Lecture 21, 22: Frontal Lobes (Lateral Aspect) Flashcards
Where is the frontal lobe?
Anterior to the Central sulcus
Name all the sulci and gyri in the frontal lobe
- Central sulcus
- Precentral gyri
- Superior Precentral sulcus
- Inferior Precentral sulcus
- Superior frontal gyrus
- Superior frontal sulcus
- Middle frontal gyrus
- Inferior frontal sulcus
- Inferior frontal gyrus
Name the areas in this image by their names not their Brodmann areas:
- No color
- Beige to Brown
- Purple
- Purple and Beige (47/12, 45, 44)
- Purple and Beige to Brown
- Green, yellow and blue
- Red
- Precentral Gyrus: Motor and Premotor (4, 6)
- Pars Triangularis, Pars Opercularis: Broca’s Area (45, 44)
- Pars Obirtalis and adjacent cortex (47/12)
- Mid-ventrolateral PFC (45, 47/12)
- Ventrolateral PFC (47/12, 45, 44)
- Dorsolateral PFC (9, 46, 9/46)
- Fronto-polar region (10)
Where is the prefrontal cortex?
Part of the Frontal Lobe anterior to the Precentral gyrus (excluding the Fronto-polar region)
What Brodmann area is the Premotor cortex?
6
Brodmann area of the Pars Triangularis
45
Brodmann areas of the Prefrontal cortex
- 8
- 9
- 9/46
- 46
- 44
- 45
- 47/12
Brodmann area of the Motor cortex
4
Brodmann area of the Pars Orbicularis
47/12
Brodmann area of the Pars Opercularis
44
Which area is responsible for fine motor movement?
Motor cortex
What area(s) is (are) responsible for Language in the PFC?
Borca’s Area:
45, 44
What does PFC mean?
Pre-frontal cortex
What area of the PFC is responsible for articulation?
44 (Pars Opercularis)
Brodmann area of the mid-dorsolateral PFC?
9, 46, 9/46
Brodmann area of the Posterior dorsolateral PFC?
8 and rostral 6
Brodmann area of the Mid-ventrolateral PFC?
45, 47/12
Brodmann area of the Fronto-polar region?
10
Which area of the PFC is responsible for the cognitive and active retrieval of information from memory?
45 (Pars Triangularis)
Which part of the Frontal lobe is granular? agranular?
- Agranular: Precentral gyrus
- Granular: PFC
What does granular and agranular mean?
- Agranular: no clear layer IV
- Granular: Clear separation between layers III and V
True or False
The frontal lobes are the ‘seat of intelligence’
False
True or False
If you damage your frontal lobe you lose all of your intellectual function.
False
True or False
Patients with frontal lesions perform adequately on the traditional tests measuring:
- intelligence
- perception
- short-term memory
True
True or False
Patients with frontal lesions can do everything, including planning and organizing everyday activities.
False
Struggle to organize everyday activities.
What is a problem with the studies of patients with frontal lesions?
They are not specific
What tests can we use to assess frontal lobe function?
- Tests of divergent thinking
- Fluency tasks
- Temporal ordering tasks
- Recency discrimination tasks
- Self-ordered pointing task
What is the Test for convergent thinking?
- Ask questions to the patient which have a unique answer.
- Ex: The sun is a star
- not sensitive to frontal lobe damage
What is the Tests for divergent thinking?
- Ask questions to the patient and ask to provide different answers to the same question
- Sensitive to frontal lobe damage
- This task requires creativity to come up with answers
What is the Fluency task?
- There are two types of fluency tasks:
- Verbal
- Non-Verbal
What is a Verbal Fluency task?
- Produce as many 4-letter words as possible in a limited amount of time
- Use dominant left hemisphere
- Patients:
- very little spontaneous speech
What is Non-verbal Fluency task?
- Draw as many different abstract designs as possible in a limited amount of time
- Uses non-dominant right hemisphere
What is the recency discrimination task?
