Limbic System Flashcards
Limbic system - does what
emotions, feelings, mood, motivation
motivation has a lot to do with our patterns of movement
Which cortex is particularly important for reward and motivation
Orbitofrontal cortex
Limbic system - functional lobe - where is it
Medial surface of each hemisphere - upper boundary is the cingulate sulcus
Primary limbic cortex includes
Cingulate gyrus
Parahippocampal gyrus
Uncus
ACC
ACC is extremely important for
depression and mood
Limbic association includes what
Parts of the thalamus hippocampus amygdala hypothalamus insula parts of basal forebrain orbitofrontal cortex
Hippocampus is located
Mediotemporal
Cingulate gyrus sits above what
corpus callosum
amygdala sits where
next to hippocampus
these are all deep and medial structures
Emotions =
physiological responses to negative/positive stimuli
Emotions - Brain
Changes in arousal level, cognitive functions, attention, memory
Emotions - Body
Endocrine, autonomic, musculoskeletal responses (freezing, flight, expression of fear or surprise through facial expression)
Emotions are
automatic, largely unconscious behavioral and cognitive responses triggered when the brain detects a pos/neg stimulus
Feelings =
Conscious experiences, conscious perception of those physiological emotional responses
Afraid, sad, angry
We are afraid because we run!
Neural control of emotional responses to external stimuli - Emotional stimuli to sensory systems activates what
Emotion systems (amygdala) and then if it is salient it is activated Amygdala acts as decision making body
Neural control of emotional responses to external stimuli - Emotional stimuli to sensory systems activates emotional system (amy) and then salient so gets activated and then what
Hypothalamus and brainstem
Spinal cord and autonomic ganglia
Effector cells
And then you get the emotional response
Emotion - Amygdala - Animal study
Classic conditioning with the mouse - tone (conditioned stimulus) and shock (unconditioned)
Even without shock and just heard the tone, the stress response is still triggered
There is associated learning going on
Emotion - Amygdala - Human study
Human lesions of amygdala and person will fail to undergo fear conditioning
Their emotional learning is poor and they do not recognize facial expressions of fear
Other brain areas that contribute to emotional processing
Cortex - ACC, prefrontal, orbitofrontal
Other brain areas that contribute to emotional processing - prefrontal is particularly important for
social emotions - complex feelings associated with social interactions - empathy, pride, embarassement, guilt
Other brain areas that contribute to emotional processing - damage to prefrontal cortex (TBI) - leads to
impaired social relations and impaired social emotion processing
Other brain areas that contribute to emotional processing - human lesion to orbitofrontal
Behavioral control, say things that are socially unacceptable, impulsive, outbursts of physical and verbal aggression, lack of emotion about the outcome
Other brain areas that contribute to emotional processing - lesion to ACC
Major depression, bipolar disorders
Monkey study with orbitofrontal cortex showed what
the orbitofrontal cortex codes for preference, reward, and motivation
ACC activation in someone who is depressed
Lower levels of ACC activation in someone who is depressed
ACC activation - normal people with no hx of depression but have them recall sad events and what do you see
ACC lights up (and it does not with thinking about positive events)
ACC has association with what kind of stimuli
negative
What else are they doing in research with the ACC
Inc activity in ACC predicted responsiveness to tx with antidepressant
drugs
Person who is depressed and has a certain level of activity of the ACC may respond better to drugs than someone who does not have that activation
