Lecture 2: Neuropsychology- The Limbic and Executive Systems Flashcards
PET and fMRI studies also suggest the _____ and _____ lobes are strongly connected
- frontal
- temporal
The limbic system includes the ____ areas surrounding the ____
- forebrain
- thalamus
Traditionally regarded as critical for emotion
What are the functions of the limbic system (6)?
- Pavlovian learning or classical conditioning = stimulus-response learning
- Spatial and temporal learning
- Learning about emotional stimuli
- Affective state = 1) personality = semi-permanent, 2) mood/affective = short term
- Responding to stress
- Vigilance/attention
List key structures of the limbic system (4)
- Hippocampus
- Amygdala
- Hypothalamus
- Prefrontal cortex
What cortical sites are used for the long-term storage of declarative information (2)? What are their functions?
- Wernicke’s area = meaning of words (language comprehension)
- Temporal cortex = memories of objects, faces, et.
What is the function of the hippocampus and where is it located?
- Responsible for “amplifying information” to learn and store new memories
- Located in the medial temporal lobe
What are the two types of memory systems present in our brains?
- Declarative Memory
- Nondeclarative Memory
What is declarative memory and how is it sent through the brain?
HIGH yield
- Anything you can describe to someone in words
- Projections from the hippocampus are sent to varying cortical/sensory regions associated w/ specific memories ( i.e. auditory cortex for auditory memories)
What is Nondeclarative memory (4)?
Motor learning, habits, bias and prejudice
What brain structures are used for long-term memory of declarative information?
A variety of cortical sites (e.g. Wernicke’s area for the meaning of words, temporal cortex for the memories of objects and faces, etc.)
What brain structures are used for short-term memory of declarative information?
hippocampus and related structures
What brain structures (4) are used for Long-term storage of Nondeclarative information?
Low yield
- cerebellum
- basal ganglia
- premotor cortex
- other sites related to motor behavior
What brain structures are used for Short-term memory of Nondeclarative storage?
Low yield
sites unknown but presumbly widespread
What does damage to the hippocampus lead to?
Deficits in memory formation
Explain the hippocampus cortical interactions
Declarative information no matter the sensory system it is coming from, will go back to the hippocampus where it will be “amplified” and made into memory and stored back into the cortices (initial site of processing)
What is Long Term Potentiation (LTP)?
A process involving persistent strengthing of synapses that lead to a long-lasting increase in signal transmission between neurons
What are the key receptors that are needed for memory formation?
Glutamate Receptors
- AMPA receptors- Activated by glutamate, moves Na+ into the neuron
- NMDA receptors (silent activators)- Mg2+ blocks channel so it can NOT be activated by glutamate
What structure in the limbic system plays a role in emotion?
Amygdala
Explain the location and function of the amygdala
- A bilateral structure from the medial temporal lobe
- Main function: Related to emotion, particularly in the processing of aversive information
- Other roles
1. Associating emotions with memories
2. Activation associated w/the presence of pheromones (i.e. sexual attraction)
The Circuit of the Amygdala
What is the main learning and emotional control center of the amygdala?
Basal-lateral nuclei
Explain the pathway from the amygdala to the prefrontal cortex
- The basal-lateral nuclei of the amygdala connect to various reward areas (i.e. ventral basal ganglia) into the mediodorsal nucleus of the thalamus
- From the thalamus information is sent to the orbital and medial prefrontal cortex
Review Slide 16
The circuit between the prefrontal cortex and amygdala is an essential factor in diagnosing depression. Explain what is seen in a healthy individual vs a depressed individual.
- Healthy Individual: Lots of inhibition from the PFC to amygdala (b/c the amygdala tends to mediate negative emotion)
- Depressive Individual: Inhibition is less b/w PFC and amygdala. Low activity of PFC, high activity of amygdala
Explain the connection between the amygdala and the hippocampus and how it affects learning.
- Amygdala connects directly to the hippocampus to enhance our learning process
- Emotionally relevant info is much easier to remember than neutral stimuli
- Amgydala directs its own boost to the hippocampus if the stimuli has some kind of emotinal component (doubling up on activation)
Explain the Judgement of Trustworthiness
Example of Amygdala Activation
The amygdala is activated by potentially negative stimuli (i.e. untrustworthy person) regardless of whether you’re conscious of the stimulus or not (explicit vs implicit)
Review Slide 18
What other circuits are affected by mood disorders (e.g. depression, bipolar, post-partum, etc)?
