KINE 3P94 FINAL EXAM ALL EXPECTED QUESTIONS & ANSWERS 2024/2025 SCORED A+

What performs feedback, planning, and execution of the cerebral cortex? - ANS-Spinal cord How does sensory information arrive to the brain (what pathway)? - ANS-Dorsal column medial lemniscal pathway What is the function of the primary somatosensory cortex (S1)? - ANS-discriminates among different intensities and qualities of sensory information Where is the S1 located? - ANS-Near the midline What does the S1 tell you? - ANS-- 1st stage of sensory information - basic characteristics of what you are doing What is the DCML? - ANS-Dorsal column medial lemniscal Where is the DCML? - ANS-- Base of the brain - to the left or right side depending on where the information from the body comes from What does the sensory association cortex do? - ANS-- 2nd stage of sensory information - more complex information, putting things together to have meaning What is the somatotopic organization? - ANS-Specific location on the cerebral cortex respond to specific regions of the body - for sensory (received) and motor (send out) information What is the homunculus man? - ANS-- greater size of representation on the brain corresponds to greater information/sensitivity to information - body parts that are not sensitive to sensation are represented less How does the organization in the homunculus work? - ANS-adaptable and plastic - recognizes and adapts to experience/training/injury How does the homunculus relate to impairment? - ANS-Able to identify where on the cerebral cortex the damage has occurred if looking at the deficits (and vice versa if you know where the damage is you can predict the deficits) what are the 4 studies that support variability? - ANS-- monkey fingers sewn together - amputations and transplants in humans - musicians - blind and braille readers What is the flow of information? - ANS-S1 - sensory association cortex (SAC) - premotor areas - primary motor areas (M1) What is the primary motor cortex (M1)? - ANS-involved in the executive control of movement What does the M1 determine/command for? - ANS-- force - direction - muscles - how it is split (homunculus) - FMS (fine motor skills) - GMS (gross motor skills) M1 vs S1 - ANS-M1 - division of GMS and FMS - control of movement S1 - division of body parts - receives sensory information Both - can recognize and adapt based on activity, injury, training ect. - needed for movement control and voluntary control Where do M1 neutrons project? - ANS-directly and indirectly on motor neurons into the spinal cord What does the M1 control? - ANS-motor movement How are monkeys trained to reorganize M1? What did they find? - ANS-- trained to reach for food in different sized wells - Large well used GMS and small well used FMS - Gradually decreasing well size as training went on - Baseline = small M1 - 2nd training = increased challenge and increased FMS (increased motor cortex representation and activation) What occurs in extinction of training and retraining in monkeys? - ANS-extinction = return to baseline retraining = increased FMS again, but to maintain you must have continuous training Why is constraint induced therapy used in stroke patients? - ANS-- from the stroke a person experiences limited strength/movement in affected side so the patient will rely on unaffected arm - this will alter the representation at brain level (M1/S1) to favour affected side When is constraint therapy used? - ANS-- when the affected side becomes weaker, don't rely on it at al What did they find when constraint indices therapy was used? - ANS-- by constraining the unaffected arm (forces them to use affected arm) - representation on brain will increase greatly - unaffected area decreases, affected side increases Does brain size activation correlate to motor function? - ANS-Not at all - a higher activation of the brain does not always mean an improvement in motor function TMS - ANS-Transcranial Magnetic Stimulation - Uses magnetic fields to stimulate nerve cells in the brain - non-invasive How is TMS different from MRI? - ANS-MRI - Actual activation and increased blood flow TMS - stimulates and measures AP changes - not exact activation of the area, however may have just moved closer to threshold so that when movement occurs it is easier to activate 3 types of coding neurons - ANS-- force - direction - muscle What is force coding? - ANS-signalling for how much force to produce How was force coding determined (Study)? - ANS-Measure EMG activity in arm movement - passive/assisted, active, active with a load - measure the activity of the flexors/extensors during flexion What were the results of the force coding study? - ANS-M1 activation = EMG activity activation during active and active with a load more activation during active with a load, because have to produce more force to resist against the load What did the force coding study tell us about passive/assisted movement? - ANS-the neurons are coding for force and not just muscle movement - no force is produced in passive movement (no EMG activation = no M1 firing) What did the force coding study find about sequential order movements? - ANS-found that when contraction is held the M1 firs above baseline, but the frequency decreases/remains active 2 types of force coding - ANS-- Tonic type - phasic-tonic type Tonic type force coding - ANS-How much force you are producing - increases as force production increases Phasic-tonic type force coding - ANS-Change in force production - as force production increases, frequency of firing decreases - neutrons fire most at the start/when there is a change in force What are direction coding neurons? - ANS-Determine which direction the movement is going in (up, down, left, right) How does direction coding work? - ANS-firing rate/behaviour depends on which direction you want to move in and the preferred direction of the neurons What is the direction coding preferred direction - ANS-The direction they fire the most in Why does a single M1 neuron not specify direction of movement? - ANS-because different M1 neurons have different preferred directions How do you determine the movement of the limb? What is this called? - ANS-Resultant vector (sum of vectors) - take in all direction and length of vectors to predict the direction of the movement - population coding How are vectors involved in direction coding? - ANS-vectors are drawn in direction of neuron's preferred firing rate and the length of the vector shows the firing rate how is the speed of a movement determined? - ANS-length of the preferred direction vector Study that shows that their is a difference between direction and muscle coding - ANS-moving hands upward when in a supinated vs pronated position while measuring EMG activity of the flexors and extensors - did not matter which muscle is was there was more activity when moved in an upward direction (code for direction of up, not the muscle that preforms the action) What is the issue with the study that shows the difference between direction and muscle coding - ANS-certain muscles always preformed actions in the same direction difference between muscle and direction coding - ANS-Muscle coding - doesn't care which direction it is going, just the muscle it is activating Direction coding - doesn't care which muscle it is activating, just the direction it is going What is needed in order to get an understanding of movement? - ANS-movement must be signalled by the activity of a large population of neurons and not a single neuron Where are the secondary motor areas? - ANS-in front of the primary cortex Where do the secondary motor areas project to? - ANS-M1 and spinal cord - can bypass the M1 2 parts of the secondary motor area - ANS-- Premotor cortex - supplementary motor area What 2 ways are the secondary motor areas activated? - ANS-Before M1 and movement - premotor cortex = externally triggered - supplementary motor area = internally triggered Externally triggered vs internally triggered - ANS-External = response is activated by a signal/stimulus internal = response is activated by will/knowing the pattern of movement and when/how to preform it What is the premotor area (PMA)? - ANS-An area within the motor cortex lying within the frontal lobe anterior to the primary motor c