Neural Oscillations pt. 2

hierarchical cognitive control study

delta oscillations correspond with abstraction/hierarchical control with theta oscillations corresponding with working memory

rules in prefrontal cortex study

trained two monkeys to fixate on a central point and respond differently based on the color or orientation presented. with sets of rules that you prioritize one response over the other

• The goal was to see what happens to PFC representation when you need to switch rules

how are rules related to the hierarchical model

a critical cognitive ability is the flexibility to change one’s behavior based on context. these context-dependent stimulus-response mappings are rules that are needed to change behaviors

behavioral task

fixation→ rule cue→stimulus→response

switch cost

there is a decrease in performance when switching from one task/response to another

• orientation rule appears to be dominant

what area of the monkey’s brain was recorded

PFC- principal sulcus

• PFC neuronal spiking activity was selective for rules but more neurons are selective for the orientation rule

LFP oscillation results

alpha and beta oscillations and synchrony increased

beta oscillation

levels of beta synchrony was stronger when comparing preferred vs, non-preferred rules

alpha oscillation

• beta synchrony increased when a rule was selected

• neuronal groups were more selective for the orientation rule and showed an alpha-band increase when the color rule was selected

• was present when trying to inhibit the dominant rule (orientation)

summary of findings

in the lateral PFC, they found:

• beta synchrony selects task-relevant rules (color and orientation)

• alpha synchrony de-selects or inhibits a dominant but irrelevant rule (orientation)