9-11

Lec 9:Learning and Memory 

Memory: automatically and incidentally encodes info without intention or specifically attending to it 

  • Organized according to the contents; different types of memories are stored by and in diff parts of the brain

Long term memory 

  • Medial temporal lobe (hippo/surrounding cortices)/ diencephalon

    • Facts and events→ declarative memory

  • Striatum→ skills and habits (non-declarative)

  • Neocortex→ priming (non-D)

  • Amygdala (emotional) → classical conditioning (non-D)

  • Cerebellum (skeletal) → classical conditioning (non-D)

  • Reflex pathways→ nonassociative learning (non-D)

H.M

  • Suffered epileptic seizures

  • Had a bilateral MTL surgical resection (hippo,amygdala, and surrounding cortex) 

  • Impaired ability to learn new facts and events (declarative memory) 

  • Intact language, IQ, working memory and non-D memory skills

  • Contained retrograde amnesia→ memory for events that occurred before surgery are still in tack

  • Anterograde amnesia→ was permanent; lacked memory of events that occurred after surgery

    • Lost contact with the past and could not recognize people he saw everyday plus himself

  • HM→ intact working memory 

  • Conclusions (Miller) 

    • Ability to acquire new declarative memory= distinct function of MTL 

    • MTL not required for:

      • immediate (working) memory 

      • Habit and skill memory 

    • MTL can’t be ultimate storage site for long-term memory 

Rey-osterrieth complex figure test 

  • HM had no recall of having drawn a complex figure 

Mirror drawing test 

  • Having to draw an object without having direct visualization and instead is visible through a mirror

E.P

  • Amnesic since 1992

  • Severe damage to medial temporal lobe but little non-MTL damage 

Non-declarative test 

  • Priming

  • Given a set of words and then only given part of the word and outcome is recorded 

  • EP

    • Can associate word and word blank but can not distinguish between two sets of words when asked bout them 

Method of serial reproduction 

  • Demonstrates memories of experiences evolve and change and become reconstructed

  • More illusions rather than actual memory 

Eyewitness testimony 

  • Not considered material evidence 

  • Highly fallible 

  • Nature of the question→ alters nature of memory 

Implanting false memories 

  • Changing stories of things that happened but it will change the memory of the event

Autobiographical memory

  • Highly specific 

  • 30 Q’s → standardize by critical events 

  • Higher levels of obsessions (tendency) 

  • Memory distortion can occur→ there is a forgetting curve

Memories are figments of our imagination 

  • Imaginations are reconstructions of our memories 

  • purpose= predict the future; not stay in past 

Lec 10: Speech and Language 

Language 

  • Combination of sounds for communication 

  • Symbolic system that is guided by rules 

Components of language 

  • Phoneme→ fundamental language sounds 

  • Morphemes→ smallest meaningful unit of words 

  • Lexicon→ collection of all the words in a language

  • Syntax→ rules of grammar 

  • Semantics → meaning of words and sentences 

  • Prosody→ vocal intonations 

  • Discourse→ stringing sentences together to form a meaningful narrative 

Bimodal integration 

  • speech= more than vocalization 

  • Accompanied by gestures (visual) 

  • Cocktail party effect

    • Can hear speech better in a noisy environment if lips are visible 

    • Can focus on one speaker only by observing the lips 

  • McGurk Effect 

    • See and hear conflicting syllables → hear the syllable that is seen 

Language learning 

  • R/L distinction in Jap speakers

  • French R 

  • [Kh] sound in arabic, hebrew 

  • [Ch] in german 

  • Infants 

    • Prefer to listen to speech 

    • Can makes sounds used in all languages 

Functional neuroanatomy 

  • Wernicke-geschwind model 

    • Words sounds sent to A1 

    • Word meaning is represented in Wernicke’s area

    • Meaning is sent to Broca’s area thru arcuate fasciculus 

    • Broca sends instructions for speech articulation to motor cortex 

    • Read, visual areas send info to angular gyrus, Wernicke’s , or Broca’s 

Language mapping 

  • Effects of cortical stim 

    • Total arrest of speech 

    • Hesitation/ slurring of speech 

    • Speech distortion/ repetition of speech 

    • Confusion of number 

    • Naming difficulties 

    • misnaming/ preservation 

    • Widespread cortical activation for language within the brain 

Disorders 

  • Aphasia 

    • Disorder of language, writing (agraphia) or reading (alexia) 

