1. Introduction To Psychology
October 26th
The APA defines Psychology as “a diverse
discipline, grounded in science, but with nearly
boundless applications in everyday life. Some
psychologists do basic research, developing
theories and testing them through carefully
honed research methods involving observation,
experimentation and analysis. Other
psychologists apply the discipline’s scientific
knowledge to help people, organizations and
communities function better.”

2. Psychology is a Science
• Psychology uses scientific methods to study
the brain, the mind, and mental states in
order to create theories: cognitive
behaviorism, behaviorism, humanism,
existential humanism, nature, nurture,
psychosexual, object relations, psychosocial,
Adlerian, physiological/genetic/evolutionary
and multiculturalism.

3. What is the Brain
• The brain is the portion of the central nervous
system in vertebrates (animals with bones)
that lies within the skull.

4. The human mind
• The human mind is the portion of the brain
where we think and make decisions. It is the
area where we perceive things and create a
response to them.

5. What are Mental States
• A mental state is a mental condition in which
the qualities of a state are relatively constant
even though the state itself may be dynamic,
e.g. a manic state, a paranoid state, a
depressed state, an anxious state.

6. Psychology Studies Human and Animal
Behavior
• Many problems in human society are often
related to the interaction of environment and
behavior or genetics and behavior.
• The fields of socio-ecology and animal behavior
deal with the issue of environment behavioral
interactions both at an evolutionary level and a
proximate level.
• Social scientists study both human and animal
behavior as a framework in which to interpret
human society and to understand possible causes
of societal problems.

7. Psychologist Study and Research
• The character traits and associated behavior and activities
of a person or group of people.
• Actions and words used to influence a person or group to
behave in different ways.
• A random sample group of people are a group of
individuals who could be used in a research testing
situation.
• Every person in the area under study has an equal chance
of being included in the sample.
• The process of selecting this sample on the basis of chance
is called randomization.

8. Research
• An example of research study that would
correlate a theory might be a study between
enrollment in a class and rate my professor
evaluations, and the correlation between the
demand for a product and its price.
• Correlations are useful because they can indicate
a predictive relationship that can be used in
understanding the brain, the mind, mental states,
behavior, stimulus and response.

9. Research
• Statistics is a numerical value or function used
to describe a sample or population
• In statistical research, dependence refers to
any statistical relationship (dependency)
between two or more random variables or
two or more sets of data.
• Correlation refers to any of a broad class of
statistical relationships involving dependence.

10. Psychologist are
• To use research to understand the brain, the
mind, mental states, and behavior.
• To use variables to predict human brain
activity, belief systems, mental states,
character development, and behavior.
• To describe human behavior in a way that will
categorize a clear and accurate diagnosis.

11. Industrial Psychologist/Organizational
Psychologist
• Industrial psychologists study the behavior of
employees in a work setting.
• The workplace is a social system, the
application of industrial psychology is useful in
understanding its complexity.
• They analyze the way a person works, their
skills, duties, obligations, and general
satisfaction with their job on a day-to-day
basis.

12. Industrial/Organizational Psychologist
• This information is extremely helpful to
company overseers who must create training
programs, feedback and rewards systems, and
make hiring decisions as well as engage in
recruitment practices.
• Companies use industrial psychologists to
train their own staff so that the organizations
can run smoothly and at peak capacity.

13. Industrial/Organizational Psychologist
• One of the most interesting aspects of industrial
psychology is how employee behavior affects
others individuals on the job and organization in
general. Industrial psychology can be used to
reduce counterproductive behavior, enhance
team effectiveness, and boost morale. It is also
vital in conflict resolution. Many individuals find
the brunt of their work dissatisfaction rooted in
their relationships with managers and colleagues.

14. Clinical Psychologist
• Clinical Psychologist are concerned with the assessment,
diagnosis, treatment, and prevention of mental disorders.
• While some clinical psychologists specialize in treating
severe psychological disorders, such as schizophrenia and
depression, many others may help people deal with
personal issues, such as divorce or the death of a loved
one.
• Clinical psychologists provide an opportunity to talk and
think about things that are confusing or worrying, offering
different ways of interpreting and understanding problems
and situations. They are trained to use a variety of
approaches aimed at helping individuals, and the strategies
used are generally determined by the specialty they work
in.

