Biological Foundations Flashcards
Synaesthesia
- Cross sensory experience could be related to creativity
- Tends to run in families
- Together sensation
- Theory that we start out this way + eventually lose this ability
Human Genome Project
map entire structure of human genetic material
•Identify precise order of molecule that make up each of the thousands of genes
•Consist of just 20,000 genes
•Human complexity due to subtleties in how those genes are expressed + regulated
Genes x Environment
–Impossible to separate genetic + environmental influences
•Interaction of nature + nurture responsible, always working together
(Caspi’s study examining violent criminal behaviour)
Epigenetics
- changes in gene expression that are due to non-genetic (‘epi-‘outer’) influences
- environmental type influence, not part of genetic makeup
Heredity
genetic transmission of characteristics from parents to offspring
Heritability
estimate of the genetic portion of the variation in some specific trait
-variability within pop, estimate of how much/% of the variation is determined by genetic influences
Twin Studies & Adoption Studies
•Help researchers study impact of genetic vs environmental influences
•Monozygotic vs. dizygotic twins
•How similar are twins with same genes, but raised apart
•Minnesota monozygotic: 2 men scary similar, in diff countries
•Shared environ: no one has same experiences, no one treated same
oless similar, family emphasize + encourage differences + uniqueness
Behaviour is Determined by Multiple Factors
•exceedingly complex
•Single-cause explanations may be accurate,
but incomplete
•Behaviour governed by complex network of interacting factors
–Heredity/Biology/Environment/Culture
•break down nature vs. nurture into components
The Nervous System
•body’s electrochemical communication circuitry •Central nervous system (CNS) •Peripheral nervous system (PNS) –Somatic nervous system –Autonomic nervous system •Sympathetic nervous system •Parasympathetic nervous system
Neurons
- Are the basic unit of the nervous system
- Operate through electrical impulses
- Communicate with other neurons through chemical signals
- Excitable
- Gets multiple info from thousands of diff neurons
Three types of neurons
- Sensory neurons (afferent neurons): pick up sensation for outside world
- Motor neurons (efferent neurons): brain to muscle
- Interneurons: communicate betw sensory + motor
When do neurons fire?
- Excitatory signals: increase likelihood neuron will fire, less polarized
- Inhibitory signals: decrease likelihood neuron will fire, hyperpolarizing
- affect the polarization
- Neurons fire (generate action potential) if excitatory input reaches certain threshold
All-or-noneprinciple
- neuron fires with same potency each time (fires/doesnt)
- how frequently neuron fires can vary
Action potential
neural impulse passes along axon + causes release of chemicals from terminal buttons
•Na + K goes through specific channels, need to be open
•Starts polarized, rapid depolarization along axon
•Repolarized
Common Neurotransmitters
- Acetylcholine: motor control at junction of nerves + muscles
- Epinephrine: adrenaline
- Norepinephrine: general alertness
- Serotonin: emotional regulation
- Dopamine: feel good, feel rewarded
- GABA: major inhibitory transmitter
- Glutamate: major excitatory
Neurotransmitters
•chemical substances that carry signals from one neuron to another
•stored in vesicles inside terminal buttons
•Action potentials cause vesicles to fuse to presynaptic membrane + release contents into synapse
-received by postsynaptic receptors on the postsynaptic membrane
•Receptors pick up specific neurotransmitters
Antagonists
Beta-blockers, botox (botulinum toxin) Inhibit neurotransmitters’ actions by –Blocking release of neurotransmitters –Destroying neurotransmitters in synapse –Mimicking a neurotransmitter + blocking binding
Agonists
Enhance neurotransmitters’ actions by
–Increasing the release
–Blocking the re-uptake, stays in synapse
–Mimicking a neurotransmitter + activating a postsynaptic receptor
•Cocaine, methamphetamine
The Brain: From the Bottom Up
- Cortical Structures: Complex Mental Activity
- Subcortical Structures: Emotion & Basic Drives
- Cerebellum: Movement
- Brain Stem: Survival
- What matters is ratio of brain weight
- Brain is interacting systems
Brainstem
•Controls life sustaining functions of the autonomic nervous system (breathing, digestion, heart rate)
–Medulla oblongata
–Pons
-Midbrain
•Reticular formation: alertness, sleep, neurons that project up to cerebral cortex