Chapter 16 Flashcards
What are the boundaries of the frontal lobes
What percentage of the neocortex does it occupy
All matter anterior to the coronal suture and above the sylvian fissure
30-35%
What is M1?
What does it control?
Primary motor cortex
Controls force and direction
Subcortical structures - basal ganglia, red nucleus, spinal cord
What is the PMC?
What is it comprised of?
Premotor cortex
supplementary motor area (SMA), dorsal PMC, ventral PMC, inferior frontal gyrus (broca’s area)
What does the PMC influence - and through what?
Movement directly - corticospinal projections
Indirectly - M1 projections
What are the functions of the PMC
Selecting movements in response to external (PMC) and internal (SMA) cues
What is the PFC?
What is in input for?
Prefrontal cortex
mesolimbic dopamine cells
What is the PFC divided into?
Dorsolateral PFC (DLPFC)
Orbitofrontal cortex (OFC)
Ventromedial prefrontal cortex (VMPFC)
What does the DLPFC connect to?
What cues does it play a part in?
Reciprocal connections with posterior parietal areas and the superior temporal sulcus
Internal cues
From where does the OFC receive input?
To where does it project?
What does in influence
Input from all sensory modalities
Projects subcortically to the amygdala and hypothalamus
Influences physiological changes involved in emotional responses
External cues
From where does the VMPFC receive input?
To where does it project?
What does in influence
Input from DLPFC, posterior cingulate cortex, medial temporal cortex
Connects subcortically with amygdala, hypothalamus, periaqueductal grey matter
Linked to emotional expressions throughout the body
What is the AAC
What does it connect to
Anterior Cingulate cortex
Bidirectional with motor, premotor, prefrontal cortex, insula, von economo neurons
When is the AAC used?
Brain regions active at rest
When thinking about the past/future
When mind wandering
Emotional behaviours
What are executive functions (3)?
Planning and selecting response options
Ignoring extraneous stimuli and persisting at the task at hand
Keeping track of behaviours in order to know when to initiate the next behaviour in a sequence
Ability to guide behavior toward a goal
- Non-routine (not a habit)
- Unstructured, novel situations
What are the functions of the Prefrontal cortex?
What can it be regulated by (4)
Controls the cognitive processes that select appropriate movements at the correct time and place
Regulated by
Internalized and externalized info
Context
Self-knowledge
PMC - Internal cues
What part of PMC?
DLPMC - temporal order of actions (temporal memory)
Projections from dorsal + ventral streams facilitate the selection of subsequent actions in a sequence
PMC - External cues
Where are the stimuli?
What part?
Stimuli in environment - ex. full laundry bin and you decide to do laundry
Feedback about rewarding properties of stimuli - associating winning a game with getting ice cream
Orbitofrontal
PMC - Context cues
What part of frontal lobe? Where does the information come from?
Modify our behaviour in different social roles and different contexts
Behaviours are modified based on sensory information conveyed to the inferior frontal cortex from the temporal lobe
Autonoetic awareness
Autobiographical knowledge of experiences and goals - info about ones accomplishments, relationships with other people, etc
Functions of frontal lobe
Ability to:
Plan and select relevant activities
Keep goal in mind, ignore distracting stimuli
Remember having completed action
Organize & plan sequence of behaviors
Respond to internal, external, context cues
Cognitive control
The process that allows information processing and behavior to vary adaptively from moment to moment depending on current goals, rather than remaining rigid and inflexible
Left side controls
Language / Speech
Right side controls
Facial expressions / memory retrieval
Disturbances in motor function
Difficulty making fine, independent finger movements
Loss of speed and strength of hand and limb movements
Movement programming
Movements = preplanned; planned sequence then executed
Left and right premotor corticies participate in this
Voluntary gaze
Difficulty controlling eye movements (with frontal lobe lesions)
Corollary discharge
Signal that informs other areas of the brain that movement is about to happen
Frontal lobe to parietal and temporal association areas, then sensory system can anticipate the motor act
Broca’s area
How does it retrieve words
What does damage lead to
Retrieves words on the basis of an object, word, letter, or meaning (cues from the environment)
Damage leads to agrammatism
Supplementary speech area
Retrieves words without external cues
Damage leads to mutism
Convergent thinking
Definitions of words, questions of fact, arithmetic problems, puzzles,
- Not deficient following frontal lobe damage
Divergent thinking
Creative and less fact based thinking
- Deficient following frontal lobe damage
Behavioural spontaneity
Low output
Rule breaking
Shaky script
Perseveration
Strategy formation
Impaired at developing novel cognitive plans or strategies
Response inhibition
Perseverance - unable to update response strategies
Frontal lobes play a role in behavioural flexibility
Risk taking / rule breaking
Bad at following instructions
Take more risks
Self regulation
lack of autonoetic awareness
Loss of autobiographical knowledge
Associative learning
Difficulty learning from experience
Frontal lobe lesions
Impaired on recency memory tasks, but not recog mem tasks
Temporal lobe lesions
Impaired on recog tasks but not recency tasks
What does the difference between frontal and temporal lobe lesions mean?
Memory location system may exist separately from the memory recog system
Pseudo-depression
What does it show?
Lesions where?
Show outward apathy and indifference, loss of initiative, reduced sexual interest, little overt emotion, and little or no verbal output
Lesions on left frontal lobe
Pseudo-psychopathic
What does it show?
Lesions where?
Immature beh, lack of tack and restraint, coarse language, promiscuous sexual beh, increased motor activity, general lack of social graces
Lesions on right frontal lobe