15. Counseling Psychologist
• Facilitates personal and interpersonal functioning
across the life span with a focus on emotional, social,
vocational, educational, health-related, developmental,
and organizational concerns. Through the integration
of theory, research, and practice, and with a sensitivity
to multicultural issues, this specialty encompasses a
broad range of practices that help people improve their
well-being, alleviate distress and maladjustment,
resolve crises, and increase their ability to live more
highly functioning lives. Counseling psychology is
unique in its attention both to normal developmental
issues and to problems associated with physical,
emotional, and mental disorders.

16. Counseling and Psychotherapy
• Counseling is appropriate for the lower level patient who
cannot tolerate the therapist’s being neutral and therefore
is not a candidate for psychotherapy. When counseling, the
therapist can advise, direct, support, suggest medications.
• Therapeutic intervention is appropriate for mid and high
level patients. The essence of the psychotherapy with mid
to high level patients is the therapist’s identification of the
clinical vicissitudes (state of being changeable).
• therapeutic technique is bringing to the center of the
patient’s attention firmly and empathetically the denied
maladaptive self-destructive aspect of the defenses that
protect their mental state/self.

17. Counseling and Therapy
Think of the following:
• With lower level patients self-activation leads to separation anxiety
and abandonment depression which leads to self destructive defenses.
• Self-activation is precipitated by real later life situations that require
self assertion, autonomous functioning and/or by events that involve
separation.
• These events interrupt the self destructive defenses and the patient
begins to experience the abandonment depression and then defends
by giving up self assertion and activating self destructive defenses
whose symptoms can vary from obesity to anorexia, from clinging to
others to distancing from others, from sexual promiscuity to the
avoidance of sex, from alcoholism to drug addiction.
• There are three clinical types based on the patient’s capacity to
function: lower level, mid level, and high level

18. APA Mission Statement
• “The mission of the APA is to advance the
creation, communication and application of
psychological knowledge to benefit society
and improve people’s lives.”
• This is also the mission of this class.

19. Abnormal Psychology
• Psychologist use a Subjective, Objective,
Assessment Plan (SOAP) to diagnose a patient.
• Symptoms — subjective — what a
patient describes about their condition and/or
complain about.
• Signs — objective — what a Psychologist can
sense, i.e. hear, see, smell, and process when
listening to the patient.

20. Diagnosis
Knowledge of:
• Diagnostic and Statistical Manual of Mental
Disorders DSM-IV-TR Fourth Edition (Text
Revision) the APA approved text for diagnosis.
• Knowledge of research on appropriate,
effective, and efficient treatment plan

21. Multi-axial Diagnosis
• 5-axis diagnostic system is a multi-axial system
that facilitates comprehensive and systematic
evaluation of the patient and takes into
account:
• Axis I: Psychological diagnosis(s)
• Axis I diagnosis(s) are called the primary
diagnosis. If there is more than one primary
diagnosis (dual diagnosis, comorbid
diagnoses) the primary one is mentioned first.

22. Some Axis I Diagnosis
• Some primary diagnosis ADHD, eating disorders ,
Organic Mental Disorders ( Dementia arising from
Alzheimer’s, basically anything that has a physical
medical cause, i.e. a brain tumor), Psychoactive
Substance Use Disorders, Psychosis (schizophrenia,)
Mood Disorders ( depression, bi-polar, Anxiety/
Neuroses ( panic disorder, phobias, OCD, PTSD,)
Somatoform Disorders, Dissociative Disorders (Multiple
Personality Disorder, psychogenic fugue), Sexual
Disorders (exhibitionism, fetishism) Sleep Disorders

23. Axis II
• Developmental diagnoses and diagnoses first
diagnosed in infancy or childhood, e.g.,
developmental delays, mental retardation, autism,
language and speech disorders
• Personality Disorders, e.g., paranoid, avoidant,
obsessive compulsive, passive aggressive, histrionic,
borderline, narcissism, dependence, schizotypal
personality

24. Axis II
• These diagnoses are difficult to make and are
often only made after several visits.
• The listing of personality disorders and mental
retardation on Axis II rather than Axis I ensures
that consideration is given to the possible
presence of these conditions which might be
overlooked when attention is focused on the
usually more florid (a blatant or highly
disorganized state) Axis I disorders, i.e., the
primary disorder.

