Chapter 7: Brain Mechanisms and Emotions Flashcards
Week 3: Cognitive and Biological Processes
neurons
- humans brain contains 86 billion neurons, each with up to 10,000 synases
- neurons communicate through synapses, which are tiny gaps where chemical signals are exchanged
neurotransmitters
are released at the synapse to activate or inhibit other neurons
neuromodulators
are peptides that influence neurotransmitter activity, affecting brain regions more widely
neuroimaging techniques
noninvasive methods like PET and fMRI allow researcher to visualise brain activity in real time and identify regions involved in emotional states
electrophysiological methods
techniques such as EEG, MEG, and TMR measure electrical or magnetic signals from neurons to study brain functions
lesions and stimulation
accidental damage, experimental lesions, or stimulation of brain regions help identify the role of specific areas in emotions
hindbrain
includes regions like the medulla, pons and cerebellum
medulla
controls cardiovascular activity
the pons
sleep and breathing
cerbellum
motor coordination
forebrain
contains key structures:
- thalamus
- hippocampus
- hypothalamus
- amygdala
- cerebral cortex
thalamus
integrates sensory information and plays a role in decision-making and memory
hippocampus
central to memory processing
hypothalamus
regulates biological functions such as hunger, temperature, and aggression
amygdala
key for processing emotions, especially fear
cerebral cortex
involved in higher functions like decision-making, planning, and emotional regulation, particularly in the frontal lobes
MacLean’s triune brain theory
MacLean proposed that the human forebrain evolved into 3 systems, each linked to emotional and behavioral functions developed at different stages of vertebrate evolution
the striatal region
the earliest part of the forebrain, involved in basic behaviors like territory defense, foreaging, and social bonding, evolved in reptiles
damage to striatum
disrupts goal-directed behaviors, though individuals may still engage in planned activities
the limbic system
in mammals, the limbic system (thalamus, hippocampus, and amygdala) evolved to support emotions related to caregiving, social bonding, and communication. plays a role in regulating the ANS and costisol response, helping mammals navigate complex social environments
Kluver and Bucy
removing parts of the limbic system in monkey led to doctilicy and loss of fear
Olds and Milner
stimulation of the limbic system in rats caused intense self-rewarding behaviors
epilepsy studies
temporal lobe epilepsy, involving the limbic system, triggered powerful emotional experiences
consistent brain activation
emotional experiences activate certain brain regions, both subcortical and cortical areas, such as visual cortex, regions for understanding others, and the frontal cortex
apprasial
assessing whether an event is novel, relevant, rewaring or harmful
bodily feelings
tracking emotional responses in the body
facial expressions
brain regions involved in expressing emotions
conceptualization and regulation
regions that help regulate and understand emotions, as well as empathize with others
affective neuroscience
mapping out how specific brain regions and their networks are involved in various emotion-related processes, offering insights into how the brain processes, regulates, and responds to emotions
LeDoux’s theory of the amygdala
he proposed that the amygdala, rather than the entire limbic system, is the key brain structure responsible for processing emotions
classical conditioning and the amygdala
LeDoux’s research showed that the amygdala is central to classical conditioning, where emotional significance is learned
the amygdala and fear
although often linked to fear, the amygdala is not exclusively activated by fear. it responds to a range of emotions and stimuli based on their relevance to current goals
dopamine
central to wanting rewards and drives approach-oriented behaviors, such as exploring or seeking affection
opioids
involved in liking rewards and contribute to the pleasure and satisfaction we get from rewards, like enjoying food or affection
nucleus accumbens
involved in the brain’s reward system and rich in dopamine and opioids
periaqueductal gray (PAG)
a subcoritcal brain region involved in emotions, particularly in pain, threat, and caregiving. it plays 3 key roles:
- pain modulation
- threat detection
- caregiving
pain modulation and PAG
the PAG helps manage pain by releasing opioids that inhibit pain signals before they reach the cortex, allowing individuals to focus on escaping threats rather than immediate pain
threat detection and PAG
it is activated by images or stimuli that evoke negative emotions, such as threats or distress, indicating its role in processing danger and negative affect
caregiving and PAG
the PAG is part of a caregiving system in mammals, activated by distressing sounds, such as an infant’s cry, and by images of distress. it supports behaviors like nurturing and compassion
anterior insular cortex
a key brain region involved in the awareness of bodily sensations and the experience of emotion. involved in transforming bodily sensations into emotional experiences
key functions of anterior insular cortex
- bodily sensations
- self-awareness (e.g. looking at our own face)
- context and decision-making
- broad emotional involvement
Edmund Rolls
studied individuals with damaged orbifrontal cortex, which is responsible for tracking rewards and associating them with specific contexts. damage to this area results in difficulty understanding which actions lead ot rewards, often causing inappropriate emotions, disinhibited behaviors, or lack of emotional response
what parts of the prefrontal cortex are activated when labeling emotions?
