Chapter 16 - Frontal Lobe Flashcards
What major brain areas make up the prefrontal cortex?
- Dorsolateral prefrontal cortex (DLPFC)
- Orbitofrontal cortex (OFC)
- Ventromedial prefrontal cortex (VMPFC)
- Dorsomedial prefrontal cortex (DMPFC)
What system is the cingulate involved in?
- Involved in the limbic system
- Anterior cingulate cortex is involved in the PFC
What’s the role of the PFC in initiating a motor sequence?
- It does not specify a precise movement, rather it makes a decision about which goal to select
- It is M1 that produces the skilled movement, while the premotor cortex sequences the actions
- 1) prefrontal plans 2) premotor organizes movement 3) M1 executes movements
What can damage to the premotor cortex impact?
- Individual would be unable to execute a series of skilled movements as these movements cannot be planned
What can damage to M1 impact?
- Individual would be unable to perform skilled movements such as a pincer grip
As movements progress from simple to more complex, what does fMRI reveal?
- As movements become more complex, more areas of the brain are recruited to plan, organize, and execute these movements
What brain regions are implicated in the frontal eye fields?
- The superioir colliculus in the tectum
- The posterioir parietal region
- Involved in unconscious eye movements (darting around)
What is the supplementary motor area involved in?
- Active when mentally rehearsing an action/sequence of movements
- Located in the premotor cortex
What connections are recieved and sent in the DLPFC?
- Recieves: Posterior parietal and temporal regions
- Sends: STS (and other temporal regions) and the posterioir parietal
*most reciprocal
What connections are received and sent from the OFC?
- Receives: All sensory modalities, temporal lobe/STS, and amygdala
- Sends: Amygdala and hypothalamus
*most reciprocal
Which networks does the triple network model encapsulate?
- Default mode network
- Executive control network
- Salience network
What is the default mode network involved in?
- Functionally connected regions that are active when a person is at rest, rather than engaged in specific cognitive tasks
- Ex. Self-reflection, memory, imagining the future
What is consistently high activity in the DMN cirrelated to?
- Depression
- Involved in self-rumination
What is the executive control (or frontoparietal) network involved in?
- Involved in executive function, goal-directed behaviour, and decision making
- i.e., externally-driven processes
- Maintains working memory
- Opposite of DMN
What is consistently low levels of activity in the ECN correlated to?
- Depression
What is the salience network involved in?
- Operates to modulate other brain network’s activities, and is most active when a behaviour change is needed in response to environmental stimuli
- Will filter salient stimuli and recruit relevant network
- Will shift attention to external stimuli
What does increased activity in the salience network mean for the DMN?
- Lowers activity in the DMN as attention is being shifted externally
- Increased activity in the ECN
What would happen if the salience network wasn’t working?
- There would be excessive activity in the DMN, causing lapses in attention
T/F: The DMN and ECN are often active together.
- FALSE
- They completely contradict each other
In general, what types of broad functions does the frontal lobe do?
- Decision-making
- Planning
- Motivation
- Working memory
- Problem-solving
- Abstract/flexible thinking
- Self-awareness
Premotor cortex vs. prefrontal cortex?
- Premotor - selects coordinated action sequences (i.e., making movement)
- PFC - controls cognitive processes that select the appropriate movements at the correct time and place (i.e., plans movement)
How does the PFC select goals and plan movements?
- Internal cues
- External cues (environmental stimuli)
- Context cues (social cues)
- Autonoetic awareness (self-knowledge, helps access autobiographical info)
What’s the main function of the dorsolateral prefrontal cortex (DLPFC)? What other functions is it involved in?
- Main: Internally-motivated behaviour
- Other: Abstract reasoning, cognitive flexibility, working memory, attention
What may damage to the DLPFC result in?
- May become overly reliant on external cues; easily distracted
- This can result in pseudodepression.
How does pseudodepression differ from regular depression?
- Pseudodepression does not include the mental affect that major depressive disorder involves, individual just appears low energy