11b memory pt 1

What is the Atkinson and Shiffrin modal model of memory?

The 1968 modal model describes memory as information moving among three major stores: sensory memory, working/short-term memory, and long-term memory. Attention transfers selected sensory information into working memory, encoding creates long-term memories, and retrieval returns long-term information to working memory.

[Diagram] Trace information through the complete modal model of memory.

Environmental input enters sensory memory; attended information moves into working memory; encoding moves information from working memory into long-term memory; retrieval reactivates long-term information in working memory for conscious use. Unattended sensory information and unrehearsed working-memory information may be lost.

What role does attention play in the modal model?

Attention acts as a selective mental spotlight. It chooses a small portion of the large sensory input stream for further processing in working memory, preventing sensory overload; sensory traces that are not attended generally fade.

What is encoding?

Encoding is the set of processes that transform information being handled in working memory into a form that can be represented in long-term memory. Effective encoding depends on how the material is processed, organized, and connected to prior knowledge.

What is retrieval?

Retrieval is the activation of information stored in long-term memory and its placement into working memory for conscious consideration, decision-making, or use on a test.

[Application] A student notices a term on a slide, thinks about its meaning, remembers it next week, and uses it on an exam. Which modal-model processes occurred?

The visual input briefly entered sensory memory; attention selected the term into working memory; meaningful processing encoded it into long-term memory; the exam question later cued retrieval back into working memory.

What is sensory memory, and what is its main value?

Sensory memory is a brief, fleeting store of relatively raw visual or auditory information. It preserves incoming stimulation long enough for initial analysis and attentional selection, creating continuity despite rapidly changing sensory input.

What is iconic memory?

Iconic memory is the visual form of sensory memory. It briefly preserves a rich influx of information from the eyes but fades especially quickly because the visual environment supplies more information than can be consciously processed.

What is echoic memory?

Echoic memory is the auditory form of sensory memory. It briefly preserves recently heard sounds, allowing a person to mentally replay the last words of a conversation even if attention was initially elsewhere; it generally lasts longer than iconic memory.

[MCQ trap] How do the capacity and duration of sensory memory differ?

Sensory memory has a large capacity for incoming sensory detail but an extremely short duration. Iconic traces fade very rapidly, while echoic traces can remain for several seconds; the lecture notes indicate auditory information may sometimes remain available for up to roughly 10 seconds.

Why did Baddeley replace the idea of passive short-term memory with working memory?

The term working memory emphasizes active mental work rather than simple temporary storage. Working memory maintains and manipulates information needed for current tasks, such as reasoning, comprehension, planning, and responding.

Why is working memory described as a limited-capacity bottleneck?

Only a small amount of information can be actively maintained and manipulated at once. Competing tasks must share this limited capacity, so multitasking or trying to control attention across too many inputs reduces performance.

What are the four components of Baddeley's working-memory model?

The central executive controls attention and coordinates three specialized systems: the visuospatial sketchpad, phonological loop, and episodic buffer.

What is the central executive?

The central executive is the attentional-control system of working memory. It allocates limited resources, switches focus, inhibits distractions, and coordinates information handled by the visuospatial sketchpad, phonological loop, and episodic buffer.

What is the visuospatial sketchpad?

The visuospatial sketchpad temporarily maintains and manipulates visual and spatial information, such as imagining an object's appearance, remembering where something was located, or mentally rotating an image while the object is absent.

What is the phonological loop?

The phonological loop temporarily maintains speech-based and auditory information through inner speech or rehearsal. It supports tasks such as holding a phone number in mind, understanding language, and preparing an appropriate verbal response.

What is the episodic buffer?

The episodic buffer temporarily binds information from different sources into integrated episodes. It links material from the phonological loop and visuospatial sketchpad with information retrieved from long-term memory, allowing a coherent event or moment to be represented.

[Application] Which working-memory component is most involved in each task: mental rotation, silently repeating a number, coordinating both tasks, and combining them with a remembered event?

Mental rotation uses the visuospatial sketchpad; silent repetition uses the phonological loop; allocating attention between them uses the central executive; integrating their information with long-term knowledge into one episode uses the episodic buffer.

[MCQ trap] Why are two verbal tasks more likely to interfere with each other than one verbal and one visual task?

Two verbal tasks compete for the same limited phonological-loop resources. A verbal and visual task draw more heavily on different subsystems, although both still require the limited central executive, so interference is reduced rather than eliminated.

What is rote rehearsal?

Rote rehearsal is the repeated maintenance of information in working memory, such as repeating a phone number or a line from a script. It can preserve exact information temporarily and sometimes improve later memory, but repetition alone does not guarantee understanding.

What do the Rundus and Glenberg, Smith, and Green findings imply about rehearsal?

