Lecture Notes: Memory & Language (PDF)

Memory X.Liu PSYC 5130 STM vs. LTM X.Liu PSYC 5130 Trade-off Pattern separation: The system will treat the retrieval cue like a novel stimulus and thus encode a new pattern in CA3, instead of recalling the old one. Pattern completion: The system will reactivate old memories instead of encoding new p...

Memory X.Liu PSYC 5130 STM vs. LTM X.Liu PSYC 5130 Trade-off Pattern separation: The system will treat the retrieval cue like a novel stimulus and thus encode a new pattern in CA3, instead of recalling the old one. Pattern completion: The system will reactivate old memories instead of encoding new patternseparated ones for truly novel episodes. Solution: –Hippocampus is fine-tuned –Strategic influences from other brain areas X.Liu PSYC 5130 Complementary Learning Systems Episodic Semantic X.Liu PSYC 5130 Slow Learning Integration Event has a.66 probability of occurring: only with a slow learning rate (.005) does it converge on an accurate estimate across discrete events X.Liu PSYC 5130 Another Facilitator? X.Liu PSYC 5130 Sleep X.Liu PSYC 5130 X.Liu PSYC 5130 Stages of Sleep EEG – Electrodes on the scalp monitor the brain’s activity – Two basic patterns of activity: Alpha activity when resting Beta activity when alert – Records sleepers to identify particular patterns of waveform activity Corresponds with different stages of sleep X.Liu PSYC 5130 X.Liu PSYC 5130 Participant in a Sleep Study X.Liu PSYC 5130 X.Liu PSYC 5130 A Typical Pattern of Sleep Stages During a Single Night The dark blue shading in this figure indicates REM sleep. X.Liu PSYC 5130 Lifespan Change X.Liu PSYC 5130 Complementary Learning Systems Episodic X.Liu PSYC 5130 Semantic Sleep & Memory The hippocampus teaches the cortex during SWS through replay Place Cells in the Hippocampus X.Liu PSYC 5130 Skaggs & McNaughton, 1996 Sleep & Memory The hippocampus teaches the cortex during SWS through replay During REM sleep, the cortex incorporates new memories into existing knowledge (Singha et al., 2022) X.Liu PSYC 5130 Why Sleep is Necessary Wake X.Liu PSYC 5130 Sleep X.Liu PSYC 5130 Language X.Liu PSYC 5130 A Brief Overview of Language Speech perception: mapping auditory input to known speech sounds Lexicon: “dictionary” of words Semantics: meaning Orthography: spelling Morphology: structure of units of meaning Syntax: putting together units of meaning Production: articulating speech sounds X.Liu PSYC 5130 The Brain Two Hemispheres Corpus Callosum: neural fibers that connects and transfers information between the two hemispheres. Cerebral Cortex: The outer covering of the brain’s cerebral hemispheres (Gray matter) X.Liu PSYC 5130 The Brain Hemispheres are controlled by opposite side of the body Stimuli projected on the right ear projects on to the left hemisphere Language = Left hemisphere (for most right-handed individuals) Hemispheric specialization happens through maturation, after birth, and throughout childhood X.Liu PSYC 5130 “Split-brain” Patients Corpus Callosum severed to prevent the spread of epileptic seizures from one side of the brain to the other X.Liu PSYC 5130 “Split-brain” Patients X.Liu PSYC 5130 X.Liu PSYC 5130 https://www.youtube.com/watch?v=ZMLzP1VCANo&t=216s Dichotic Listening Use your headphone/earphone!!! You will hear some spoken words over headphones Please write down the words that you hear, and let’s see if we hear the same words J X.Liu PSYC 5130 Dichotic Listening Experimental task in which subjects listen to spoken words over headphones, with a different word spoken into each ear Most people show an advantage for words piped into the right ear—that is, into the left hemisphere X.Liu PSYC 5130 Pat Bike Cow Take Lake Row Dark Cut Book He Fun Rain Top Sew Kit Met Man Lawn Race Boot Pink Bat Hike Pow Make Bake Hoe Bark Hut Look Bee Bun Pain Mop Bow Mitt Pet Can Gone Pace Toot Sink Language Disorders Egyptians reported speech loss after blow to head 3000 years ago Broca (1861) finds damage to left inferior frontal region (Broca’s