Psych Part 2 Flashcards
Biological Basis of Schizophrenia
If one twin has schizophrenia, other twin has 50% likelihood.
Stress-diathesis theory - genetics is the basis but stress required for onset.
Dopamine hypothesis: dopamine pathway is hyperactive. Potentially overabundance and activity of receptor. Dopamine antagonists are sometimes successful. Positive Symptoms. Maybe hyperactivation of temporal lobes as well.
Maybe hypoactivation of frontal lobes. Negative symptoms.
Biological Basis of Depression
Genetics; links to dopamine, serotonin, and norepinephrine.
Often accompanies other brain disorders: Parkinsons, Brain trauma
Neurodevelopmental Disorders
Arise in utero or shortly after.
Down Syndrome (Trisimony 21)
ADHD - understimulation in regions of the brain
ASD - hypothesis that is under-formation of mirror neurons.
Neurocognitive Disorders
General term - dementia. A severe loss of cognition beyond normal aging trajectory.
Alzheimers - most common, 50% of people over 90 will have.
Parkinsons
Alzheimers
Anterograde amnesia - no new memories.
Retrograde amnesia - stepwise, so loss of most recent memories first.
Includes visual memory.
Cortical disease resulting from neural plaques (beta-amyloid protein and neurofibrillary triangles [tau protein]). May cause cell death by impeding cell nutrient/waste transport. There is some evidence of loss of ACh function in the hippocampus.
Parkinsons
A movement disorder, loss of dompaminergic neurons in the basal ganglia and substantia nigra.
Symptoms: resting tremor; slow movement; rigidity; shuffle; 50-80% develop dementia.
L-dupa; can cross the blood brain barrier and has some positive effect.
3 types of stressors
Catastrophe, life changes, daily hassles
Prolonged stress
immunosuppression; infertility; hypertension
Response to Stressors
Physiological - sympathetic nervous system
Cognitive - hypothalamus releases corticotropin releasing hormone (CRH) –> pituitary releases adrenocorticotropic hormone (ACTH) –> Adrenal glands releases Cortisol (glucocorticoid) –> causes shift from glucose energy to fat, but keeps blood glucose high as this is essential for brain.
Nonassociative learning
Repeated Exposure to a stimulus
Habituation - tuning out a stimulus. Dishabituation is the reverse process.
Sensitization - Increased responsiveness to repeated stimulus or particularly noxious stimulus. Does not usually result in long term change.
Associative Learning
Classical
Operant
Timing is essential for both these modes of learning.
Classical Conditioning
Two stimuli are paired so that the response to one stimuli changes.
Neutral stimulus - does not elicit an intrinsic response.
Unconditioned response - elicits unconditioned response
Conditioned stimulus - originally neutral
Conditioned response - learned response to conditioned stimulus
Process for developing/maintaining conditioned responses (Classical or Operant)
Acquisition
Extinction
Spontaneous recovery
Generalization
Discrimination
Note that we are highly predisposed to adaptive associations. Ex. Taste-aversion.
Operant (instrumental) conditioning
Punishment + reward –> new behaviour
Punishment pathways are largely mediated by the amygdala.
Reward pathways are largely mediated by the hippocampus.
B. F. Skinner
Rat in a box experiment. Push lever for food, push lever to end electric shock.
Reinforcement
Anything in operant conditioning that increases the likelihood of a behaviour.
Can be positive (addition of good)
Can be negative (removal of bad)
Primary reinforcement - innately satisfying
Secondary reinforcement - Learned reinforcers that must be paired with primary reinforcement to generate learned behaviour.
Reinforcement Schedule
Required in Operant Conditioning.
Continuous: rapid acquisition and rapid extinction. Best method to teach a new behaviour.
Intermittent: Longer acquisition period, longer retention
4 important intermittent reinforcement schedules
A fixed ratio - reinforcement after a set number of instances of behaviour. Produces a high response rate, more behaviour = more reward.
A variable ratio - reinforcement at variable number of instances of behaviour. Slowest rate of extinction.
A fixed interval - reinforcement after a set amount of time
A variable interval - reinforcement at irregular intervals
Punishment in Operant Conditioning
Decreases behaviour.
Punishment can be positive or negative.
Positive - present undesirable stimulus
Negative - removal of desirable stimulus
Punishment is less effective than reward. Typically if punishment stops behaviour will too.
Rewards are more specific than punishment. The former says what to do. The later says what not to do - much broader!
Cognitive process that affect associative learning
Behaviourism - all psychological phenomena are explained by the observable antecedents of behaviour and their consequences.