- Mediodorsal nucleus of the thalamus
- Orbital and medial prefrontal cortex
The __________ is a major output pathway of the limbic system.
Hypothalamus
What are some functions of the hypothalamus (4)?
- Autonomic Motor Function→”Fight of Flight”
- drive toward reward pathways
- hunger pathways
- Mediates a lot of behavioral responses to emotional and memory cues
Explain the mechanism of the Sham Rage Experiments and what was discovered by the results.
Sham Rage Experiment
- Done on cats who expressed aggressive responses in absense of stimuli
- Two lesions were performed with different outcomes:
1. Lesion posterior to hypothalamus→connection to brainstem and body LOST→Sham rage LOST
2. Lesion through the hypothalamus→connection to brainstem and body INTACT→Sham rage INTACT - These results illustrate that the hypothalamus is the relay station sending averse stimuli to the rest of the body to elicit a response
What is the function of the Prefrontal cortex and Cingulate gyrus (cortical areas)?
Provide executive (aka top-down) control but also process emotions
_______ is strongest for the emotion of disgust
Localization
When is the insular cortex strongly activated?
during exposure to stimuli perceived as “disgusting”
Also the primary taste cortex
The insular cortex reacts to ______ stimuli and is _____ in drug addiction so not completely dedicated to disgust.
- frightening
- active
The ______ hemisphere seems to be more responsive to emotional stimuli than the ______.
- right
- left
Ex. Asymmetrical smiles
What is the result of damage to the right temporal cortex?
difficultly identifying emotions of others (facial expressions)
What is the result of damage to the left temporal cortex?
unable to recognize who people are
What 4 things does the prefrontal cortex combine to create personality?
- experience
- emotion
- motivation
- mood
NOTE=Combines both permanent and transient information
People with greater activity in the _____ hemisphere tend to be happier, more outgoing, and friendlier
right
People with greater activity in the _____ hemisphere tend to be socially withdrawn, less satisfied with life, and prone to unpleasant emotions
left
What is the result of damage to the prefrontal cortex?
impairs decision making
- Leads to impulsive decision-making without pausing to consider consequences
- Stems fom a failure to anticipate unpleasantness of an outcome
What part of the brain controls real/emtional smiles?
Also known as Duchenne smile
The limbic system
What controls Volitional (forced) smiles?
Also known as pyramidal smile
the Motor cortex
What happens to the smile when a patient has Emotional/Real (motor) Paresis?
Also known as Duchenne smile paresis
- Pt CAN NOT have a real/emotional (duchenne) smile
- CAN have a volitional/forced (pyramidal) smile
What happens to the smile when a patient has Voluntary/Forced (motor) Paresis?
Also known as pyramidal smile paresis
- Pt CAN NOT have a volitional/forced (pyramidal) smile
- Pt CAN have a real/emotional (duchenne) smile
What causes emotional/real facial paresis?
Low Yield
a lesion from the descending extrapyramidal projections from medial forebrain and hypothalmus
What causes voluntary/forced facial paresis?
Low yield
a lesion from the descending pyramidal and extrapyramidal projections from motor cortex and brainstem
What is the function of the limbic loop and explain the pathway
- Function: motor and reward behavior
1. Dopamine generated in Substantia nigra and is released from the ventral tegmental area
2. Synapses on the Nucleus accumbens (ventral striatum)
3. Nucleus accumebens sn activated and reward system is generated (i.e. drugs, sex, money, etc)
Where do we see abnormal activation of the limbic loop?
OCD (a lot of dopamine is released)
changes in circuit leads to obsessive thoughts and compulsive behavior
Why do we emote (9)?
- Prepares the body for action through the initiation of an appropriate autonomic response
- Provides a flexible and efficient means of responding to a given stimulus that is largely based on the individual’s experience
- Provides drive or motivation to respond
- Facilitates the communication of one’s mood state and responded tendency (e.g. anger, aggression)
- Facilitates social bonding and communication
- Influences the cognitive evaluation of stimuli and resulting judgements
- Faciliates and enhances memory storage for specific events
- With the assistance of memory = provides persistent motivation and direction even in the absence of a specific stimulus
- Triggers recall of specific memories
What is the James-Lange Theory and what 2 predictions did it lead to?
