Outline principles that define the biological level of analysis
Principles of
Biological Level of
Analysis
Patterns of behavior
can be inherited
Description
Example in research
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Individuals may have a predisposition towards
certain behaviors due to inherited genes.
We each have 46 chromosomes, half from mom and
half from dad.
1 out of 2 (50%) chance child and parent will share
any particular gene.
Genetics have some influences in areas such as
personality, intelligence, and mental illness
Two key ways of researching this link between genes
and behavior is through correlational and linkage
studies.
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Tellegen et al. (1988)
Bouchard et al. (1990) Minnesota twin study
Nurnberg and Gershon (1982) found a
correlation on genetic influence on
depression in twins research
Researcher at Stanford (Dr. Gotlib) who is
using fMRI scans to look at the genetic
predisposition for depression to see if
daughters with depressed mothers have a
stronger predisposition towards depression.
Animal research
may inform our
understanding of
human behavior
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Cognitions,
emotions, and
behaviors are
products of the
anatomy and
physiology of our
nervous and
endocrine systems
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There is an
evolutionary basis
of behavior
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Researchers use animals in physiological research
because it is assumed that most biological processes
are the same in animals as in humans. Animal
research is used when it is unethical to conduct the
study on humans.
About 90% of animals used in animal testing have
been rodents and birds.
Many experiments conducted on animals are
considered unethical for human testing.
Experimental research is most common in animal
research because scientists are able to find a causal
relationship among variable such as the effects of
hormones on brain processes.
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Researchers study the physiological origins of
behavior such as neurotransmitters, hormones, genes,
and brain processes when they try to explain
cognitive processes, like memory, or abnormal
behaviors, like depression.
Reductionist approach to the study of behaviorbreaking down complex behavior into smaller parts,
like focusing on the role of a gene, a
neurotransmitter, or a specific part of the brain.
By using FMRI, MRI, and other brain scanning
technology, scientists can look brain activity and how
products of our nervous and endocrine systems work.
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Evolutionary forces have shaped aspects of human
and animal behavior, playing a role in genetic
mutations.
Darwin’s theory of natural selection (species
adapting to their environment) leads to evolutionary
change in individuals with certain characteristics that
show greater survival and reproduction rates than
those individuals who do not.
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Martinez and Kesner (1991) looked at the
role of acetylcholine on memory.
Rosenzweig and Bennett (1972): effect of
deprivation on brain development
Gazzaniga, Bogen, & Sperry (1963) spilt
brain studies
Harlow (1848) case study of Phineas Gage.
Kim et al. (1997): Participants had fMRI
scans while thinking in each language.
Cunningham et al. (2004): participants had
FMRI scans while pictures of either White or
Black faces flashed before them.
Chang et al. (2010) cultural evolution with
mate preference.
Explain one study related to localization of function in the brain.
Gazzaniga and Sperry
(1967)
How it relates to the
localization of function
in the brain
The aim of this experiment was to investigate the effects of hemisphere disconnection,
when the corpus callosa is surgically severed as a last resort to prevent epileptic
seizures, and to show that each hemisphere has different functions. Researchers wanted
to learn about hemisphere lateralization, especially relating to language specialization in
the left hemisphere. Each hemispheres primary connections are to the opposite side of
the body. The left side of the brain, dominant for most speech functions, receives
information from the right eye, while the right side of the brain, dominant in
visuospacial tasks like drawing, receives information from the left eye. Normally, it
does not matter which side of the brain information travels too, that information is
immediately passed to the other side via the corpus callosa. Having a severed corpus
callosa means there is a block in communication between the two hemispheres of the
brain. The two hemispheres can operate independently and each may be oblivious to
what the other side is doing. For more information on this study, look at the textbook
pages (94-97)
The brain exhibits ‘localizations of function’ meaning that different parts of the brain
carry out different functions, like memory, language, etc. Brain damage to a specific
area of the brain can result in great loss of its corresponding function. The study shows
how language is dominant in the left side of the brain because participants were unable
to verbalize what they saw if the image or word showed up on the left side of the screen,
since that information would be processed in the right hemisphere. They were only able
to verbally label the stimuli if it was presented on the right side of the screen. Yet, even
though the participant cannot vocally label the stimuli if presented on the left, he can
use his left hand to draw, write, grab, or point to what he just saw on the right side of
the screen because the right side of the brain controls the left hand, where functions like
drawing are prominent.
