Unit 3 Flashcards
psychedelics and consciousness
decrease functional connectivity w/n default network (alter sense of self)
-increase functional connectivity b/w primary visual cortex and brain (hallucinations, synaesthesia)
default mode network
linked to higher order consciousness (daydreaming, self reflection, recalling memories, feeling complex emotions)
- overactive in depression
- Alzheimer’s disease possibly targets default mode network (memory)
- attention: allows attention to internal thoughts and stimuli
higher order consciousness
metaconsciousness, sense of self, emotions, memories
primary consciousness
awareness and perception of environment and senses (e.g. sights, sounds, etc.)
locked-in syndrome
when people are consciously aware, but cannot physiologically respond (low wakefulness)
locked-in syndrome and fMRI
asked control patients and patients diagnosed as vegetative state yes/no questions
- if yes: imagine playing tennis (triggers motor cortex)
- if no: imagine navigating familiar environment
- fMRI results indicated that functional connectivity was similar among control and vegetative state patients –> locked in syndrome
coma
low levels of wakefulness and consciousness
lucid dreaming
low level of wakefulness, high consciousness
-being aware/controlling dreams
change blindness
being unaware of changes b/w two alternating images b/c selective attention is directed elsewhere (color of dude’s pants)
inattentional blindness
being unaware of stimuli b/c attention is directed elsewhere (gorilla)
early stage selection model
sensory input –> filter is applied before information is perceived (e.g. processed) based on rudimentary/physical characteristics –> attended messages are passed through to next stage of processing
late stage selection model
sensory input–> all information is perceived/processed –> we are only consciously aware of some of the info processed/perceived
problems with early stage selection model
experimental evidence: some info that is “unattended” can still pass through filter and be processed at later stages (e.g. yelling your name during cocktail party phenomenon of cat/dog)
Dorsal Attention Network
allows for selective attention of external stimuli, communicates with sensory and motor networks (e.g. directing visual field, swiveling eyes around, moving hands) to influence perception and coordinate movement
top-down attention
controlled, voluntary, goal-oriented
e.g. looking for Waldo in Where’s Waldo
external: deliberating trying to swat annoying mosquito
Internal: actively thinking/pondering philosophy
bottom-up attention
unintentional, automatic, reflexive
e.g. scanning a book and red text standing out
Internal: distracting thoughts when taking exam
External: noticing annoying mosquito
salience networks
involved in internal and external bottom-up attention
-activate in response to highly salient (captivating) stimuli/emotions
divided attention
multitasking, when attention is split between two stimuli
e.g. mind-wandering, distracted driving
modal model of memory
Input → sensory memory (seconds-long, ex. object permanence, immediate) → short-term memory (up to 30 seconds, limited capacity, can prolong duration through mental rehearsal (e.g. vocalizing, constantly repeating in your mind)) → long term memory (last for days, years, and even decades, larger capacity)
explicit memory
declarative: episodes and facts, memories that you can describe/declare
- episodic and semantic
implicit memory
nondeclarative: skills, associations, and habits
- procedural memory, priming, conditioning
episodic memory
particular events (e.g. first day of school)
semantic memory
memory of facts (capital of France)
procedural memory
implicit; skills (e.g. riding a bike)
priming
being more likely to recall a word heard recently
conditioning
learning by establishing relationships between behavior and positive/negative reinforcement or pairing neutral stimulus w/ response
HM and amnesia
suffered from seizures so had to have his hippocampus, amygdala, and surrounding cortex removed suffered anterograde amnesia (inability to create long-term memories after injury) and retrograde amnesia (inability to recall long-term memories formed prior to injury
-amnesia affects memories formed in close proximity to when the brain injury occurred (e.g. HM was able to remember events from childhood)
HM and nature of memory
HM had ability to recall info presented several seconds ago, retained prior skills (procedural memory) and able to learn new skills, inability to plan for future
-HM’s case showed that there are different types of memory, which are supported by different brain regions/networks
constructive nature of memory
Memory is not a video replay, but constructive (building blocks, malleable, we don’t remember everything but are selective in what is stored and can be retrieved)
-Influenced by multiple sources (e.g. semantic knowledge of facts, expectations such as repeated stories, environment, mood)
synaptic plasticity
changes in the strength of synaptic connections b/w neurons due to molecular and cellular mechanisms AND birth of new neurons (neurogenesis)
Long Term potentiation
