Lecture 20 (Unit 4) Executive Functions
Unlike the busy sensory processes that occur in the other lobes, the frontal lobes were not easily linked to an easily defined function and were dubbed as .......
"The silent lobes."
(LEARN) Frontal lobe dysfunction often reflects more than the direct damage to the frontal lobes themselves; that is damage to the frontal lobes produces wide ripples effects through the whole brain.
(LEARN) Damage to different parts of the frontal lobes produces distinct, clinically different syndromes. The most common are dorsolateral and orbitofrontal syndromes.
With regard to executive functions, the prefrontal cortex can do (list 3 things)
- Form goals and objectives and then devise plans of action to attain those goals -Select the cognitive skills needed to implement the plans, coordinates those skills, and applies them in the correct order -Evaluates our actions as success or failure to our intentions
Two broad types of cognitive operations are linked to prefrontal lobe executive functions
-An ability to form plans and to guide behavior by internal representations -The capacity of 'switching gears' when something unexpected happens
VLPFC function in short term memory
1. Cue specification, strategic search of MTL stored representations 2. Maintenance of retrieved information
Prefrontal cortex accounts for ____% of the total cortex in humans and _____% in chimps.
29 17
Mirror neurons, which fire when another person is observed doing a certain action, may play a role in not only _____ _____, but also in ____ sharing _____ (an ability to recognize and vicariously experience what another individual is undergoing)
Action understanding Emotion sharing empathy
Dorsal Anterior Cingulate cortex function
Activity monitor
Explain perseverative behavior
An inability to initiate behaviors, or once initiated be equally unable to stop
Resultant activity is monitored by the the _____ ______ cortex (part of the limbic system), which signals any need for adjustment.
Anterior cingulate
Ventral is equivalent to
Bottom
What is posterior parietal cortex responsible for?
Bringing things to attention.
Personality can be broken into 5 components
COANE Conscientiousness, Openness, Agreeableness, Neuroticism, and Extroversion
MTL function in short term memory
Comparison of retrieval cue and stored representations using pattern completion
What is openness?
Creative, imaginative, intelligent, curious, and adventurous
List the four prefrontal cortex areas
DLPFC = Dorsolateral prefrontal cortex VLPFC = Ventrolateral prefrontal cortex APFC = Anterior prefrontal cortex MPFC = Medial prefrontal cortex
In future planning what is the function of the encoding interaction of the MTL
Different features bound into episodic representation
Plan formulation: List the functions of the following DLPFC ACC THAL MTL PPC
Dorsolateral Prefrontal Cortex = Goal Processor Anterior Cingulate Cortex = activity monitor Posterior Parietal Cortex = attention controller Thalamus = Gating and report relay Mediotemporal lobe = episodic store
What specific area of the lobe are executive functions found?
Dorsolateral frontal lobe.
Patients with damage to the _____ _____ _____ have difficulty in 'switching gears' in this type of task.
Dorsolateral prefrontal cortex
Explain field-dependent behavior
Easily distracted, will engage in activities because objects are present in the environment (e.g drink from an empty cup, even though actions make no sense
Evidence suggests that intact frontal lobes are necessary to carry out all .... , ....., and ....... .
Executive functions Personality Morality
The prefrontal cortex has _____ over mammalian and primate evolution. A greatly ________ _________ cortex is a distinctively ________ and primate feature.
Expanded Enlarged Human
What lobe is responsible for executive functions?
Frontal lobe.
When personality is expressed, which lobe is responsible?
Frontal lobe.
What is one way to define the prefrontal cortex?
Granular frontal cortex (layer 4 is present - thalamic input)
What is agreeableness?
Helpful, warm, caring, softhearted, and sympathetic
Progressively ____-level representations of perceived information formed in the ______ cortex
Higher Posterior
APFC (anterior prefrontal cortex) function in short term memory
Higher level mnemonic control operations
Explain mental rigidity
Inability to change their mental state or approach to a problem (Wisconsin card sorting task)
What is personality?
Individual differences among people --> pertaining to behavior pattern, cognition, and emotion.
The Wisconsin Card Sorting Test is used to determine an
Individual's competence in abstract reasoning, and the ability to change problem solving strategies when needed
What are executive functions?
It is an umbrella term for the management (regulation, control) of cognitive processes.
