Exam3Lec2Limbic&ExecutiveSys Flashcards
What regions does the limbic system include?
Forebrain areas surrounding the thalamus (traditionally regarded as critical for emotion)
Cortical and Subcortical regions (hippocampus + amygdala)
note that the limbic system is expanded to the hypothal, olfactory system, etc
PET and fMRI studies also suggest that what structures are connected to the limbic system?
Frontal and temporal lobes
What are key structures of the limbic system?
- Hippocampus
- Amygdala
- Hypothalamus
- Prefrontal cortex
What are 6 functions of the limbic system?
- Pavlovian learning or classical conditioning
- Spatial and temporal learning
- Learning and emotional stimuli
- Affective state
- Responding to stress
- Vigilance/attention
What’s another name for the Hippocampus?
what other names refer to the hippocampus
- Medial Temporal lobe (sits inside and wraps around the inside of the temp lobe)
- Post, pero,entero-rhinal
posterior to the optic chiasm
What is so special about the hippocampus having layers?
It increases the surface area and gives it a simple circuit b/c it serves as an amplifier for when we learn something for it to become a permanent memory.
amplifies info to learn and store new memories
What structures serve as short-term memory storage for declarative memory?
Hippocamous and related structures
declarative learning is memory that you can put into words
For any kind of declarative learning, it comes thru the hippocampus and then gets stores in the cortical region where it was 1st processed.
What is the long term storage for declarative info?
A variety of cortical sites: wernicke’s, termporal cortex
What is non-declarative memory?
Memory that cannot be put into words such as motor learning (muscle memory) and biasis/ prejudices.
short term site are unknown but long term storage can include cerebellum, basal ganglia, premotor cortex, etc
What is the purpose of the hippocampus-cortical interactions?
Amplify information and store it back to where it came from to make an memory
If you injure the hippocampus, can you make new memories?
NO, you can’t, but you can remember things prior to your injury
What is the purpose of the LTP (long term potentation)?
Strenghtening certain circuits in the brain to make a memory. The hippocmapus allows us to strengthen the synaptic connection in a specific part of your neural network.
strenghtening of synapses
Where is the amygdala located?
Anterior to the hippocampus
repsonds to phremones weakly
What is the circuit of emotion and learning and mediates negative emotion
The amygdala
What inhibits the amygdala?
The orbital and medial prefrontal cortex
someone with depression looses control from the PFC onto the amyg, so amyg runs wild with neg emotion. A person with depresison has low pre-frontal activity and high amy activity
What two structures are involved in memory and feelings?
- Amygdala dependent associative learning (emotional component)
- Hippocampal-dependent explicit memory (actual context of learning)
Judgement of trustworthiness has to do with what structure?
Amygdala: the amy is highly active for negative emotion whether you are paying attention to a stimuli or not (conscious of it or not)
For affective disroders, what do you see changes in?
See changes in the circuit b/w the amy and the prefrontal cortex and some hypothalamus
What is the major output pathway of the limbic system?
The hypothalamus
mediates fight/flight, drives the reward system, and sends connections out for facial recognition
What are some examples of autonomic targets for the hypothal?
Fight or flight responses such as nose and eye dilating, sick to stomach, sweating , etc
With a lesion POSTERIOR to the hypothalamus, what happens to the connection b/w the brainstem and body and is sham rage lost or intact?
Connection b/w brainstem and body is lost and sham rage is LOST
With a lesion THROUGH the hypothalamus, what happens to the connection b/w the brainstem and body and is sham rage lost or intact?
Connection b/w brainstem and body is intact and sham rage is INTACT
What was concluded with the sham rage experiment?
Hypothalamus is what mediates fight or flight and ANY aggressive response
proves hypothal is the relay station
What are the cortical areas of the limbic cortex?
Insular/cingulate cortex , pre-frontal cortex, right temporal cortex
What is the fxn of the cortical areas of the limbic cortex?
Provides executive control, but also process emotions. Localization is strongest for the emotion of disgust.
When is the Insular cortex is strongly activated?
During the exposure to stimuli perceived as disgusting
also the primary taste cortex
The insular cortex (insula) also plays a role with what type of stimuli?
It reacts to frightening stimuli and active in drug addiction, so it its not completely dedicated to disgust
plays a role for craving drugs
Is limbic damage unilateral or bilateral? Explain this concept
Unilateral
* The right hemi is more responsive to emotional stimuli than the left
unilateral damage leads to problems in the ability to identify emotions of others
If you were to damage your left and right temporal cortex in the lymbic system, what problems can occur with each one respectively.
If you damage left temp cortex: you lose the ability to know who you are (provides factual info/ID info)
If you damage right temp cortex: you lose ability to identify emotions of others (provides emotional info)
What does asymmetrical smiles imply?
You have stronger emotional output from right side of the brain, so your smile is more higher on the left.
What does the prefrontal cortex combine in order to create personality?
- Experience
- Emotion
- Motivation
- Mood
personality disorders stems from problems with frontal cortex
differences in frontal cortex activity relate to personality
Generally, people with greater activity in the right hemi have what type of personality?
Happier, more out-going, friendlier
differences in frontal cortex activity relate to personality
Generally, people with greater activity in the left hemi have what type of personality?