25. • An Axis II diagnosis should not be made while
the patient is suffering from an Axis I
diagnosis. For example, a person with
depression should not be diagnosed with a
personality disorder while the depression is
still present; depression does not allow a true
evaluation of a person’s personality.
• In this case, the Axis II diagnosis is deferred.

26. Axis III
• All physical diseases are mentioned here, whether the disease
symptoms are related to the psychiatric disorders or not.
• These general medical conditions are potentially relevant to
the understanding or management of the individual’s mental
disorder.
• In some cases it is clear that the general medical condition is
directly related to the development or worsening of mental
symptoms.
• When a mental disorder is judged to be a direct physiological
consequence of the general medical condition it should be
diagnosed on Axis I and the general medical condition should
be recorded on both Axis I and Axis III.

27. • For example, when hypothyroidism (thyroid gland does not
make enough thyroid hormone) is a direct cause of
depressive symptoms, the designation on Axis I is mood
disorder due to hypothyroidism with depressive features,
and the hypothyroidism is listed again on Axis III.
• Some general medical conditions may not be directly
related to the mental disorder, but have important
prognostic or treatment implications. For example:
• when the diagnosis on Axis I is major depressive disorder
and on Axis III is arrhythmia( abnormal heart rhythm), the
choice of pharmacotherapy for the depressive disorder is
influenced by the arrhythmia.

28. Axis IV
• Axis IV: Psychological stress factors affecting the patient,
e.g., stressors, past and present, which have an influence
on the patient at the time of the evaluation.
• These factors may include situations dating from childhood
up to the
• present day.
• Possible psychosocial or environmental problems include:
negative life events, environmental difficulties or
deficiencies, familial or other interpersonal stressors,
inadequate social support or personal resources, problems
relating to the context in which a person’s difficulties have
developed.

29. Axis V: Global Functioning of the
Patient
• This gives a broad evaluation of the individual’s ability
to cope with their present life situation and can also be
used as a measure of the need for hospital admission.
This information is useful in planning treatment and
measuring its impact as well as in predicting outcome.
• The Global Assessment of Functioning (GAF) scale can
be used to quantify this
• level of functioning.
• The GAF scale was developed specifically to rate
psychological, social and occupational functioning
global functioning of the patient.

30. • The Global Assessment of Functioning (GAF) is a numeric scale
• (0 through 100) used by mental health clinicians and physicians to subjectively
rate the social, occupational, and psychological functioning of adults, e.g., how
well or adaptively one is meeting various problems-in-living. The score is often
given as a range, as outlined below:
• 91 - 100 Superior functioning in a wide range of activities, life's problems never
seem to get out of hand, is sought out by others because of his or her many
positive qualities. No symptoms
• . 81 - 90 Absent or minimal symptoms (e.g., mild anxiety before an exam), good
functioning in all areas, interested and involved in a wide range of activities,
socially effective, generally satisfied with life, no more than everyday problems or
concerns (e.g., an occasional argument with family members).
• 71 - 80 If symptoms are present, they are transient and expectable reactions to
psychosocial stressors (e.g., difficulty concentrating after family argument); no
more than slight impairment in social, occupational, or school functioning (e.g.,
temporarily falling behind in schoolwork).

31. • 61 - 70 Some mild symptoms (e.g., depressed mood and mild
insomnia) OR some difficulty in social, occupational, or school
functioning (e.g., occasional truancy, or theft within the
household), but generally functioning pretty well, has some
meaningful interpersonal relationships.
51 - 60 Moderate symptoms (e.g., flat affect and
circumstantial speech, occasional panic attacks) OR moderate
difficulty in social, occupational, or school functioning (e.g.,
few friends, conflicts with peers or co-workers).
41 - 50 Serious symptoms (e.g., suicidal ideation, severe
obsessional rituals, frequent shoplifting) OR any serious
impairment in social, occupational, or school functioning (e.g.,
no friends, unable to keep a job).

