Memory: of information for later retrieval

• The process by which we encode (record), store (retain), and retrieve information i.e. a process of 3R • Process by which information is: • Acquired (process of recording information in a form usable to ) • • Stored in the brain (the retention of encoded infor. over time) • Storage • Later retrieved (Material in memory storage has to be located and brought into to be useful) • Retrieval • Eventually (possibly) forgotten

Information processing approach • Computer as a model for our memory • A stimulus that registers on our senses can be remembered only if it • 1. Draws , which brings it into ; • 2. Is encoded, or transferred to storage sites in the brain, and • 3. Is retrieved for use at a later time. • Three types of memory • • Short-term memory (STM) • Long-term memory (LTM) • Can hold vast quantities of information for many years • According to this three-system approach to memory there are different memory storage systems or stages through which information must travel if it is to be remembered (Atkinson & Shiffrin, 1968,1971)

Information-Processing Model of Memory Retrieval

Sensory Attention Short-term Encoding Long-term Stimulus memory memory memory

Forgetting Forgetting

Atkinson and Shiffrin’s (1971) Modal Model

 Environmental Input  Sensory Registers  Detect sensory input from the various modalities  Visual, auditory, haptic, etc.  are held for only a few hundred milliseconds  Short-Term Store (STS)  Lasts a few seconds and is made up of:  Temporary  Control processes:  Rehearsal  Coding  Decisions  Retrieval strategies  Long-Term Store  Permanent memory store

Atkinson and Shiffrin Model

•12 items 7±2 • (1960) Miller’s Magic Number •Partial Report Paradigm (1956)

Sensory Memory

• Stores all the stimuli that register on the senses • Lasts up to three seconds • Two types Sensory Sensory • Input Memory • Visual • Usually lasts about 0.3 seconds • George Sperling’s tests (1960s) • Sperling’s Experiment

• Presented matrix of letters for 1/20 seconds • Report as many letters as possible • Subjects recalled only half of the letters • Was this because subjects didn’t have enough time to view entire matrix? • No • How did Sperling know this? Sperling’s Iconic Memory Experiment Sperling’s Iconic Memory Experiment Sperling’s Iconic Memory Experiment Sperling’s Iconic Memory Experiment Sperling’s Experiment

• Sounded low, medium or high tone immediately after matrix disappeared High • Tone signaled 1 row to report Medium • was almost perfect Low • Memory for images fades after 1/3 seconds or so, making report of entire display hard to do Sensory Memory

• Echoic memory • Sensory memory for auditory input that lasts only 2 to 3 seconds • Christopher Darwin and others (1972) put headphones on subjects and all at once played three sets of spoken letters – in the right ear, in the left ear, and in both ears at once. • Subjects then received a visual signal indicating which to report. • Using this study and others, researchers have found that echoic memory holds only a few items but lasts for two or three seconds, and perhaps even longer, before activation in the fades.

• Why do we need sensory memory? Short-term Memory

• Function • Conscious processing of information • Attention is the key • Limits what info comes under the spotlight of short-term memory at any given time • From the sensory register, the brain encodes information - converts it into a form that can be stored in short-term memory – visual, acoustic or semantic encoding. • Also known as working memory

Sensory Attention

Input Sensory Working or Memory Short-term Memory Memorize the following list of numbers:

1 8 1 2 1 9 4 1 1 7 7 6 1 4 9 2 2 0 0 1 Write down the numbers in order. Now, try again…

1812 1941 1776 1492 2001 Short-term Memory • Limited capacity • Can hold 7 ± 2 items for about 20 seconds • Maintenance rehearsal • The use of repetition to keep info in short-term memory • Memory span • The longest list of items that a person can repeat back immediately after presentation in correct order on 50% of trials • Miller observed this span to be approx 7 (Miller’s Magic Number) for adults • CHUNK • The largest meaningful unit in the presented material that the person recognizes • Without rehearsal, we remember 4 ± 2 chunks • With rehearsal, we remember 7 ± 2 chunks • Ericsson & Chase (1982) 8931944349250215784166850612094888856877273141861 0546297480129497496592280 Memory span not limited in terms of bits but rather in terms of chunks

• Forgetting is due to decay of the trace • The capacity for storage is small • Trace is a phonetic code