- the dorsal medial prefrontal cortex for attending to emotions
- the venrtromedial prefrontal cortex for categorizing emotions
mindfulness meditation
invovled directing attention and categorizing transient emotional states or the challenges of social living in a physically calm state. increased activation of prefrontal cortex regions and reduced activity in amygdala, helping with emotional regulation
damage to prefrontal cortex
patients with damage to this area often display inappropriate emotional responses in social contexts, such as excessive pride in awkward situations or overly intimate behavior with strangers
neuroimaging studies
brain scans show that when people regulate emotions, the prefrontal cortex is activated
taking a third-person perspective
looking at emotions from a detached viewpoint activates the medial preforontal cortex, helping with self-reflection and emotional regulation
prefrontal cortex
is crucial for modifying emotional responses (emotion regulation) based on context, such as adjusting behavior in social setting
reappraisal process
- involves left lateral prefrontal cortex
- reduces amygdala and insular cortex activity
brain areas activated when empathizing
- medial prefrontal cortex
- anterior insular cortex
- anterior cingulate cortex
cognitive empathy
understanding others mental states activates different regions, including the precuneus and temporal parietal junction
frontal temporal lobar dementia
impairs empathy, making it difficult to read emotions or engage in social behaviors
dorsal anterior cingulate cortex
sevres as the mind’s alarm system attenuated to social pain and separation. this region is active during conflicts between stimuli or individual goals, and it is also involved in physical pain, tracking the unpleasantness of each sensation. also initiates body’s inflammation response
Lisa Barett
proposed that emotions are constructed in the brain through broad networks that first assess the valence (good or bad) and arousal of events
Philip Kragel, Kevin LaBar and Lauri Numenmaa
identified distinct patterns of brain activation for specific emotions
guilt
activates the ventral anterior cingulate cortex
shame
linked to increased activtiy in the dorsolateral prefrontal cortex and posterior cingulate cortex
embarressment
associated with the ventrolateral prefrontal cortex and amygdala
pride
activates the posterior medial cortex, involved in self-referential processing
sexual desire
involves the hypothalamus
gratitude
activates the anterior cingulate cortex and medial prefrontal cortex
romantic jealousy
linked to the basal ganglia
envy
shows activation in the inferior/middle frontal gyrus and dorsomedial prefrontal cortex
Roland Griffiths and Robin Carhart-Harris
explored the brain activation during key mystical experiences, such as those induced by meditation or psilocybin
default mode network (DMN)
this network, which is active during self-referential thinking and spontaneous thought, is deactivated during mystical experiences
emotions linked to deactivation of DMN
self-transcendent emotions like awe, joy, and ecstacy
psilocybin and meditation
these experiences lead to long-lasting effects on emotions like awe and ecstasy, often linked with a loss of self
core mentalizing network
helps us understand stories and other people’s emotions
- medial prefrontal cortex is a central part
- this network supports emotions related to relationships, emphasizing the social nature of human emotions