32. • 31 - 40 Some impairment in reality testing or communication (e.g., speech is at
times illogical, obscure, or irrelevant) OR major impairment in several areas, such
as work or school, family relations, judgment, thinking, or mood (e.g., depressed
man avoids friends, neglects family, and is unable to work; child frequently beats
up younger children, is defiant at home, and is failing at school).
• 21 - 30 Behavior is considerably influenced by delusions or hallucinations OR
serious impairment, in communication or judgment (e.g., sometimes incoherent,
acts grossly inappropriately, suicidal preoccupation) OR inability to function in
almost all areas (e.g., stays in bed all day, no job, home, or friends)
• 11 - 20 Some danger of hurting self or others (e.g., suicide attempts without clear
expectation of death; frequently violent; manic excitement) OR occasionally fails to
maintain minimal personal hygiene (e.g., smears feces) OR gross impairment in
communication (e.g., largely incoherent or mute).
• 1 - 10 Persistent danger of severely hurting self or others (e.g., recurrent violence)
OR persistent inability to maintain minimal personal hygiene OR serious suicidal
act with clear expectation of death.

33. Disorders Usually First Diagnosed in
Infancy, Childhood, or Adolescence
• monitoring of children and adolescents with language and learning disorders
(LLDs). LLDs are among the most common developmental disorders the clinician is
likely to encounter. About 50% of children with an LLD also have a comorbid Axis I
psychiatric disorder.
• The diagnosis of an LLD requires a discrepancy, based on age and intelligence,
between potential and achievement.
• The clinician collaborates with parents and school personnel to clarify the
diagnosis, implement appropriate treatment and remediation, and monitor
progress.
• The clinician is instrumental in identifying and treating comorbid conditions,
including the determining the appropriateness of medication.
• Long-term prognosis depends on the type and severity of the language/learning
disorder, the availability of remediation, and the presence of a supportive family
and school environment.
• Key Words: Language, learning, disorders, disabilities, diagnosis, treatment,
children, adolescents, practice parameters, guidelines.

34. PL 94-142/ Individual with Disabilities
Education Act (IDEA)
• In 1975, Congress passed Public Law 94-142
(Education of All Handicapped Children Act),
now codified as IDEA (Individuals with
Disabilities Education Act). In order to receive
federal funds, states must develop and
implement policies that assure a free
appropriate public education (FAPE) to all
children with disabilities.

35. IDEA
• IDEA (Individuals with Disabilities Education Act)
was created to provide full legal rights and
services for students with disabilities to receive
an appropriate education in school communities.
These services are rendered on the basis of a
student's Individualized Education Program (IEP)

36. IDEA
• (IDEA) is an important tool for providing Free Appropriate
Public Education (FAPE) to students with disabilities. IDEA
provides special education to eligible students with disabilities
in the least restrictive learning environment.
• These services are provided to children between 3-21 years of
age. To avail the benefits of IDEA, a child must meet the
eligibility criteria in one of thirteen qualifying disabilities. To
qualify for IDEA a child must have a disability that creates
hindrance in his or her education. Thus eligibility for IDEA
depends upon the severity of the impairment of a child.

37. • Different categories of disabilities that are
included in IDEA are autism, deaf/blind, specific
learning disabilities, hearing impaired, deafness,
mental retardation, orthopedic impairment,
speech or language impairment, visual
impairment, traumatic impairment and other
health problems.
• It includes mental illness, but not behavioral
issues.

38. Other Handicap Impaired (OHI)
• Other health impairment means having limited
strength, vitality or alertness, including a heightened
alertness to environmental stimuli, that results in
limited alertness with respect to the educational
environment, that—(i) Is due to chronic or acute health
problems such as asthma, attention deficit disorder or
attention deficit hyperactivity disorder, diabetes,
epilepsy, a heart condition, hemophilia, lead poisoning,
leukemia, nephritis (is an inflammation of one or both
kidneys), rheumatic fever, and sickle cell anemia; and
(ii) Adversely affects a child’s educational performance.

39. OHI
• Generally speaking, analysis of OHI eligibility
first considers the child’s health condition and
its general effects on the child, then looks
separately at the disability’s effect on the
child’s educational performance.

40. Experimental Research
October 29th
Research designs can be used where:
• There is time priority in a causal relationship
(cause precedes effect),
• There is consistency in a causal relationship (a
cause will always lead to the same effect), and
• The magnitude of the correlation is great.

41. Cause and Effect
• Causality is the relationship between an event
(the cause) and a second event (the effect),
where the second event is understood as a
consequence (end result) of the first.

42. Hypothesis
• A conditional proposition or a premise used in
an argument. The antecedent of a conditional
proposition is the “if” and the consequent is
the “then”. A mere assumption or guess.

