Psych: first half

Development

Changes and continuities that occur individual across ones lifespan

Evolution

Gene and environment interactions across the evolutionary history of a species

Maturation

Biologically-times of changes according to a genetic plan. How it unfolds is influenced by ones environment

Learning

Relatively permanent changes in thoughts, behaviours and feelings as a result of experiences

Interactionist Perspective

View that holds that maturation and learning interact during development

Habituation

Can an infant tell it’s changed?

Dishabituate, then reaction: Yes!

No reaction: No

Event-related Potentials

How does the brain react to this?

Changes in brain activity in specific areas indicate response to a certain stimuli

High-amplitude sucking method

Do they like this?

Measure baseline, if increases, stimulus is introduced. If they like it, they’ll keep sucking quickly, if not they’ll slow down.

Preference Method

Which do they like more?

Level of attention towards one stimuli relative to another indicates preference

Competence-Performance Distinction

Failing a task not due to a lack of cognitive abilities but an inability to demonstrate those abilities

Longitudinal Design

The same individuals are studied repeatedly over their lifespan, allows researchers to asses developmental change.

\- Expensive

\- Time consuming

\- Participants may drop out or improve on tests due to repeated exposure

Cross-sectional Design

Individuals from different age groups are studied at the same point in time.

\- Fast comparison, less expensive and time consuming

\- Uncover age differences

\- Cannot distinguish age from generational effects

\- Cannot directly asses individual developmental change

Monozygotic twins

Genetically identical, same sperm and ovum

Dizygotic twins

\~50% shared genes, different sperm and ovum

Genotype

One’s inherited genes

Phenotype

Expression of genotype- observable characteristics and behaviour

Dominant-Recessive Inheritance

Expression of a trait determined by a single pair of alleles

Homozygous

Two identical alleles of a gene

Heterozygous

Two different alleles, dominant is expressed in phenotype, recessive is heritable

Polygenetic Inheritance

Expression of a trait determined by the interaction of multiple genes

Codominance

Expression of a trait determined equally by two dominant alleles

Eg. ABO blood types: AB

Sex-linked Inheritance

Expression of a trait determined by genes on the X or Y chroms

Canalization Principle

In a species, genotype restricts phenotype to a small number of possible developmental outcomes, some are buffered against environmental variability

Eg. all babies babble the same

Range of reaction principle

Genotype establishes range of phenotypes in response to individual life experiences (nutrition)

Passive gene/env’t correlation

Env’t parents chose to raise their children in is influence by parents genes, likely compliment child’s genes (athletic vs intelligence env’t)

Evocative Gene/env’t correlation

Traits inherited affect how others react to/behave towards us

\- Angry child: negative reaction

\- Happy child: positive reaction

Active Gene/env’t correlation

Genotypes influence the kinds of environments we seek (risk taker looks for thrills)

Critical Period

Time in development when a particular env’t stimulation is **necessary** to see **permanent changes** in specific abilities

Experience Expectant Brain Growth

Brain expects a certain amount of env’tal input. with this input, brain develops normally

Experience Dependent Brain Growth

Brain develops according to our own personal experiences

Sensitive Period

Dvpmt’l period where a specific type of learning is easiest, less rigid than critical period. Learning can still occur after, flexible timing of stim. required for normal development

Adaptation

Biological trait that helps an individual survive and reproduce in its habitat; thrive in psychical env’t

Natural Selection

Differential survival and reproduction of organisms as a result of heritable differences

Individual differences, differential reproduction, heritability

3 essential components of natural selection

Individual Differences

Variation among individuals for any characteristic

Differential Reproduction

Some individuals will have more offspring than others

Heritability

Offspring of successful reproducers will resemble their parent’s variable characteristics

Stabilizing Selection

Selection against any change from species-typical adaptive design; generally stable over generations

Darwin Fitness

Average reproductive success of a genotype relative to alternate genotype

Evolution

Change of gene frequency over generations, in part due to introduction of new gene variants via mutations

Sexual Selection

Component of natural selection. Acts on traits that influence ability to obtain a mate resulting in differential reproductive success

Subtypes: Inter/intra-sexual selection

Inter-sexual selection

Female choice for mate.