area) of a language impaired patient, in postmortem analysis X.Liu PSYC 5130 Brain areas involved in Language X.Liu PSYC 5130 Broca’s aphasia Paul Broca & Tan (Louis Victor Leborgne) Broca’s patients - production impaired but comprehension relatively intact Broca’s patients often had right hemiparesis (weakening of the right arm and leg) X.Liu PSYC 5130 Examples X.Liu PSYC 5130 Examples What brought you to the hospital? Yes... ah... Monday... ah... Dad... Peter Hogan, and Dad... ah...hospital... and ah... Wednesday... Wednesday nine o'clock and ah Thursday... Ten o'clock ah doctors... two... two... an doctors and... ah... teeth... yah... And a doctor an girl... and gums, an I. X.Liu PSYC 5130 Broca’s aphasia Primarily expressive –Speech retains meaningfulness –Slow –Disjointed –Poorly articulated X.Liu PSYC 5130 Wernicke’s Aphasia Wernicke (1874) –Ten years later… –10 clinical cases –Identified a second cortical language area –Left temporal lobe just posterior to the primary auditory cortex X.Liu PSYC 5130 Examples X.Liu PSYC 5130 Examples What brings you to the hospital? Boy, I'm sweating, I'm awful nervous, you know, once in a while I get caught up, I can't mention the tarripoi, a month ago, quite a little, I've done a lot well, I impose a lot, while, on the other hand, you know what I mean, I have to run around, look it over trebbin and all that sort of stuff. X.Liu PSYC 5130 Wernicke’s Aphasia With damage, primarily receptive impairment Difficulty understanding language Speech production has superficial structure, rhythm, but incomprehensible X.Liu PSYC 5130 Broca and Wernicke Broca: Damage to left side of the frontal lobe è Difficulty to speak Wernicke: Damage to left side of the temporal lobe è Difficulty to understand language Broca’s aphasia Wernicke’s aphasia Halting speech; tremendous difficulty in choosing words; fairly good speech comprehension. Difficulty in understanding language; fluent speech, often nonsensical. Also called motor aphasia or expressive aphasia. Also called sensory aphasia or receptive aphasia. X.Liu PSYC 5130 Wernicke-Geschwind Model Arcuate fasciculus is the bridge from the Wernicke’s X.Liu PSYC 5130 area to the Broca’s area Conduction Aphasia Relatively well-preserved auditory comprehension Spontaneous speech production will be fluent and generally grammatically and syntactically correct Patients will show a marked inability to repeat words or sentences when prompted by an examiner. X.Liu PSYC 5130 Broca’s area (B only: BA 44) mild, aphemia Broca/Anterior/Production (B+: IFG, BG, insula) deficits in articulation, grammar comprehension Word Deafness (W: superior temporal gyrus/sulcus) selective word-comprehension deficits Wernicke/Posterior/Receptive (W+: superior temporal, inferior parietal) deficits in comprehension and production of meaningful speech Conduction (arcuate fasciculus, inferior parietal) impaired repetition, preserved comprehension and spontaneous speech Global Aphasia (left perisylvian region) impaired comprehension and production, residual overlearned speech Transcortical Sensory (disconnection W area from sensory inputs) severe comprehension deficit, preserved repetition Transcortical Motor (anterior to B area, supplementary motor areas) deficits similar to Broca’s aphasia, preserved repetition Atypical/Subcortical (head of caudate in basal ganglia or anterolateral thalamus) (Akinetic) mutism (SMA and/or anterior cingulate) X.Liu PSYC 5130 Anomia (pure naming deficits) (left anterior/medial temporal) Question: Is this statement correct? Broca’s area is solely responsible for language production, and Wernicke’s area is solely responsible for language comprehension X.Liu PSYC 5130 Wernicke-Geschwind Model Arcuate fasciculus is the bridge from the Wernicke’s X.Liu PSYC 5130 area to the Broca’s area fMRI e.g., Which part of the brain is responsible for speech comprehension? Experimental Condition Control Condition Listening to a word Listening to a tone X.Liu PSYC 5130 Hickok & Poeppel (2007) X.Liu PSYC 5130