- The autonomic arousal and skeletal action occurs first in an emotion. The emotion that is felt is the label that we give the arousal of organs and muscle
1. People with a weak autonomic or skeletal response should feel less emotion
2. Increasing one’s response should enhance an emotion
bottom-up process: that body responds to stimulus and then the brain is labeling that response w/a specific emotion
What 3 mixed evidence was discovered that counteracts the James-Lange theory?
- Paralyzed people reported feeling emotion to the same degree as prior to their injury
- People with autonomic failure (no fight/flight response) still report feeling emotion but less intensely
- Increase physiologocal arousal increase attraction to potential mates
emotional respone is a behavioral response
What is Mobius Syndrome?
It is a condition where their emotional output is attenuated so they aren’t able to generate normal facial expressions/body language but they still feel intense emotions.
What is the result of Mobius syndrome?
facial paralysis and the inability to move the eyes from side to side
What does Morbius Syndrome imply about emotion?
It implies that peripheral responses might enhance our emotions, especially how we interpret out emotions. But emotion is starting from a cognitive point and it becomes a feedback cycle
What key things does Executive Objectives identify?
- Key differences between male and female brains
- Key brain areas that process: emotion, memory, language, drug abuse and reward
describes the main fxns of each cortical lobes association area
What are the functions of the frontal lobe (3)?
- Movement
- Complex behaviors: personality, planning, working memory,changing strategies, self-awareness, attention to emotionally related stimuli, and spontaneity of behavior
- Production of speech (Broca’s area)
What are the functions of the parietal lobe (3)?
- Somatosensory perception
- Some visually and acoustically related functions (i.e. attention)
- Perception of space and monitoring the body’s position in space
What is the function of the occipital lobe?
vision
What are the functions of the temporal lobe (3)?
- Hearing
- Some functions in vision, memory, and factors of personality and social behavior
- Comprehending spoken words (Wernickes area)
What does an “association area” mean?
Essential for mental functions that are more complex than detecting basic dimensions of sensory stimulation, for which primary sensory areas appear to be necessary
Review Slide 41
basically a higher order brain area in frontal, parietal and temporal cortices that integrates lots of different information
What structues can association areas connect to?
LOW yield
- Thalamic nuclei
- Mediodorsal
- Lateroposterior
- Pulvinar
- Ventral anterior/ventral lateral
Which lobe is strongly involved in attention control?
Right parietal lobe
What is the result of damage to the parietal lobe?
Creates hemispatial neglect = ignoring half of visual and proprioceptive space
If you have have a left parietal lobe lesion, what can occur?
- Minimal Right Neglect
- You are generally fine because the right parietal lobe compensates for both left and right visual spaces
Left partial lobe plays a minimal role for the right visual field
If you have a right parietal lobe lesion, what can occur?
- Severe Left Neglect
- Not good b/c you can only attend to 1/2 of visual space and can’t recognize the other half (ex. drawing half a clock)
Partial bilateral lesion of both parietal lobes, what can occur?
- Severe Right Neglect
What area of the temporal area is involved in recognition?
Fusiform face gyrus
Review Slide 45
strong activation in the presence of stimulus which resembles a face
What is prosopagnosia?
Damage to fusiform face gyrus causes Face blindness: can’t identify yourself or others through facial recognition
What structure in the frontal lobe provides a rehearsal loop to keep information active during processing and manipulation (working memory)?
prefrontal cortex
Ex: someone tells you a phone # w/o having somewhere to write it down and you say it over and over again in your head
Different regions of which structure works together to produce personality and is responsible for behavioral control?
- Pre-frontal cortex (frontal lobe)
- For behavioral control, as you age, your pre-frontal cortex is maturing/developing. Full development occurs in your 20s
What is the function of Wernicke’s area? Where is it located in the brain?
- comprehension of speech
- temporal lobe
What is the function of Broca’s area? Where is it located in the brain?