Eg. Peacocks: be most attractive to a mate

Intra-sexual selection

Male competition to win a mate

Eg. Elk: dominate a rival

Sexually selective trait

A feature only presented/exaggerated during breeding season; sex specific

Cooperation

Actor benefits, recipient benefits

Altruism

Actor loses, recipient benefits

Selfish

Actor benefits, recipient loses

Spite

Actor loses, recipient loses

Eusocial Hymenoptera

Social organization- most individuals serve the colony without reproducing

Eg. Ants, bees, wasps

Direct fitness

Fitness from personal survival and reproduction

Indirect Fitness

Fitness from the reproduction of close genetic relatives

Inclusive fitness

Ability to pass genes to next generation, taking into account shared genes passed on by relatives

Relatedness

Probability that actor and recipient share gene in question

0\.5

Sibling relatedness

0\.5

Parent relatedness

0\.25

Half sibling relatedness

0\.25

Uncle/aunt relatedness

0\.125

First cousin relatedness

rB>C

Hamilton’s Rule

Phenotype Matching

Evolution of relatedness between individuals based on assessment of phenotypic similarity

Direct Reciprocity

Individuals help each other, both benefit

Indirect reciprocity

Individuals help others, who have helped others (reputation)

Cell body

Part of neuron, contains genetic info, maintains structure, provides energy

Dendrites

Part of neuron, receives signal from other neuron

Axon

Part of neuron, long fiber, transmits signal to axon terminals, very in length

Terminal ends

Part of neuron, connects to other dendrites of nearby neurons

Glial cell

Provide structural support nourishment and insulation for neurons

Shwann Cells

Glial cells in PNS

Oligodendrocytes

Glial cells in CNS

Cl- Na+

Outside the cell at resting potential

K+ A-

Inside the cell at resting potential

\-70 mv

Resting potential

Leak Potassium Channel

Always open, K+ passes through, maintains resting potential

Voltage-gated potassium channels

Drives action potential

NA+ in, K+ pushed out, peak 40 mv, K+ leaves, undershoot, K+ reenters

Resting potential events

Refractory period

Neuron can not easily propagate another action potential after one has just occurred

Absolute refractory period

Immediately after action potential is initiated, until dips bellow -50v. Due to Na+ channels closing, unable to open for a period

Relative Refractory period

After absolute period until resting potential is reestablished. Due to undershot, a stronger stim. is required to bring to threshold

Myelin sheath

Fatty, insulating tissue; enhances travelling speed of action potential down axon (not entire axon)

Saltatory conduction

Electrical impulse skips from node to node down the full length of an axon, very fast travel.

Synapse

Junction where neurons communicate; indirect connection between neurons

EPSP

Excitatory post-synaptic potential; excite the post-syn neuron toward action potential, must reach -50mv

Temporal summation

high frequency stimulation by one presynaptic neuron

Spatial summation

Simultaneous slower stimulation by several presynaptic neurons

Spatiotemporal Summation

Simultaneous, high frequency stimulation form several presynaptic neurons

IPSP

Inhibitory Post-synaptic potential; hyperpolarizing post-syn membrane, chloride enters cell

Radial Glial Cell

Scaffolding in development of nervous system, guide migration of new neurons

ND: Genetics

ND: Partially determined by location in ventricular zone where a founder cell originates

ND: Environment

ND: Affected by surrounding cells (other neurons) and external environment

Eg. cataracts- inhibit input

Founder cells

Produce “baby”/newborn neurons

Neurogenesis

1. Production of new neurons

Migration

2. Leave home with glial cells and neurons

Differentiation

3. Neurons specialize

Maturation

4. Neurons connect with “partners”/other specialized neurons

Single Cell Recording

Functional: Functions of individual neurons

CT Scan

Structural:

Low resolution slices of the brain

Uses radiation

Cheaper

MRI

Structural: Higher resolution images of the brain

Uses magnetic fields when H+ atoms align

Time consuming

Expensive

PET scan

Functional:

Radioactive tracers (glucose) injected into blood

Specific

Dynamic imaging (metabolic resonance)

fMRI

Functional:

Clear image of brain activity

Measures blood O2 levels and use of O2 throughout brain

Imprecise mapping (delay between activity and O2 spike)

Dynamic imaging

EEG

Functional:

Records electrical activity of brain

Uses cap of electrodes

Rough image of activity for specific populations of neurons