- Uses verbal and non-verbal material
- Goal: discriminate between the items shown most recently vs the items shown a long time ago
- Frontal lobe lesion patients are impaired
Who created the Recency discrimination tasks?
Philip Corsi
True or False
Patients with damage on the medial temporal region are impaired in the recency discrimination tasks.
False, patients with damage on the medial temporal region are not impaired in these tasks
What is the procedure when using the recency discrimination tasks?
Verbal condition
- Show many cards in sequence
- Each card has two words
- Some cards have a “?”
- Q: Which item of the two words did you see more recently?
Image example of card:
What is a normal performance in the recency discrimination task (verbal)?
70%
What is the procedure when using the Recency discrimination task (non-verbal)?
- Show many cards of images (images could be drawings of object or abstract paintings)
- Each card has two images
- Some have a “?”
- Q: Which of the two have you seen more recently?
What part of the brain is tested by the non-verbal recency discrimination task?
nondominant right hemisphere
What is the self-ordered pointing task?
- Stimuli:
- concrete words
- abstract words
- representational drawings
- abstract designs
- Patients see a card with images and they have to pick an object towards which they point
- Next card has the same images but in different locations
- The patient has to point to a different image that they pointed previously
- The patient has to keep track of which images they pointed before
How do Frontal patients react to the tests?
- They respond normally to environmental stimuli
- difficulty in using these stimuli to regulate their actions
- May fail to use verbal feedback
- Persevere with response even when they are wrond
- Rule-breaking behaviour on experimental tasks
- can’t follow instructions
What are the two examples seen in class where you can see the behaviour of frontal patients to experimental tasks?
- Maze-learning tasks
- Wisconsin card sorting test
What is a maze learning task?
- Stylus maze task
What is the stylus maze task?
- Patients use a stylus to try to find the solution to a maze.
- They can move up, down, right and left (not diagonally)
- When they “hit a wall” a light will go up, telling them that their move is incorrect.
- When they make a wrong move they have to go back to their previous position and try another choice.
- They work on the same maze multiple times to see if they learn the correct path with the least amount of mistakes
How do frontal patients do in the stylus maze task?
- Failure to use feedback to correct themselves
- Patient perseveres when wrong answers
- Rule-breaking behaviour
- Loss of inhibition
What is the Wisconsin Card Sorting test?
- Patients have to sort the cards
- They have to figure out the pattern according to which they have to sort by listening to the experimenter’s feedback
- After 10 correct responses, the pattern to sort changes and they have to figure out the pattern from feedback again.
- 3 ways to sort:
- colour
- shape
- number
How do frontal patients do in Wisconsin Card Sorting task?
Patients persevere with their response. They have trouble adapting to the new pattern.
Which part of the brain is used during the Wisconsin Card Sorting task?
Dorsolateral PFC
Which test is an important tool for diagnosis of frontal lobe dysfunction ?
Wisconsin Card Sorting Task
Who was Jacobsen?
- Jacobsen did studies of cerebral function in primates
- Emphasized the neuro-physiological approach as psychological
- Lesions to the nervous system as a tool for psychological analysis
- Learn about different parts of the brain by creating lesions
- To investigate the function of frontal lobes:
- proper experimental task
- Restrict experimental lesions to the frontal areas
- control lesion in another brain region
What is the Delayed Response task?
- DR task
- You have two identical objects
- Hide food under one of them
- The screen goes down and hides the objects
- Show objects and the monkey has to retrieve the food
What is the Visual Discrimination task?
- Big and small boxes
- The monkey has to always select the big box to get reward
- Position of the boxes changes at each trial
How did the monkeys with bilateral frontal lesions did in both tasks?
- Delayed response task
- Impaired
- Visual discrimination task
- successful
How did the monkeys with bilateral parietal lesions did in the delayed-response and visual discrimination tasks?
