Chapter 16 - Frontal Lobe Flashcards
(64 cards)
1
Q
What major brain areas make up the prefrontal cortex?
A
- Dorsolateral prefrontal cortex (DLPFC)
- Orbitofrontal cortex (OFC)
- Ventromedial prefrontal cortex (VMPFC)
- Dorsomedial prefrontal cortex (DMPFC)
2
Q
What system is the cingulate involved in?
A
- Involved in the limbic system
- Anterior cingulate cortex is involved in the PFC
3
Q
What’s the role of the PFC in initiating a motor sequence?
A
- 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
4
Q
What can damage to the premotor cortex impact?
A
- Individual would be unable to execute a series of skilled movements as these movements cannot be planned
5
Q
What can damage to M1 impact?
A
- Individual would be unable to perform skilled movements such as a pincer grip
6
Q
As movements progress from simple to more complex, what does fMRI reveal?
A
- As movements become more complex, more areas of the brain are recruited to plan, organize, and execute these movements
7
Q
What brain regions are implicated in the frontal eye fields?
A
- The superioir colliculus in the tectum
- The posterioir parietal region
- Involved in unconscious eye movements (darting around)
8
Q
What is the supplementary motor area involved in?
A
- Active when mentally rehearsing an action/sequence of movements
- Located in the premotor cortex
9
Q
What connections are recieved and sent in the DLPFC?
A
- Recieves: Posterior parietal and temporal regions
- Sends: STS (and other temporal regions) and the posterioir parietal
*most reciprocal
10
Q
What connections are received and sent from the OFC?
A
- Receives: All sensory modalities, temporal lobe/STS, and amygdala
- Sends: Amygdala and hypothalamus
*most reciprocal
11
Q
Which networks does the triple network model encapsulate?
A
- Default mode network
- Executive control network
- Salience network
12
Q
What is the default mode network involved in?
A
- 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
13
Q
What is consistently high activity in the DMN cirrelated to?
A
- Depression
- Involved in self-rumination
14
Q
What is the executive control (or frontoparietal) network involved in?
A
- Involved in executive function, goal-directed behaviour, and decision making
- i.e., externally-driven processes
- Maintains working memory
- Opposite of DMN
15
Q
What is consistently low levels of activity in the ECN correlated to?
A
- Depression
16
Q
What is the salience network involved in?
A
- 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
17
Q
What does increased activity in the salience network mean for the DMN?
A
- Lowers activity in the DMN as attention is being shifted externally
- Increased activity in the ECN
18
Q
What would happen if the salience network wasn’t working?
A
- There would be excessive activity in the DMN, causing lapses in attention
19
Q
T/F: The DMN and ECN are often active together.
A
- FALSE
- They completely contradict each other
20
Q
In general, what types of broad functions does the frontal lobe do?
A
- Decision-making
- Planning
- Motivation
- Working memory
- Problem-solving
- Abstract/flexible thinking
- Self-awareness
21
Q
Premotor cortex vs. prefrontal cortex?
A
- 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)
22
Q
How does the PFC select goals and plan movements?
A
- Internal cues
- External cues (environmental stimuli)
- Context cues (social cues)
- Autonoetic awareness (self-knowledge, helps access autobiographical info)
23
Q
What’s the main function of the dorsolateral prefrontal cortex (DLPFC)? What other functions is it involved in?
A
- Main: Internally-motivated behaviour
- Other: Abstract reasoning, cognitive flexibility, working memory, attention
24
Q
What may damage to the DLPFC result in?
A
- May become overly reliant on external cues; easily distracted
- This can result in pseudodepression.
25
How does pseudodepression differ from regular depression?
- Pseudodepression does not include the mental affect that major depressive disorder involves, individual just appears low energy
26
What's the main function of the orbitofrontal cortex (OFC)?
- Assists in context-appropriate behaviour and impulse inhibition
- Conscious awareness of emotional states produced by rest of limbic system (i.e., the amygdala)
27
What may damage to the OFC result in?
- Social gaffes (socially inappropriate)
- Loss of affect
- Impulsive behaviour
- Disinhibited behaviour
28
What are the main functions of the ventromedial prefrontal cortex (VMPFC)?
- Decision-making and also involved in episodic memory
- Role in subjective value assessment
- Integrative hub (emotional, social, memory, etc.)
29
What may damage to the VMPFC result in?
- Can lead to reduced empathy
- Reduced capacity to make rational decisions
30
Which frontal lobe area may have less connectivity in individuals who have psychopathy?
- The VMPFC
31
Who popularized the lobotomy in humans?
- Egas Moniz in the 1950s
32
Which part of the frontal lobe did lobotomies target?
- The OFC
33
What are the major symptoms of frontal lobe lesions?
