• We often complain about memory.
• It is common to claim “I have a terrible memory!” but not “I am amazingly stupid.”
• While we forget things like appointments or names, we rarely forget important events.
• Failing to recognize someone may suggest they were not significant to us.
• We often blame a bad memory as an excuse in such situations.
• Despite its fallibility, our memory is remarkably good.
• Schacter (2001) describes the seven sins of memory as the necessary consequences of the virtues that make memory rich and flexible.
• Human memory might be less reliable than a computer’s, but it is equally capacious, more flexible, and user-friendly.
• The case of Clive Wearing shows the devastating effects of memory loss due to disease (Wilson, Baddeley, & Kapur, 1995).

WHY DO WE NEED MEMORY?

• Clive Wearing was an extremely talented musician and expert on early music, leading a major London choir.
• He was once invited to perform before the Pope during a papal visit to London.
• In 1985, Clive contracted herpes simplex virus, which crossed the blood-brain barrier and caused encephalitis, leading to severe brain damage.
• The virus typically causes cold sores, but in rare cases like Clive’s, it can lead to life-threatening brain inflammation.
• After recovering consciousness, Clive suffered from dense amnesia, unable to store information for more than a few seconds.
• He repeatedly believed he had just recovered consciousness, a belief he wrote down in a notebook, crossing out previous entries and replacing them with similar statements.
• Clive retained a sense of his identity and had vague memories of significant events in his life, like his time at Cambridge and conducting Handel’s Messiah.
• However, his memory was very sketchy; for example, he could not recognize a photo of his college or recall the content of his own book on composer Lassus.
• He also could not recall common facts, such as who wrote Romeo and Juliet, or that he had remarried, despite greeting his new wife enthusiastically every time she appeared.
• Clive’s amnesia incapacitated him, preventing him from following a book or TV program, and he would get lost if he left his hospital room.
• He described his state as living in a “permanent present” and “hell on earth,” comparing it to being dead all the time.
• Despite his severe memory impairment, Clive’s musical abilities remained intact; he could conduct his choir, read music, and accompany himself while singing.
• During these moments of musical engagement, Clive briefly seemed like his old self, though the distress returned once he stopped playing.
• Over 20 years later, Clive remains severely amnesic but has grown calmer and more accepting of his condition.

ONE MEMORY OR MANY?

• Clive’s case highlights the importance of memory in daily life but does not reveal much about its nature.
• Clive’s brain damage affected multiple areas, leading to issues beyond amnesia.
• His preserved musical memory and skills suggest that memory is not a single, unified system.
• Other studies have shown that amnesic patients can repeat back a telephone number, indicating intact immediate memory, and can learn motor skills at a normal rate.
• Amnesic patients often show improved performance in tasks, even though they deny having encountered the situation before, demonstrating that some forms of learning are preserved.
• These findings suggest that memory consists of multiple systems rather than a single global one.
• The first chapters of the book aim to unpack the complexity of memory, laying the foundation for understanding how these systems influence our lives and change throughout different life stages.
• Later chapters will explore what happens when memory systems break down.
• The authors are presenting psychological theories of memory, which can evolve and vary among researchers.
• Despite different terminology and theoretical approaches, there is general agreement among those studying memory.
• The authors will explain the concept of theory that supports their approach to understanding memory

