Memory Revised By Pauline Davey Zeece, University Of Nebrask

Memory Revised by Pauline Davey Zeece, University Of Nebraska Lincolnc

Studying memory Building memories: Encoding Memory storage Retrieval: Getting information out Forgetting Memory construction errors Improving memory Memory Persistence of learning over time through the encoding, storage, and retrieval of information Information-processing model Compares human memory to a computer’s operation 4 Stages in Information-Processing Model Encoding Getting information into the memory system Storage Retaining encoded information over time Retrieval Getting information out of memory storage Information-Processing Model: Stages in Forming Memories Recording to-be-remembered information as a fleeting sensory memory Processing information into short-term memory, where it is encoded through rehearsal Moving information into long-term memory for later retrieval Sensory memory: Immediate and very brief recording of sensory information in the memory system Short-term memory: Activated memory that holds a few items briefly before the information is stored or forgotten Long-term memory: Relatively permanent and limitless storehouse of the memory system Includes knowledge, skills, and experiences 6 Modified Three-Stage Processing Model of Memory Atkinson and Shiffrin’s classic three-step model helps us to think about how memories are processed, but today’s researchers recognize other ways long-term memories form. For example, some information slips into long-term memory via a “back door,†without our consciously attending to it (automatic processing). And so much active processing occurs in the short-term memory stage that many now prefer to call that stage working memory. 7 Working Memory Newer understanding of short-term memory Includes the conscious and active processing of: Incoming information Information retrieved from long-term memory Working memory is more efficient when individuals focus on one task at a time, without distractions. 8 Want to try to see how good your working memory is? In Class Demonstration Two-Track Memory System Implicit (nondeclarative) memory Retention of learned skills, or classically conditioned associations, without conscious awareness Formed via automatic processing Explicit (declarative) memory Retention of facts and personal events that can be consciously retrieved Formed via effortful processing Building Memories Automatic processing and implicit memories Implicit memories include automatic skills and classically conditioned associations. Effortful processing and explicit memories Explicit memories become automatic with experience and practice. This Photo by Unknown author is licensed under CC BY . Your two-track mind processes information efficiently via parallel processing, which involves processing of many aspects of a problem at the same time. This method is the brain’s natural mode of information processing for many functions. 13 Sensory Memory First stage in forming explicit memories Records immediate and very brief information and is fleeting in nature Iconic memory - Picture-image memory of a scene Echoic memory - Sensory memory of sounds Capacity of Short-Term and Working Memory Short-term memory Miller proposed that individuals can store about seven bits of information during the short-term stage. Other researchers confirmed that individuals can recall about seven digits or about six letters or five words without distraction. 16 Short-Term Memory Decay Unless rehearsed, verbal information may be quickly forgotten. Data from Peterson & Peterson, 1959; see also Brown, 1958. 17 Effortful Processing Strategies Chunking: Organizing items into familiar and manageable units Occurs naturally Mnemonics: Memory aids Includes techniques that use vivid imagery and organizational devices Effortful processing requires closer attention and effort, and chunking and mnemonics help us form meaningful and accessible memories. Memory researchers have also discovered other important influences on how we capture information and hold it in memory. 18 Memory Storage Retaining information in the brain Synaptic changes Retaining Information in the Brain Capacity for storing long-term memories has no real limit. Research findings Information is not stored in a single and specific spot. Memories as neural networks 26 The Hippocampus Explicit memories for facts and episodes are processed in the hippocampus (orange structure) and fed to other brain regions for storage. 