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Chapter 2
Biological Foundations of
Psychology
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
The Study of the Biological Bases of
Psychology
• Pre-adaptation
– Describes the process by which an existing system (e.g.
physical disgust/physical pain) is co-opted (“hi-jacked”) in
order for new human functions to develop (e.g. moral
disgust/response to social exclusion)
• Nervous system
– Divided into Central Nervous System (CNS) and
Peripheral Nervous System (PNS)
– CNS includes the brain and spinal chord
– PNS includes the somatic system and autonomic system
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
Neurons, the Building Blocks of the
Nervous System
• Basic unit of the nervous system = Neuron
– Specialized cell that transmits neural impulses or
messages to other neurons, glands and muscles
Figure 2.2 Schematic Diagram of a
Neuron.
Arrows indicate the direction of the
nerve impulse. Some axons are
branched; the branches are called
collaterals. The axons of many
neurons are covered with an insulating
myelin sheath that helps increase the
speed of the nerve impulse.
(Adapted from Human Anatomy by Anthony J. Gaudin
and Kenneth C. Jones. Copyright © 1988 by Anthony
J. Gaudin and Kenneth C. Jones. Reprinted by
permission of the authors.)
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
Neurons, the Building Blocks of the
Nervous System
• Neurons vary greatly in size and shape
• Neurons are classified into three categories
– Sensory neurons – transmit impulses from receptors
to CNS
– Motor neurons – carry outgoing signals from CNS to
muscles and glands
– Inter-neurons – connect sensory and motor neurons
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
Neurons, the Building Blocks of the
Nervous System
• Action Potentials
– Information travels along neuron in form of neural
impulse called an action potential
– Each action potential is the result of movement of
electrically charged particles (ions) in and out of
neuron
– Movement of ions controlled by ion channels - when
these are closed the neuron is referred to as “resting”
– When a neuron is depolarized above the excitation
threshold cell membrane is temporarily unstable,
resulting in action potential
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
Neurons, the Building Blocks of the
Nervous System
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
Neurons, the Building Blocks of the
Nervous System
• Synaptic transmission and neural coding
– All-or-none law – a neuron is either firing action
potential, or not, so how can the nervous system code
for/represent complexity of experience?
– Power of nervous system lies in the complexity of the
connections between neurons
– Lock-and-key action – the way a neurotransmitter and
receptor fit together, which causes a change in
permeability of ion channels, either excitatory or
inhibitory
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
Neurons, the Building Blocks of the
Nervous System
• Neurotransmitters
– More than 70 identified
– Acetylcholine – involved in memory and attention and
transmits signals between nerve and muscle
– Norepinephrine – an increase or decrease in the brain
correlates with increase or decrease in mood level
– Dopamine – mediates effects of natural rewards (e.g.
food) and effects of drugs of abuse
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
Neurons, the Building Blocks of the
Nervous System
• ...Neurotransmitters
– Serotonin – important role in mood regulation
– Glutamate – excitatory in nature – linked with learning
and memory
– GABA – inhibitory in nature – helps control muscle
movement
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
The Organization of the Brain
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
The Organization of the Brain
• The hindbrain
– Medulla
• Controls breathing & some reflexes which aid upright posture
– Pons
• Important in the control of attentiveness
– Reticular formation
• Network of neurons controlling arousal, also plays role in
ability to focus attention
– Cerebellum
• concerned primarily with control of movement & important for
learning new motor responses
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
The Organization of the Brain
• The midbrain
– Superior and inferior colliculus
• Important for transmitting sensory information to brain & in
movement control
– Substantia nigra
• Key part of dopamine-containing pathway – deteriorates in
Parkinson’s disease
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
The Organization of the Brain
• The forebrain
– Includes cerebrum (split into two hemispheres) and
sub-cortical structures
– Thalamus
• Directs incoming information from sense receptors to cerebrum
– Hypothalamus
• Regulates eating, drinking & sexual behavior. Exerts control
over ANS & also role in sensation of emotions
– Pituitary gland
• Part of system of glands called endocrine system involved in
production of hormones
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
The Organization of the Brain
• ...The forebrain
– Limbic system
• Provides additional control over some instinctive behaviors
regulated by central core
• Hippocampus – special role in recent memory
• Amygdala – involved in emotional behavior, e.g. fear
– Cerebral cortex
• Receives information from sensory systems; controls motor
responses and contains association areas which are
concerned with memory, thought and language
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
The Organization of the Brain
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
The Organization of the Brain
• Mapping the brain
– Recent development of sophisticated computer
methods allow detailed images of human brain
without damaging or distressing patient
• Methods include computerized axial tomography (CAT or
CT), magnetic resonance imaging (MRI), and positron
emission tomography (PET)
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
The Organization of the Brain
• Asymmetries in the brain
– Language
• Understanding about brain mechanisms for language largely
derived from studies of patients with brain damage.
• Aphasia – language deficit caused by brain damage
• Broca’s area – involved in speech production
• Wernicke’s area – involved in speech comprehension
– Split-brain research
• The brain normally acts as integrated whole but for some
epilepsy patients, the corpus callosum surgically severed these split-brain patients provide important insights into brain
function
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
The Organization of the Brain
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
The Organization of the Brain
• ...Asymmetries in the brain
– Hemispheric specialization – split-brain research
indicates two hemispheres function differently
• Left hemisphere – controls ability to express self through
language and skilled in mathematical abilities
• Right hemisphere – comprehends only simple language but
highly developed in spatial and pattern sense
• Specialization does not mean two hemispheres work
independently but rather they continually integrate activities
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
The Autonomic Nervous System
• Autonomic system
– System of nerves outside of the brain & spinal chord
• Autonomic nervous system (ANS)
– Activities it controls are autonomous or self-regulating
(e.g. digestion & circulation)
– ANS has two divisions – sympathetic & parasympathetic
– Sympathetic nervous system – active during excitement
– Parasympathetic nervous system – associated with rest
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning
The Endocrine System
• Endocrine system
– System of glands which secrete hormones to be
transported through the bloodstream to act in various
ways on cells of different types
– Pituitary gland “master gland” which controls
secretion activity of other endocrine glands
Use with Atkinson & Hilgard’s Introduction to Psychology 15th edition
Nolen-Hoeksema, Fredrickson, Loftus, Wagenaar
ISBN 9781844807284 © 2009 Cengage Learning