THEORIES, MAPS, AND MODELS

• In the 1950s, many believed psychological theories should resemble theories from physics.
• Clark Hull studied learning in white rats and developed a general theory of learning, using postulates and equations modeled on Newtonian physics (Hull, 1943).
• Hull’s rival, Edward Tolman (1948), proposed that rats form “cognitive maps,” or internal representations of their environment through exploration.
• The debate between Hull and Tolman persisted from the 1930s to the 1950s, but neither side could solve how to investigate these representations.
• The authors view theories as being like maps, which summarize knowledge simply and help guide understanding.
• A good theory will prompt new questions, leading to further discovery.
• The type of theory, like a map, depends on the questions being asked, with different maps serving different purposes (e.g., navigating an underground versus walking).
• Psychological theories operate at various levels of explanation and focus on different issues.
• For instance, an argument between a shopkeeper and a customer could be explained differently by sociologists, social psychologists, cognitive psychologists, and physiological psychologists.
• All these explanations are relevant, but none is the single “correct” interpretation.
• This contrasts with reductionism, which aims to reduce explanations to lower levels, such as from social psychology to cognitive psychology, and ultimately to physics.
• While it is valuable to explain phenomena at different levels, reductionism is impractical for applied problems, much like using subatomic physics to design bridges instead of Newtonian mechanics.
• The book aims to outline the psychology of memory, which is essential for understanding human behavior at interpersonal and social levels.
• The authors believe that psychology can interface with neurobiology to deepen our understanding of the various types of memory.
• They hope to demonstrate the fruitful connection between psychological, interpersonal, and neurobiological explanations throughout the book.

HOW CAN WE STUDY MEMORY?

• The case of Clive Wearing shows the importance and complexity of memory but raises the question of how to best study it.
• The study of human memory dates back to Aristotle and has been a key question in the philosophy of mind, though without firm conclusions.
• A lecture by philosopher A. J. Ayer demonstrated the limitations of philosophy in understanding memory, particularly through his claim that his memory was devoid of imagery.
• Ayer’s example highlights the challenge of using introspection to study memory, as people differ in what they experience in similar situations (e.g., visual imagery in memory).
• Introspection is limited for two main reasons:
  • People differ in their conscious experiences in the same situations.
  • A large part of our mental processes are nonconscious, and what is available to conscious awareness is not necessarily a good guide to the workings of the mind.
• While philosophy still addresses important issues about the mind, it is now widely accepted that these questions should be pursued alongside empirical scientific approaches.
• In the late 19th century, Sir Francis Galton studied imagery by asking people to reflect on their breakfast table, discovering a wide range of vividness in their memories.
• These differences in vividness were not correlated with the accuracy of memory, suggesting that nonconscious processes play a role in memory accuracy.
• This raises questions about whether people have different memory systems or strategies, or whether they just describe the same experiences differently.
• Subjective reports are interesting but do not provide a solid basis for understanding how memory works.
• Moving beyond introspection began in 19th-century Germany with psychophysics, which mapped relationships between physical stimuli (e.g., brightness, loudness) and psychological experiences.
• Initially, learning and memory were seen as unsuitable for experimental study.
• This view was overturned by German philosopher Hermann Ebbinghaus, who conducted experiments on himself over two years and demonstrated that systematic relationships could be established between learning conditions and the amount learned.
• Ebbinghaus published the first classic book on the science of memory (Ebbinghaus, 1885) and later studied color vision, intelligence, and other questions in experimental psychology.
• Ebbinghaus simplified the experimental study of memory by creating nonsense syllables (e.g., zug, pij, tev), which were devoid of meaning but verbally learnable and reportable.
• He served as his own subject, maintaining constant conditions like the room, time of day, and rate of presentation to avoid finding meaning in the stimuli.
• Ebbinghaus established basic principles of learning, which became foundational for future work in memory research.
• The Ebbinghaus tradition was further developed in the US, focusing on how new learning interacts with existing knowledge, leading to the “verbal learning approach.”
• This approach, popular from the 1930s to the 1960s, used associations between stimuli and responses, often involving remembering lists of nonsense syllables or words (McGeoch & Irion, 1952).
• The verbal learning approach was characterized by careful mapping of memory phenomena rather than building grand theories, as proposed by figures like Clark Hull.
• After the collapse of grand theories, this “dust bowl empiricism” approach gained broader acceptance, leading to the founding of The Journal of Verbal Learning and Verbal Behavior (later The Journal of Memory and Language).
• A second development in memory research came from Gestalt psychology, originating in Europe in the 1930s and later influencing North American studies.
• Gestalt psychologists emphasized the importance of internal representations and the active role of the rememberer, rather than focusing on observable stimuli and responses.
• Despite suffering from Nazi persecution, Gestalt psychology influenced memory research by introducing a focus on how learners organize material.
• Two influential figures of this approach were George Mandler and Endel Tulving, both of whom grew up in Europe, emigrated, and were trained in North America.
• In Britain, a third approach to memory emerged, led by Frederick Bartlett, who rejected studying memory through meaningless material, instead using complex material like folk tales from other cultures.
• Bartlett’s focus reflected his interest in social psychology and the importance of the rememberer’s “effort after meaning.”
• His approach emphasized memory errors and explained them in terms of participants’ cultural assumptions about the world, introducing the concept of internal representations or schemas.
• Bartlett’s method differed from Ebbinghaus’s tradition, as it relied on complex tasks, but it faced the challenge of studying internal representations of the world.
• The development of computers during and after WWII provided a possible solution to the problem of studying internal representations.
• Mathematicians like Norbert Wiener (1950) and physiologists like Gray Walter (1953) described machines demonstrating control similar to purposive behavior.
• Kenneth Craik, a Scottish psychologist working with Bartlett, proposed in his 1943 book The Nature of Explanation the idea of using computers to model psychological theories.
• Craik carried out early experiments using analog computers, applying his theoretical model to practical wartime problems, such as gun-aiming in tanks, before tragically dying in 1945.
• Craik’s ideas inspired a new psychological approach based on the computer metaphor, gaining traction among young researchers after the war.
• Donald Broadbent’s 1958 book Perception and Communication applied Craik’s ideas, focusing on work done at the Medical Research Council Applied Psychology Unit in Cambridge, much of it driven by practical wartime problems.
• In 1967, Ulric Neisser synthesized and summarized this growing field in his book Cognitive Psychology, which gave the field its name.
• The analogy of digital computers led to the view of human memory as comprising one or more storage systems, with three essential components: encoding (entering information), storage, and retrieval.
• These three components interact: how material is encoded affects how it is stored, which in turn limits what can be retrieved.
• A simple analogy is a shopping list: writing legibly (encoding) affects how the information is stored and later retrieved; if the ink is smudged (impaired storage), it hinders retrieval.
• The discovery of multiple interrelated memory systems complicates this further, showing that memory is not a singular, uniform system.