Using one or more examples, explain functions of two hormones in human behavior.
Hormone and its function
Example
Oxytocin:
Experimental manipulation of oxytocin levels have shown an increase in trust.
 Secreted by the
 Baumgartner et al. (2008) looked at the role of oxytocin in trust in
hypothalamus and acts
economic behavior.
primarily as a
Procedure:
neurotransmitter in the
 Participants played a ‘trust game’ used by economists and neuroscientists to
brain.
study social interaction. Player 1 (investor) receives money and must decide
 Plays a part in birth and
whether to keep or share it with player 2 (trustee). If money is shared, it
breastfeeding, helping
triples in size. Then player 2 must decide if this sum should be shared
create a bond between
(trust) or kept (violation of trust).
mother and child, as well as  Participants received either oxytocin or placebo during their second round
sex and bonding. Which is
of the game.
why it is known as the ‘love  50% of the time, participants received feedback that their trust was broken
hormone’.
by the trustees.
 Known to increase feelings Results:
of generosity, relaxation,
 Participants in placebo group were likely to show less trust after feedback
closeness towards others,
of a betrayal and invested less.
and facilitates relationship
 Participants in the oxytocin group continued to invest at similar rates after
formation and positive
receiving feedback on a breach of trust.
communication.
 fMRI scans showed decreases in responses in the amygdala, which is
involved in emotional processing and has oxytocin receptors.
 Thus, oxytocin may play a role in maintaining relationships, why people are
able to forgive and mend long-term relationships.
Cortisol:
 Produced by the adrenal
cortex in response to stress
in order to restore the body
back to its normal balance.
 Connected to fight or flight
responses, arousal, stress
hormone, memory.
Newcomer et al. (1999) experiment to investigate how levels of cortisol
interfere with memory.
Procedure:
 Double-blind, randomized, and controlled experiment lasting 4 days.
 Three groups: group 1 was given a high level of cortisol (160mg per day)
which is the amount of cortisol levels in response to a major stressful event.
Group 2 was given a low level of cortisol (40mg per day) equivalent to
levels of cortisol in blood during a minor stressful event. The 3rd group was
given a placebo pill.
Results:
 Group 1 performed worse on verbal declarative memory test than group 2
and performed worse than placebo group after day 1.
 Group 2 showed no memory decrease.
 Thus, several days of exposure to cortisol at high doses can decrease verbal
declarative memory.
Using one or more examples, explain effects of neurotransmitters on human behavior.
Neurotransmitter and its effect
Example
Acetylcholine
Martinez and Kesner (1999) looked at the effects of
 A well-known neurotransmitter that plays a critical acetylcholine on short-term memory development.
Procedure:
synaptic role in the initial formation of memory.
 Rats were trained to go through a maze, where they
received food at the end. Once the rates had been
trained they were split into 3 groups.
 Group 1 was injected with a chemical that blocked
acetylcholine receptor sites, thus decreasing the
amount of available acetylcholine.
 Group 2 was injected with an enzyme that breaks
down and helps restore acetylcholine.
 Group 3 was the control group
Results:
 Group 1 was slower at finding their way around the
maze and made more errors than group 2 or 3.
 Group 2 rats were quicker and made fewer mistakes
than the control group
 This shows that acetylcholine has positive effects
on memory.
Dopamine
Berridge and Kringelbach (2009) Dopamine in pleasure
 Involved in goal-directed behavior, such as pleasure seeking
seeking, control of movement, emotional responses, Procedure:
and addictive behavior
 Used fMRI scans to study brain areas involved in
the experience of pleasure.
Results:
 The orbitofrontal cortex, involved in dopamine, was
active when the participants reported feeling
pleasure.
 Concluded that dopamine is involved in pleasure
seeking, which could explain addictive behavior.
Discuss two effects of the environment on physiological processes (for example, effects of jet lag on
bodily rhythms, effects of deprivation on neuroplasticity, effects of environmental stressors on reproductive
mechanisms)
Environmental Effect on Physiological Processes
1. Effects of deprivation on Neuroplasticity:
 Also known as Brain Plasticity, refers to the ability
of the brain to respond to and be modified by
experience.