- production of speech
- frontal lobe
What is the function of the left hemsiphere in language?
- Left hemisphere: grammar/syntax rules
- Analysis of right visual field, writing speech, lexical and syntatic language
Review 52
What is the function of the right hemisphere in language?
- Right hemisphere: emotional inntonation
- Analysis of left visual field, emotional coloring of lang=PROSODY, spatial abiities, singing, humming
Review Slide 52
In the experiment shown in the image below:
- In Trial 1 you passively viewed the word “table”
- In Trial 2 , you solely listened to the word “table”
What areas of the brain are strongly activated in each trial?
- Trial 1: visual cortex
- Trial 2: audition cortex
In the experiment shown in the image below:
- In Trial 3 you solely spoke the word “table”
- In Trial 4 , you had to generate a word associated with the word “table”
What areas of the brain are strongly activated in each trial?
- Trial 3: Recognition processing and motor processing in brocas areas to actually say it
- Trial 4: Requires cognitive processing, incorporating temporal and frontal lobe circuit
The limbic system also mediates sexual behavior, mention how each structure below plays a role
1. Amygdala (medial nucleus)
2. Medial preoptic/sexually dimporphic
3. Ventromedial & Periaqueductal gray
4. Pineal
5. Pituitary
- Amygdala (medial nucleus): pheromones
- Medial preoptic/sexually dimporphic: male sexual behavior
- Ventromedial & Periaqueductal gray: femal sexual behavior
- Pineal: sexual development
- Pituitary: hormone control
What brain structure is responsible for male sexual behavior?
Medial preoptic/sexually dimorphic
What brain structure is responsible for female sexual behavior?
Ventromedial and Periaqueductal gray
What brain structure is responsible for pheromones?
Amgydala (medial nucleus)
What gland is responsible for sexual development?
Pineal gland
What brain structure is responsible fo hormone control?
Pituitary
What is the relationship between gender and neural activity?
You see greater similarities in brain activity/ares between everyone that attracted to females/males. (HeM and HoW/ HeW and HoM)
two aspects to sexuality: sex and gender
He=Heterosexual
Ho=Homosexual
How do differences in sex hormones play a role in learning?
- We have differences in the number of estrogen and testosterone receptors leading to different levels of brain-derived neurotrophic factor in the hippocampus. This changes the way we learn.
- This is why women is better at spatial reasoning and men are better at linear reasoning tasks
- Which of the following limbic structures is primarily responsible for the implicit feeling of trustworthiness?
A. Hippocampus
B. Amygdala
C. Hypothalamus
D. Prefrontal Cortex
B. Amygdala
- The James-Lange Theory suggests that autonomic arousal and skeletal action occurs prior to an emotion. Which of the following findings would support this claim?
I. Paralyzed people report feeling emotion to the same degree prior to injury
II. People with “pure autonomic failure” report feeling emotion but less intensely
III. Increasing physiological arousal increases attraction to potential mates
IV. Individuals with Moebius syndrome feel strong emotions.
A. I, II, IV
B. II, III
C. III, IV
D. I, II, III
B. II, III
- Which of the following cortical regions is strongly activated during exposure to stimuli perceived as “disgusting?”
A. Prefrontal Cortex
B. Cingulate Gyrus
C. Insular Cortex
D. Hypothalamus
C. Insular Cortex
- A 22-year-old man is rushed to the ED following a motorcycle accident that caused severe damage to his right temporal lobe. All of the following are symptoms likely associated with injury to this region of the brain EXCEPT:
A. Difficulty recognizing faces
B. Inability to comprehend spoken words
C. Difficulty identifying the emotions of others
D. Inability to attend to the left visual field
D. Inability to attend to the left visual field (Parietal lobe)
- Patients with abnormal activation of the limbic loop often suffer from conditions such as obsessive-compulsive disorder (OCD). Which of the following best describes the pathophysiology of this condition?
A. Excess stimulation of nucleus accumbens via increased dopamine production
B. Excess stimulation of ventral tegmental area via increased dopamine production
C. Excess stimulation of nucleus accumbens via increased serotonin production
D. Excess stimulation of ventral tegmental area via increased serotonin production
A. Excess stimulation of nucleus accumbens via increased dopamine production