HOW MANY KINDS OF MEMORY?

• As the cognitive approach to psychology gained influence, the belief in a single memory system based on stimulus-response associations shifted towards the idea that multiple memory systems were involved.
• During the 1960s, a broad model emerged suggesting that information from the environment is first processed by sensory memory systems, acting as an interface between perception and memory.
• Information was then believed to pass to a temporary short-term memory system before being stored in long-term memory (LTM).
• The most influential version of this model was proposed by Atkinson and Shiffrin in 1968, known as the “modal model,” as it represented many similar memory models at the time.
• Several assumptions of the modal model were later questioned, leading to further elaboration and refinement.
• The number of memory types remains controversial, with some theorists rejecting the concept of static memory stores and instead focusing on memory processes (e.g., Nairne, 1990, 2002; Neath & Surprenant, 2003).
• These theorists suggest that common processes across different memory tasks imply a unitary memory system, rather than multiple distinct stores.
• The view presented here supports both the idea of memory structures (like stores) and the processes operating on them, similar to how the brain requires analysis of both static anatomy and dynamic physiology.
• While similarities across different memory tasks should be acknowledged, differences between memory systems should not be ignored.
• Regardless of the emphasis on similarities or differences, the overall view of memory remains consistent: distinct memory types help structure our understanding of human memory.
• The model assumes separate sensory, short-term, and long-term memory systems, each further subdivided into components.
• However, it is not assumed that information flows in a simple linear fashion from the environment to long-term memory.
• There is evidence that information flows in both directions: knowledge stored in long-term memory can influence attention and, in turn, what is processed and remembered.
• For example, a football fan may notice and remember specific plays that a less engaged viewer misses due to their stored knowledge shaping their focus.
• Sensory memory, which relates more to perception than to memory, was a topic of considerable interest during the 1960s, illustrating the principles of encoding, storage, and retrieval.
• However, sensory memory will not be a focus for the remainder of the discussion, which will instead cover short-term, working, and long-term memory systems.