    • Does not include disorders that result from→ loss of sensory input; motor paralysis or incoordination 

    • Fluent

      • Impairment in reception of language 

      • Wernicke’s aphasia (sensory aphasia) 

        • Deficit in classifying sounds

        • Word salad 

        • Confusion of phonetic characteristics 

        • Can’t write 

        • Can read in some cases 

      • Transcortial aphasia (iso syndrome) 

        • Can repeat, understand, and name obj

        • Can’t speak spontaneously 

        • Can’t comprehend words 

      • Anomic aphasia (amnesic) 

        • Can comprehend, produce speech, and can repeat 

        • Difficulty naming objects 

      • Conduction aphasia 

        • Can speak, name objects, and understand speech 

        • Can’t repeat 

        • Can’t perform guided speech commands 

    • Nonfluent

      • Broca’s aphasia (expressive) 

        • Can understand speech 

        • Can’t produce or have difficulty producing speech 

      • Transcortical motor aphasia 

        • Good repetition, poor spontaneous production 

      • Global aphasia 

        • Labored speech, poor comprehension 

    • pure aphasia 

      • Alexia 

        • Inability to read

      • Agraphia 

        • Inability to write 

      • Word deafness 

        • Can’t hear or repeat words 

*can be selective disorders 

Lec 11: Personality, decision making, and social behavior 

Prefrontal cortex 

  • Most recent addition in evolution 

  • Present in all mammalian species 

  • Associated with the expansion of cognitive abilities

  • Massive synaptogenesis in this region in infants (7-12 mnths) 

  • Functions

    • Abstract reasoning 

    • Executive function 

    • Social behavior 

    • Personality 

  • Ratio of frontal lobe to brain= largest 

    • In other species= smaller 

    • ratio= associated with expansion in cognitive abilities 

  • Core deficits with lesions 

    • Motor planning, gaze, speech 

    • Loss of divergent thinking and spontaneous production 

    • Impaired response inhibition and inflexibility 

    • Inability:to manage delayed outcomes 

    • Impulsivity is increased 

    • Impaired social behavior 

    • Personality changes 

  • Testing 

    • Matrix reasoning 

      • Selection of the item from the list that best fits the missing slot 

        • Uses logic and abstraction, sensitive to frontal lobe damage 

    • Wisconsin card sorting 

      • Sort according to unspoken rule; examiner changes the rule and patient only receives correct/incorrect feedback 

    • Stroop task 

      • Name the color, not the word 

        • Sensitive to frontal and anterior cingulate deficits 

    • Iowa gambling task 

      • Has “good” or “bad” decks; subjects do not go broke unless they have a frontal deficit

      • normal= no broke

    • Tower construction 

      • Tower of london→ reach goals shown to the subject 

      • Tower of Hanoi→ reach goal told to subject 

Verbal fluency 

  • Letter (phonemic) fluency 

    • Name as many words beginning with a certain letter within a minute 

      • No dup or doubles allowed 

      • Avg for 18-29 yrs = 13 words 

  • Category fluency 

    • Name as many words that belong to the category within a minute 

      • Avg for 18-29 yrs= 20 words 

  • Trail making test (Pt. B)

    • Sequencing numbers and letters by connection of dots 

    • Sensitive to task switching deficits 

      • Requires intact working memory

      • Reaction times is key measure

      • Sensitive measure of executive function 

Clinical case study 

  • FTD 

    • Poor judgement 

    • Lack of instant disinhibition 

    • Lack of apathy 

    • Compulsive overeating 

    • Have relative intact MMSE visuospatial/ language functions 

    • Failed tasks of generation/ executive function