Cognitive Psychology - accounts for how cognition accounts for behaviour. Does not deny stimulus pairing though. Notes as well that cognitive “expectation” is present in something like operant conditioning.
Ex. Insight learning and latent learning.
Insight learning
Previously learned behaviours are suddenly employed in new ways.
Latent Learning
something is learned but only later expressed (ie. observable)
When does learning occur most rapidly?
When it is biologically relevant
Long-term memory storage
Involves long-term permanent structural and functional changes:
New connections.
New pre/post-synaptic membranes.
Changes in production and release of neurotransmitter.
Increased dendritic branching/protein synthesis.
Observational Learning
Also known as social or vicarious learning.
Imitation perpetuation - dependent upon perception of how successful behaviour is and the reinforcement received.
Albert Bandra
Imitation will occur even if consequences are not witnessed. However, more likely to occur if you consider yourself akin to the modeler.
Observational Learning Biological Processes
Mirror Neurons: Fire when performing AND observing a task.
Hypothesis of function:
1) Fire when connecting sight and actin
2) Help us understand and imitate actions successfully
3) Proposed that potentially relevant in vicarious emotions
4) Potential absence of mirror neurons may contribute to ASD
Encoding
the process of transferring sensory input into memory
Working Memory
Composed of:
1. Phonological Loop
2. Visuospatial sketchpad
3. Central Executive
4. Episodic buffer
Very limited. Some characteristics:
(1) Serial position effect - most likely to remember the first and last items in a list
(a) Primacy effect - earlier has the longest time to be encoded
(b) Recency effect - still in phonological loop
Aids to memory
Mnemonic - any technique for improving retention/memory retrieval
ex. rehearsal
Chunking - organization into discrete groups
Hierarchies of knowledge - Furniture –> Chair/couch
Depth of processing - think harder
Acronyms
Dual-coding hypothesis - easier to remember when words and images are combined
Method of Loci -
Peg word method - assign numbers to images
Self-reference effect - easier to remember if relevant to self.
Types of Memory Storage
Sensory Memory
Short-term Memory (distinct from working memory)
Long-term memory
Sensory Memory
Initial recording of sensory info into memory, very brief.
Iconic memory: photographic memory (tenths of seconds)
Eidetic memory: ability of some small children to remember vivid detail of an image for a few minutes.
Echoic memory: Sound (last 3 - 4 seconds)
Broadbent Filter
Sensory memory must pass through this filter to short term memory otherwise it will fade.
Short-term memory
Limited in space and duration. 7 +/- 2 digits for about 20 seconds unless actively processed.
Long-term memory
Potentially has infinite capacity.
Implicit/procedural memory - conditioned association/knowledge of how to do something
Explicit/declarative - can voice what is known. requires conscious recall. Two types:
(1) Semantic - factual
(2) Episodic - autobiographical
Brain regions and memory
Explicit - hippocampus
Implicit - cerebellum
Amygdala - connection of memory and emotions
Infantile Amnesia
Loss of explicit memories but not implicit ones after the age of 4.
Retrieval
Recall - free or cued. Free, from “thin air”.
Recognition - Identifying specific info from a larger group
Reproductive memory - fidelity of storage of stimulus and subsequent recall
Re-learning
Retrieval Cues
Priming - prior activation of nodes, leads to unconscious influence of decision-making.
Mood-dependent memory - recall is more likely when in the same mood
Flashbulb memory - emotionally intense experiences
Stages of memory process
Attention, encoding, retaining, retrieval
Memory Loss
Can occur at any stage in the memory loss process.
Aging effects of memory
Memories that are not frequented are quicker to be lost.
Prospective memory deteriorates quickly - remembering to do something without reminder. This also impacts time keeping.
Forgetting/Learning
Both occur exponentially
Interference in Memory
Can result in a failure to retrieve info.
Proactive Interference - previous information interferes with an ability to remember information.
Retroactive Interference - new information interferes with retrieval of old information.
Positive Transfer
Opposite to interference.
Previous knowledge improves memory retention of new information.
Memory construction and source monitoring
NOT fool proof.
We can add details that are not actually remembered.
We draw on schemes more than actual information.
Misinformation effect - subtle insertions of misinformation can result in false memories. This is why leading questions can be so problematic.
False memories - repeatedly imagined scenarios can generate false memories.
Theory of Reconstructive Memory
States that memory recall is not episodic but constructed from similar experiences, social expectations, perceptions, cues, and feelings.
Note that a persons assessment of the validity of a memory is therefore not an effective proxy for the validity of a memory.
Source monitoring
We are ineffective in our capacities to monitor where memories come from.
