Memory CogSci_11 PDF

Memory I. Three-stage modal model of memory A. Sensory memory - Photographic memory B. Short-term/working memory C. Long-term memory II. Types of long-term memory A. Explicit memory B. Implicit memory III.Neurobiology of memory processing I. Where in the brain is long-term memory stored? II. Long-te...

Memory I. Three-stage modal model of memory A. Sensory memory - Photographic memory B. Short-term/working memory C. Long-term memory II. Types of long-term memory A. Explicit memory B. Implicit memory III.Neurobiology of memory processing I. Where in the brain is long-term memory stored? II. Long-term potentiation (LTP) III.The hippocampus and frontal lobes IV. Memory disorders: Evidence for separate memory systems A. Explicit memories: the hippocampus B. Implicit memories: cerebellum and basal ganglia C. Organic vs. psychogenic amnesia − Alzheimer’s disease V. Three stages of memory processing and forgetting A. Encoding failure B. Storage decay C. Retrieval failure VI. Memory as reconstruction A. Reconsolidation B. Schemas C. Source amnesia VII. Savant syndrome and hyperthymesia VIII.Scientific explanations of déjà vu IX. Effects of sleep deprivation on learning, memory, and cognition Three-Stage Model of Memory Three-stage modal model of memory (Atkinson-Shiffrin model): Sensory memory Working memory or short-term memory Long-term memory Sensory memory Holds sensory information very briefly (1/2 to 4 secs) Large capacity store Sensory input is held very briefly in sensory memory to allow selection and processing of information Now often considered to be a part of perception (Eriksen & Collins, 1967) Two types of sensory memory: Iconic memory (photographic memory): visual sensory memory Echoic memory: auditory sensory memory Eidetic imagery (photographic memory): characterized by relatively long-lasting and detailed images of visual scenes that can sometimes be scanned and “looked at” as if they had real existence (Leask, Haber, & Haber, 1969) Group of schoolchildren was shown a picture for 30 seconds. Picture was taken away, and children asked whether they could still see anything and, if so, to describe what they saw. Some children showed evidence of this kind of memory. Ø 10-year-old boy, looking at blank easel from which a picture of Alice in Wonderland had just been removed, is asked whether he sees something there (on the blank easel) Participant (P): I see the tree, gray tree with three limbs. I see the cat with stripes around its tail. Experimenter (E): Can you count those stripes? P: Yes (pause). There’s about 16. E: You’re counting what? Black, white or both? P: Both. E: Tell me what else you see. P: And I can see the flowers on the bottom. There’s about three stems but you can see two pairs of flowers. One on the right has green leaves, red flower on bottom with yellow on top. And I can see the girl with a green dress. She’s got blond hair and a red hair band and there are some leaves in the upper left-hand corner where the tree is. ² Eidetic imagery is relatively rare – only 5% or so of tested schoolchildren have it and proportion is much smaller in adults ² It is not an especially useful form of mental activity. Contrary to popular lore, memory experts don’t generally have eidetic imagery; their skill is in organizing material in memory, rather than in storing it in picture form. Short-term memory (STM) or working memory Holds items that are actively being thought about Has limited capacity - 7 +/- 2 items, e.g., letters, words, dots, though this number can vary by task - Number of words you can speak in 1.5 seconds Also limited in time, but longer than sensory memory - Lasts 5 to 30 seconds - Information decays rapidly unless maintained in consciousness through rehearsal Working memory (Baddeley) is now the preferred term because it emphasizes that this is an active, rather than a passive, process − Includes a phonological loop (associated with the left hemisphere) that briefly stores sounds, and a visuospatial sketchpad (associated with the right hemisphere) that stores visual and spatial information o Two visuospatial tasks will interfere with each other if performed simultaneously, as will two items in the phonological loop o However, people can perform a verbal task and a spatial task simultaneously - Episodic buffer: another component of working memory that can hold and combine information from phonological loop, visuospatial sketchpad and long-term memory to form a story – important in time sequencing - Central executive: integrates information from phonological loop, visuospatial sketchpad, and episodic buffer o Similar to attention/sensory memory in Atkinson Shriffin model Long-term memory (LTM) Repository of all one’s knowledge Unlimited in the amount it can store No time limit Types of Long-Term Memory ² Explicit/declarative memory (with conscious recall): recall or