Notes on Neuroscience of Executive Functions

Neural Oscillations: Key mechanism in cognitive control.
- Phase: Probability of a neuron's firing at any given time.
- Synchrony/Coherence: The effectiveness of communication among different brain regions. This includes:
- Phase coherence: alignment of phases of oscillatory signals across regions.
- Effective cognitive control requires high levels of synchrony between neurons and networks.
- Power: Strength of an oscillating signal.

Local Oscillations: Associated with specific cognitive control tasks or responses.
Long-range Synchrony: Vital for communication between disparate brain regions.
Importance of coherence in facilitating neural communications across regions.

Active memories are represented by specific patterns of neuronal activity:
- A subset of pyramidal neurons firing in synchrony.
Memory encoding shows different frequency oscillations:
- Theta waves (4-10 Hz): Related to memory consolidation.
- Gamma waves (20-80 Hz): Associated with higher frequency cognitive processing.

Theta-Gamma Coupling: Critical for working memory (WM) capacity.
- Higher synchronization correlates with better memory performance.
Visual short-term memory research highlights:
- Oscillatory dynamics play a role in memory capacity, influenced by theta and gamma phases.

Cognitive control incorporates different oscillatory components.
The dynamics depend on how tasks require varying levels of abstraction and perceptual load.
Variations in set sizes impact the oscillatory patterns observed (Delta, Theta, Beta):
- Set size: Refers to the number of items held in WM.
- Abstraction level: Complexity of the cognitive task.

Synchronous Oscillatory Neural Ensembles: Support rule representation in the PFC.
- Rules define stimulus-response relationships and enable task flexibility.
Rule Selection and Deselection: Critical for effective cognitive control.
- Different rules activate distinct patterns of neuron firing and oscillation synchrony.

Beta oscillations are observed to increase when a relevant task rule is selected:
- Alpha oscillations serve an inhibitory role, reducing influence from non-preferred rules.
Evidence suggests differing neural responses to high and low abstraction tasks based on oscillatory activity.

Studies demonstrate the dominance of certain rules (e.g., orientation) over others within cognitive tasks.
Neuronal activity reflects not just task engagement but also flexibility in responding to relevant contextual changes.
Switch Costs: The cognitive load associated with switching from one task rule to another.

Investigate emotional and motivational influences on oscillatory dynamics.
Explore the application of alpha synchrony in educational settings for assessing cognitive load and readiness to learn.
Analyze interactions between the PFC and other brain regions during rule-switching to understand comprehensive cognitive control mechanisms.