Baddeley and Hitch (1974)

• Attempted to simulate an STM deficit to see how STM influenced reasoning, comprehension, and tasks. • The Technique: • Require participants to repeat a sequence of digits out loud while concurrently performing a variety of cognitive tasks. The digits should fill up STM and interfere with doing the tasks. • The Test: • Increasing the STM load by adding more digits should cause more interference in reasoning. However … • The Results: • Participants were able to reason without difficulty, even when repeating sequences of up to eight digits. • Reaction times did slightly increase with digit load but the number of errors did not increase. Baddeley and Hitch (1974): Implications

• Since the error rate of the reasoning task remained constant across digit loads (around 5%), working memory does not appear to depend entirely on the same underlying memory system as digit span. • There does, however, appear to be some interaction between these systems, as the processing time did increase with increasing number of digits to be recalled. • To address these difficulties, Baddeley and Hitch (1974) proposed a model of working memory (WM) -- a system that supports complex cognitive activities like reasoning instead of just storage (like STM). Baddeley and Hitch’s (1974): Multi-Component Model

• Central executive: an attentionally-limited system that selects and manipulates material in two slave systems: • Phonological loop: holds sequences of acoustic or speech-based items • Visuo-spatial sketchpad: holds visually and/or spatially encoded items and arrays Short-Term Memory as “Working Memory”

• Holds only the most recently activated, or conscious, portion of long-term memory, and it moves these activated elements into and out of brief, temporary memory storage • STM not limited to phonemic encoding • Loss of information not only due to decay • Baddeley and Hitch model (1974) – 3 components of working memory • Phonological rehearsal loop • Visuospatial sketchpad • Executive control system

• WM is a term used to describe short-term memory as an active workspace where information is accessible for current use. • Baddeley’s model of working memory contains three elements: • A “central executive” • Auditory working memory • Visuo-spatial working memory • Material can enter conscious workspace from senses or from long-term memory Evidence for Phonological Loop

• Phonological similarity effect: • BBGTCD is harder to memorize than FKYWMR • Wordlength effect: • Pay,wit,bar,hop,sum vs. helicopter, university, television, alligator,opportunity • Subvocal articulation, auditory noise, interferes with Visuospatial sketchpad

• Closely related to visual imagery • Used to encode nonverbal visual and spatial information. • Disrupted by performing additional visuospatial tasks, eye movement, or irrelevant visual material (Baddley 1992) Central executive • Attentional control • Making changes to practiced routine. (Example: Altering driving to work routine when there is a traffic accident) • Dividing attention • Multitasking • Switching attention from one task to another Problems with the Three-Component Model of WM Chunking • The three-component model of WM cannot explain why memory span can sometimes exceed the capacity of the subsystems (as much as 15 words in a sentence) for words in a sentence • Aspects of LTM (e.g. grammar) help to chunk the items; yet, we lack an explanation of how LTM and WM interact for digit span (6 or 7 items) • If the phonological loop can store only about three items, where are the rest stored? If they are stored in visual STM, how does this interact with phonological STM? • Word span length vs. sentence span (Baddlely, Vallar, and Wilson 1987) • Some anterograde amnestics have excellent prose passage immediate recall, despite very poor delayed recall. Too much information for the phonological loop. Where is it stored?

• LTM modulating factors! • Number of words stored in memory is susceptible to variables such as word frequency and imageability (Hulme, Roodenrys, Brown, and Mercer 1995) • Multimodal integration • Where and how is information from the two subsidiary systems combined?

The Episodic Buffer • Episodic Buffer -- A newly proposed fourth component of the WM system. • Originally assumed to be controlled by the central executive. • Holds integrated episodes or scenes • Multimodal store integrating information from visual and auditory modalities • Integrates information from long and short term stores • Can explain “chunking” to improve STM capacity • A storage system with a capacity of around 4 chunks of information in a multidimensional code. • Information is retrieved through conscious awareness – consciousness pulls info together. • Allows for the binding of previously unrelated concepts -- disrupting the executive does not impair binding, so it may be automatic/passive The Current Model

• An elaboration of the original three-part model with a few major changes: • Added two links from phonological and visuo-spatial subsystems to LTM • Arrow A: language acquisition • Arrow B: visual and spatial mapping • Added the episodic buffer • Accessed through either subsystem and/or the central executive • Possibly linked to emotions