- Delayed-Response task:
- impaired
- Visual discrimination task:
- impaired
True or False
In Jacobsen’s experiments with monkeys and the delayed-response and visual discrimination tasks, the monkeys were first trained really well in both tasks and then they received an injury in a part of their brain.
True, they either received a bilateral frontal lesion or a bilateral parietal lesion
What process is used in the delayed-response task?
- Memory: remember the location of the food was hidden
- Inhibition: inhibit interference of previous trials
Who coined the term working memory?
Miller, Galanter and Pribram (1960)
What is short-term memory?
Temporary storage of small amounts of material over brief periods of time.
What is working memory?
- brain system that provided temporary storage and manipulation of the information
- online maintenance of recent entries […] and reactivated relevant representations from long-term memory, together with their dynamic monitoring and manipulation, for the purpose of thought and the execution of planned action.
Are working memory and short-term memory the same thing?
No, working memory involves information manipulation
What is the neural substrate?
It’s the brain regions that subserve working memory
Which are the regions of the brain that constitute the neural substrate?
- Supramarginal gyrus
- Inferior Parietal region
- Posterior Parietal region
- Occipito-parietal cortex
- Occipito-temporal cortex
- Superior temporal cortex
- Inferior temporal cortex
What is the function of the supramarginal gyrus in working memory?
- Left:
- phonological aspects of working memory
What is the function of the inferior parietal region in working memory?
- Left:
- Auditory-verbal working memory
What is the function of the posterior parietal cortex in working memory?
- Manipulation of information in working memory
- ex: mental rotations
What is the function of the occipito-parietal cortex in working memory?
- Right:
- visuo-spatial working memory
What is the function of the occipito-temporal cortex?
Visual-verbal working memory
What is the function of superior temporal cortex in working memory?
Auditory working memory
What is the function of the inferior temporal cortex in working memory?
Visual object working memory
What brain path does the information travel in the following example?
Watch lecture recording.
- 2 actions:
- Look computer screen
- V1
- Association cortex
- Visual working memory
- Occipito-infero-temporal cortex
- Listen (ST lobe)
- A1
- Association cortex
- Look computer screen
True or False
Working Memory has a limited capacity
True
Following from what you know about the neural substrate, describe the working memory.
- processing and manipulation of information that occupies current awareness
- local computations occurring within specialized posterior cortical regions
- online maintenance and processing
- interaction with different PFC regions
- contribute to various aspects of the executive processing
What is the effect of a damage to the PFC onto working memory?
- impairements
- Due to deficits in executive processing:
- loss of inhibitory control
- failure to allocate attention to different types of information and monitor the contents of working memory in the posterior cortical regions
Which part of the PFC is responsible of keeping track of the information within working memory?
Mid-dorsolateral PFC
What kind of information the mid-dorsolateral PFC monitors?
Both spatial and non spatial information
What is the epoptic process?
- tracking of the relative status of stimuli
- events in working memory
True or False
Epoptic processing is the same thing working memory
FALSE
What part of the PFC is required during the self-ordered pointing task?
Mid-dorsolateral PFC
Why do we need the mid-dorsolateral PFC when doing the self-ordering pointing task?
We need to monitor the choices that we made
What are the symptoms of patients with damage on the mid-dorsolateral PFC?
- No difficulty with short-term memory tasks
- ex: can reproduce a sequence of numbers (5,4,2,9,6,..)
- CAN’T give digit from a list at random:
- they can’t keep track of the numbers that they already said
What is Petrides hypothesis of the Mid-dorsolateral PFC and how it keeps track of the information?
A system that holds coded representations of events that are expected to occur, so as to mark their occurrence or non-occurrence.
What was the study that was made with an MRI scan to see which areas where involved in a working-memory task?
