Dataview
LIST
FROM #Collection
WHERE file.name = this.Entry-For📗 -> Chapter 9: Executive Function
🎤 Vocab
BG - Basal Ganglia
SNc - Substantia Nigra Pars Compacta
VTA - Ventral Tegmental Area
❗ Information
Executive function thought to occur primarily in the PFC.
- Receives input from many high level areas, posterior cortical association areas, motivational and emotional areas
PFC also helps working memory / robust active maintenance
✒️ -> Scratch Notes
In one classic example, a patient with PFC damage visited a researcher’s home and, upon seeing the bed, proceeded to get undressed (including removal of his toupee!), got into bed, and prepared to sleep.
…
without the PFC, behavior is much more reflexive and unthinking, driven by the affordances of the immediate sensory environment, instead of by some more abstract and considered plan or goals.
Shifting behavior
The PFC is skilled at rapidly updating what is maintained in it
Features top-down biasing of associated patterns of activity
- Contrasts with behavioral adaption that happens slowly via updating weights (posterior cortex or basal ganglia)
Task Switching Paradigms - Wisconsin card sorting task (WCST) in adults
- Dimensional change card sorting task (DCCS) in children
The computational models in this chapter show how the basal ganglia (BG) and midbrain dopamine
areas (specifically the ventral tegmental area, VTA) play a critical role in the rapid, strategic updating
of PFC activity states. Specifically, we’ll see that robust active maintenance requires an additional control
signal to switch between maintaining existing information vs. updating to encode new information.
The biological properties of the PFC/BG system that we reviewed above are captured in a computational
model called PBWM (prefrontal cortex basal ganglia working memory)
9.10 - Summary of Key Points
• The prefrontal cortex (PFC) encodes information in an active state through sustained neural firing, which is more flexible and rapidly updatable than using synaptic weight changes.
• The basal ganglia (BG) drives updating (dynamic gating) of PFC active memory states, enhancing flexibility.
• Phasic dopamine signals from midbrain nuclei have the right properties for training BG gating, by transferring reward associations earlier in time to the onset of stimuli that predict subsequent rewards.
• The PFC influences cognitive processing elsewhere in the brain via top-down excitatory biasing. The A-not-B model demonstrates how the emergence of PFC active maintenance abilities can support behavioral changes that infants show as they develop.
• The Stroop model demonstrates how the active maintenance of task information can guide behavior and help to overcome conflicting options.
• BG dynamic gating can support flexible cognitive function by dynamically encoding some information while ignoring other irrelevant information, and updating the contents of active memory. The SIR and n-back models demonstrate these abilities.
• Medial and ventral areas of PFC (orbital prefrontal cortex (OFC) and anterior cingulate cortex (ACC)) convey affective information about stimuli and actions, respectively, and are important for properly evaluating potential actions to be taken (decision making, problem solving, etc)
🧪 -> Examples
- Big picture: general reaction
Did you generally find the overall content understandable or compelling or relevant or not, and why, or which aspects of the reading were most novel or challenging for you and which aspects were most familiar or straightforward?)
Big Picture)
The content was interesting, and broadly addressed a number of things I've been wondering about executive function and higher level decision making. Wrapping my mind around the network interactions is still a bit challenging for me, and understanding the different roles that the PFC, BG, PVLV, and more play in just working memory is a bit overwhelming. My biggest takeaway was all of the actors involved in the process, and how complicated it is. I'll be hoping to learn more in lecture.
- Specifics: specific reaction to one aspect of the reading
Did a specific aspect of the reading raise questions for you or relate to other ideas and findings you’ve encountered, or are there other related issues you wish had been covered?
Specifics)
I was surprised by the role that the basal ganglia plays in higher level decision making. I was previously under the impression that its main role was in organizing motor movement, and I'm happy to learn more about it and dispel my misconceptions.
🔗 -> Links
Resources
- Put useful links here