Chapter 14 How Do We Learn and Remember? PDF

Chapter 14 HOW DO WE LEARN AND REMEMBER?  The Brain is Plastic Experiences that change the brain – Development – Culture – Preferences – Coping Learning is common to these experiences. Neuroplasticity: The nervous system’s potential for physical or chemical cha...

Chapter 14 HOW DO WE LEARN AND REMEMBER?  The Brain is Plastic Experiences that change the brain – Development – Culture – Preferences – Coping Learning is common to these experiences. Neuroplasticity: The nervous system’s potential for physical or chemical change, which enhances its adaptability.  Connecting Learning and Memory Learning – A change in an organism’s behavior as a result of experience Memory – The ability to recall or recognize previous experience – Memory trace A mental representation of a previous experience Corresponds to a physical change in the brain, most likely involving synapses Studying Learning and Memory in the Laboratory Classical conditioning (Pavlovian conditioning) – Learning procedure whereby a neutral stimulus such as a tone (CS) comes to elicit a response (CR) because of its repeated pairing with some event such as the delivery of food (US); also called classical conditioning or respondent conditioning – CS + US  UR; after several pairings: CS  CR.  Classical / Pavlovian Conditioning Conditioned stimulus (CS) – In classical conditioning, an originally neutral stimulus that triggers a conditioned response (CR) after association with an unconditioned stimulus Unconditioned stimulus (US) – A stimulus that unconditionally—naturally and automatically—triggers an unconditioned response (UR)  Classical / Pavlovian Conditioning Unconditioned response – In classical conditioning, the unlearned, naturally occurring response to the unconditioned stimulus, such as salivation when food is in the mouth Conditioned response – In Pavlovian conditioning, the learned response to a formerly neutral conditioned stimulus  Eye-Blink Conditioning A tone (CS) is associated with a painless puff of air (US) to the participant’s eye. Blinking is normal reaction (UR) to a puff of air. Learning has occurred when blinking is a response to the CS alone (CR).  Fear Conditioning A tone (CS) is presented just before a brief, unexpected mild electric shock (US). When CS is presented later without the shock, the animal acts afraid (CR), becoming motionless. WHAT IS THE UR IN THIS PROCEDURE, AND HOW DOES IT RELATE TO THE CR?  Operant Conditioning Edward Thorndike (1898) – Learning procedure in which the consequences (such as obtaining a reward) of a particular behavior (such as pressing a bar) increase or decrease the probability of the behavior occurring again – Also called instrumental conditioning  Thorndike’s Puzzle Box Cat gradually learned that its actions had consequences: on the initial trial, the cat touched the releasing mechanism only by chance as it restlessly paced inside the box. Cat learned that something it had done opened the door, and it tended to repeat its behaviors from just before the door opened.  Memory Systems Memory forms the basis of our experiences and perceptions of the self. How would you feel if you lost your memory? If you could not remember your past? Or if you could not make new memories? MEMORY DOES NOT RESIDE IN A SINGLE SYSTEM. We want to understand how the brain stores information, and how it accesses stored information from memory. Memory is fragile! It is affected by many disorders including: dementias, loss of oxygen, and head injury.  Learning, Memory, and Amnesia Multiple Memory Systems – Different kinds of learning and memory use independent neural processes Amnesia – Partial or total loss of memory  Two Categories of Memory Implicit memory – Unconscious memory: Subjects demonstrate knowledge, such as a skill, conditioned response, or recalling events on prompting, but cannot explicitly retrieve the information. Explicit memory – Conscious memory: Subjects can retrieve an item and indicate that they know they retrieved the correct item.  Two Categories of Memory Declarative memory – Ability to recount what one knows, to detail the time, place, and circumstances of events; often lost in amnesia Procedural memory – Ability to recall a movement sequence or how to perform some act or behavior From a practical point of view, there is little difference between the implicit– explicit distinction and the procedural– declarative distinction.  