PS267 Lecture Notes - Lecture 8: Inferior Parietal Lobule, Inferior Frontal Gyrus, Basal Ganglia
Goal Selection and Action Planning - Affordance Competition Hypothesis (affordance is any
way you can interact with an object - sets stage for how we plan action)
● Anytime you interact with the world you can do many things with your motor system
● Diagram shows potential actions
● Basal ganglia is like gatekeeper for final motor movement
● Multiplicity of actions to choose, context/attention/etc influences
● Single celled recording in monkeys - shows magnitude of action potentials
○ Delay period when monkey knows it will be one of two locations
○ Given a cue that tells them where to point - when cue given premotor cortex
starts to fire, inhibition for other target
Competition between two movement goals - patting yourself on the head/rubbing your stomach
● Patients with NO corpus callosum are better at doing perpendicular axes drawings (two
different movements)
Repetition suppression in the motor system
● When you see something once and see it again a second time, you habituate it the
second time - visual cortex doesn’t respond as much the second time
● Well experiment - set of stimuli for inducing repetition suppression → will you open or
close the well? How are they making that movement? → very similar sequences can
share diff outcomes and kinematics → left inferior frontal gyrus and inferior parietal lobule
are differentially sensitive to outcomes in kinematics - repetition suppression shows
really sensitive to what they are seeing - LEFT = more repression when image
sequences involve kinematics, INFERIOR = more suppressive effects when outcomes
are being repeated rather than kinematics - frontal care more about kinematics, parietal
more about outcome
Movement initiation and the basal ganglia
● Basal ganglia gatekeeper allows certain action to take place
● Pathways are ways of differentiating between two diseases
● When you inhibit an inhibitor you are disinhibiting, causing things to happen
● When you excite inhibitor - it is more inhibitory
● Huntingtons
○ Huntington gene = huntingtons
○ Autosomal, so if one has it one doesn’t you have 50% chance
○ Doesn’t usually manifest itself until age 30
○ Leads to dementia
○ Selectively attacks caudate nucleus
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Goal selection and action planning - affordance competition hypothesis (affordance is any way you can interact with an object - sets stage for how we plan action) Anytime you interact with the world you can do many things with your motor system. Basal ganglia is like gatekeeper for final motor movement. Multiplicity of actions to choose, context/attention/etc influences. Single celled recording in monkeys - shows magnitude of action potentials. Delay period when monkey knows it will be one of two locations. Given a cue that tells them where to point - when cue given premotor cortex starts to fire, inhibition for other target. Competition between two movement goals - patting yourself on the head/rubbing your stomach. Patients with no corpus callosum are better at doing perpendicular axes drawings (two different movements) When you see something once and see it again a second time, you habituate it the second time - visual cortex doesn"t respond as much the second time.