results in strengthening existing synapses and growth of new synapses
long-term depression
results in weakening/eliminating existing synapses
Morris water maze
- With successive trials, the time it takes for animal to reach fixed platform decreases and path becomes more linear
- When platform is moved to different location, animal takes time to adjust but the time it takes for them to learn and master movement to new platform is markedly less than the initial time to master the first task
LTP process: rodent hippocampus
- tetanic stimulation (repeated high frequency electrical stimulus) of presynaptic axons leads to action potentials traveling down the neuron depolarizes the axon terminal
- depolarization triggers opening of voltage-gated Ca2+ ion channels, allowing Ca2+ ions to enter
- further depolarization by Ca2+ ions stimulates vesicles containing glutamate to fuse with membrane and release glutamate into synaptic cleft
- glutamate in synapse binds to NMDA and AMPA receptors
- when glutamate binds to AMPA receptors, triggers opening and allows influx of sodium ions
- influx of sodium ions triggers further depolarization in postsynaptic cell. At a certain threshold, the Mg2+ ions blocking pore of NMDA receptors are removed so that when glutamate binds to NMDA receptors, NMDA receptors open, allowing Ca2+ to flow through
- Ca2+ activates kinases, which then lead to signaling pathways (phosphorylation) and further physiological changes (LTP, creation of proteins and more AMPA receptors)
- AMPA receptors are trafficked to postsynaptic membrane, increasing sensitivity to glutamate and leading to LTP
stages of learning/memory
encoding –> consolidation –> retrieval
Levels of Processing
there are varying degrees of processing information, each with varying levels of effectiveness
shallow processing
ineffective, passive form (e.g. skimming textbook, rehearsing material)
deep processing
more effective, active form (e.g. drawing connections elaborating on the meaning)
experimental evidence for LOP
when comparing rhyming, fill in the blank or capital letters, participants who were assigned to FITB –> rhyming –> capital letters better recalled word
circumplex model of emotions (define, x-axis and y-axis)
model of organizing emotions based on valence (pleasant/unpleasant) and intensity
evolutionary purpose of emotions (Darwin)
- communicate with other people/learn from others
2. organize and motivate action
basic emotions (who, what are basic emotions?)
Paul Ekman proposed that there are 6 basic emotions: anger, fear, surprise, disgust, joy, sadness that are universally recognizable, distinct and measurable
components of emotion (4)
physiological reactions (bodily reactions, ANS), input appraisal (what is in the environment and what does it signify), conscious experience (what it feels like to yourself), expression (outwardly conveying emotion)
James-Lange theory of emotion
I am sad because I am crying
stimulus –> physio response –> conscious experience of emotion
Cannon-Bard theory of emotion
simultaneously and independently stimulus –> physio AND conscious experience of emotion
-physiological response and conscious experience are independent and supported by different brain systems
hypothalamus and emotion
coordinates with autonomic nervous system and pituitary gland (secretes hormones related to emotions and stress)
Schacter-Singer Two Factor Theory
conscious processing of emotion is influenced by context AND physio response
-physio response can amplify emotional experience
constructive nature of emotion
-social, environmental expectations, past memory of similar events
limbic system (components)
amygdala, hippocampus, hypothalamus, parts of default mode network
-associated with memory and emotion
amygdala (inputs and outputs)
outputs: to autonomic components of emotion (hypothalamus) and regions that shape subjective experience of emotion (pathways to cortex)
inputs: from sensory and non-sensory regions of cortex and hippocampus
amygdala and emotion
associated with fear
- lesions to amygdala prevent fear conditioning in mice and block classical conditioning with positive stimuli
- possibly related to intensity of emotions more so than fear
reward and pleasure (associated brain regions, NTM)
dopamine VTE (ventral tegmental area) releases dopamine onto nucleus accumbens and prefrontal cortex
depression (anhedonia, rumination)
rumination: overthinking, repetitively focusing on symptoms of distress
anhedonia: inability to feel pleasure
consolidation
moving memory from fragile state to more permanent state
retrieval
getting info OUT OF memory
encoding specificity
when we encode info, we also encode surrounding context in addition to stimulus
-e.g. underwater vs. on dry ground
self-reference effect
retrieval is better when you relate concepts to yourself, create your own cues
retrieval cues (definition, efficacy compared to free recall)
visual/verbal stimuli that trigger retrieval; more effective than free recall
cued recall
recall using retrieval cues
ways to promote successful retrieval
concept maps and organizational trees
HM (what was his condition, what did his case study reveal about the nature of memory?)