SENSORY MEMORY

• In a dark room, waving a sparkler creates a trail that rapidly fades, indicating that the visual image is temporarily stored and quickly forgotten.
• This phenomenon underlies how movies work, where a sequence of static images is perceived as continuous because the perceptual system stores visual information long enough to integrate successive images.
• Neisser (1967) named this brief visual memory system “iconic memory” and its auditory counterpart “echoic memory.”
• In the early 1960s, Bell Laboratories researchers, such as Sperling (1960, 1963) and Averbach & Sperling (1961), used information-processing methods to study iconic memory.
• Sperling (1960) presented a visual array of twelve letters in three rows of four and asked participants to recall as many as possible. Most could only recall four or five letters.
• Despite recalling only four or five letters, participants felt as if they had briefly seen more letters but had forgotten them before they could report them.
• Sperling addressed this by cuing participants to recall only one of the three rows using a tone (high for the top row, medium for the middle, and low for the bottom row), providing a way to estimate the total number of letters stored.
• The timing of the recall cue affected the number of letters recalled. When tested immediately, recall provided an estimate of total memory store capacity, with performance decreasing as the tone was delayed.
• Sperling’s 1963 experiment showed that performance declined more with a bright visual field than with a dark one, suggesting that brightness interferes with the memory trace, a process known as masking.
• Michael Turvey (1973) identified two types of masking:
  • Brightness masking: The effect increases with the brightness of the mask and occurs when both the stimulus and mask are presented to the same eye, indicating a peripheral retinal process.
  • Pattern masking: Occurs when a target is followed by a mask with similar features (e.g., jumbled letters) and operates even when the target and mask are presented to different eyes, suggesting it affects a later stage of visual processing after the two-eye information is combined.
• Brightness masking leads to a composite perception of the target and mask, with a brighter mask making the target less distinct.
• Pattern masking disrupts the perception of a clear image before the information can be adequately processed, and it is relatively insensitive to brightness.
• In a dark room, waving a sparkler creates a fading visual trail, indicating the brief storage and rapid forgetting of visual information.
• This phenomenon underlies how movies are perceived as continuous, with the perceptual system storing visual information long enough to integrate successive static images.
• Neisser (1967) termed this brief visual memory system “iconic memory” and the auditory counterpart “echoic memory.”
• Researchers at Bell Laboratories, such as Sperling (1960, 1963) and Averbach & Sperling (1961), used information-processing methods to study iconic memory.
• Sperling (1960) presented a 12-letter array and asked participants to recall as many letters as possible, with most recalling four or five letters.
• Participants felt they had briefly seen more letters but forgot them before reporting.
• Sperling cued participants to recall one of the three rows using a tone, estimating total memory storage based on the results.
• Timing of the recall cue affected recall performance, with immediate recall providing an estimate of memory capacity and delayed tones leading to decreased performance.
• Sperling (1963) found that performance declined more with a bright visual field than a dark one, indicating that brightness interferes with the memory trace through masking.
• Michael Turvey (1973) identified two types of masking:
  • Brightness masking: Increases with mask brightness, occurs when the stimulus and mask are presented to the same eye, indicating a peripheral retinal process.
  • Pattern masking: Occurs when a target is followed by a mask with similar features (e.g., jumbled letters), operates even when the target and mask are presented to different eyes, suggesting it affects later visual processing.
• Brightness masking creates a composite perception of the target and mask, with brighter masks making the target less distinct.
• Pattern masking disrupts the clear perception of an image before the information can be adequately processed and is insensitive to brightness.
• Iconic memory provides a coherent representation of the visual world, allowing movies to be perceived as continuous rather than as static frames.
• Early stages of iconic memory are aspects of perception; more stable stages are discussed in relation to short-term memory.
• The auditory system has a brief sensory memory component, referred to as “echoic memory” by Neisser.
• Errors in recalling a long telephone number differ based on whether the number is heard or read.
  • With visual presentation, errors increase from the beginning to the end of the sequence.
  • With auditory presentation, the last one or two items are recalled more accurately than middle items (Murdock, 1967).
• This recency advantage disappears when another spoken item (e.g., “recall”) is interposed between presentation and recall.
• Crowder and Morton (1969, 1970) showed that the nature of the suffix is critical:
  • Non-disruptive suffixes: Visual or nonspeech auditory suffixes (e.g., a buzzer) do not disrupt performance.
  • Disruptive suffixes: Spoken suffixes disrupt recall, regardless of their meaning.
• Crowder and Morton proposed a “precategorical acoustic store” as the basis for the auditory recency effect.
• The interpretation of the auditory recency effect as memory or perception remains controversial (Jones, Hughes, & Macken, 2006; Baddeley & Larsen, 2007).
• The auditory recency effect is robust enough to play a significant role in studies of verbal short-term memory and has been proposed as an alternative to conventional short-term memory models (Jones et al., 2006).
• An adequate explanation of echoic memory likely requires integration with a broader theory of speech perception.