28 Explicit and conscious memories are either semantic or episodic. Semantic memory: Explicit memory of facts and general knowledge Episodic memory: Explicit memory of personally experienced events Explicit Memory System Hippocampus: Neural center located in the limbic system Helps process explicit memories for storage 27 Explicit Memory System: The Frontal Lobes Memories migrate for storage via the memory consolidation process. Right and left frontal lobes store different information. A good night’s sleep supports memory consolidation. Slow-wave sleep Memory consolidation: Neural storage of a long-term memory Separate brain regions process explicit and implicit memories. From the rhythmic patterns of activity displayed by the hippocampus and the brain cortex, researchers have posited that the brain is replaying the day’s experiences as it transfers them to the cortex for long-term storage. 29 Hippocampus Hero Among animals, one contender for champion memorist would be a mere birdbrain—the Clark’s Nutcracker—which, during winter and spring, can locate up to 600 caches of pine seed it had previously buried. 30 Implicit Memory System: The Cerebellum and Basal Ganglia Cerebellum Plays an important role in forming and storing memories created by classical conditioning Basal ganglia Help form memories for physical skills, which are also implicit memories As adults, our conscious memory of our first four years is largely blank, an experience called infantile amnesia. To form and store explicit memories, we need a command of language and a well-developed hippocampus. Before age four, we don’t have those learning tools. 31 Retrieve and Remember Your friend has experienced brain damage in an accident. He can remember how to tie his shoes but has a hard time remembering anything you tell him during a conversation. How can implicit versus explicit information processing explain what’s going on here? ANSWER: Our explicit conscious memories of facts and episodes differ from our implicit memories of skills (such as tying shoelaces) and classically conditioned responses. The parts of the brain involved in explicit memory processing may have sustained damage in the accident, while the parts involved in implicit memory processing appear to have escaped harm. 33 Effect of Emotions on Memory Processing Excitement or stress triggers hormone production. It provokes the amygdala to boost activity in the brain’s memory-forming areas. Flashbulb memories: Clear memories of emotionally significant events Occur via emotion-triggered hormonal changes Retained due to rehearsal Flashbulb memory: Clear memory of an emotionally significant moment or event. 34 Review Key Memory Structures in the Brain Frontal lobes and hippocampus - Explicit memory formation Cerebellum and basal ganglia - Implicit memory formation Amygdala - Emotion-related memory formation Synaptic Changes: Kandel and Schwartz More serotonin is released during learning. The cell’s synapses become more efficient, which increases the efficiency of neural networks. The number of synapses increases with experience and learning. 36 Synaptic Changes Long-term potentiation (LTP): Increase in a synapse’s firing potential Believed to be a neural basis for learning and memory After LTP, a current passing through the brain would not erase old memories. Before LTP, an electric current that passes through the brain can wipe out very recent memories. 37 Figure 7.7 - Our Two Memory Systems 38 Retrieval: Getting Information Out Measuring retention Retrieval cues Measuring Retention Recall: Memory demonstrated by retrieving information learned earlier Fill-in-the-blank test Recognition: Memory demonstrated by identifying items previously learned Multiple-choice test Relearning: Memory demonstrated by time saved when learning material for a second time Our recognition memory is quick and vast. Indicators of memory strength include: Response speed when recalling or recognizing information Speed at relearning Tests of recognition and of time spent relearning demonstrate that we remember more than we can recall. 