suffered from seizures; had hippocampus removed
- was still able to recall info repeated seconds ago and procedural memory
- suffered from anterograde and retrograde amnesia, but only in regards to memories near time of brain injury
- since he was able to retain some types of memory wile losing others, HM’s case demonstrated that there are different types of memory, each with different corresponding brain regions
retrieval mode
process of intentionally directing your attention to test material
cellular (synaptic) consolidation
long-term potentiation that increases responsiveness of postsynaptic neuron to presynaptic neuron
-occurs within hours
systems consolidation
dealing with connectivity b/w neural networks involving hippocampus and cortex
-occurs within hours to days
retrieval practice
practicing retrieval by repeatedly testing yourself
constructive nature of memory
influenced by emotions, mood, prompts, expectations of environment
memory (definition)
retaining, retrieving, and encoding information
cocktail party effect
ability to pay attention to certain stimulus even with distracting surrounding/isolate attention
selective attention
directing attention towards specific stimulus
inattentional blindness
being unaware of stimulus bc attention is directed elsewhere
change blindness
not detecting changes in alternating pictures, reduced with directed selective attention
early stage processing model
filter is applied BEFORE info is processed/perceived
-filter selects based on physical characteristics; only “attended” info is processed
ISSUES: experimental evidence suggests that even “unattended” info is processed (noting our name being called out in the middle of a party)
late stage processing model
all info is processed, but filter determines what info we become consciously aware of
McKay dichotic listening experiment
subjects asked to only pay attention to stimulus coming in from one ear (e.g. they threw stones at the bank) but input from other year implying nature of bank (e.g. money, river) affected participant’s perception of what bank was
external and internal attention
external: paying attention to environmental stimuli
internal: paying attention to sense of self, self-reflection, memory, emotions
dorsal attention network
related to external attention
DRM paradigm (false memory, gist)
participants form false memories, but will retain “gist” of information??
top-down processing
purposeful, consciously looking, goal-oriented (where’s Waldo)
bottom-up processing
passive, unintentional, noticing stimuli out of the blue
salience networks
related to top-down and bottom-up processing
primary consciousness
awareness of environmental stimuli
higher-order consciousness
awareness of self, emotions, metaconsciousness
panpsychism
everything (even rocks) possess consciousness
cambridge declaration on consciousness
don’t test on animals
default mode network and disease
Alzheimer’s
levels of wakefulness (arousal) and conscious awareness: vegetative state, locked-in syndrome, lucid dreaming, coma
vegetative state: high levels of wakefulness (still exhibit physiological symptoms) but low levels of conscious awareness
locked-in syndrome: low levels of wakefulness but high level of conscious awareness
lucid dreaming: high level of conscious awareness, medium level of wakefulness
coma: low levels of consciousness and wakefulness
psychedelics and state of consciousness (functional connectivity b/w different cortexes)
increase functional connectivity b/w visual cortex (hallucinations)
divided attention (distracted driving)
when attention is directed elsewhere
task-unrelated thought
when attention is not on the task at hand
Descartes theory of consciousness
I think because I am??
von economo neurons (dolphins)
social
unconscious processing (blindsight, deaf hearing)
we can still process stimuli, even if we are not consciously aware of them
- blindsight: even when lacking the corresponding photoreceptors in primary visual cortex, individuals can react to visual stimuli corresponding to the associated photoreceptors
- deaf hearing: same concept but with primary auditory cortex and tonotopic organization
Iowa gambling task (unconscious and conscious processes)
physiological process precede conscious awareness of stimuli
what stimulates or inhibits synaptic plasticity?
inhibited by stress, anxiety
stimulated by new experiences
Long Term Depression (what stimulates it, calcium levels, receptors, glutamate, morphological changes)
low-frequency tetanic stimulation, reduces calcium levels, so no trafficking of AMPA receptors to membrane, reduced sensitivity to glutamate and binding of glutamate to AMPA receptors –> weakening of eliminating synapse completely
relationship b/w EPSP amplitude and time
with high-frequency tetanic stimulation, EPSP strength (amplitude) increases
EPSP amplitude decreases over time bc overstimulation is not healthy (needs time to package glutamate in vesicles, replenish supply of glutamate, etc.)
Morris water maze
over successive trials, animal’s path to target became more linear and time elapsed decreased
-even with new target, the animal was able to learn new pathway faster