- Disturbances of motor function
- Loss of divergent thinking
- Environmental control of behaviour
- Poor temporal memory
- Other symptoms
34
What does Tueber's visual search task test for?
- Can determine if individual suffers from an altered voluntary gaze, which would be tied to a frontal lobe lesion
- Damage to frontal eye fields, specifically
- Individual must be able to spot the same shape/figure among many shapes displayed
35
Convergent thinking vs. divergent thinking?
- Convergent - only one solution possible, what IQ tests are based on (ex. arithmetic, factual questions etc.)
- Divergent - multiple solutions are sought, more abstract
36
What behaviours may occur if frontal lobe lesions cause a loss of divergent thinking?
- Experience loss of behavioural spontaneity, so they may appear lethargic or lazy, make fewer spontaneous facial movements and expressions
37
In terms of divergent thinking, what may a left or right frontal lesion result in?
- Left - patients rarely speak
- Right - talk excessively (no goal)
38
What's perseveration?
- Tendency to emit repeatedly the same verbal or motor response to varied stimuli
- Ex. getting stuck on a topic/emotion
39
What does the Chicago Word Fluency test for?
- Tests for verbal spontaneity
- Performance will be impacted by lesions anywhere in the PFC
40
T/F: Frontal lobes are less asymmetrical compared to other brain regions.
- TRUE
41
What does Gottman and Milners' design fluency test for?
- Tests for non-verbal behavioural spontaneity
- Patient must draw as many random, non-representational drawings as possible
42
How may a person perform on the design fluency test if they have frontal lobe lesions?
- There will be a dramatic decrease in the amount of drawings produced
- OFC is most sensitive to these lesions
43
What's the most common symptom of damage to frontal lobes?
- Impaired at using environmental cues (feedback) to regulate or change behaviour
- Ex. poor response inhibition, maintain the same cognitive set
44
What does the Wisconsin Card sorting task test for?
- Assesses perseveration - the ability to utilize environmental feedback to shift cognitive set
- 3 ways to sort the cards (colour, number of elements, shape)
45
Which frontal lobe lesion produces the most deficits in the Wisconsin card sorting task?
- The left DLPFC (unable to adapt to changing rules)
46
What's the Stroop test?
- Patient must name the colour of the ink as quickly as possible
- Can be used to measure response inhibition as patient must inhibit reading the colour name and focusing on the ink
47
Which lesions affect performance in the Stroop test the most?
- Left frontal lesions, specifically the DLPFC
48
What's the purpose of the Iowa Gambling task?
- Measures decision-making, risk-taking, and impulsivity
49
How do controls and patients differ in their performance on the Iowa gambling task?
- Controls quickly learn which deck has the best payoff and play from the safe decks
- OFC patients (and VMPFC) play predominantly from the bad decks and lose all their money
50
Across species, which functions in the PFC involved in?
- Involved in working memory and guides actions in time (temporal memory)
51
What does a delayed-response or a delayed non-matching sample task assess?
- Assesses working memory, specifically in the DLPFC
52
What two major regions may be damaged that would result in poor temporal memory?
- The DLPFC and the medial temporal regions
53
Which brain regions make up the medial temporal lobe?
- Perirhinal cortex
- Parahippocampal cortex
- Entorhinal cortex
- Hippocampus
- Amygdala
54
What does the perirhinal cortex engage in?
- Receives ventral stream input
- Involved in visual object memory
55
What does the parahippocampal cortex engage in?
- Receives dorsal stream input
- Involved in visual spatial memory
56
What does the entorhinal cortex do?
- Acts as an interface between the neocortex and the hippocampus
57
What's one of the first structures to be affected by Alzheimer disease?
- The entorhinal cortex
58
During the blue and white button monkey study, what did a lack of firing in the DLPFC signify?
- Meant that the monkey already forgot what to choose/couldn't make a selection
59
What other symptoms may arise from frontal lobe lesions?
- Changes in social behaviour and personality can be marked (i.e., Phineas Gage)
- Atypical sexual behaviour
60
What's pseudopsychopathy?
- Also called acquired sociopathy
- Individual exhibits immature behaviour, lack of tact and restraint, poor decision-making/impulsive
- Usually caused by damage to OFC and/or VMPFC in the right hemisphere
61
How do adult cases of pseudopsychopathy differ from development cases?
- Violent behaviour/aggression is rare in adult cases compared to developmental cases
- Developmental cases are more severe
62
How can OFC lesions affect sexual behaviour?
- May lead to reduced inhibitions
(ex. public masturbation)
63
How can DLPFC affect sexual behaviour?
- May reduce libido, but performance is unaffected
64
How are the frontal lobes related to the dorsal and ventral streams?
- The frontal lobes are considered the end point for dorsal and ventral streams
