Neuroplasticity

How Does the Brain Change?  Plasticity: a property of the brain that allows it to change as a result of experience, drugs, or injury  Neurogenesis: New neurons are produced in some brain regions (e.g., the hippocampus)

Brain Changes with Use  London Taxi Drivers:  Larger hippocampi  Only found in part associated with spatial memory  Not found in London bus drivers

Cortical Remapping with Non-Use  Phantom limb:  Reflects cortical remapping in Somatosensory cortex

Recovery after Major Damage Jodie Cameron

Radical Hemispherectomy  surgical removal of an entire cerebral hemisphere  remaining hemisphere takes on functions of missing one  Depends on age of surgery

Genes and Behavior

the study of how genes and environment interact to influence psychological activity Behavioral Genetics

Genotype and Phenotype  Genotype: an organism’s genetic makeup; never changes  Phenotype: an organism’s observable physical characteristics; always changing  Genetics (nature) and environment (nurture) both influence phenotype

MZ twins more alike

Adoption Studies  Adoption studies:  compare Identical twins raised apart  compare adopted children with adoptive relatives  Similarity of biological relatives, despite different environment, is likely due to genetic factors

Parent-Adoptive Child Correlations

Gene/Environment Interactions Caspi, et al ( 2002)

Caspi Study: Gene/Environment Interaction  Methods: Collected info about more than 1,000 New Zealanders from birth until adulthood  Measured: Mistreatment by parents Type of MAO gene Criminal record at age 26

Results

Gene- Environment Interaction  MAO Gene: predisposition to anti-social behavior as adult  Early Life Mistreatment: predisposition to anti- social behavior as adult  Both together: development of anti-social behavior

Electrical & Chemical Processing in the Brain

Neuronal Structures & Functions  Dendrites: receive incoming information  Cell Body: integrates incoming info  Axon: transmits electrical signal  Axon Terminal: release of neurotransmitter

Electrical Processing Neurons receive electrical signals from other neurons If signal is large enough, neuron generates Action Potential Sends signal down axon to next neurons