Rundus (1971) showed that greater rehearsal can improve memory, but Glenberg, Smith, and Green (1977) showed that additional rehearsal time does not always help. Repetition is useful for maintaining material, whereas applying a concept in new ways usually requires deeper processing.

What is chunking, and why does it improve working-memory efficiency?

Chunking organizes several separate elements into one meaningful unit. Because working memory is limited by the number of active units, grouping three letters into one familiar acronym can make them function as one chunk rather than three unrelated items.

[Application] Why is remembering U-T-S-C easier as the chunk 'UTSC' than as four unrelated letters?

Prior knowledge binds the four letters into one meaningful unit. Working memory can therefore maintain one organized chunk instead of separately tracking four elements, increasing functional efficiency without literally increasing basic capacity.

What is the levels-of-processing principle?

Craik and Lockhart's levels-of-processing account proposes that deeper, meaning-based processing produces stronger and longer-lasting memories than shallow analysis of surface features.

[MCQ trap] Distinguish shallow and deep processing with an example.

Shallow processing focuses on appearance or sound, such as asking whether a word is printed in capitals. Deep processing focuses on meaning and associations, such as explaining the concept in one's own words, connecting it to prior knowledge, or applying it to oneself.

[Application] Which study method should produce better transfer to a novel exam problem: repeatedly rereading a definition or explaining and applying it?

Explaining and applying it should produce better transfer because it requires deeper semantic processing and multiple connections. Rereading may increase familiarity but can remain shallow and may not prepare the learner to use the concept in a new context.

What are the major properties of long-term memory?

Long-term memory is the relatively enduring store of knowledge that can later be accessed. It supports many sensory and conceptual modalities, has a virtually limitless estimated capacity, and can retain information from childhood into very old age, although access depends on successful retrieval.

[MCQ trap] Does failure to recall something prove it is absent from long-term memory?

No. Recall requires both stored information and successful retrieval. Tip-of-the-tongue states and later remembering show that information can be present but temporarily inaccessible.

What is state-dependent retrieval?

State-dependent retrieval is improved recall when the learner's internal physiological or psychological state at retrieval resembles the state present during encoding. More broadly, matching relevant study and test conditions can provide useful retrieval cues.

What is transfer-appropriate processing?

Memory improves when the mental operations used during encoding match those required at retrieval. For example, practicing difficult multiple-choice applications better prepares a student for a multiple-choice exam than only rereading notes.

[MCQ trap] How does transfer-appropriate processing differ from state-dependent retrieval?

Transfer-appropriate processing concerns a match between cognitive operations at study and test; state-dependent retrieval concerns a match in internal state or relevant conditions. Practicing recognition questions for a recognition test illustrates transfer-appropriate processing, not merely state dependence.

What is the tip-of-the-tongue phenomenon?

It is a temporary retrieval failure in which a person feels that the knowledge is available but cannot currently produce it. Moving on and returning later can help because the retrieval block may resolve while attention is directed elsewhere.

What is the serial-position effect?

Items at the beginning and end of a sequence are usually recalled better than items in the middle. The resulting serial-position curve combines a primacy effect for early items and a recency effect for late items.

What produces the primacy effect?

Early items receive more opportunity for rehearsal and encoding into long-term memory, so they are recalled better than middle items. The primacy effect therefore reflects a long-term-memory advantage.

What produces the recency effect?

The most recently presented items are still active or 'fresh' in working memory when immediate recall begins, so late items are recalled well. A delay or distracting task before recall should reduce this working-memory-based advantage.

[Graph identification] How is a serial-position curve interpreted?

High recall at the left side indicates primacy, low recall in the middle indicates the weakest serial positions, and high recall at the right side indicates recency. The graph is typically U-shaped rather than showing a steady decline.

How can the serial-position effect guide studying?

Students may naturally remember the first and most recent topics better, so material studied in the middle of a long session or course sequence deserves deliberate retrieval practice, spacing, and reorganization rather than additional passive reading.

What is the broad taxonomy of long-term memory?

Long-term memory divides into declarative/explicit memory and non-declarative/implicit memory. Explicit memory includes episodic and semantic memory; implicit memory includes procedural memory, priming, and conditioning.

Distinguish declarative/explicit from non-declarative/implicit memory.

Declarative memory is consciously accessible and can usually be described verbally, including events and facts. Non-declarative memory influences behaviour without requiring conscious recollection and is often difficult to explain verbally, including skills, priming, and conditioned associations.

What is episodic memory?

Episodic memory is explicit memory for personally experienced events situated in a particular time and place, such as remembering where one was and what happened during a birthday celebration.

What is a flashbulb memory?

A flashbulb memory is a vivid, emotionally intense episodic memory for the circumstances surrounding a consequential event. People often report very high confidence and a feeling of reliving it, but vividness and confidence do not guarantee accuracy.

