biological bases of behavior
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Biological Bases of Behavior. Laurel McKay Period 1. Physiological Techniques. EEG- measures changes in brain electrical activity, can allow for localization of functions in the brain CAT Scans-make cross-sectional images of the brain - PowerPoint PPT PresentationTRANSCRIPT
Biological Bases of Behavior
Laurel McKayPeriod 1
EEG- measures changes in brain electrical activity, can allow for localization of functions in the brain
CAT Scans-make cross-sectional images of the brain
MRI- similar to a CAT scan but generates more detailed pictures of the brain
Functional MRI’s and PET Scans allow scientists to view the brain as it is working, uses a diffusion of radioactive glucose in the brain to highlight the point of interest
PET Scan
Physiological Techniques
Central Nervous System: brain & spinal cord Peripheral Nervous System: all other nerves Brain= central processing center for thoughts, motivations &
emotions (made up of neurons) In the spinal cord neurons are bundled together into nerves Afferents=nerves sending info to the brain Efferents=nerves conveying info from the brain Most movements are controlled by the brain but some are
controlled by transmission from afferent to efferent cells
Functional Organization of the Nervous System
The Peripheral Nervous System can be divided into: - Somatic Nervous System-Autonomic Nervous System
Somatic: responsible for voluntary movement of large skeletal muscles
Autonomic: controls the nonskeletal or smooth muscles (ex: in the heart and digestive tract)
Functional Organization of the Nervous System (cont.)
Functional Organization of the Nervous System (cont.)
Autonomic Nervous System divides into:◦ Sympathetic Nervous System◦ Parasympathetic Nervous System
Sympathetic: associated with processes that burn energy, fight or flight reaction
Parasympathetic: associated with conserving energy
Brain’s 3 regions: Forebrain, Midbrain, Hindbrain Forebrain= limbic system, hypothalamus, thalamus &
cerebral cortex Limbic System: area of the brain involved in learning,
emotion, and memory, includes the hippocampus (learning and memory formation), the amygdala (used when angry) , and the septum (used when fearful)
Hypothalamus: controls the temperature and water balance of the body & the ANS & the endocrine system
Thalamus: gateway for sensory input to the brain Cerebral Cortex: outer layer of the brain, used in higher
cognitive functions (thinking, language use, etc.)
Neuroanatomy
Neuroanatomy (cont.) Midbrain=reticular
activating system (consciousness, attention, wakefulness), processes sensory input
The midbrain, hindbrain, thalamus & hypothalamus form the brain stem (junction between the brain & spinal cord)
Hindbrain=cerebellum, medulla oblongata & pons Cerebellum: controls muscle tone and balance Medulla Oblongata: controls heart rate, swallowing,
breathing, and digestion Pons: passes info from one brain to another Cerebral Cortex: covers the outer surface of the brain Corpus Callosum: a band of nerves that joins together
the two halves of the brain
Neuroanatomy (cont.)
Frontal Lobe: higher level thought and reasoning, contains the primary motor cortex
Parietal Lobe: somatosensory info, contains the primary somatosensory cortex (temp., pressure, texture and pain)
Temporal Lobe: auditory input Occipital Lobe: visual input Apraxia: inability to organize movement Agnosia: inability to process sensory input Alexia: the inability to read
Neuroanatomy (cont.)
Neural Transmission Nerves=bundles of neurons Soma= cell body Dendrites=branch out from the
soma Axon=a long, tube-like
structure that responds to input from dendrites and soma
Myelin Sheath=fatty coating around the axon
Terminal buttons=knobs on the branched end of the axon
Resting potential: the electrical charge of a neuron at rest Once the electrical charge reaches minus 50 millivolts the
neuron will be ready to fire which leads to… Action Potential: the nerve impulse/ sending the message During action potential the axon membrane is pierced by ion
channels, then sodium ions rush into the axon After the impulse there is a negative after-potential (a drop in
electrical charge below the resting potential) Neurotransmitters: chemical messengers that cross the
synapse (ex: acetylcholine, serotonin, dopamine)
Neural Transmission (cont.)
Neural Transmission (cont.)
Relays info from one part of the body to another using glands that release hormones
Pituitary Gland: master gland, releases hormones to other glands, controlled by the hypothalamus
Adrenal gland secretes epinephrine (adrenaline) and norepinephrine (noradrenaline)
Thyroid Gland: at the front of the neck, regulates metabolism
Endocrine System
The application of principles of evolutionary theory to the study of behavior
Traits: distinctive characteristics or behavior patterns that are determined by genetics
A dominant trait is more likely to be expressed in offspring than a recessive trait
The environment influences us too Nature vs. Nurture debate Genetic Abnormalities cause disorders such as Down’s
Syndrome (a break in the 21st chromosome)
Genetics