics of older adults. They found a loss of physical performance (FR, related to height) as well as a loss of cognitive abilities (MMSE).

Alzheimer's disease

Memory distortion in Alzheimer's disease is a disorder common in older adults. One study compared patients with mild to moderate Alzheimer's disease versus age matched healthy adults.^[46] Alzheimer's patients had more severely reduced short-term memory. Visual short-term memory is also impaired in sporadic, late-onset as well as familial Alzheimer’s disease, when assessed using delayed reproduction tasks.^[39][47][48] These studies point to a deficit in visual feature binding as an important component of the deficit. Episodic memory and semantic abilities deteriorate early in Alzheimer's disease. Since the cognitive system includes interconnected and reciprocally influenced neuronal networks, one study hypothesized that stimulation of lexical-semantic abilities may benefit semantically structured episodic memory. They found that Lexical-Semantic stimulation treatment could improve episodic memory.^[49]

Aphasia

Aphasias commonly occur after left-hemisphere stroke or with neurodegenerative conditions such as primary progressive aphasias.^[50] Patients with left temporoparietal focal lesions may suffer a deficit of verbal short-term memory, which may also be a feature of logopenic primary progressive aphasia.^[51][52][53]

Many language-impaired patients complain about short-term memory deficits. Family members confirm that patients have trouble recalling previously known names and events. These signals are supported by studies reporting that many aphasics also have trouble with visual-memory required tasks.^[54]

Schizophrenia

Core symptoms of schizophrenia patients have been linked to cognitive deficits. One neglected factor that contributes to those deficits is the comprehension of time.^[55]

Post-traumatic stress disorder

Posttraumatic stress disorder (PTSD) is associated with altered processing of emotional material with strong attentional bias toward trauma-related information. It interferes with cognitive processing. Aside from trauma processing specificities, a range of cognitive impairments have been associated with PTSD state, including attention and verbal memory deficits.^[56]

Intelligence

Few studies have been done on the relationship between short-term memory and intelligence. One study examined whether people with PTSD had equivalent levels of short-term, non-verbal memory on the Benton Visual Retention Test (BVRT), and whether they had equivalent levels of intelligence on the Raven Standard Progressive Matrices (RSPM). They found that people with PTSD had worse short-term, non-verbal memory on the BVRT, despite having comparable levels of intelligence on the RSPM, concluding impairments in memory influence intelligence assessments in the subjects.^[57]

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Mini–mental state examination

Mini–mental state examination

The mini–mental state examination (MMSE) or Folstein test is a 30-point questionnaire that is used extensively in clinical and research settings to measure cognitive impairment. It is commonly used in medicine and allied health to screen for dementia. It is also used to estimate the severity and progression of cognitive impairment and to follow the course of cognitive changes in an individual over time; thus making it an effective way to document an individual's response to treatment. The MMSE's purpose has been not, on its own, to provide a diagnosis for any particular nosological entity.

Alzheimer's disease

Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems with language, disorientation, mood swings, loss of motivation, self-neglect, and behavioral issues. As a person's condition declines, they often withdraw from family and society. Gradually, bodily functions are lost, ultimately leading to death. Although the speed of progression can vary, the typical life expectancy following diagnosis is three to nine years.

Episodic memory

Episodic memory

Episodic memory is the memory of everyday events that can be explicitly stated or conjured. It is the collection of past personal experiences that occurred at particular times and places; for example, the party on one's 7th birthday. Along with semantic memory, it comprises the category of explicit memory, one of the two major divisions of long-term memory.

Aphasia

Aphasia

Aphasia is an inability to comprehend or formulate language because of damage to specific brain regions. The major causes are stroke and head trauma; prevalence is hard to determine but aphasia due to stroke is estimated to be 0.1–0.4% in the Global North. Aphasia can also be the result of brain tumors, brain infections, or neurodegenerative diseases.

Stroke

Stroke

A stroke is a medical condition in which poor blood flow to the brain causes cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functioning properly.