Champod & Petrides (2007)
- Memorize patterns
-
Manipulation task:
- Show sequence of images
- Give two options
- Pick the second image in the sequence
-
Monitoring task:
- Show a sequence of images
- Give two options
- Pick the one that wasn’t in the sequence
What did Champod & Petrides (2007) found?
- Posterior parietal and within the intraparietal sulcus
- manipulation of visual information in working memory
- Mid-dorsolateral prefrontal cortex
- monitoring of the visual information
What is the externally ordered (serial order) task?
- Show participant 4 trial-unique abstract stimuli
- Test:
- Select the stimulus which was presented earlier in the sequence
- Involves mid-dorsolateral cortex
What is the mid-ventrolateral cortex?
- Areas 45 and 47/2
- Active retrieval
What is active retrieval?
- Actively retrieve information from long-term memory.
- NOT an automatic process.
- The individual has to make an effort to obtain the information.
- Beyond simple recognition
Give an example of a moment when you do an automatic retrieval from LTM?
See a familiar face and know their name.
What role does active retrieval by the mid-ventrolateral cortex plays in working memory?
- Required when stimuli in memory do not bear stable relations to each other
- Retrieval cannot be automatically driven by strong, stable and unambiguous stimulus or context relations
What is automatic retrival?
- Triggered by stimulus
- connections between posterior temporal and parietal association areas
- May involve subcortical structures
What parts of the brain are involved in active retrieval and how?
-
Mid-ventrolateral PFC
- interacts with posterior temporal and parietal association cortex to bring information into working memory
- This is a top-down process:
- Starts from the mid-ventrolateral frontal cortex to retrieve the information that is stored in multiple places in the association cortex
How is the mid-ventrolateral PFC connected to the rest of the brain?
- Area 45 to posterior parietal and temporal via SLF II and AF
- Area 45 and 47/12 to mid-superior temporal (ventral language)
What was Petrides interpretation of the role of area 45 in dominant hemisphere?
Active retrieval of semantic information
True or False
The role of area 45 in the dominant hemisphere in the human is an adaptation of its general role in active retrieval of information.
True, it is specialized in semantic information retrieval
Describe the experiment by Kostopoulos & Petrides regarding the ventrolateral PFC
- Three conditions:
- Active retrieval of a specific face
- Active retrieval of a specific location
- Control: passive recognition
- After performing a dozen of trials subjects have seen all possible relationships between the face appearance and its location
- Requires active retrieval of the required features on a trial-per-trial basis
We know that the left mid-ventrolateral PFC is for active retrieval of verbal material, what is the functionality of the one on the right hemisphere?
Active retrieval of non-verbal material
Face, location
Where is the posterior dorsolateral PFC?
Areas 8 and 6 (DR = Dorso-rostral)
What is the role of the posterior dorsolateral PFC?
- High-level conditional allocation of attention to competing stimuli in the environment
- visual search
- Allows to switch attention flexibly between different aspects of the visual, auditory and somatomotor environment based on instructions.
- Conditional associative learning
Give an example of situation where you would be using the posterior dorsolateral PFC?
Looking for a friend in the crowd. Crosses paths with another friend who is looking for a friend C. You then switch to the task of looking for C instead of A.
Where does the conditional associative learning happens in the brain?
Posterior dorsolateral PFC
Where does the visual-visual associations take place?
Area 8
Where does the visual-motor associations happen?
Area 6DR
What are the symptoms of lesions to the dorsal premotor cortex?
- Area 6DR
- Impair ability to learn conditional associative visuo-motor responses.
Describe the test by Petrides to identify damage to the dorsal premotor cortex.
- Associate 6 different colors with 6 different hand postures
- Patients with brain damage to rostro-dorsal area 6 are impaired
True or False
Damage to the area 6DR impairs patients on conditional associative visual-motor learning. This means that they also have an impairment in goal-directed behaviour.
FALSE
Instrumental behaviour does not involve “if-then” rules.
Patients are able to learn new goal-directed movements, remember these movements and switch from one movement to another normally