 Aspects of experience can shape features of brain
structures. The neutral wiring of the brain is flexible
and constantly evolving based on environmental
experiences.
2. Effects of Light on Melatonin secretion levels
leading Seasonal Affective Disorder.
 Melatonin is a hormone with a role in the sleepwake cycle.
 Secretion of melatonin is due to changes in light.
 Research has shown that Seasonal Affective
Disorder (SAD) is related to the seasonal variations
(light) in the production of melatonin. SAD is when
patients have symptoms of depression correlated
with less light in Autumn and Winter seasons.
Example in Research
Rosenzweig et al. (1972): The role of environmental
stimulation on brain plasticity.
Procedure:
 10-12 Rats were placed in an enriched environment
(EC), a large cage with plenty of toys, stimulation,
and maze training.
 The other group of rats were placed in an
impoverished environment (IC), in isolation in a
cage with only food and water in it.
 Rats were in respective cages for 30-60 days before
being put down so researchers could study changes
in their brains.
Results:
 Found that the anatomy of the brain was different in
EC than IC
 EC rats had increased thickness and higher weight
of the cortex than IC
 EC rats had developed more acetylcholine
receptors, a neurotransmitter that is important in
learning and memory.
Rosen et al. (1989): To compare the severity of sadness
of those living in different latitudes.
Procedure:
 1671 men and women across the country completed
a Seasonal Pattern Assessment Questionnaire
(SAPQ) asking for information about the time of
year the subjects felt better or worse.
 Degree of change in mood and behavior were
affected by season and factors like sleep patters,
weight gain, and energy level.
Results:
 Greatest seasonal mood variation in New York,
lowest in Florida.
 Variations of sleep patterns highest in New
Hampshire and New York and lowest in Florida.
 Overall, about 40% of respondents felt worse in
winter months.
 SAD sufferers were found to be higher in northern
latitudes (less light, shorter days in winter) than
southern (more light, longer days in winter).
 SAD exists and may be due to less light and
melatonin production.
Discuss the use of brain imaging technologies in investigating the relationship between biological factors and
behavior. (CAT, PET, fMRI).
Brain Imaging
Their use
Strengths and Weaknesses
Example in research
technologies
CAT
Strengths:
Andreasen, 2001 and
 A Computer
(Computerized
G.N. Smith et al. 1997
enhanced X-ray of brain
 It is the least expensive
Axial
used CT scans to look for
structures.
of the brain scans and is used
Tomography).
abnormalities in the brain
widely in research.
 Multiple X-rays are
Known now as CT shot from many angles: top,  Extremely useful for
structures of people
or Computerized
suffering from specific
bottom, back, front, or sides showing structural changes in
Tomography.
types of mental illness.
to show the brain at any
the brain.
(pg. 88 of textbook).
depth.
Weakness:
 Structural images are
the only kind of image a CT scan
can produce, making it hard to
see how the brain and behavior
are related.
PET (Positron
Strengths:
Posner and Raichle, 1994
 Requires the
Emission
used PET scans to
injection of a radioactive
 Can examine brain
Tomography)
tagged substances (glucose
function, mapping actual activity investigate brain
localization of cognitive
containing small amounts of in the brain over time.
functions by looking at
radioactivity) into a
 Neuroscientists use
patterns of brain
participant. They serve as
PET to pinpoint the areas of the
markers of blood flow that
brain that handle various mental activation in more
complex cognitive tasks.
shows where the brain is
activities
(p. 89 in textbook).
most active.
 Can also be used to
 Can provide a
study the activity of specific
color-coded map that
neurotransmitters
indicates which areas of the
Weakness:
brain became active when
 Much less precise than
participants perform an
the fMRI
activity or think.
 Shows activity over a
60 second period and is very
expensive.
fMRI (Functional
Strengths:
Wexler et al. (2001) used
 Modification of the
magnetic
fMRI scans to identify
regular MRI technique,
 Provide much better,
resonance
patterns of brain activity
which uses magnetic fields,
higher resolution, 3D images of
imaging)
associated with cocaine
radio waves, and
the brain that provide structural
cravings in cocaine
computerized enhancement
and functional information.
addicts. (pg. 89 of
to map out brain structure.
