Biological Bases of Behavior ❮ 91❯ rapid review
Neuropsychologists—those who explore the relationships between brain/nervous
systems and behavior. Neuropsychologists are also called biological psychologists or
bio psychologists, behavioral geneticists, physiological psychologists, and behavioral
neuroscientists. Studying patients with brain damage linked loss of structure with loss of function.Lesions—precise destruction of brain tissue, enables more systematic study of the
loss of function resulting from surgical removal (also called ablation), cutting of neural
connections, or destruction by chemical applications.CT scans and MRIs show structure.• Computerized axial tomography (CAT or CT)—creates a computerized image
using x-rays passed through the brain to show structure and/or the extent of a lesion.• Magnetic resonance imaging (MRI)—creates more detailed computerized images
using a magnetic field and pulses of radio waves that cause emission of signals that
depend upon the density of tissue.EEGs, PET scans, and fMRIs show function.• EEG (electroencephalogram)—an amplified tracing of brain activity produced when
electrodes positioned over the scalp transmit signals about the brain’s electrical activity
(“brain waves”) to an electroencephalograph machine.• Evoked potentials—EEGs resulting from a response to a specific stimulus presented
to the subject.• Positron emission tomography (PET)—shows brain activity when radioactively
tagged glucose rushes to active neurons and emits positrons.• Functional MRI (fMRI)—shows brain activity at higher resolution than the PET
scan when changes in oxygen concentration near active neurons alter magnetic
qualities.Central nervous system (CNS)—brain and spinal cord.Peripheral nervous system (PNS)—portion of the nervous system outside the brain
and spinal cord; includes all of the sensory and motor neurons, and subdivisions called
the autonomic and somatic nervous systems.Autonomic nervous system (ANS)—subdivision of PNS that includes motor nerves
that innervate smooth (involuntary) and heart muscle. Its sympathetic nervous system
prepares the body for “fight or flight”; the parasympathetic nervous system causes bodily
changes for maintenance or rest.• Sympathetic nervous system—subdivision of PNS and ANS whose stimulation
results in responses that help your body deal with stressful events.• Parasympathetic nervous system—subdivision of PNS and ANS whose stimulation
calms your body following sympathetic stimulation by restoring normal body
processes.Somatic nervous system—subdivision of PNS that includes motor nerves that stimu-
late skeletal (voluntary) muscles.