Human Memory It is good to have an end to journey towards; but it is the journey that matters, in the end. Ursula K. Le Gui

The Memory Process Three step process…. 1.Encoding: The processing of information into the memory system. 2.Storage: The retention of encoded material over time. 3.Retrieval: The process of getting the information out of memory storage.

Information Processing Model of Memory

Sensory Memory Stores all the stimuli that register on the senses Lasts up to three seconds Two types –Iconic memory Visual Usually lasts about 0.3 seconds Sperling’s tests (1960s) –Echoic memory (we’ll come back to this) Sensory Input Sensory Memory

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

Sensory Memory Echoic memory –Sensory memory for auditory input that lasts only 2 to 3 seconds 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 AKA working memory Working or Short-term Memory Sensory Input Sensory Memory Attention

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 CHUNK –Meaningful unit of information –Without rehearsal, we remember 4 ± 2 chunks –With rehearsal, we remember 7 ± 2 chunks –Ericsson & Chase (1982)

Long-term Memory Working or Short-term Memory Sensory Input Sensory Memory Attention Long-term memory Retrieval Once information passes from sensory to short-term memory, it can be encoded into long-term memory Encoding

Explicit Memories Episodic Memories Semantic Memories

Implicit Memories Procedural Memories Conditioned Memories

Take out a piece of paper and name all the Presidents…

Encoding Information Primacy Effect Recency Effect Serial Positioning Effect

Spacing Effect DO NOT CRAM!!!!!!!!!!!! Ebbinghaus’s Forgetting Curve

The Ways we can encode… Visual Encoding: the encoding of picture images. Acoustic Encoding: the encoding of sound, especially the sounds of words. Semantic Encoding: the encoding of meaning.

Long-term memory - Encoding Elaborative rehearsal –A technique for transferring information into long- term memory by thinking about it in a deeper way 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

Semantic Networks Red Roses Flowers Daisies Sunrise Sunsets Clouds Fire House Fire Engine Truck Bus Ambulance Cherry Apples Green Yellow Orange

Take out a piece of paper….. Name the seven dwarves….. Now name them…..

Was it easy or hard? It depends on several things…. If you like Disney movies? When was the last time you have seen the movie? Are people around you being loud pain in the butts so you cannot concentrate?

Recall Versus Recognition Recall you must retrieve the information from your memory fill-in-the blank or essay tests Recognition you must identify the target from possible targets multiple-choice tests

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 illusion 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)

Forgetting

Retroactive Interference: new information blocks out old information. Proactive Interference: old information blocks out new information. Calling your new girlfriend by old girlfriends name. Getting a new bus number and forgetting old bus number.

Storing Memories Long Term-Potentiation long-lasting enhancement in signal transmission between two neurons that results from stimulating them synchronously. In other words…they learn to fire together and get better at it…creating a memory.

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

Improving Memory Practice time –Distribute your studying over time Depth of processing –Spend ‘quality’ time studying Verbal mnemonics –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

Eyewitness Testimony Estimates of 2,000-10,000 wrongly convicted in U.S. based on eyewitness testimony Distortion Bias Inaccuracy