Memory Categories Terms that Terms that Commonly used describe conscious describe unconscious dichotomies memory memory – One memory category Explicit Implicit necessitates recalling Declarative Nondeclarative specific information. Fact Skill – The other refers to Memory Habit knowledge of which we Knowing that Knowing how are not consciously Locale Taxon aware. – Pavlovian conditioning Conscious recollection Skills and Thorndike’s and Elaboration Integration Skinner’s operant Memory with Memory without learning are included in record record this analysis: they are Autobiographical Perceptual forms of implicit learning. Representational Dispositional Semantic Nonassociative Working Reference  Processing Memories Short-term memory (few minutes) – Information is held in memory only briefly, then discarded; involves the frontal lobes. Long-term memory (indefinite duration) – Information is held in memory indefinitely, perhaps for a lifetime; involves the temporal lobe. No single place in the nervous system can be identified as the location of memory or learning.  Storing Memories Information from each sensory modality (e.g., vision, audition) is processed and stored in different neural areas. Martin and colleagues (1995) – Recall of colors activated a region in the ventral temporal lobe. – Recall of action words activated a region in the middle temporal gyrus. Memory Distribution What Is Special about Personal Memories? Episodic memory – Autobiographical memory for events pegged to specific place and time contexts Episodic amnesia (e.g., Patient K. C.) – Inability to recall any personal experience – Associated with frontal lobe injury or reduced blood flow to the frontal lobes – Frontal lobes may allow us to mentally travel through our past. What Is Special about Personal Memories? Highly superior autobiographical memory (HSAM) – People display virtually complete recall for events in their lives, usually beginning around age 10. – Many can describe any episode, including the day of the week and the date.  MULTIPLE MEMORY SYSTEMS 2 main divisions Short-term memory (STM) includes - working memory Long-term memory (LTM) includes - explicit, implicit and emotional memory  MULTIPLE MEMORY SYSTEMS Short-term (STM): Limited capacity (between 5 and 9 bits of info), degrades quickly unless we rehearse or it transfers to LTM. Long-term (LTM): unlimited capacity, relatively permanent. Neuropsychologists mostly interested in disorders of LTM Multiple Memory Systems  LONG-TERM MEMORY (LTM) TAXONOMY Figure 9.1 (p. 228) Principles of Neuropsychology, 2nd Edition, by Eric A. Zillmer, Mary V. Spiers, and William C. Culbertson Copyright  2008 Wadsworth Publishing, a division of Thomson Learning. All rights reserved.  LTM is not just about remembering info from distant past. Rather we talk about registering info (encoding), organising information in a way that is meaningful to us (storage), and recalling/retrieving information when needed. LTM: ability to learn & retain new information. (Remote memory: concerns memory for long (distant) past events.) THERE IS NO ONE MEMORY STORAGE CENTRE, BUT RATHER MULTIPLE STRUCTURES AND SYSTEMS! Medial Temporal Structures Participating in Memory  THE HIPPOCAMPAL COMPLEX OF THE MEDIAL TEMPORAL LOBE Figure 9.2 (p. 230) Principles of Neuropsychology, 2nd Edition, by Eric A. Zillmer, Mary V. Spiers, and William C. Culbertson Copyright  2008 Wadsworth Publishing, a division of Thomson Learning. All rights reserved.  Long-Term Explicit Memory Explicit (Declarative) memory Events, facts, and episodic memories Conscious intentional remembering “Top-down” processing Episodic memory Autobiographic Person’s recall of singular personal events Semantic Memory All non-autobiographical knowledge— knowledge about the world Does not depend on medial-temporal lobe– ventral-prefrontal-lobe memory system that subserves episodic memory  The Hippocampus and Spatial Memory Animals with especially good spatial memory should have bigger hippocampi than do species with poorer spatial memories. – The hippocampal formation in food- storing birds and rodents is larger than that of birds and rodents that do not store food.  Inferring Spatial Memory Size of the hippocampi in both birds and mammals appears to be related to the cognitive demands of two highly spatial activities, foraging for and storing food. Posterior region of the hippocampus in London taxi drivers is significantly larger than the same region in the control participants.  