Neurodegenerative disease

Neurodegenerative disease

A neurodegenerative disease is caused by the progressive loss of structure or function of neurons, in the process known as neurodegeneration. Such neuronal damage may ultimately involve cell death. Neurodegenerative diseases include amyotrophic lateral sclerosis, multiple sclerosis, Parkinson's disease, Alzheimer's disease, Huntington's disease, multiple system atrophy, and prion diseases. Neurodegeneration can be found in the brain at many different levels of neuronal circuitry, ranging from molecular to systemic. Because there is no known way to reverse the progressive degeneration of neurons, these diseases are considered to be incurable; however research has shown that the two major contributing factors to neurodegeneration are oxidative stress and inflammation. Biomedical research has revealed many similarities between these diseases at the subcellular level, including atypical protein assemblies and induced cell death. These similarities suggest that therapeutic advances against one neurodegenerative disease might ameliorate other diseases as well.

Primary progressive aphasia

Primary progressive aphasia

Primary progressive aphasia (PPA) is a type of neurological syndrome in which language capabilities slowly and progressively become impaired. As with other types of aphasia, the symptoms that accompany PPA depend on what parts of the left hemisphere are significantly damaged. However, unlike most other aphasias, PPA results from continuous deterioration in brain tissue, which leads to early symptoms being far less detrimental than later symptoms. Those with PPA slowly lose the ability to speak, write, read, and generally comprehend language. Eventually, almost every patient becomes mute and completely loses the ability to understand both written and spoken language. Although it was first described as solely impairment of language capabilities while other mental functions remain intact, it is now recognized that many, if not most of those with PPA experience impairment of memory, short-term memory formation and loss of executive functions. It was first described as a distinct syndrome by M. Marsel Mesulam in 1982. Primary progressive aphasias have a clinical and pathological overlap with the frontotemporal lobar degeneration (FTLD) spectrum of disorders and Alzheimer's disease. However, PPA is not considered synonymous to Alzheimer's disease due to the fact that, unlike those affected by Alzheimer's disease, those with PPA are generally able to maintain the ability to care for themselves, remain employed, and pursue interests and hobbies. Moreover, in diseases such as Alzheimer's disease, Pick's disease, and Creutzfeldt-Jakob disease, progressive deterioration of comprehension and production of language is just one of the many possible types of mental deterioration, such as the progressive decline of memory, motor skills, reasoning, awareness, and visuospatial skills.

Logopenic progressive aphasia

Logopenic progressive aphasia

Logopenic progressive aphasia (LPA) is a variant of primary progressive aphasia. It is defined clinically by impairments in naming and sentence repetition. It is similar to conduction aphasia and is associated with atrophy to the left posterior temporal cortex and inferior parietal lobule. It is suspected that an atypical form of Alzheimer's disease is the most common cause of logopenic progressive aphasia.

Schizophrenia

Schizophrenia

Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations, delusions, and disorganized thinking. Other symptoms include social withdrawal, decreased emotional expression, and apathy. Symptoms typically develop gradually, begin during young adulthood, and in many cases never become resolved. There is no objective diagnostic test; diagnosis is based on observed behavior, a psychiatric history that includes the person's reported experiences, and reports of others familiar with the person. To be diagnosed with schizophrenia, symptoms and functional impairment need to be present for six months (DSM-5) or one month (ICD-11). Many people with schizophrenia have other mental disorders, especially substance use disorders, depressive disorders, anxiety disorders, and obsessive–compulsive disorder.

Time perception

Time perception

The study of time perception or chronoception is a field within psychology, cognitive linguistics and neuroscience that refers to the subjective experience, or sense, of time, which is measured by someone's own perception of the duration of the indefinite and unfolding of events. The perceived time interval between two successive events is referred to as perceived duration. Though directly experiencing or understanding another person's perception of time is not possible, perception can be objectively studied and inferred through a number of scientific experiments. Some temporal illusions help to expose the underlying neural mechanisms of time perception.