43. Dependent and Independent Variable
• The terms "dependent variable" and
"independent variable" are used to distinguish
between two types of quantities being
considered (hypothesis).
• separating them into those available at the start
of a process (independent variables) and those
being created by it (dependent variables).
• Dependent variables are dependent on the
independent variables.

44. Experimental Group
• A group of subjects exposed to the
independent variable of an experiment
(compare control group). Typically, the
experimental group is treated with the
independent variable to test an experimental
hypothesis.

45. Control Group
• The resultant effect, measured by a
dependent variable, is compared with the
control group. The control group is practically
identical to the experimental group, although
the experimental group is changed according
to some key variable of interest, while the
control group remains constant during the
experiment. Each field develops their own
specific, important controls.

46. random assignment
• Random assignment refers to the use of
chance procedures in psychology experiments
to ensure that each participant has the same
opportunity to be assigned to any given group.
Study participants are randomly assigned to
different groups, such as the experimental
group or treatment group. Random
assignment might involve such tactics as
flipping a coin, drawing names out of a hat or
assigning random numbers to participants.

47. Experimenter Bias
• Experimenter's bias is the phenomenon in
experimental science by which the outcome of
an experiment tends to be biased towards a
result expected by the human experimenter.
The inability of a human being to remain
completely objective is the ultimate source of
this bias

48. double-blind
• Double-blind trials describe a study in which
both the investigator or the participant are
unaware of (blind to) the nature of the
experiment.
• Double-blind trials are thought to produce
objective results, since the expectations of the
researcher and the participant about the
experiment do not affect the outcome.

49. placebo
• Some participants (unknown to the
investigator and the participant) are given a
substance, behavior, cue, expectation that has
no effect on the study. This is called a
placebo.
• Some given a placebo may respond to meet
the perceived expectations of the investigator
this phenomenon is called the placebo effect.

50. Example
• The independent variable is typically the variable representing the value
being manipulated or changed and the dependent variable is the observed
result of the independent variable being manipulated. For example
concerning nutrition, the independent variable of daily vitamin C intake
(how much vitamin C one consumes) can influence the dependent
variable of life expectancy (the average age one attains). Over some
period of time, scientists will control the vitamin C intake in a substantial
group of people. One part of the group will be given a daily high dose of
vitamin C, and the remainder will be given a placebo pill (so that they are
unaware of not belonging to the first group) without vitamin C. The
scientists will investigate if there is any statistically significant difference in
the life span of the people who took the high dose and those who took
the placebo (no dose). The goal is to see if the independent variable of
high vitamin C dosage has a correlation with the dependent variable of
people's life span. The designation independent/dependent is clear in this
case, because if a correlation is found, it cannot be that life span has
influenced vitamin C intake, but an influence in the other direction is
possible.

51. Mean, Mode, Median, Range
• The "mean" is the "average" you're used to, where you
add up all the numbers and then divide by the number
of numbers.
• The "median" is the "middle" value in the list of
numbers. To find the median, your numbers have to be
listed in numerical order, so you may have to rewrite
your list first.
• The "mode" is the value that occurs most often. If no
number is repeated, then there is no mode for the list.
• The "range" is just the difference between the largest
and smallest values

52. standard deviation; statistical
significance
• To understand standard
deviation we have to start
with the idea of a normal
distribution or bell curve
The midpoint of the bell
curve will be the average
value. So take for example
the height of males in the
U.S. If we graphed it, the
curve would have a bell
shape.

53. • The most common value
would be near the top of
the bell shape and the
least common values
would be at the tail ends
of the bell curve. If you
drew a line that cut the
bell in half starting at the
peak of the bell and going
down then that line
would represent the
average height, around
5’10″.

54. • Dark blue is one standard
deviation from the mean.
For the normal
distribution, this accounts
for about 68% of the set,
while two standard
deviations from the mean
(medium and dark blue)
account for about 95%,
and three standard
deviations (light, medium,
and dark blue) account
for about 99.7%.

55. • Now the standard deviation is a measure of
how much variation there is in the population.
If the standard deviation is small then the bell
curve will be a very tall thin bell meaning
everyone is pretty close to average. Whereas if
the standard deviation is large then the bell
curve is a short fat bell meaning everyone is
fairly unique and not too close to the average.

