Biological Correlates Flashcards
General adaptation syndrome (GAS)
Body’s stress response
- Alarm => Resistance => Exhaustion
Practice effects
Gains in score on retesting
fMRI
Measure brain activity by detecting associated changes in blood flow
- Uses magnetic fields and radio waves
- Does NOT measure glucose, only blood flow
Epigenetic mechanisms
- DNA methylation
- Histone modification
Proximal stimulus
Stimulus registered by sensory receptors
- Ex. pattern of light falling on retina
Distal stimulus
Provides info for proximal stimulus
- Ex. Shoe on floor
Absolute threshold
Lowest intensity of stimulus that can be sensed reliably
- Depends on emotions, importance
- Intensity level detected 50% of time
Difference threshold/just noticeable difference
Smallest difference that is sufficient for a change in a stimulus to be noticed
Weber’s Law
Change required to meet difference threshold depends on value of original stimulus (Weber fraction)
Signal detection theory
How organism differentiates important signals from unimportant ones (noise)
- Comparison b/w false alarm and hit rate
- Hit rate > false alarms = high sensitivity
- Mediated by bias, has decision-making component
Place theory
Hear different pitches b/c different sound waves trigger activity at different places along cochlea’s basilar membrane
Attention
Selects sensory info for perceptual processing
Selective attention
Focus on one stimulus at exclusion of other
Divided attention
Split perceptual resources b/w multiple stimuli
Shadowing
Repeating digits presented to a specific ear
Project image to a visual field and it will be represented in _____ hemisphere of brain
Opposite
Bottom-up processing
Construction of perceptions from individual pieces of information
Top-down processing
Brings influence of prior knowledge to make perception more efficient
- AKA context effects
Gestalt principles
Perception of surroundings as being made of distinct, stable objects
- Organizes sensory info into distinct forms (objects)
- Nearness, similarity, common region (background), continuity, closure
Interposition
Depth perception
Parallel processing
Use of multiple pathways to convey info about same stimulus
- Process multiple pieces of info about stimulus at same time
- Starts at level of bipolar and ganglion cells in eye => lateral geniculate nucleus and visual cortex
Feature detection
Sequential processing => provides basic info about feature of object
Circadian rhythm
Daily balance b/w wakefulness and sleep
Drive for sleep is opposed by biological clock of _____
SCN in hypothalamus
- Maintains homeostatic equilibrium
- Maintains drive for wakefulness by inhibiting release of melatonin by pineal gland
- Affected by light
Stage 1 sleep
Light sleep
- Alpha waves, more relaxed than beta waves
Stage 2 sleep
Bursts of brain wave activity that indicate full transition into sleep
- Sleep spindles
Stage 3 sleep
Transition to deep sleep
- Delta waves (much longer than alpha waves)
Stage 4 sleep
Deepest sleep
- All delta waves
Rapid eye movement (REM)
Period of high brain activity during stage 1
- Does not occur during first sleep cycle
- Brain relives stimuli from day and consolidates important info into memory
- Dreaming occurs here
Non-REM sleep
Largest portion of sleep
- Lower brain activity
Stimulants
Raise CNS activity
- Increase monoamine neurotransmitters (epinephrine, dopamine)
Reward pathway
Drugs increase levels of dopamine and reward feeling
- Nucleus accumbens, hypothalamus, amygdala
Neuroleptics
First antipsychotic drugs used to treat schizophrenia
- Negative side effects = cognitive dulling
Atypical antipsychotics
Block dopamine receptors
- Less likely to have negative side effects than neuroleptics
First phase of memory formation
Sensory memory
- Temporary, unconscious
Second phase of memory formation
Short-term memory/working memory
- Auditory representation
- 7 ± 2 pieces of info
Techniques to maintain info in working memory
Chunking, rehearsal
Negative priming
Implicit memory effect where prior exposure to a stimulus unfavorably influences response to same stimulus
Priming
Change in response to stimulus due to subconscious memory effects
Flashbulb memory
Claim to remember detail of what you were doing when receiving news of emotionally arousing event
False memory
Given with high confidence
Neural plasticity
Ability of brain’s networks of synapses and neurons to change
- Most apparent during early development
Long-term potentiation
Increase in likelihood that presynaptic input will trigger potential in postsynaptic neuron
Semantic networks
Used by long-term memory to organize info in networks of meaningfully related memories
- Leads to spreading activation
Decay
Fading of a memory
- Weakening of connections making up neural network
Serial-position effect
Primacy + recency effects
Interference
Prevents successful memory retrieval due to similar information
- Can be retroactive or proactive
Retroactive interference
Newly learned info that prevents successful retrieval of related older memories
Proactive interference
Previously held knowledge prevents successful retrieval of newly learned info
Source monitoring
Person attributes memory to particular source
Memory construction
Memories updated w/ new info = reactivates neural network
What two structures in body change in regards to aging and memory?
Hippocampus and prefrontal cortex
Semantic memory
General world knowledge we have accumulated throughout lives
- Type of explicit/declarative memory (along w episodic)
Episodic memory
Declarative info people have of specific experiences
Crystallized intelligence
Ability to use old/learned knowledge/experience
Fluid intelligence
Ability to solve new problems/adapt
Cognitive changes
Late adulthood
Source amnesia
Inability to remember how previously learned info has been aquired
Alzheimer’s disease
Hippocampus = first to be affected
- Amyloid plaques, neurofibrillary tangles, cognitive dysfunction
- Particular dysfunction in tasks of verbal fluency and negative priming
Korsakoff’s syndrome
Deficit in ability to recall events for newer memories
- Due to lack of vitamin B1 => damage to frontal cortex and thalamus
Parkinson’s disease
Deterioration of substantia nigra
- Dopamine deficiency
- Impairment of motor abilities
- Substantia nigra can’t function to initiate movement
Requirements for inferring causality
Correlation
Random assignment
Temporality
Symptoms of schizophrenia
Delusions
Hallucinations
Disorganized speech
Prevalence of schizophrenia
1%
Physiological aspects of schizophrenia
- High levels of dopamine
- Smaller structures in brain
Physiological process associated with depression
Hypothalamic-Pituitary-Adrenal axis (HPA)
Opponent-process theory
Four cones are associated w/ process of color and they’re grouped into two pairs (red-green and blue-yellow)
- Each group can be stimulated simultaneously
- Only one cone from each group can be activated at a given time
Concentrations of light sensitive chemicals in rods and cones _____ in dark environment
Increase => increase sensitivity of rods and cones when moving to dark