SHORT-TERM AND WORKING MEMORY

• Short-term memory (STM) refers to the temporary storage of small amounts of material over brief delays. The exact mechanism of storage is not specified and remains open to investigation. Performance often involves contributions from long-term memory, which must be considered when evaluating temporary storage systems. Research typically focuses on verbal material, but STM is not limited to verbal information and also includes visual, spatial, and less extensively, smell and touch information.

• Working memory is based on the assumption that a system exists for the temporary maintenance and manipulation of information. It is essential for performing complex tasks, providing a mental workspace for thought. Working memory is typically linked to attention and utilizes resources from both short-term and long-term memory (Miyake & Shah, 1999). Various models have been proposed, each reflecting the theorist’s area of interest and theoretical style. The multicomponent model, originally proposed by Baddeley and Hitch (1974), integrates research on STM with its functional role in cognitive activities such as reasoning, comprehension, and learning. This model has been influential and remains a primary focus in the study of working memory (Baddeley, 2007). Details and further exploration of working memory will be covered in Chapter 4.

LONG-TERM MEMORY

• Long-term memory is classified according to Squire (1992) into two broad categories: explicit (declarative) memory and implicit (nondeclarative) memory.

• Explicit memory involves conscious recall of specific events and factual information. This includes remembering personal experiences, such as meeting a friend on holiday, and factual knowledge, such as the meaning of a word or the color of an object.

• Implicit memory involves learning that influences performance without conscious awareness. Examples include skills like riding a bicycle or recognizing a friend’s handwriting more easily due to prior exposure.

• A more detailed exploration of these memory types will be covered in subsequent chapters.

Explicit memory

• Long-term memory can be divided into semantic and episodic memory.

• During the 1960s, advancements in automatic language processing by computer scientists led to the need for knowledge representation in computers, prompting psychologists to study how humans store semantic information.

• Endel Tulving (1972) introduced the distinction between semantic and episodic memory, which has been widely adopted since.

• Semantic memory encompasses general knowledge about the world, including facts, sensory attributes, and societal norms. It includes information like the color of a lemon or how to book a theater seat.

• Episodic memory involves the recall of specific events or personal experiences. For example, remembering the exact moment you learned about an old friend’s death is episodic memory.

• An event can be stored in both semantic and episodic memory. Semantic memory can reflect general knowledge acquired from multiple episodes, while episodic memory allows for the re-experience of specific events.