56. • There is an important relationship between the
standard deviation and the percentage of the
population near the average. It is always the case that
if you go one standard deviation to the left and to the
right of the average value then you will cover 68% of
the population. If you go two standard deviations in
each direction you will cover 95% of the population. So
in the height example, if the standard deviation is 3
inches then 68% of the male population will be
between 5′ 7″ and 6’1″ and if you go two standard
deviations then 95% of the male population will be
between 5′ 4″ and 6’4″.

57. • You’ll often see this idea misinterpreted in media reports
on polling results. Suppose candidate A is ahead of
candidate B in a poll by 52 – 48% with a margin of error of
2%. The media will report that the difference in the poll
falls within the margin of error and therefore the race is a
dead heat. This is absolutely false and shows they don’t
understand standard deviations and normal distribution.
Since the margin of error is the same as 2 standard
deviations then there is a 95% chance that candidate A will
end up with between 50 and 54% of the vote. This isn’t a
dead heat. There is a 95% chance that candidate A will get
at least 50% of the vote. Candidate A is clearly winning
according to the polls.

58. • It is important to keep in mind that everything we
said is based on the assumption of a normal
distribution or a bell curve. While there are many
famous examples of normal distributions in
nature there are also plenty of examples of things
that don’t follow a normal distribution. The
mathematics gets a little trickier when there isn’t
a normal distribution. So people often make the
mistake of just assuming that something has a
normal distribution and this can lead to errors as
we discussed in the post about the black swan.

59. Statistical Significance
• The concept of statistical significance is very
important in understanding if a result is valid
or not and yet its meaning is almost always
misinterpreted. This post will attempt to
clarify what it means to have a result that is
“statistically significant”.

60. • When reading scientific papers you will often see
that the experimenter has run some statistical
test (usually a t-test) and reported that the
results were significant at a level of p < .05. What
this means is that there is a less than 5% chance
that the results were just due to randomness. The
flip side of that is that there is a 95% chance that
the difference in the variable between the test
group and the control group is a real difference
and not just due to chance.

61. • You see, the test that was being run is
basically a test that compares your hypothesis
(that there is a difference between the test
group and the control group) to what is called
the “null” hypothesis (that there is no
difference between the test group and the
control group and the result you are seeing is
just due to random chance probably caused by
a sample that is either too small or poorly
chosen).

62. • This might be a little clearer with an example. Suppose
I did an experiment to test the idea that left handed
people are smarter than right handed people and I
selected 100 left handed people and 100 right handed
people at random and gave them an IQ test. The
results show that the average IQ of the left handed
people was 120 and the average IQ of the right handed
people was 108. When I run a t-test on the data I get p
= .04 or a significance level of 96%. This doesn’t mean
that if I select 1 left handed person and 1 right handed
person from a crowd that there is a 96% chance that
the difference in their IQ will be 12.

63. • What it means is that there is a 96% chance
that difference in IQs between left handed
and right handed people is real and that you
will see this difference in any sample that is
large enough or well selected. The difference
won’t necessarily be 12 points as in the
current experiment but there will be a
difference in the favor of the left handed
people.

64. Correlational Research
(prediction)
• Correlational studies are used to look for
relationships between variables. There are
three possible results of a correlational study:
a positive correlation, a negative correlation,
and no correlation. The correlation coefficient
is a measure of correlation strength and can
range from –1.00 to +1.00.

65. Direction: Both variables increase or
decrease at the same time.
• Positive Correlations:. A correlation coefficient
close to +1.00 indicates a strong positive
correlation.
• Negative Correlations: Indicates that as the
amount of one variable increases, the other
decreases (and vice versa). A correlation
coefficient close to -1.00 indicates a strong
negative correlation.
• No Correlation: Indicates no relationship
between the two variables. A correlation
coefficient of 0 indicates no correlation.

66. Strength
correlation coefficient r
• In statistics, dependence (the result is dependent on the
relationship between the variables) refers to any statistical
relationship between two random variables or two sets of data.
Correlation refers to any statistical relationships involving
dependence (occurring because of the relationship)
• An examples of dependent phenomena include the correlation
between the physical statures of parents and their offspring.
• Correlations are useful because they can indicate a predictive
relationship that can be exploited (statistical term) in practice.
• An example of an electrical utility may produce less power on a
mild day based on the correlation between electricity demand and
weather. In this example there is a causal relationship, because
extreme weather causes people to use more electricity for heating
or cooling; however, statistical dependence is not sufficient to
demonstrate the presence of such a causal relationship.

