cognition

  • everything that the cerebral cortex does is cognition
  • the cerebral cortex dominates the humans brain
  • from the cerebral cortex comes
    • action
    • perception
    • emotion
    • motivation
    • executive function
    • thought
    • memory

emotion

  • bodily expression of emotion is the only way to release them
  • the body is used to both facilitate and dissipate emotion
    • both critical components of a rich emotional life

thalamic attention

  • visual information travels through the retina, thalamus and then to the primary visual cortex
    • thalamus is the translator for the visual cortex
  • the same thalamic neuron that gets info from the retina also gets information from the brainstem
    • and also a large part from primary visual cortex
    • which is the feedback of having processed the retinal information, larger than the amount of info from the retina
      • outnumbers in quality, quantity
      • but the retina is more equal than the others
  • the input back from the visual cortex is huge
    • it tells us what we expect to see
    • it is a perceptual habit to cut down the amount of time it takes to decipher a visual scene by using expectations
    • enables faster perceptual judgements
  • disadvantages of being programmed to see what wee expect to see
    • it feeds in expectations that are status quo
    • it feeds into to stereotypes
    • every once in a while, those expectations are wrong

  • perceptual learning provides a shortcut path to recognizing certain patterns

  • the basic mechanisms that support attentions are not well understood and is still an area of research

memory

  • amnesia: lack of memory
    • no recall
  • there are three basic types of memory
    • working memory: the here and now
    • implicit
    • explicit (declarative)
  • explicit memories are formed from working memory
    • working memory is transferred to explicit memory by consolidation
    • encephalitis is the inability to form explicit memories
  • implicit memory is like riding a bike
    • all motor actions
    • mirror tracing
    • emotional memories (basis for PTSD)
    • implicit perceptual memories

PTSD

  • emotional memory
    • emotional memories of a traumatic event
    • triggers that remind an individual of the traumatic event
      • trigger debilitates the patient
  • traumatic events are particularly memorable
    • since emotion facilitates memory formation
  • trauma occurs in an emotionally charged environment
    • re-exposure to triggers from the environment can cause the same emotional reaction, that the original trauma triggered
    • this is PTSD
    • triggers can be smelling, hearing or remembering something from the sensory environment from the traumatic event
      • their body gets transported to the same emotional
  • beta blockers are used to treat PTSD
    • memory usually work with body and emotion together
    • beta blockers experience the trigger without the body reaction
    • the emotion is now hopefully relearn with the body reaction gone

explicit memory

  • two types of explicit memories
    • semantic memory
    • episodic memory
  • semantic memories are facts to be remembered
    • i.e. the first president
  • episodic are memories of things that happened
    • the birthday party
    • these are richer in detail compared to semantic memories

  • when episodic memories are repeated over and over, some parts of it become semantic memories

  • episodic memories enable oneself to transport oneself to the location and the event
    • while semantic are just certain facts from the episodic memory
    • re-experiencing the sensory details are possible
    • they are not tape-recorder snapshot memories
      • these are perceptual snapshots whose interpretation can change over time

underlying memory formation circuitry

  • bilateral hippocampus removal prevents declarative memory formation
    • story of H.M
    • H.M’s memory was studied for decades
  • the hippocampus is a required structure for memory formation
    • it is an old type of cerebral cortex
    • it is not in the neo cortex
  • the working memory to be consolidated to semantic or episodic events
    • is facilitated by the hippocampus
  • the hippocampus ships out information to the neo cortex
    • if it is semantic memory, it stays in the neo cortex
    • it doesn’t go back to the hippocampus
  • there are no absolutes in memory
    • the recall might change it a bit or not

hollywood amnesia

  • all old memory is gone but ability to form new memory stays
    • not based in neurobiological reality

clinical amnesia

  • lost hippocampal function causes typical clinical amnesia
  • cyclic transfer between hippocampus and neo cortex strengthen memory
    • the most recalled are the memory stored for the longest
  • the most recent memory is lost first with memory degradation
    • then slowly the more older memory is lost
  • losing memory is challenging
    • amnesia and alzheimers

language and disability

  • without the neocortex we are not producing, understanding or using language
    • a concrete example of cognition is found in language

  • humans cannot understand animal language as much as other human language

  • left hemisphere is dominant one for language production
    • the area primarily responsible for language comprehension is closer to auditory cortex
    • the area primarily responsible for language production is closer to motor cortex

aphasias

  • impairments in language abilities are called aphasia
  • there are many types of aphasia
    • damage to werneke’s region: problem with language comprehension
    • damage to broca’s region: problem with language production
  • although it is easy to define expressive aphasia and receptive aphasia as separate aphasias,
    • in reality both types of aphasia will show some problems with both comprehension and expression
  • in an expressive aphasia when Broca’s area is damaged,
    • one cannot mentally repeat the motor actions of the speech one hears
    • and so the ability to comprehend speech will be partially compromised

prosody

  • properties of prosody
    • body language
    • facial expression
    • gesticulations
    • context
  • properties of speech
    • loudness
    • timing
    • pitch
    • rhythm
  • prosody and speech go together in communication
    • this is why we can communicate without words
    • prosody is everything we do to how we speak
  • in the right hemisphere, comprehension and production of prosody occurs
    • this mirrors the area of semantic comprehension and production of speech in the left hemisphere

intellectual disability

  • one of the emergent properties of the cerebral cortex is intelligence

  • g factor: measure of intelligence similar to IQ for test performance

  • cerebral cortex and cerebellar cortex contribute to different types of intelligence

  • problems with cognitive development (intelligence) affects 5% of the population
    • inherited types of intellectual disability
  • no one common problem underlies all the cognitive disabilities