[MCQ trap] What does conflicting research on flashbulb memories show?

Flashbulb memories can feel exceptionally clear and certain while their details change or contain errors. Confidence and emotional intensity are therefore not reliable measures of objective memory accuracy.

What is semantic memory?

Semantic memory is explicit knowledge of facts, concepts, word meanings, and general information about the world without requiring recollection of the episode in which the information was learned.

How can an episodic memory become semantic knowledge?

Learning often begins with an episode containing context, such as remembering the lecture in which a term was introduced. With repeated use, the learner may retain the factual meaning while losing the original learning context, leaving primarily semantic knowledge.

What is procedural memory, and which brain region is emphasized?

Procedural memory is implicit memory for how to perform practiced skills, such as mirror tracing or riding a bicycle. Performance can improve without conscious recollection of learning episodes; the lecture emphasizes the basal ganglia as important for procedural learning.

What is priming?

Priming is an implicit facilitation effect in which processing one stimulus makes related or previously encountered information faster or easier to process later, often without conscious awareness of the earlier influence.

[Application] How does seeing 'doctor' make 'nurse' or 'syringe' easier to process?

Activation spreads to semantically related concepts, lowering the processing needed for those concepts when they appear. This improved speed or accessibility is semantic priming, not necessarily conscious recall of the word 'doctor.'

[Application] How does a word-stem completion task test priming?

After exposure to words such as OCTOPUS or CLIMATE, a person becomes more likely or quicker to complete fragments such as O_T_P_ _ or _L_M_TE with those studied words. Facilitation can occur even when the person does not consciously remember seeing the original list.

Why is conditioning classified as non-declarative memory?

Conditioning stores learned associations that alter responses to stimuli without requiring conscious recollection or verbal description of the original learning episode. The learned behavioural effect can remain even when explicit memory for acquisition is unavailable.

[Scenario classification] Classify remembering graduation, knowing Toronto is in Ontario, typing automatically, faster recognition after prior exposure, and salivating to a learned cue.

Graduation = episodic explicit memory; Toronto fact = semantic explicit memory; typing skill = procedural implicit memory; facilitated recognition = priming; learned salivation = conditioning. The last three are non-declarative/implicit.

Who was patient H.M., and what surgery did he receive?

H.M. (1926-2008) developed severe seizures and underwent bilateral removal of medial temporal-lobe tissue, including much of the hippocampal region. Scoville and Milner reported the memory consequences in 1957; seizures improved, but major memory impairments followed.

What was H.M.'s major post-surgery memory profile?

He developed profound anterograde amnesia and partial, temporally graded retrograde amnesia, yet his short-term/working memory and general intelligence remained relatively intact.

What is anterograde amnesia?

Anterograde amnesia is impaired formation of new long-term memories for events occurring after brain injury or surgery. H.M. could maintain a conversation briefly but would not recognize the person later once the interaction left working memory.

What is retrograde amnesia?

Retrograde amnesia is loss of memories formed before brain injury or surgery. H.M.'s retrograde loss was partial rather than eliminating his entire pre-surgery past.

What does temporally graded retrograde amnesia mean?

Memory loss varies with time relative to the injury: more recent pre-injury memories are generally more vulnerable, whereas older remote memories are better preserved. It is not a random collection of missing time periods.

[MCQ trap] If H.M. could hold a number briefly but could not remember learning it the next day, what was preserved and what was impaired?

Immediate working/short-term maintenance was preserved, but formation of a new long-term declarative memory was impaired. This dissociation shows that working memory and long-term declarative encoding are separable functions.

Could H.M. form any new memories after surgery?

Yes. Although he could not reliably form new declarative memories, he could acquire non-declarative skills such as mirror tracing and sequence learning. His performance improved with practice even though he had no conscious memory of previous practice sessions.

[Application] Why is H.M.'s mirror-tracing improvement not evidence that his declarative memory recovered?

The improvement reflects procedural learning: skill performance became more accurate across sessions, but he could not consciously recollect the training episodes or explain improvement by remembering prior practice. Preserved implicit learning coexisted with impaired explicit memory.

What major conclusion follows from H.M.'s preserved skill learning?

Memory is not a single system. Medial temporal structures, including the hippocampus, are crucial for forming new declarative memories, whereas procedural learning can depend on other systems and survive profound declarative amnesia.

What happened to Clive Wearing?

Herpes simplex encephalitis caused severe brain damage and profound anterograde and retrograde amnesia. He lacked a continuous understanding of how one moment connected to the next and could not recall most of his past life, although some recognition and emotional attachment, especially toward his wife, remained.

[Comparison] How do H.M. and Clive Wearing both challenge the idea that memory is unitary?