recognition of information; can be verbally transmitted - Episodic memory: recall of personal facts - Semantic memory: recall of general facts ² Implicit/non-declarative memory (without conscious recall): memory that influences one’s behavior or thought but does not itself enter consciousness; cannot be verbally transmitted - Procedural memory: Recall of how to do things Where in the Brain is Long-Term Memory Stored? How does storage work? Karl Lashley (1950) – Rats learn maze – Lesion cortex – Test memory ➜ Memories do not reside in single, specific spots Long-term potentiation (LTP): mechanism through which learning occurs in brain A long-term increase in the excitability of a neuron to a particular synaptic input caused by repeated high-frequency activity of that input ☞ Stimulating a particular neural circuit will increase the sensitivity of neurons in that circuit, increasing the probability that they will fire again Process involves binding of glutamate to NMDA receptor What LTP means psychologically: Both positive and negative thoughts tend to be self-reinforcing The more it snows (Tiddely pom), The more it goes (Tiddely pom), The more it goes (Tiddely pom), On snowing. And nobody knows (Tiddely pom), How cold my toes (Tiddely pom), How cold my toes (Tiddely pom), Are growing. – The House at Pooh Corner Two structures that play particularly important roles in the processing and storing new explicit memories are Frontal lobes: recalling information and holding it in working memory Hippocampus: “save” button for explicit memories ² The hippocampus acts as a loading dock where the brain temporarily holds to-beremembered information ² Items then migrate for storage elsewhere in process called memory consolidation Ø Example: - Removing a rat’s hippocampus 3 hours after it learns the location of some tasty new food prevents long-term memory formation - Removal 48 hours later does not (Tse, Langston, Kakeyama et al., 2007) v After a training experience, the greater one’s heart rate efficiency and hippocampus activity during sleep, the better the next day’s memory will be (Peigneux, Laureys, Fuchs et al., 2004; Whitehurst, Cellini, McDevitt et al., 2016) Memory Disorders: Evidence for Separate Memory Systems Dissociation: when brain damage affects two behaviors very differently, this suggests that the two behaviors are produced by different processes Ø Clive Wearing, an English musician, suffered damage to his hippocampus as result of encephalitis – If you walk out of the room, then come back 10 minutes late, he won’t remember you, but he can still conduct a choir and play the piano and harpsichord beautifully The hippocampus is central to the formation of explicit memories People with full temporal lobe amnesia (damage to the hippocampus and surrounding areas) cannot form new explicit memories though they can form new implicit memories They often have normal IQs and can carry on a normal conversation but cannot remember anything that happened more than a few minutes previously The posterior hippocampus contains place cells, neurons involved in spatial navigation Volume of the posterior hippocampus of London taxi drivers was found to be larger than that of control participants Also, the longer an individual had been a taxi driver, the larger was the volume of the posterior hippocampus (Maguire, Gadian, Johnsrude et al., 2000) Two structures that play important roles in the formation of implicit memories are Cerebellum: involved in learning of procedural memories for skills Basal ganglia: deep brain structure important in motor sequencing Ø Parkinson’s disease involves degeneration of parts of the basal ganglia v Cases of organic amnesia have provided evidence for the distinction between different memory systems (e.g., implicit and explicit) Organic amnesia: physical cause Brain injury through accident or stroke Korsakoff’s amnesia (Wernicke-Korsakoff syndrome): amnesia caused by brain damage resulting from thiamine deficiency, usually as a result of chronic alcoholism Psychogenic (“hysterical”) amnesia: psychological cause Dissociative identity disorder (multiple personality disorder): disorder in which a person exhibits two or more distinct and alternating personalities Alzheimer’s Disease Disease occurring in latter part of life that is characterized by deterioration of memory, reasoning, and language abilities Common form of neurocognitive disorder (deterioration of intellectual abilities; another common cause is vascular dementia) Occurs in 7% of population above age of 65 and up to 40% of people older than 80 years Associated with loss of neurons in cortical and sub-cortical regions: ventricles may be enlarged – patients might end up losing as much of 50% of their brain mass Produces severe degeneration of large parts of the brain: can eventually destroy most of the hippocampus and cortical gray matter Brains of