Long-term Memory

• Once information passes from sensory to short-term memory, it can be encoded into long-term memory • Eelatively permanent storage system that has the capacity to retain vast amounts of information for long periods of time. Retrieval

Sensory Working or Encoding Sensory Attention Long-term Short-term Memory memory Input Memory Long-term memory - Encoding • Elaborative rehearsal • A technique for transferring information into long-term memory by thinking about it in a deeper way (in a more meaningful way and associating it with other knowledge that is already in long-term memory). • Levels of processing • Semantic is more effective than visual or acoustic processing • Craik & Tulving (1975) • Self-referent effect • By viewing new info as relevant to the self, we consider that info more fully and are better able to recall it Levels of Processing: Craik and Lockhart (1972) • Incoming information processed at different levels • Deeper processing = longer lasting memory codes • Encoding levels: • Structural = shallow • Phonemic = intermediate • Semantic = deep Figure 7.4 Levels-of-processing theory Long-term memory

• Non Declarative/Procedural (Implicit) • Memories of behaviors, skills, etc. • Demonstrated through behavior • Declarative (Explicit) • Memories of facts • Episodic – personal experiences tied to places & time • Semantic – general knowledge • Semantic network Semantic Networks

Bus Truck

Ambulance House Orange Fire Engine

Fire

Yellow Gree Red n Apples Cherry Rose Sunrise s Daisies Sunsets Clouds Flowers Storage: Long-Term Memory Subsystems

Types of long-term memories

Explicit Implicit (declarative) (nondeclarative) With conscious Without conscious recall recall

Facts-general Personally Dispositions- knowledge experienced Skills-motor classical and (“semantic events and cognitive operant memory”) (“episodic conditioning memory”) effects Retrieval

• Retrieval • Process that controls flow of information from long-term to working memory store • • The types of memory elicited through the conscious retrieval of recollections in response to direct questions • • A nonconscious recollection of a prior experience that is revealed indirectly, by its effects on performance Retrieval – Explicit Memory

• Free-recall test • A type of explicit memory task in which a person must reproduce information without the benefit of external cues • Recognition task • A form of explicit memory retrieval in which items are presented to a person who must determine if they were previously encountered • Retrieval failure • Tip-of-the-tongue (Brown & McNeill) Retrieval – Explicit Memory

• Context-Dependent Memory • We are more successful at retrieving memories if we are in the same environment in which we stored them

• State-Dependent Memory • We are more successful at retrieving memories if we are in the same mood as when we stored them Retrieval – Implicit Memory

• Showing knowledge of something without recognizing that we know it • Research with amnesics • Déjà vu • The that a new situation is familiar • Eyewitness testimony • Eyewitness transference • Unintentional plagiarism Forgetting If we remembered everything, we should on most occasions be as ill off as if we remembered nothing. William James • Lack of encoding • Often, we don’t even encode the features necessary to ‘remember’ an object/event • Decay • Memory traces erode with the passage of time • No longer a valid theory of forgetting • Jenkins & Dallenbach (1924)

Interference theory

• Forgetting is a result of some memories interfering with others • Proactive interference • Old memories interfere with ability to remember new memories • Retroactive interference • New memories interfere with ability to remember old memories • Interference is stronger when material is similar Forgetting

•Repression • There are times when we are unable to remember painful past events • While there is no laboratory evidence for this, case studies suggest that memories can be repressed for a number of years and recovered in therapy Memory Construction

• Schema theory • Preconceptions about persons, objects, or events that bias the way new information is interpreted and recalled • • The tendency to incorporate false postevent information into one’s memory of the event itself • Illusory memories • People sometimes create memories that are completely false Improving Memory

• Practice time • Distribute your studying over time • Depth of processing • Spend ‘quality’ time studying • Verbal • Use rhyming or acronyms to reduce the amount of info to be stored Improving Memory • Method of loci • Items to be recalled are mentally placed in familiar locations • Interference • Study right before sleeping & review all the material right before the exam • Allocate an uninterrupted chunk of time to one course • Context reinstatement • Try to study in the same environment & mood in which you will be taking the exam