67. • In loose usage, correlation can refer to any
departure of two or more random variables
from independence to dependence.

68. Perfect Correlation
• Perfect positive correlation (a correlation co-
efficient of +1) implies that as one variable
moves, either up or down, the other variable
will move in the same direction.

69. Negative Correlation 0.0
• a zero correlation is a score which shows that
there is no relationship between two or more
variables.
A correlation of –1 indicates a perfect negative
correlation, meaning that as one variable goes
up, the other goes down.

70. Correlation does not imply causation
"ignoring a common cause" and questionable
cause are phrases used in science and statistics
to emphasize that correlation between two
variables does not automatically imply that one
causes the other, but rather a possible cause or
areas for further investigation; in other words,
correlation can be a hint

71. Biology and Behavior

72. Neuron: overview
• A neuron also known as a nerve cell
• It is an electrically excitable cell that processes and
transmits information by electrical and chemical
signaling
• Chemical signaling occurs via synapses, specialized
connections with other cells
• Neurons connect to each other to form networks
• Neurons are the core components of the nervous
system, which includes the brain, spinal cord, and
peripheral ganglia.

73. A number of specialized types of neurons exist:
• sensory neurons respond to touch, sound, light
and numerous other stimuli affecting cells of the
sensory organs that then send signals to the
spinal cord and brain.
• Motor neurons receive signals from the brain and
spinal cord, cause muscle contractions, and affect
glands.
• Interneurons connect neurons to other neurons
within the same region of the brain or spinal
cord.

74. • Dendrites are the branches of neurons that receive signals from
other neurons and pass the signals into the cell body
• A cell may have hundreds or thousands of dendrites, but may have
only one axon. The dendrites carry signals from other neurons into
the soma, whereas the axon carries a single signal from the soma to
the next neuron.
• Dendrites are the branches of neurons that receive signals from
other neurons and pass the signals into the cell body
• A cell may have hundreds or thousands of dendrites, but may have
only one axon. The dendrites carry signals from other neurons into
the cell body whereas the axon carries a single signal from the cell
body to the next neuron.
• The movement of the charged ions in the dendrite causes an
electrical current, which spreads to the cell body briefly before
being restored to normal.

75. Neuron

76. • Neurons have specialized projections called dendrites
and axons. Dendrites bring information to the cell body
and axons take information away from the cell body.
• Information from one neuron flows to another neuron
across a synapse. The synapse contains a small gap
separating neurons. The synapse consists of:
• a presynaptic ending that contains neurotransmitters,
mitochondria and other cell organelles
• a postsynaptic ending that contains receptor sites for
neurotransmitters
• a synaptic cleft or space between the presynaptic and
postsynaptic endings.

77. Dendrite
• A dendrite from one neuron and
an axon from another neuron
meet at a synapse, which is a
very narrow gap between the
two cells. When electrical
impulses reach the end of an
axon, they trigger the release of
special chemicals called
neurotransmitters from the
axon. These chemicals cross the
synapse to the dendrite, where
they trigger the flow of ions into
or out of the cell.

79. cell body (soma)
• the part of a cell that contains the nucleus and
surrounding cytoplasm exclusive of any
projections or processes, such as the axon and
dendrites.

80. axon
• An axon is a long, slender projection of a
nerve cell, or neuron, that conducts electrical
impulses away from the neuron's cell body or
soma.

81. myelin
• the myelin sheath, around the axon of a
neuron. It is essential for the proper
functioning of the nervous system. Myelin is
an outgrowth of a type of glial cell.

82. resting potential
• The resting potential of a cell occurs when the
cell has a negative value, which by convention
means that there is excess negative charge
inside compared to outside.
• The resting potential is mostly determined by
the concentrations of the ions in the fluids on
both sides of the cell membrane and the ion
transport proteins that are in the cell
membrane.

83. • Neurons send messages electrochemically. This means
that chemicals cause an electrical signal. Chemicals in
the body are "electrically-charged" -- when they have
an electrical charge, they are called ions. The
important ions in the nervous system are sodium and
potassium (both have 1 positive charge, +), calcium
(has 2 positive charges, ++) and chloride (has a
negative charge, -). There are also some negatively
charged protein molecules. It is also important to
remember that nerve cells are surrounded by a
membrane that allows some ions to pass through and
blocks the passage of other ions. This type of
membrane is called semi-permeable.