patients contain many amyloid plaques, which contain a core of misfolded b-amyloid protein surrounded by degenerating axons and dendrites, and neurofibrillary tangles, dying neurons that contain twisted filaments of tau protein Deficiencies of acetylcholine: failure to show eyeblink conditioning Causes of Alzheimer’s Genetic component Higher risk of disease in those who have previously suffered a stroke or head trauma Conditions associated with cardiovascular disease, e.g., obesity, diabetes, high blood pressure, high cholesterol, smoking, and lack of exercise, increase risk Associated with low levels of vitamin D and certain B vitamins Exposure to lead and toxic substances, such as air pollutants, may increase risk Article published in Lancet in 2017 noted that hearing loss is now known to be the largest modifiable risk factor for developing neurocognitive disorders, exceeding that of smoking, high blood pressure, lack of exercise, and social isolation Research indicates that use of anticholinergics is associated with reduced brain volume and lower levels of glucose metabolism, particularly in the hippocampus - Those on anticholinergics also showed poorer performance on cognitive tests - Anticholinergics include Tylenol PM, Benadryl, Claritin, Dimetapp, Paxil, and Xanax ☞ Researchers concluded that these drugs could trigger or worsen Alzheimer’s (Gray, Anderson, Dublin et al., 2015) Also, studies have found that older people with tooth and gum disease score lower on memory and cognition tests - Experts speculate that inflammation in diseased mouths migrates to the brain Most importantly… Those who stay physically active and are nonobese have lower risk of developing disease v Heart health à brain health Studies have found that people who keep their minds active tend to show less loss of intellectual functioning in general as they age – Study of nuns in convent (Snowdon, 1997) found that education and intellectual activity seem to protect against Alzheimer’s – Study also found that degree of sentence complexity and amount of positive affect expressed in writing samples when subjects were in their 20’s were negatively associated with incidence of disease and positively associated with longevity Ø There have been cases where autopsies showed presence of disease but no symptoms had been present v Use it so you don’t lose it! Q&A Q: Which regions of the brain are thicker in successful agers than in regular agers? Those regulating cognition or emotion? A: Those regulating emotions, e.g., the midcingulate cortex and anterior insula. Q: What type of activities will increase your chances of remaining sharp into old age? A: Those that require hard work and cause you to feel somewhat tired, stymied, frustrated, e.g., grappling with a math problem or pushing yourself to your physical limits. (From research by Dr. Lisa Feldman Barrett) Three Stages of Memory Processing and Forgetting Memory as an information processing system Encoding: getting information into brain Storage: retaining that information Retrieval: getting the information back out ☞ Forgetting can derive from problems in encoding, storage, or retrieval Grouchy Jumpy Sniffy Lazy Cheerful Wheezy Gabby Hopeful Wishful Pop Shorty Stubby Fearful Shy Puffy Grumpy Nifty Sleepy Droopy Dumpy Bashful Happy Smiley Dopey Sneezy Teach Doc Encoding failure: information never entered long-term memory (lack of attention) Ø Memory of penny Storage decay: information stored in long-term memory gradually fades In general, storage decay is not as severe as most people tend to think… Ø Study found that people remembered nearly 40% of foreign language vocabulary, idioms, and grammar after 50 years (and 75% when recognition tests are used) Ø People who had taken psychology class remembered about 70% of broad general facts and research methods 10 years later (Bahrick, Bahrick, & Wittinger, 1975) Is storage decay simply due to the passage of time or to interference from new memories formed during this interval? Research suggests that storage decay is primarily due to interference Ø Participants learned lists of nonsense syllables, then either slept or engaged in normal daily activities ➔ Recall was significantly better when participants slept during the retention interval (Jenkins & Dallenbach, 1924) The degree to which memories interfere with each other depends on their similarity Ø It’s harder to remember a list of letters if all the letters rhyme (V, G, P, D) Retrieval failure: failure to access information that is stored in long-term memory – “forgotten” material is not completely erased but merely inaccessible Some common causes of retrieval failure Lack of appropriate retrieval cues (due to encoding specificity principle) Ø Ex: Inability to recognize student from your biology class at a dorm party Repression of painful or anxiety-provoking information Ø There have been documented cases