In order to study the structures (or mechanisms) that are involved in
generating behavior, we must view the organism being studied as a
machine made up of billions of neurons and ask the question: “How
is this creature constructed to be able to do that?”
The field of biological psychology involves many people working in a
wide variety of areas of specialization. A few of the types of
professionals who participate in research in biological psychology are
psychologists, biologists, physiologists, engineers, neurologists, and
psychiatrists. The study of the brain is called neuroscience, and
biopsychology is also known as behavioral neuroscience.
The basic goal of biological psychology is to explain behavior in terms
of physiological processes, particularly those of the nervous
system. The findings of basic research in biological psychology may
be applied to improving the lives of both humans and animals.
List the five viewpoints of biological psychology using one word for
Description (Hint: This viewpoint asks, “What are the structural and
functional features of the behavior?”)
Evolution (Hint: This viewpoint asks, “How did patterns of behavior
come to be so different in some species and so similar in others?”)
Development (Hint: This viewpoint asks, “How does behavior
change over the life span?”)
Mechanisms (Hint: This viewpoint asks, “What aspects of bodily
function produce behavior?”)
Applications (Hint: This viewpoint asks, “How can we use our
discoveries to improve health and well-being?”)
Studying differences among species highlights the ways in which
neural mechanisms have been shaped by evolution to solve the
particular problems that each species faces. For example, some bats
use hearing to hunt and navigate, but others use vision. Each method seems to be an adaptation to the kind of food eaten by the particular
species. Conversely, studying similarities among species reveals the
degree to which a feature is continuous, or “conserved,” presumably
due to a common ancestry. For instance, some sex hormones are
found in all mammals, suggesting that these evolved long ago.
However, these data need to be interpreted with care because some
adaptations are so useful that they have evolved independently in
numerous lines of species
The process of change during the life span is formally called
ontogeny . As behaviors emerge and decline during development
and old age, parallel changes in the nervous system may be
observed. For example, memory in monkeys improves over several
years, suggesting that the neural circuits underlying memory are
slow to mature. Learning ability emerges before the capacity to form
long-term memories in rodents, suggesting that learning and
memory involve different neural processes.
The most commonly used study method in biological psychology is
the somatic intervention approach, in which the experimenter alters
body or brain structure .
An alternative experimental approach to the one described in the
previous question is the behavioral intervention approach, in which
behavior is the independent variable and an effect in the body or
brain is the dependent variable.
A particularly plastic feature of neurons are the dendritic spines,
which seem to be constantly undergoing alteration as a
consequence of inputs.
The experiment of Cooke et al. (2000) found that, in male rats raised
either in isolation or in social groups, differences in social experience
resulted in systematic changes in a brain region involved in
processing odors. Similarly, in biological psychology lectures your
instructor is attempting to alter your brain (with varying degrees of
success). Winning a contest (a social factor) can increase a man’s testosterone levels, and reciprocally, increased testosterone levels
are associated with increased dominance and aggressiveness in
For the following levels of analysis, select the numbers that would
place them in order from the most complex level of analysis to the
7 Synaptic level
4 Neural systems level
3 Brain region level
8 Molecular level
2 Organ level
1 Social level
6 Cellular level
5 Circuit level
At least 20% of the present population of the world suffers from
neurological and/or psychiatric disorders. Three psychiatric disorders
that are especially prevalent in the United States are disorders of
mood, anxiety, and impulse control/attention deficit.
The World Health Organization estimates that over 15 % of all
disease burden in the United States, in terms of lost productivity, is
due to mental disorders.
Humans have studied animal behavior and physiology since before
recorded history, both for agricultural purposes and in order to
survive. Most animals used in research are lab-reared rodents—
about 93% of all mammals used in research belong to this group.
Animal research has provided major findings in all of the main fields
of psychology. Introductory psychology textbooks often present these
findings without specifying their source in animal research rather than
in studies of human subject
The Hebrew Bible and New Testament make no mention of the brain,
apparently ascribing wisdom to the heart. This notion was still prominent by the time of the ancient Greek scholar Aristotle,
according to whom the function of the brain was to cool the blood.
In dissecting human and animal bodies, the Greek physician
Herophilus (350 BCE) noted the connection of separate nerves to
each region of the body and also noted that the nerves arise from the
spinal cord. During the second century, Galen noted the behavioral
changes associated with head injuries in gladiators.
Leonardo da Vinci’s drawings of the nervous system were especially
remarkable because they provided cross-sectional views of
structures. Examples of nervous system components that he studied
include the nerves of the arm and the fluid-filled ventricles of the
René Descartes likened the operation of the body to that of a(n)
machine and proposed a mechanism for the production of spinal
reflexes. He also wrestled with the question of how the mind could
control the body and proposed an interface of sorts, located in the
pineal gland. He selected this structure because unlike most
structures of the brain, which are doubled with one in each
hemisphere, the pineal gland is unitary, like consciousness. He also
believed the gland to exist only in humans, and we know now that this
is not true.
Dualism, the assertion that an immaterial soul exists in parallel with,
and exerts control over, the material body permitted early scientists
to study the body without being obviously guilty of heresy. Dualism is
rejected in biological psychology, which asserts instead that all facets
of behavior can be understood as purely physical processes of the
A popular nineteenth-century idea called phrenology held that the
behavior of individuals can be predicted from the pattern of lumps
and bumps on the skull. Other investigators rejected this notion,
arguing that the brain operates as a whole, without any localization
of functions to specific regions. We know now that although the whole
brain is active in most behavior, peaks of activity are seen in different
locations depending on the task being performed. Broca advanced the localizationist position when he presented an
analysis of a patient who had lost the ability to talk; this patient had
suffered brain damage limited to the left frontal region of the brain,
which came to be known as Broca’s area.
Workers in the early twentieth century developed systematic methods
for measuring learning and memory, first in humans and then in
animals. Pavlov described the process of conditioning, which
opened up many new avenues for research. In other early work,
Lashley’s “search for the engram” was undertaken, using a
combination of training and brain lesions to try to discover the
anatomical basis of memory traces.
Galton was disappointed in his search for a consistent relationship
between head size and intelligence by two methodological problems:
lack of a direct measure of brain size and lack of a systematic way of
measuring a person’s intelligence.
Three ways in which brain size has been measured, from the
nineteenth century to today, are (1) overall head size; (2) skull
volume; and (3) MRI measurements of living brains.
In The Organization of Behavior, D. O. Hebb describes two
theoretical mechanisms that could, in principle, provide the necessary
processing to accomplish complex cognitive tasks. The first of these
is the concept of cell assemblies, which describes how brain cells
that are initially connected in a somewhat random fashion can
become organized into circuits as a consequence of activation. The
second mechanism, now known as the Hebbian synapse, describes
how synaptic connections can become strengthened through use.
According to Adam Zeman, aspects of consciousness that most
scientists agree on include the following:
Consciousness permits us to make plans and to create mental
simulations of the future. Consciousness is bound up somehow with the activity of the
Some brain activity is unconscious.
The deep brain regions are important for arousal.
The topmost brain regions are responsible for our experienc