Pathway:

Primary sensory cortex, where 3rd order neurons get to the cortex. Rough idea of what it might me (quality) →

Secondary sensory cortex, have more recognition of what it is, more discrete recognition →

Association Cortex, where we decide how we feel about the stimulus & decide what we should do about it →

Motor planning area, know we know what we want to do so this is where we create the plan →

Primary Motor Cortex, where the plan is executed

Primary Somatosensory Cortex

• receives information from tactile and proprioceptive receptors (3 neuron pathway)

  • 1st = peripheral afferent/dorsal column neuron

  • 2nd = medial lemniscus neuron (aka dorsal column)

  • 3rd = thalamocortical neuron

( visual and auditory have their own regions ***)

• Helps in our awareness of our environment…Discriminative touch & proprioception

  • awareness through somatosensation

  • able to determine location of stimulus

  • understand shape, size and texture of a structure

Primary Cortices

• Primary Auditory Cortices (PAC): receives info from the ears by a pathway that synapses at the inferior colliculus and medial geniculate body

  • in this case both cortices receive input from both ears, so damage to one side will not affect just one side (there are reinforcements)

• Primary Vestibular Cortices (PVC): receives information regarding head movement and position relative to gravity, info goes to both sides

• Primary Visual Cortex: information travels from the retina (cranial nerve 2) to the thalamus the to the primary visual cortex

  ( remember all sensory must go to the the thalamus first prior to the cortex***)

  Association Areas

• Dorsolateral Prefrontal (decision making & motor)

• Parietotemporal (special senses & maintaining equilibrium)

• Ventral & Medial Dorsal Prefrontal

  …these are all still linked to the function of the region

These association play a big role in our personality and how we interpret our environment. Regions affect…

• Personality

• Interpretation of Sensation (what it is and how we feel)

• Processing of Memory

• Emotions

• Intelligence

Dorsolateral Prefrontal

• function = self-awareness & executive function

• Executive function includes…

  • decide a goal

  • how to plan & how to execute the plan

  • Monitoring execution of the plan

Parietotemporal

• cognitive intelligence, including language, written and auditory communication

  • problem solving

  • comprehension of communication

  • understanding spatial relationships

( people who are functionally illiterate they still utilize this region to understand other cues, reading is a learned skill)

Ventral & Medial Dorsal Prefrontal

• close to the cingulate gyrus ( close to the limbic system) so it works with the limbic system

  • impulse control

  • personality

  • reactions to surroundings

SUMMARY of the 3 Association Areas

Dorsolateral Prefrontal Association Area: goal-oriented behavior & self awareness

Parietotemporal Association Area: sensory integration, problem solving, understanding language and spacial relationships

Ventral & Medial Dorsal Prefrontal Association: emotion, motivation & personality

Working Memory (short term: what’s happening in the next 5 mins)

• Maintains goal-relevant information (for a short time), matching memory to new experiences

• Essential for language, problem-solving, mental navigation and reasoning

• Multitasking requires working memory and is central to cognition

• The prefrontal cortex & the parietotemporal association cortex maintain, manipulate and update info in working memory…whats coming in vs what you already know (makes the connection)

Communication

• Wernicke’s Area: comprehension of spoken language & interprets symbols

  • understanding the words

  • even working in individuals who can’t read etc…

So you know what someone say and now what do you say back..

• Broca’a Area: provides instructions for language output

  • planning the movements (activates muscles) to produce speech

  • “ in order to blurt anything out”

  • correlates words when writing (the “inner voice to write”)

• these are bi-lateral, but weighted differently

If the cortex is not working correctly…Terms to Know

• Apraxia: loss of task performance, w/out loss of movement

  • you’ll have all the ROM and strength but unable to understand how to put it together/utilize

  • damage will keep you from making a good clear plan

• Agnosia: loss of the sensation

  • Mainly seen as loss of touch, but can affect any of the 5 senses

• Receptive (Wernicke’s) aphasia: cannot really understand spoken language (may be able to hear) and all other language is impacted…patients will make up words, substitute wrong words, disordered syntax (all with realizing what they’re truly saying)

  • cannot understand what they are hearing or what the words are

  • they don’t understand what they themselves are saying (aka produces word salad)

• Expressive Aphasia (Broca): hallmark is the ability to understand written and verbal language but unable to generate the appropriate words…patients are aware of the nonsense articulations

  • cannot express themselves

  • these individuals are frustrated that they can’t match what they want to say versus what is actually said

  • when working with these patients, you must communicate with very direct/straight forward questions (yes/no)

Spatial Perception

(damage to the dorsolateral prefrontal association area)

• Body: mental representation of how the body is anatomically arranged

• Body in relation to its surroundings: enables individuals to locate objects in space & navigate accurately

• External world: ability to plan a route from point A to point B

Symptoms of Right Parietal Lobe Lesions

• Hemineglect Syndrome (seen post stroke)

  • ignores anything to the left ( visual field)

  • happens after right side lesions

  • loss of recognition of spatial relations

  • Eyes are working fine the brain just does not process the input coming in from that one side

These patients will draw a clock with all the numbers to the right, only read what is on the left side…no general understanding of layouts