of individuals who had been treated in hospital emergency rooms for childhood sexual abuse, yet these individuals failed to recall the episode when interviewed as adults (Williams, L.M., 1994; Schooler, Bendiksen, & Ambadar, 1997) Memory Reconstruction Memory as reconstruction: what we think we remember often never really occurred – we filter information and fill in missing pieces v Whenever we retrieve a memory, the brain rewrites it a bit – it is slightly altered chemically by a new protein synthesis that links it to our present concerns and understanding (reconsolidation) v Because the processes involved in memory reconstruction are unconscious, we can be convinced that our memories are accurate even when they are partially or even wholly wrong Ø 73 ninth-grade boys were interviewed, then re-interviewed 35 years later – When asked to recall how they had reported their attitudes, activities, and experiences, most men performed at a rate no better than chance – 1 in 3 now remembered having received physical punishment though, as ninthgraders, 82% said they had (Offer, Kaiz, Howard et al., 2000) Researchers are experimenting with manipulating reconsolidation to treat people with traumatic memories People are asked to recall the traumatic or negative experience At the same time, they are given - Propranolol, a memory-blocking drug or - A brief painless electric shock This disrupts reconsolidation of the memory, “erasing” it in part v Treatment still in experimental stages at this point Schemas: generalized information about a situation or event (e.g., things people do at birthday parties) In general, people show enhanced recall for schema-consistent material but there are exceptions Repisodic memory: recall of a supposed event that is really the blending of details over repeated and related episodes Ø If asked to recall the details of last Monday’s lunch, you might produce a repisodic memory based on what you usually do for lunch Source amnesia or source confusion: attributing to the wrong source an event that we have experienced, heard about, read about, or imagined Ø Case of Donald Thomson, a psychologist studying memory who was accused of rape after being interviewed on live television Savant Syndrome and Memory Savant syndrome: people who are born with severe intellectual disability but show superior ability in one intellectual domain, such as music, art, or mental arithmetic About 10% of children with autism have savant talents Analysis of case history of 13 musical savants – All had severe deficits in ability to understand and use language – 5 were blind or partially so – All showed an extraordinarily intense interest in performing music beginning at a very young age, usually before age 4 (Treffert, 2008) Savant syndrome is largely attributable to a seemingly limitless memory Musical savants can play back, note for note, long passages of music heard just once Artistic savants can reproduce exact copies of animals or people or scenes from memory Human calculators can tell you the day of the week that corresponds with any given day of any given month and year, past or future ☞ Suggests that memory capacities are potentially virtually limitless... Possible to create savant-like memorization skills and artistic abilities in people without autistic traits by disrupting left anterior frontal lobe with TMS Hyperthymesia of Superior Autobiographical Memory: Rare condition in which one has virtually perfect memory from about age of 10 Larry Cahill and James McGaugh constructed extensive memory tests to assess extent of each memory for each of six subjects - What was the date of the fall of the Berlin wall? - How many times did it rain in 1986? Associated with enlarged hippocampus and caudate nucleus: standard deviation of 7 or 8 – equivalent to a 10-foot tall person, as opposed to 5’9” Often associated with OCD type behavior; only 1 of 6 are married Déjà Vu Who experiences déjà vu? About 60% of population Negatively correlated with age Positively correlated with socioeconomic level and education Positively correlated with stress and fatigue More common in people who travel Scientific explanations (Alan S. Brown, 2003): Dual processing explanation − Incoming sensory data follow several different pathways − A slight alteration in transmission speed in one pathway could cause the brain to interpret the data as two separate experiences Attentional explanation − A fully processed perceptual experience that matches a minimally processed impression received moments earlier produces a strong feeling of familiarity − The original impression may not have been fully processed due to a physical distraction or a mental distraction, such as preoccupation with other thoughts Memory explanation: − Implicit familiarity without explicit recollection Ø Ex: Seeing a lamp in your friend’s apartment that is similar or identical to one that