What is morality?
It is the differentiation of intentions, decisions, and behaviors between what's good vs. what's bad.
What are characteristics of the orbitofrontal syndrome
It is the opposite of dorsolateral syndrome: the patients are behaviorally and emotionally disinhibited
Medial is equivalent to
Midline
DLPFC function in short term memory
Monitoring and verification of retrieved information
Ventral Anterior Cingulate Cortex function
Monitoring emotions
What is neuroticism?
Moody, worrying, and nervous
What is another function that frontal lobes have?
Motor control
What is one way to define the prefrontal cortex?
Non-motor areas
personality think of the acronym
OCEAN
In future planning what is the function of the encoding interaction of the DLPFC
Organization of material to be remembered
What is conscientiousness?
Organized, responsible and hardworking
What is extroversion?
Outgoing, friendly, lively, active, and talkative
Whiles whales and dolphins have large brains, it is the ______ rather than the _____ cortex that has expanded in these animals.
Parietal Frontal
Where pathways
Parietal lobe DLPFC
Frontal lobe syndrome - dorsolateral: List common symptoms of this syndrome
Perseverative behavior, field-dependent behavior and mental rigidity. As well as the flat affect.
DLPC receives input from the _____ _____ cortex ( the attention controller) and outputs to the _____ _____ cortex.
Posterior Parietal Secondary motor
The ______ lobes carry out executive functions and express personality and morality.
Prefrontal
Connections of the prefrontal cortex
Prefrontal cortices are reciprocally interconnected and receive projections from most, if not all distinct functional units of the brain
In morality, describe the principle of double effect
Principle of double effect: Used to explain the permissibility of an action that causes a serious harm, such as the death of a human being, as a side effect of promoting some good end. (Side effect vs. Intentional harm)
What is one way to define the prefrontal cortex?
Projection zone of the dorsal medial nucleus of the thalamus. The DM nucleus is critical for gating of information to and from prefrontal cortex. This feedback contributes to selective attention, enhanced responses for relevant stimuli and suppressed responses for distractive stimuli.
Personality can be determined through a variety of test like the _____ ______ test or by _____-______
Rorsach Inkblot Test Self-report
The frontal lobes are particularly vulnerable in numerous non-focal disorders such as
Schizophrenia, Tourette's syndrome, and AD(H)D
In future planning what is the function of the encoding interaction of the VLPFC
Semantic/phonological elaborative processing of MTL representations to ensure traces are distinct
Lateral is equivalent to
Side
What pathways
Temporal lobe VLPFC
Explain where the orbitofrontal cortex is located
The part of the ventromedial prefrontal cortex that overlies the eyes
(LEARN) Orbitofrontal syndrome
Their affect is rarely neutral, constantly oscillating between euphoria and rage, with impulse control ranging from poor to non-existent. Their ability to inhibit the urge for instant gratification is severely impaired: they do what they feel like doing, when they feel like doing it, without any concern for social taboos or legal prohibitions.
Dorsal is equivalent to
Top
The explicit making of moral right and wrong judgement coincides with activation in the _______, while intuitive reactions to situations containing implicit moral issues activates the left ______.
VMPFC Temporoparietal junction (TPJ)
What parts of the cortex form 'memories of the future'
Via the activity in the DLPFC and VLPFC
Temporal lobe =
What
The VLPFC receives inputs from the ____ pathways
What
DLPFC receives inputs from the _____ pathways out of the _____ cortices
Where Sensory
With regard to ADHD, the frontal lobes are of an ' _____ ____' combining frontal, ____ and _____ cortex. Thus damage to the prefrontal cortex or its pathways may result in _____ ______.
With regard to ADHD, the frontal lobes are part of an 'attentional loop' combining frontal, brainstem, and posterior cortex. Thus, damage to the prefrontal cortex or its pathways may result in attentional impairment.
Short term memory =
Working memory
What are examples of executive functions?
Working memory, reasoning, task flexibility, and problem solving, as well as forming goals and planning behavior.
Explain the flat affect
an emotionless voice and facial expression
Consciousness in the brain think of aka
dlPFC
Evidence suggests that the dorsolateral prefrontal cortex ______________________
forms plans of action
Extraversion think of the area in the brain aka
vmPFC
Parietal lobe =
where