84. • Action potentials are caused by an exchange of ions across the
neuron membrane. A stimulus first causes sodium channels to
open. Because there are many more sodium ions on the outside,
and the inside of the neuron is negative relative to the outside,
sodium ions rush into the neuron. Remember, sodium has a positive
charge, so the neuron becomes more positive and becomes
depolarized. It takes longer for potassium channels to open. When
they do open, potassium rushes out of the cell, reversing the
depolarization. Also at about this time, sodium channels start to
close. This causes the action potential to go back toward -70 mV (a
repolarization). The action potential actually goes past -70 mV (a
hyperpolarization) because the potassium channels stay open a bit
too long. Gradually, the ion concentrations go back to resting levels
and the cell returns to -70 mV.

85. • When a neuron is not sending a signal, it is "at rest."
• When a neuron is at rest, the inside of the neuron is negative relative to the
outside.
• The concentrations of the different ions attempt to balance out on both sides of
the membrane, they cannot because the cell membrane allows only some ions to
pass through channels (ion channels).
• At rest, potassium ions (K+) can cross through the membrane easily. Also at rest,
chloride ions (Cl-)and sodium ions (Na+) have a more difficult time crossing. The
negatively charged protein molecules (A-) inside the neuron cannot cross the
membrane.
• There is a pump that uses energy to move three sodium ions out of the neuron for
every two potassium ions it puts in.
• When all these forces balance out, and the difference in the voltage between the
inside and outside of the neuron is measured, you have the resting potential. The
resting membrane potential of a neuron is about -70 mV (mV=millivolt) - this
means that the inside of the neuron is 70 mV less than the outside. At rest, there
are relatively more sodium ions outside the neuron and more potassium ions
inside that neuron.

86. action potential
(all-or-none law)
• The resting potential tells about what happens when a neuron is at
rest. An action potential occurs when a neuron sends information
down an axon, away from the cell body. Neuroscientists use other
words, such as a "spike" or an "impulse" for the action potential.
The action potential is an explosion of electrical activity that is
created by a depolarizing current. This means that some event (a
stimulus) causes the resting potential to move toward 0 mV. When
the depolarization reaches about -55 mV a neuron will fire an
action potential. This is the threshold. If the neuron does not reach
this critical threshold level, then no action potential will fire. Also,
when the threshold level is reached, an action potential of a fixed
sized will always fire...for any given neuron, the size of the action
potential is always the same. There are no big or small action
potentials in one nerve cell - all action potentials are the same size.
Therefore, the neuron either does not reach the threshold or a full
action potential is fired - this is the "ALL OR NONE" principle.

87. synaptic vesicles
• synaptic vesicles (or neurotransmitter
vesicles) store various neurotransmitters that
are released at the synapse

88. neurotransmitters
• Chemicals, called neurotransmitters, are released
from one neuron at the presynaptic nerve
terminal. Neurotransmitters then cross the
synapse where they may be accepted by the next
neuron at a specialized site called a receptor. The
action that follows activation of a receptor site
may be either depolarization or hyperpolarization
• A depolarization makes it MORE likely that an
action potential will fire; a hyperpolarization
makes it LESS likely that an action potential will
fire.

89. Acetylcholine
• Acetylcholine is a neurotransmitter that slows
the heart rate when functioning as an
inhibitory neurotransmitter. However,
acetylcholine also behaves as an excitatory
neurotransmitter at neuromuscular junctions.

90. sensory neuron
• Sensory neurons are activated by sensory
input (vision, touch, hearing, etc.), and send
projections into the central nervous system
that convey sensory information to the brain
or spinal cord. Unlike neurons of the central
nervous system, whose inputs come from
other neurons, sensory neurons are activated
by physical modalities such as light, sound,
and temperature.

91. motor neuron
• A motor neuron is a type of cell in the nervous system
that directly or indirectly controls the contraction or
relaxation of muscles, which in most cases leads to
movement.
• Motor neurons are efferent neurons.
• Efferent neurons carry information from the central
nervous system to muscles and other systems
• afferent neurons, or sensory neurons, carry information
from sensory organs and tissues such as eyes and skin
back to the central nervous system.