41 Ebbinghaus’ Retention Curve The more times Ebbinghaus practiced a list of nonsense syllables on day one, the less practice he needed to relearn it on day two. Speed of relearning is one way to measure whether something was learned and retained. 42 Retrieving a Memory Memories are held in storage by a web of associations. Retrieval cues serve as anchor points for pathways that can be followed to access a memory. The best cues come from associations formed at the time of encoding. Priming: Activation, often unconsciously, of particular associations in memory Retrieval cues: Any stimulus (event, feeling, place, and so on) linked to a specific memory 45 Retrieval Cues Memories are context dependent. Affected by the cues that are associated with a specific context State-dependent memory What is learned in one state can be easily recalled if the individual is in the same state. Mood-congruent memory: The tendency to recall experiences that are consistent with an individual's current good or bad mood Mood effects on retrieval help explain why our moods persist. When happy, we recall happy events and see the world as a happy place, which prolongs our good mood. When depressed, we recall sad events, which darkens our view of current events. 47 Forgetting Forgetting and the two-track mind Encoding failure Storage decay Retrieval failure When Do We Forget? Forgetting can occur at any memory stage. When we process information, we filter it, alter it, or lose much of it. 53 Forgetting and the Two-Track Mind Humans have two distinct memory systems controlled by different parts of the brain. Reasons for forgetting include: Encoding failure Storage decay Retrieval failure Amnesia: Loss of memory, often due to brain trauma, injury, or disease 54 Which on is th face of the penny? Forcing as Encoding Failure We cannot remember what we have not encoded. 56 Storage Decay The course of forgetting is initially rapid and then levels off with time. It is explained by the gradual fading of the physical memory trace. Memory trace: Lasting physical change in the brain as a memory forms 55 Retrieval Failure Sometimes even stored information cannot be accessed, which leads to forgetting. It stems from interference and motivated forgetting. Events and memories are not available because they were never acquired. Other memories are discarded due to stored memory decay. Sometimes, the memory is out of reach because individuals do not have enough information to access it. 58 Motivated Forgetting According to Freud, people repress painful or unacceptable memories to protect their self-concept and minimize anxiety. Memory researchers think that people: Succeed in forgetting unwanted neutral information Struggle to forget emotional events Repression: In psychoanalytic theory, the basic defense mechanism that banishes from consciousness the thoughts, feelings, and memories that arouse anxiety 61 Errors in Memory Construction Memory is not exact. One doesn’t just retrace memories, one reweaves them. Reconsolidation: The process in which previously stored memories, when retrieved, are potentially altered before being stored again All memories are false to some degree. 64 Memory Construction In this experiment, people viewed a film clip of a car accident (left). Those who later were asked a leading question recalled a more serious accident than they had witnessed. 66 Source Amnesia Faulty memory for how, when, or where information was learned or imagined Helps explain déjà vu An eerie sense that “I’ve experienced this before†Cues from the current situation may unconsciously trigger retrieval of an earlier experience. Recognizing False Memories False memories are hard to separate from real ones because they seem real. Can be persistent Repeated retellings of an event may make individuals feel like they had actually observed them. People easily remember the general idea, rather than the exact words. Memory construction errors seem to be at work in many recovered memories of childhood abuse. 69 Methods to Improve Memory Rehearse repeatedly. Make the material meaningful. Activate retrieval cues. Use mnemonic devices. Minimize proactive and retroactive interference. Sleep more. Test your own knowledge. Test your own knowledge, both to rehearse it and to find out what you do not yet know.