used to be in your aunt’s house Effects of Sleep Deprivation on Memory & Cognition Sleep deprivation causes irritability, fatigue, impaired concentration and creativity, greater vulnerability to accidents ☞ Surprisingly, people are oftentimes unaware that their concentration, judgment, etc. are impaired Sleep deprivation Impairs functioning of the prefrontal cortex, which has a negative impact on attention, memory, and decision making (Wu, Gillin, Buchsbuam et al., 2006) Reduces neuroplasticity and the proliferation of cells in hippocampus, which can result in memory impairments (Fernandes, Rocha, Rocha et al., 2015) Ø Study by Matthew Walker & Robert Stickgold (2006) found that without sleep, the brain was 40% less able to make new memories Impairs process of making broad connections and gaining creative insight Ø Participants were presented with a task where discovery of a hidden rule greatly improved speed of performance (Wagner, Gais, Haider et al., 2004) ➜ Sleep dramatically increased the likelihood of grasping the hidden rule ★ Sleep causes our brain to create new links, which is why we often wake up with solutions to previously unresolvable problems Sleep also plays an important role in emotion regulation After a night of no sleep, brain scans show a shutdown of the medial prefrontal cortex, which normally helps keep our anxiety in check (Simon, Rossi, Harvey et al., 2019) Research following youth through time found that sleep loss predicts depression rather than vice versa (Gregory, Rijksdijk, Lau et al., 2009) Sleep deprivation can produce hallucinations, delusions, and paranoia Ø Peter Tripp’s wake-a-thon Sleep debt can also cause metabolic and hormonal changes that mimic aging and lead to diabetes, obesity, hypertension, and memory impairment - Typical 18-year-old looks like 60-year-old in ability to metabolize glucose after 2 weeks of restricted sleep Sleep deprivation depresses the immune system and is associated with shorter lifespan ☞ “Poor sleep will make you fat and sad, and then kill you” Sleep deprivation in adolescents Teens now average nearly 2 hours less sleep a night than 80 years ago Insufficient sleep in adolescence increases risk of high blood pressure, heart disease, diabetes, risk-taking behavior, depression, and car accidents - Teens who sleep less than 8 hours are 3x more likely to make suicide attempts (Liu, X., 2004) - For each hour of sleep lost, odds of an adolescent’s being obese rises by 80% (Gupta, Mueller, Chan et al., 2002) Compared to A and B students, those who receive C’s, D’s, and F’s in school obtained about 25 min less sleep per night, went to bed an average of 40 minutes later, had more irregular sleep/wake schedules (greater weekend delays of sleep schedule) (Wolfson & Caskadon, 1998) Sacrificing sleep time to study actually worsens academic performance, by making it harder the next day to understand class material or do well on a test (Gillen-O’Neel, Huynh, & Fuligni, 2013) Also, a regular full night’s sleep can “dramatically improve athletic ability” (Maas & Robbins, 2010) Ø Treatment for insomnia - Treatment of underlying physical/psychological problem - Behavioral treatment (CBT-I) o Sleep restriction: go to bed and get up at the same time everyday o Stimulus control: associate your bed with sleep o Relaxation response training “Say, what's your secret?” ★ Many studies have indicated that CBT is just as effective as sleep meds and has more lasting overall benefit - Other helpful practices: o Exercise daily (preferably in late afternoon), but not right before bed o No caffeine after 5PM o Relax and dim lights hour or two before bedtime − Using screens in a dark room was associated with worse sleep outcomes than using them with the lights on − Children who used screens at bedtime consistently scored lower on quality-of-life tests (Mureku, Barker, Mutz et al., 2019) o Eat foods with more fiber and less simple carbs and saturated fat − More fiber and less saturated fat led to more slow-wave (deep) sleep − More sugar and simple carbs was associated with more frequently awakenings (St-Onge, Rogerts, Shechter, et al., 2016) o Consume milk, banana, or sunflower seeds right before bed to raise serotonin levels o Identify problematic thoughts and determine how to deal with them Some scary statistics on medical students/interns… According to the Center for Disease Control, being awake more than 24 hours impairs performance as much as having a blood alcohol level of.10% – which is legally drunk − Many interns work 80 hours per week, typically in shifts of 30 hours Medical students trained on traditional schedule, rather than alternative schedule with fewer weekly hours, made 5.6 times more diagnostic errors (Landrigan, Rothschild, Cronin et al., 2004) Video Reference Video excerpted from: Top 10 AMAZING SAVANTS With REAL SUPER POWERS https://www.youtube.com/watch?v=WZsJ6BtOh60