• Tulving (2002) limits “episodic memory” to cases where one re-experiences aspects of an original event, describing it as “mental time travel.” This capability is crucial for recalling and planning future actions.

• Amnesic patients often experience severe disruptions in episodic memory, which can significantly impact their daily lives, as evidenced by individuals like Clive Wearing.

• There is a possibility that semantic memory results from multiple episodic experiences. Amnesic patients’ difficulty in acquiring new semantic knowledge supports the idea that episodic memory plays a role in forming semantic memory.

• Although semantic and episodic memory might involve separate systems, they interact closely.

Implicit memory

• Amnesic patients exhibit severely disturbed episodic memory and a reduced ability to acquire new knowledge about the world.

• Despite these impairments, certain forms of learning remain intact, which has influenced the concept of implicit or nondeclarative memory.

• One preserved learning ability is classical conditioning. For example, amnesic patients can learn to blink in response to a tone that precedes a puff of air, though they do not remember the experience or understand the purpose of the air puff.

• Amnesic patients can also acquire motor skills. For instance, they improve their ability to keep a stylus on a moving spot of light with practice.

• In studies of word learning, amnesic patients demonstrated preserved implicit memory. Although they performed poorly on recall or recognition tasks, they could “guess” words from partial cues as accurately as control participants, indicating that information was stored despite a lack of explicit memory.

• This phenomenon, known as priming, is evident in various perceptual tasks, both visual and auditory. It is also observed in the improvement of complex activities like reading mirror writing or assembling jigsaw puzzles.

• There is ongoing debate about whether all forms of implicit learning and memory reflect a single memory system. While some attempts are made to explain them within a single framework, it is argued that they represent different learning systems in the brain, evolved for different purposes.

MEMORY: BEYOND THE LABORATORY

• Theoretical understanding of human memory involves exploring how information is encoded, stored, and retrieved.

• To be useful, theories must apply beyond laboratory settings, addressing memory functions in children, the elderly, different cultures, and in health and disease.

• Laboratory experiments provide controlled conditions for studying memory but may not fully capture how memory functions in real-world scenarios.

• Some argue that research should remain confined to the laboratory until a thorough understanding is achieved, while others, like Bartlett, believe this approach neglects important aspects of memory.

• An international conference in South Wales highlighted practical aspects of memory, such as memory for medical information and brain-damaged patients, emphasizing the need for real-world applications of memory research.

• Ulric Neisser criticized the laboratory-based tradition for neglecting socially significant aspects of memory, leading to a controversy about the value of laboratory versus real-world research.

• Theoretical developments often benefit from practical applications, such as understanding memory performance in specific groups like children, the elderly, and patients with memory problems.

• Studies of dense amnesia have illustrated the importance of episodic memory and informed clinical neuropsychology, enhancing both theory and practice.

• Research extending beyond the laboratory has uncovered significant aspects of memory not covered by existing theories, leading to new theoretical developments.

• The study of semantic memory was initially driven by computer scientists’ need for language-processing programs.

• Research into eyewitness testimony emerged from the practical need to address miscarriages of justice due to failures in understanding human memory limitations.

• Prospective memory, or remembering to do things, is a crucial but previously neglected area, reflecting a complex interaction between attention and memory.

• The book will cover these broader topics, demonstrating that theoretical and practical approaches to memory are complementary rather than mutually exclusive.

The contribution of neuroscience

• Ebbinghaus and Bartlett’s approaches to studying memory focused on psychological performance in normal individuals.

• Recent advancements have enriched this approach with data from neuroscience, exploring how the brain contributes to learning and memory.

• The book will highlight normal human memory functioning, using insights from patients with memory problems to understand memory functions better.

• Observations of patients with memory issues can reveal details about memory functions and guide further investigation.

• Modern methods allow neuroscientists to observe and record brain activity in healthy individuals during rest and complex tasks, including learning and memory.