 Can map metabolic
textbook).
 fMRI can monitor
changes that indicate brain
blood and oxygen flow in
activity to create a more precise
Kim et al. (1997):
the brain to identify areas of picture of which parts of the
Participants had fMRI
high activity by taking into
brain are active when certain
account that neurons in a
activities are being performed, or scans while thinking in
each language.
particular region are more
certain emotions or thoughts
active and thus more blood
occur.
is sent to that region.
Weakness:
 Since blood flow follows
neuronal activity by about a
second, fMRI assesses blood
flow but cannot give immediate
evidence of brain activity.
Discuss ethical considerations in research into genetic influences in behavior.
Informed Consent
Confidentiality
Genetic discrimination and
Stigmatizing
Unexpected information
Racial discrimination and
prejudices
The Iceland DNA Study
Participants should be informed about:
 the nature of the study and the procedure,
 their privacy and confidentiality rights
 what will happen to any genetic information or material obtained in the study
 Must sign a formal written consent form
Since researchers have found that behavior is influenced by genetics, then genes
may be able to predict certain behaviors. This creates the issue of whether
information obtained in a study should be protected against, for example, employers
or insurance agencies. If, for example, a person has a genetic predisposition for
depression or some disease and that information becomes public, it may become
difficult for that person to obtain a job or insurance.
Two ways to keep confidentiality and prevent discrimination by genetic inheritance:
 Assigning a coding system to the results that only a select few have access to.
 Study can be anonymous, which protects confidentiality from insurance
companies, employers, police, etc. However, this limits the scientific value of
the study because it prevents scientists from following up on the case and
investigating further.
 As shown in the confidentiality section, if results show a genetic influence on a
certain behavior and that information is made public, the participants can be
subject to genetic discrimination in their lives. They could be refused insurance
or a job due to a predisposition to a disease or mental illness.
 Stigmatizing can also be a result of lack of confidentiality. For example, if a
participant carries a gene that can influence alcoholism, that person may have
that stigma placed on them that they will become an alcoholic.
Unexpected information, such as unrevealed adoptions in the family or
misattributed paternity, can cause harm to research participants. Stress, anxiety, and
fear can also be caused by the discovery that a participant carries a gene for a
particular genetic disorder and can have a potential onset of that disorder.
 Researchers are now exploring DNA to help explain differences between people
of different races, ethnic, and aboriginal groups in different continental origins.
However, if that genetic information becomes public, it carries the message that
people of different races have different DNA that can create racial prejudices
and discrimination.
 Ethnic and Aboriginal groups may object to genetic testing due to cultural
principle since consent is a community matter for many of these groups.
 If there are racial differences in DNA and genetics influence behavior, then
there can be a risk for discrimination. Difference races have certain genetic
predispositions for specific types of disease, more so than others. For example,
some research has shown that Caucasians are more prone for alcoholism than
Asians, while Asians are more prone for depression than Caucasians.
 Iceland is one of the most genetically homogeneous countries on earth, making
it an ideal place to isolate genes for genetic research. The Iceland DNA project
was an attempt to research the genes of the entire country in search of the root
causes of, and possible cures for, some of the world’s diseases.
 Basically they would find an Icelander with a certain disease or disability and
then compare their DNA to a ‘healthy’ persons DNA and see what the genetic
differences are.
 The Icelandic government sold personal medical records to the DeCODE
company for 12 years, making personal medical records public. Insurance
companies could then deny the participants and their family’s coverage just
because a certain disease was shown to run in their family.
Discuss the use of technology in investigating cognitive processes (for example, MRI (magnetic
resonance imaging) scans in memory research, fMRI scans in decision-making research).
Technology (brain scan) and
cognition
 Cognition refers to the
mental processes of knowing,
including aspects like
awareness, attention,
perception, memory, thinking,
and reasoning.
 Cognitive processes are
very complex and can be hard
to study because it is difficult
to determine what causes
cognition. By using a
biological psychology approach
of breaking down factors and
focusing on one part of the
brain, or one cognitive task,
researchers can better
understand causation of
cognition.