Both showed devastating declarative-memory impairment alongside preserved abilities. H.M. retained working memory, intelligence, and procedural learning; Wearing retained some recognition and emotional responses. Their uneven profiles show that memory depends on multiple partially separable systems.

What is Hebb's principle, summarized as 'neurons that fire together, wire together'?

Donald Hebb proposed that repeated coordinated activity strengthens connections between neurons. When one neuron's activity repeatedly contributes to another's firing, their synaptic relationship becomes more effective, providing a cellular principle for learning.

What is long-term potentiation (LTP)?

LTP is a persistent enhancement of neural processing caused by strengthened synaptic connections after coordinated or repeated activation. It is treated as an important biological mechanism through which experience can produce lasting memory-related change.

How are glutamate and NMDA receptors related to LTP?

Glutamate activates NMDA receptors under the appropriate activity conditions, contributing to cellular changes that strengthen the synapse. The key exam relationship is that glutamatergic NMDA-receptor activity supports long-term potentiation and memory formation.

[MCQ trap] Does long-term potentiation mean information is stored in one permanently active neuron?

No. LTP refers to strengthened communication at synapses within neural networks, not a single neuron continuously firing or independently containing the complete memory.

What does cortical consolidation theory propose?

New declarative memories are initially formed rapidly with strong involvement of the hippocampal/medial temporal system. Over time, coordinated cortical representations become strengthened, so remote memories can become less dependent on the hippocampus; the cortex learns more slowly than the hippocampus.

[Sequence] Describe the three-stage consolidation pattern shown in the lecture.

First, the hippocampal region rapidly binds the components of a new memory. Second, repeated reactivation strengthens connections among distributed cortical representations, with sleep supporting this process. Third, the consolidated memory is represented more strongly across cortex and becomes less dependent on hippocampal binding.

How can sleep support memory consolidation?

Sleep can reactivate and stabilize recently encoded information, helping strengthen communication between hippocampal and cortical representations. It therefore supports longer-term storage rather than serving only as passive rest.

How does H.M.'s temporally graded retrograde amnesia support cortical consolidation theory?

Recent memories were more vulnerable because they still depended strongly on the damaged medial temporal system, whereas older memories had more time to develop distributed cortical support. This explains why damage can impair recent memories more than remote ones.

What is the gnostic or 'grandmother-cell' hypothesis?

It proposes that recognition of a complex object or person depends on a highly selective neuron that responds to that specific entity. A hypothetical 'grandmother cell' would activate when the combined defining features of one's grandmother are recognized.

What is the ensemble-coding hypothesis?

It proposes that complex objects are represented by distributed patterns of activity across populations of neurons. No single special neuron is required; recognition arises from the joint code for features such as face shape, hair, glasses, wrinkles, and clothing.

[MCQ trap] How do gnostic and ensemble coding make different predictions after loss of a neuron?

A strict gnostic account predicts that losing the one critical cell could eliminate recognition of its specific object. Ensemble coding is more distributed and therefore more robust: loss of one neuron may degrade a pattern but need not erase the entire representation.

[Short answer] Explain the complete modal model using the example of learning and answering an exam question.

The printed question first creates a brief iconic trace in sensory memory. Attention selects its relevant words into working memory, where the student manipulates them. During studying, organization and deep processing encoded related knowledge into long-term memory. At the exam, the question provides retrieval cues that reactivate that knowledge in working memory, allowing a response.

[Short answer] Recommend three working-memory or encoding strategies and explain why each helps.

Chunking groups multiple elements into fewer meaningful units, reducing working-memory load. Rote rehearsal can maintain exact information temporarily, although it is limited for understanding. Deep semantic processing connects material to prior knowledge and applications, creating stronger long-term memory than shallow rereading.

[Short answer] Explain the long-term-memory taxonomy using one example of each subtype.

Explicit memory includes episodic memory for an event, such as a birthday, and semantic memory for a fact, such as the capital of Canada. Implicit memory includes procedural skill, such as typing; priming, such as faster recognition after prior exposure; and conditioning, such as fear elicited by a learned cue.

[Short answer] Use H.M.'s impaired and preserved abilities to explain what the hippocampal case revealed about memory systems.

Bilateral medial temporal damage produced profound inability to form new declarative long-term memories and partial temporally graded retrograde amnesia, while working memory, intelligence, and new procedural learning remained. The pattern shows that the hippocampal system is crucial for declarative-memory formation but is not the sole basis of working memory, intelligence, or skill learning.

[Short answer] Connect Hebbian learning, LTP, consolidation, and distributed representation.

Coordinated neural firing can strengthen synapses according to Hebb's principle; LTP is a lasting enhancement of synaptic effectiveness involving mechanisms such as glutamate and NMDA receptors. Repeated reactivation, including during sleep, helps hippocampally bound memories develop stronger cortical representations, which may ultimately be coded across neuronal ensembles.