Paper For Above instruction

Memory is a fundamental aspect of human cognition that involves the encoding, storage, and retrieval of information. It allows individuals to retain and utilize knowledge, skills, and personal experiences over time. The study of memory encompasses understanding how memories are formed, maintained, and sometimes distorted. The modern understanding of memory is rooted in models that compare the human brain’s processes to those of a computer, emphasizing stages such as encoding, storage, and retrieval, which constitute the core of information-processing theories (Atkinson & Shiffrin, 1968). According to this model, memory begins with encoding sensory information, which then moves into short-term or working memory, and finally consolidates into long-term memory, where it can be stored indefinitely (Miller, 1956).

The distinction between sensory memory, short-term memory, and long-term memory is central to understanding human memory. Sensory memory captures immediate impressions of sensory stimuli in a fleeting manner, lasting only a fraction of a second to a few seconds. Iconic memory, the visual component, and echoic memory, the auditory component, exemplify this early stage (Sperling, 1960). Short-term memory, also called working memory, is more active and holds information temporarily, typically for about 15 to 30 seconds unless rehearsed (Baddeley, 2003). Its capacity is famously estimated by Miller (1956) as about seven items, such as digits or letters.

Effortful processing techniques, such as chunking and mnemonic devices, enhance memory formation by actively organizing and associating information to make it more meaningful and accessible (Craik & Tulving, 1975). Rehearsal, both rote and elaborative, plays a critical role in transferring information from short-term to long-term memory. Sleep additionally promotes memory consolidation, especially during slow-wave sleep, where neural processes strengthen synaptic connections (Rasch & Born, 2013).

Long-term memory encompasses explicit and implicit systems. Explicit memories, which include semantic (factual knowledge) and episodic (personal experiences) memories, depend heavily on the hippocampus, a neural center in the limbic system. The hippocampus facilitates the consolidation of these memories for long-term storage (Scoville & Milner, 1957). In contrast, implicit memories, like skills and conditioned responses, involve different neural structures, such as the cerebellum and basal ganglia, which are crucial for procedural learning (Squire & Zola, 1998). The amygdala also plays a pivotal role in emotional memories, especially those linked to fear and excitement, with hormonal changes during emotionally charged events enhancing memory strength (McGaugh, 2004).

Memory consolidation is supported by patterns of neural activity that reinforce synaptic connections through long-term potentiation (LTP), a process identified as a cellular basis for learning and memory, involving increased firing potential at specific synapses (Bliss & Lømo, 1973). Sleep, especially slow-wave sleep, facilitates this process, allowing information to transfer from temporary storage to more stable long-term repositories (Walker & Stickgold, 2010).

Retrieval of memories relies on cues that are deeply connected to the encoding context, including retrieval cues, which can be external stimuli or internal states. Context-dependent and state-dependent memories demonstrate how environmental and internal conditions—such as mood or physical surroundings—impact recall effectiveness (Godden & Baddeley, 1975). Recognition tasks generally facilitate quicker responses than free recall, and re-learning procedures demonstrate that many memories are retained despite seeming forgotten initially (Ebbinghaus, 1885).

However, human memory is not infallible. Forgetting can occur at any stage, and its causes include encoding failure, storage decay, and retrieval failure. Encoding failure refers to the inability to remember information that was never properly processed in the first place, often due to insufficient attention or ineffective encoding strategies (Craik & Lockhart, 1972). Storage decay, rooted in the physical fading of memory traces over time, was famously described by Ebbinghaus’s forgetting curve, which shows rapid initial forgetting that slows as time progresses. Retrieval failure often results from interference or insufficient cues, exemplified in phenomena such as motivated forgetting or repression, where emotional or traumatic memories are unconsciously suppressed (Freud, 1915/1950).

Memory errors include false memories and source amnesia, where individuals misattribute the origin of a memory. Reconsolidation theory suggests that retrieving memories makes them susceptible to alteration before they are stored again, which can lead to distortions. For example, leading questions can influence eyewitness testimony, increasing the likelihood of recalling a more serious accident than actually occurred (Loftus & Palmer, 1974). Such malleability emphasizes that human memory, while highly adaptive, is also inherently fragile and susceptible to distortions.

Improving memory involves various strategies, including rehearsal, making information meaningful, utilizing retrieval cues, and employing mnemonic devices such as acronyms or vivid imagery (Bellezza, 1981). Adequate sleep enhances memory consolidation by facilitating neural processes that strengthen synaptic connections (Rasch & Born, 2013). Testing oneself periodically not only reinforces learning but also helps identify gaps in knowledge, promoting more effective long-term retention (Karpicke & Roediger, 2008). Additionally, minimizing proactive and retroactive interference through organized study sessions and spaced rehearsal further optimizes memory function.

In conclusion, understanding the intricate processes underlying memory—ranging from neural mechanisms to cognitive strategies—can improve retention and reduce errors. Memory is not a perfect recorder but a dynamic system influenced by biological, environmental, and psychological factors. Advances in neuroscience continue to elucidate the complex neural networks involved in memory formation and retrieval, offering avenues for enhancing memory and addressing its failures (Eichenbaum, 2017). Recognizing that all memories are, to some extent, reconstructions highlights the importance of using effective techniques to bolster the fidelity and durability of our personal and factual memories alike.