Hemispheric Specialization for Explicit Memory Right Temporal Cortex – Removal leads to deficits on face recognition, spatial position, and maze learning Left Temporal Cortex – Removal leads to deficits in recall of word lists, recall of consonant trigrams, nonspatial associations, and on the Hebb Recurring-Digits test  Hemispheric Specialization for Explicit Memory Parietal and Occipital Cortex – Injuries may produce color amnesia, prosopagnosia (inability to recognize familiar faces), object anomia (inability to name objects), and topographic amnesia (spatial/perceptual dysfunction) Frontal Cortex – Left Prefrontal Cortex More engaged in encoding semantic and episodic information than in retrieving it – Right Prefrontal Cortex More engaged in episodic information retrieval than left Hemispheric Encoding Retrieval Asymmetry  Neural Substrates of Implicit Memory Cerebellum – Plays a role in classical conditioning – Lesions to the cerebellum abolish conditioned responses to a puff of air to the eye Basal Ganglia - Perceptual-motor learning and memory  Neural Substrates of Emotional Memory Emotional memory has unique anatomical component, the amygdala In Fear Conditioning – Noxious stimulus associated with neutral stimulus – Fear response is elicited – Fear response mediated by the amygdala Damage to the amygdala disrupts emotional memory, but not implicit or explicit memory  MEMORY Three enduring questions abound when discussing memory: How does information get into memory? How is information maintained in memory ? How is information pulled back out from memory?  MEMORY These three questions correspond to three key processes involved in memory Encoding – forming a memory code Storage – involves maintaining encoded information in memory over time Retrieval – involves recovering information from memory stores.  ENCODING Attention – Focusing awareness on a narrow range of stimuli or events. Selective attention is crucial to everyday Filter Divided attention Levels of attention – Structural encoding shallow from of processing that emphasises the physical structure of the stimulus – Phonemic encoding emphasising sound – Semantic encoding Emphases meaning Levels of processing theory = deeper levels result in longer lasting memory codes  ENCODING Enriching Encoding Elaboration – Linking stimulus to other info at the time of encoding Visual Imagery – visual imagery to represent words to remember can enrich coding Self- Referent Encoding – We remember events that involve us, making information about us increases retention. Motivation to Remember - MTR leads to greater recall – attend more, info more organised  Storage A information-processing model proposed by Atkinson and Shiffin – proposes that incoming information passes through two temporary storage buffers: The sensory store / sensory register The short-term store – Before it is transferred into long term memory Not anatomical structures in the brain but rather functionally distinct types of memory  Storage Sensory Memory The sensory memory – “preserves info in its original sensory form for a brief time, usually only a fraction of a second”. All raw information from our senses flows into the sensory registers - entry points for raw information from the senses. See these as waiting rooms where the information enters and stays for a short time. – Visual memory decays after one quarter of a second  Storage Visual and Auditory Registers Unlimited capacity – Volatile & short term – information disappears rapidly New visual info keeps coming into the sensory register – new info replaces the old info almost immediately This process is called masking Visual info is erased from the sensory register in about a quarter of a second, as new info replaces it. Auditory info - the echo lasts for a few seconds - thus enabling us to comprehend speech  Storage Short-Term Memory (STM) STM is a limited capacity store that can maintain unrehearsed info for up about 20 seconds How do we maintain info in our short-term memory? – Rehearsal : the process of repetitively verbalising or thinking about the info – Falls away due to decay and interference The capacity of the STM is limited, people can only recall about seven items in a task  Storage Chunking By chunking info into sentences or sentence fragments (of familiar info) we can process more info in the STM. Increase in size of any individual chunk decreases the total number of chunks that you can remember. To be able to chunk information, it needs to be recognised as a familiar unit – Familiarity stored somewhere in the LTM, therefore sometimes info gets transferred from LTM and used in STM – People regularly draw info out of their LTM bank to evaluate and understand info that  Storage Chunking FB - INB – CC – IAIB - M  Storage Chunking FBI - NBC – CIA - IBM  Storage Working Memory Working Memory consists of 4 components: The Phonological rehearsal loop – At work when you use recitation