 Brain scans are used to
investigate cognitive processes
by allowing researchers to see
what is happening to a
participant’s brain as that
participant conducts cognitive
tasks.
 PET, MRI, fMRI, and CAT
scans can be used.
Examples of using technology
to investigate cognitive
processes
Kim et al. (1997): Participants
had fMRI scans while thinking
in each language. Shows where
brain activation occurs when
speaking in your native tongue
compared to a second language.
A specific example of using MRI scans in
memory research
Posner and Raichle (1994) used
PET scans to investigate brain
localization of cognitive
functions by looking at patterns
of brain activation in more
complex cognitive tasks. (p. 89
in textbook).
Pg. 288 of textbook: Memory and H.M.
The study of anterograde amnesia (loss of
memories that occur after the onset of
amnesia) has proven to be a great source for
information on the brain and memory. By
using brain scans, researchers have been able
to predict causal relationships between brain
damage and memory.
Magnetic Resonance Imaging (MRI):
 Uses magnetic fields, radio waves, and
computerized enhancement to map out
brain structure.
 Produces three-dimensional pictures of
the brain that are of high resolution.
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Milner (1953) followed the peculiar case
of HM, a man who had temporal lobe
lesion surgery to relieve debilitating
seizures, only to find that the surgery
wiped out his ability to form long-term
memories.
In 1992 and 1993, HM underwent two
MRI scanning sessions to identify the
precise extent of the temporal lobe
lesion.
Researchers discovered that HM had his
hippocampus and amygdala removed,
and that there was damage to medial
temporal lobe. These findings lead to the
theory that the entire hippocampal region
(including the hippocampus, dentate
gyrus, subiculum, and entorhinal cortex)
is involved in the complex processes of
forming, sorting, and storing memories.
Explain how biological factors may affect one cognitive process (for example, Alzheimer’s disease, brain
damage, sleep deprivation).
Biological factors affect
cognitive processes
 Behavior is not the result
of biological systems
alone. It is important to
look at how biological
systems and physiology
may interact with
cognition to cause
behavior and visa versa.
 Biological psychology=
looking at how biology,
for example, neurons,
neurotransmitters,
hormones, brain structure,
genes, etc. impacts
behavior.
 Cognitive psychology=
refers to the mental
processes of knowing,
including aspects like
awareness, attention,
perception, memory,
thinking, and reasoning.
 So biological factors, like
neurotransmitters, affect
our mental processes, like
thinking.
Biological factors on the Memory
(cognition process)
Look in Pages 286-288 in textbook.
 Scientists now believe that the entire
hippocampal region (hippocampus,
dentate gyrus, subiculum, and
ethorhinal cortex) and the parahippocampal region are critical in
storing long-term memory.
 Damages neurons in the hippocampus
can severely affect memory
 Hormone levels can affect memory
storage in a variety of animals.
 One theory is that hormones
influence memory storage by altering
activity in the amygdala and a variety
of neurotransmitter systems in the
brain.
 Other animal testing has shown that
sufficient protein production is
necessary for the formation of
memories.
 Another theory is that specific
memories may depend on localized
neural circuits in the brain, meaning
that memories may create unique
pathways in the brain that signals
flow through. It could be possible to
map out specific neural pathways that
are created by specific memories.
 Most common theory is that memory
formation may create new neurons
and new neuron circuits.
An example of research
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Alzheimer’s disease= Produces
severe memory impairment in
many people typically over 65.
The hippocampus region is one
of the first areas of the brain to
sustain significant damage in
the course of Alzheimer’s
disease.
Goshe et al (2000) looked at
MRI results for 119 patients
with varying degrees of
cognitive impairment. Some
patients were normal, some had
cognitive impairment at the
time of the MRI, and others
were already diagnosed with
Alzheimer's disease. The
researchers (who did not have
access to the patients' files)
were 100% accurate when
determining which patients had
been diagnosed with
Alzheimer's disease and which
had no symptoms by looking at
the damage to the hippocampal
region. The study reported a
93% accuracy rate when
researchers were asked to
distinguish between patients
with no symptoms and patients
who had only mild cognitive
impairment, but were not yet
diagnosed with Alzheimer's
disease by looking at the brain
structure of the participants.