Socially withdrawn, less satisfied with life, prone to unpleasant emotions
What does damage to the prefrontal cortex impair?
Impairs decision making, so it leads to impulsive decision making w/o considering consequences
stems from a failure to anticipate unpleasantness of an outcome
What control emotional smiles? What controls forced smiles?
Limbic system controls emotional (real) smiles
Motor cortex controls volitional (forced) smiles
With ** voluntary facial motor paresis** due to a lesion from the descending pyramidal and extrapyramidal projections from motor cortex and brainstem, what occurs with a (A)voluntary smile and (B) response to humor
(A) voluntary smile (pyramidal volational/forced smile): smile is abnormal
(B) response to humor (duchenne-emotional/real): smile is intact
natural smile is intact because the limbic system is in intact
With emotional facial paresis due to a lesion from the descending extrapyramidal projections from medial forebrain and hypothal, what occurs with a (A)voluntary smile and (B) response to humor
(A) voluntary smile (pyramidal-volational/forced smile): smile is intact
(B) response to humor (duchenne-emotional/real) : smile is abnormal
natural smile is abnormal because the limbic system is not intact
Briefly explain the Limbic loop
- Dopamine generated in Substantia nigra and is released from the ventral tegmental area
- Synapses on Nucleus accumbens (ventral striatum)
- Nuclues accumebens in activated and reward system is generated
What is the function of the limbic loop and where do we see abnormal activation of this loop?
Function: motor and reward behavior
Abnormal activation in OCD
a lot of dopamine is released
changes in circuit leads to obsessive thoughts and compulsive behavior
Why do we emote?
why do we have emotions?
- Preparation of body by an autonomic response
- Behavioral flexibility
- Provides drive or motivation to respond
- Social/emotional cues to interact w/ each other
- Social bonding/communication
- Cognitive evaluation of stimuli and judgments
- Memory storage for specific events
- Persitannt motivation/direction w/o a specific stimulus
- 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
* People with a weak autonomic or skeletal response should feel less emotion
* Incr 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 as prior to their injury
- People with autonomic failure (no fight/flight response) still report feeling emotion but less intensely
- Incr physiologocal arousal incr attraction to potential mates
- Indiv w/ Moebius syndrome still feel strong emotions
emotional respone is a behavioral response
What is Mobius syndrome and what does it imply about emotion?
It is a condition where their emotional output is attenuated so they arent able to generate normal facial expression/body language but they still feel intense emotions.
This 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
cortical lobes
Fxn of Frontal Lobe
- Movement
- Complex behaviors: personality, working memory, spontaenous behavior
- Produduction of Speech (broccas)
cortical lobes
Fxn of Parietal lobe
- Somatosensory perception
- Some Visual and acoustic fxn: attention
- Perception of space
Cortical lobes
Fxn of Occipital and Temporal Lobe
Occipital lobe: Vison
Temporal lobe:
* hearing
* some vision, memory, personality, social behavior
* comprehending spoken words
What does an “association area” mean?
Essential for mental fxns that are more complex than detecting basic dimensions of sensory stimulation, for which primary sensory areas appear to be necesarry
basically a higher order brain area in frontal, parietalm and temporal cortices that integrates lots of diff info
Whaat structues can association areas connect to?
- Thalamic nuclei
- Mediodorsal
- Lateroposterior
- Pulvinar
- Ventral ant/ventral lateral
it can get inout from all over and it associates diff things and makes 1 big picture so we can decide how to respond to stimuli
Which lobe is strongly involved in attention control?
Right parietal lobe
If you have have a left parietal lobe lesion, what can occur?
You are generally fine because the right parietal lobe is doing all visual space so it compensates
minimal right neglect
left parietal lobe plays a minimal role in attention for rvf, its done by right parietal lobe
If you have a right parietal lobe lesion, what can occur?
You have 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
parietal damge creates hemispatial neglect: ignoring half of visial and proprioceptive space
Partial bilateral lesion of both parietal lobes, what can occur?
Severe right neglect
bc you damaged right parietal, it only gets from right, since that is lost, you neglect the right
What area of the temproal area is involved in recognition?
Fusiform face gyrus
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
Although memories are stored by the hippocampus, which structure is involved in working memory?
Prefrontal cortex (frontal lobe): provides a rehearsal loop to keep info active during processing and manipulation
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
language areas
What is wernicke’s area and broca’s area?
- Wernicke’s area: comprehension (understanding language)-temporal lobe
- Broca’s area: production of speech-frontal lobe
if you had a lesion to broca’s you can understand what is being said to you but you can’t respond
What is the fxn of the left and right hemisphere in language?
Left hemisphere: grammar/syntax rules
Rigth hemisphere: emotional inntonation
left: analysis of right visual field, writing speech, lexical and syntatic lang.
rightL analysis of left visual field, emotional coloring of lang=PROSODY, spatial abiities, singing, humming
In an expirement
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: visial cortex
Trial 2: audition cortex
In an expirement
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 grau
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 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
How does differences in sex hormones plays a role in learning?
We have differences in the number of estrogen and testosterone receptors leading to different levls of brain derived neurotrophic factor in the hippocampus. This changes the way we learn.
This is why womean is better at spatial reasoning and men is better at linear reasoning tasks