Visuo-spatial sketchpad – Allows people to temporarily hold and manipulate visual images Executive control system – This controls the focusing of attention, switching attention and dividing attention as needed. Episodic buffer – This is a temporary, limited capacity store that allows the various components of working memory to integrate info. It also serves as an interface between working memory and LTM  Storage Short-Term Memory / Working Memory STM holds the information we are consciously holding, or are aware of at any given moment. The STM has two tasks – 1: To store info briefly and 2: To work on that info. The STM can only hold as much info that can be rehearsed in 1.5-2secs, therefore can only hold a limited amount of info. (About 20 seconds of unrehearsed info) To help, the brain organises info into meaningful units. Chunking.  Storage Long-term Memory (LTM) This is defined as an unlimited capacity store that can hold info over lengthy periods of time. How is memory organised in LTM? Clustering – Schemas Organised cluster of knowledge about a particular a particular object or event based on previous experiences with the object or event – Semantic Networks Nodes representing concepts, joined together by pathways that link related concepts  RETRIEVAL Tip of the tongue phenomenon – Retrieval cue – stimuli that help us to gain access to our memories – Context cues Schemas - – More likely to remember things consistent with schema YET also remember things that are different Memories are sketchy reconstructions  RETRIEVAL Misinformation effect – “participants recall of an event they witnessed is altered by introducing misleading post-event information” – The misinformation effect occurs, even when people have been warned before hand Source monitoring – “making inference about the origins of memories” – Source monitoring error  Short-Term Memory Short-term, or working, memory (also temporal memory) – Memory for recent events and their order – Mediated by locations defined by the dorsal and ventral pathways to 2 regions of the frontal cortex Short-term memory and the Temporal Lobes – Left-posterior-temporal lesion may lead to short-term memory deficits WORKING MEMORY (WM) or “Working with memory” 1.Information is held in temporary storage. 2.Then these cognitions are subjected to mental manipulation. 3.Then, attention is required to protect this holding and manipulation from external distractions. 4.To manipulate, we need to often use information from LTM Involves 4 components: 1.Central executive (attention controlling system) 2.Phonological loop (stores speech-based information) 3.Visuospatial sketch-pad (manipulates visual/spatial information) 4.Episodic buffer (Temporary storage, integrates information through connection with LTM)  Examples of Neurological Diseases and Long-Term Memory Transient Global Amnesia Herpes Simplex Encephalitis Alzheimer’s Disease Korsakoff’s Syndrome (Permanent loss of the ability to learn new information (anterograde amnesia) and to retrieve old information (retrograde amnesia). Caused by diencephalic damage from chronic alcoholism or malnutrition that produces a vitamin B1 deficiency  Varieties of Amnesia Childhood (Infantile) Amnesia – Loss of memory for the early years of life Amnesias Rare and Common – Fugue State Form of memory loss in which individuals have no knowledge of their former life; usually transient – Amnesic for animal names or human faces or nouns or verbs  Anterograde and Retrograde Amnesia Anterograde Amnesia – Inability to acquire new memories – Global Anterograde Amnesia Impairment in the ability to form new memories across a variety of areas Retrograde Amnesia – Inability to access old memories – May be incomplete—older memories accessible but more recent memories are not  Amnesia ANTEROGRADE AMNESIA: loss of ability to encode and learn new information after a defined event (such as a head injury) or illness (such as a tumour). RETROGRADE AMNESIA: Loss of old memories from before an event or illness. Varieties of Amnesia  FORGETTING Forgetting curve – most forgetting happens immediately after Why do we forget? – Ineffective coding – Decay – memory traces fade with time – Interference – Retrieval failure – Motivated forgetting (repression) Repressed memory debate  FORGETTING – How to Reduce Forgetting Develop motivation Practice memory skills Be confident Minimize distractions Stay Focused Make connections between new material and other info already stored in LTM Use mental imagery Use retrieval cues Rely on more than memory alone Beware that your own personal schemata may distort you recall of events