Benton Visual Retention Test

Benton Visual Retention Test

The Benton Visual Retention Test is an individually administered test for people aged from eight years to adulthood that measures visual perception and visual memory. It can also be used to help identify possible learning disabilities among other conditions that might affect an individual's memory. The individual examined is shown ten designs, one at a time, and asked to reproduce each one as exactly as possible on plain paper from memory. The test is untimed, and the results are professionally scored by form, shape, pattern, and arrangement on the paper.

Raven's Progressive Matrices

Raven's Progressive Matrices

Raven's Progressive Matrices or RPM is a non-verbal test typically used to measure general human intelligence and abstract reasoning and is regarded as a non-verbal estimate of fluid intelligence. It is one of the most common tests administered to both groups and individuals ranging from 5-year-olds to the elderly. It comprises 60 multiple choice questions, listed in order of increasing difficulty. This format is designed to measure the test taker's reasoning ability, the eductive ("meaning-making") component of Spearman's g.

• "The Last Hippie" in An Anthropologist on Mars, a medical case history in a book by British neurologist Oliver Sacks.
• 50 First Dates, a film
• Ghajini, a film
• Memento, a film
• "Ænema", Tool

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An Anthropologist on Mars

An Anthropologist on Mars

An Anthropologist on Mars: Seven Paradoxical Tales is a 1995 book by neurologist Oliver Sacks consisting of seven medical case histories of individuals with neurological conditions such as autism and Tourette syndrome. An Anthropologist on Mars follows up on many of the themes Sacks explored in his 1985 book, The Man Who Mistook His Wife for a Hat, but here the essays are significantly longer and Sacks has more of an opportunity to discuss each subject with more depth and to explore historical case studies of patients with similar symptoms. In addition, Sacks studies his patients outside the hospital, often traveling considerable distances to interact with his subjects in their own environments. Sacks concludes that "defects, disorders, [and] diseases... can play a paradoxical role, by bringing out latent powers, developments, evolutions, forms of life that might never be seen, or even be imaginable, in their absence".

50 First Dates

50 First Dates

50 First Dates is a 2004 American romantic comedy drama film directed by Peter Segal and starring Adam Sandler and Drew Barrymore with Rob Schneider, Sean Astin and Dan Aykroyd in supporting roles. It follows the story of Henry, a womanizing marine veterinarian who falls for an art teacher named Lucy. When he discovers she has amnesia, and forgets him when she falls asleep, he resolves to win her over again each new day.

Ghajini (2005 film)

Ghajini (2005 film)

Ghajini is a 2005 Indian Tamil-language action thriller film directed by A. R. Murugadoss and produced by Salem Chandrasekharan. The film stars Suriya and Asin in the lead, with Nayanthara, Pradeep Rawat and Riyaz Khan in supporting roles. Harris Jayaraj composed the soundtrack and background music, while R. D. Rajasekhar and Anthony were the film's cinematographer and editor, respectively. It revolves around a businessman who suffers from anterograde amnesia and is on a spree to avenge the murder of his girlfriend.

Memento (film)

Memento (film)

Memento is a 2000 American neo-noir psychological thriller film written and directed by Christopher Nolan, based on the short story "Memento Mori" by his brother Jonathan Nolan, which was later published in 2001. The film stars Guy Pearce as Leonard Shelby, a man who suffers from anterograde amnesia, resulting in short-term memory loss and the inability to form new memories. He searches for the people who attacked him, raped and killed his wife, using an elaborate system of Polaroid photographs, handwritten notes, and tattoos to track information he won't remember. Carrie-Anne Moss and Joe Pantoliano co-star in the film.

Ænema

Ænema

"Ænema" is a song by rock band Tool, released as the third single from their second major-label release Ænima. Adam Jones made a video for the song using stop-motion animation; it is included in the Salival box set. The song reached number twenty-five on the US Mainstream Rock Tracks chart in August 1997.

Tool (band)

Tool (band)

Tool is an American rock band from Los Angeles. Formed in 1990, the group's line-up includes vocalist Maynard James Keenan, guitarist Adam Jones and drummer Danny Carey. Justin Chancellor has been the band's bassist since 1995, replacing their original bassist Paul D'Amour. Tool has won four Grammy Awards, performed worldwide tours, and produced albums topping the charts in several countries.