Physiological Psychology Chapter 1 & 2 -- Dr. Mascolo
Psychology 7 Introduction
Understanding the science of psychology starts with understanding the history of science
From the viewpoint of Western Civilization, the history of science begins with the bedrock of all knowledge…Philosophy
(“Beloved Wisdom”), which consists of different areas of focus. For example:
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Metaphysics -- What is reality?
Ontology -- What entities exist in reality?
Logic -- What are the rules of valid argumentation?
Ethics -- What principles justify an action (define morality)?
Epistemology -- What is the nature of knowledge?
Over the past few centuries, some fields of study have ducked out from under the umbrella of philosophy to become
sciences. The fundamental distinction between philosophy & science is based in this last area listed above:
Epistemology
Philosophy
Science
Epistemological Foundation
Rationalism
Empiricism
Chief Focus
Logical argument
Observation
What force powered this split? Advances in technology -- tools like microscopes, telescopes, particular accelerators, &
PowerPoint (kidding) improve our ability to make observations of nature – from the very small (e.g., individual neurons,
atoms) to the very distant (e.g., other galaxies, black holes).
With increasingly technology we can look for answers instead of only arguing about them.
Two Defining Characteristics of Science:
1. Objectivity -- free from personal bias -- established through replication – nothing in science should be taken
seriously unless it is demonstrated repeatedly by independent investigators
2. Testability – also termed falsifiability – nothing in science should be taken seriously unless it is subject to empirical
scrutiny – that is, can be tested – so Freud & Einstein both changed the 20th century world, but the former is not
considered scientific
Two Defining Goals of Science:
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Prediction -- (in the clinical world, “Prognosis”)
Control -- (in the clinical world, “Treatment”)
Positive Feedback Loop -- Productive science = More technology = New Science
Physiological Psychology Chapter 1 & 2 -- Dr. Mascolo
Chapter 1
Human & Nonhuman
Notice that Pinel does not say “Human & Animal” – because humans are part of the Animal Kingdom. He describes the
advantages of researching each kind of subject. For example, humans can agree to follow instructions involved in a
particular study. Nonhumans are often simpler to study and yet are surprisingly similar to humans, depending upon the
variable under study.
Experiments & Nonexperiments (Pinel)
or
Experimental & Nonexperimental
Pinel describes ways in which research can be carried out, and I want to focus on the most fundamental aspect of all this:
we do science in order to make cause and effect conclusions about the world. This “causal inference” is at the heart of
scientific knowledge. It’s the ability to observe a phenomenon and claim, “I know what causes that to happen.” Now, as a
conclusion, I should say that it is expressed in many different forms, but it all amounts to essentially the same thing. A
researcher, for example may announce the discovery of the genetic mutation leading to some dreaded disease, or, a
politician may propose a new law to address one of society’s problems, or you might decide that you should get off the
freeway and take side streets, and these would all be causal claims (“I know what causes this disease,” “I know what
causes this societal problem,” and “I know what’s making me late,” respectively).
The most important part of this, from my point of view, is appreciating how difficult it is to prove a causal relationship
between two phenomena. That is, proving that one event causes another to change, may sound easy and at time seem
obvious, but it is the most difficult claim in science to prove. Unfortunately, a common response to this difficulty is not to
try at all. Politicians, for example, seem happy to rely on common sense (is it really all that common?) or public outcry to
lend support to their proposals, but so far as I can tell, they manipulate all sorts of things (e.g., laws, policies, money)
without any substantial proof that they know what effect, if any, their actions will have. As just one example, how many
efforts have been made to turn around our flagging educational system in California? How many politicians,
administrators, etc. have claimed to have the answer? Are we any closer to a solution now?
In science, it’s the experimental study that can illustrate a causal relationship. Let me just add, in case there’s some
confusion, that people casually use the term “experiment” in a very loose way to refer to any scientific study. Technically,
however, science reserves that term to refer to a special type of study—one that permits the causal conclusion we’ve
been focusing on. In the simplest case, the experimenter forms two groups—experimental and control—by random
assignment. Then, the experimenter manipulates the independent variable—the experimental group receives it but the
control group does not. Lastly, the experimenter examines the dependent variable. In a well-designed experiment,
differences between the two groups can be attributed to the independent variable.
When I say “well-designed” I mean ruling out any other reasonable cause besides the independent variable. In other
words, ruling out confounded variables (see Coolidge Effect below).
Without these 2 defining features, a study may be scientific, but it is not an experimental study. When you read your text’s
description of what all’s involved in conducting a true experimental analysis, you can start to appreciate the difficulties
involved in trying to assert that one variable really causes a change in another variable.
Are you convinced that pornography causes sexual deviance? If a serial rapist is finally caught and his apartment is filled
with pornographic material, you can bet there will be calls to ban porn. They’ll be claiming that rapists are hiding behind
the First Amendment and that free speech must be curbed when the consequences are so dire for our society. If you’ve
carefully read Chapter 1 as well as these Chapter Notes, you should know what kind of experiment you’d have to conduct
to determine absolutely whether pornography really causes sexual deviance. Take a moment. What would a researcher
need to do prove this?
Hopefully you understand these materials enough to know that you would need to take a bunch of young boys and flip a
coin in order to randomly assign each to either an experimental group or a control group. Then you would have to expose
the boys in the experimental group to pornographic material, prevent the boys in the control group from ever coming into
Physiological Psychology Chapter 1 & 2 -- Dr. Mascolo
contact with such materials, and then wait a few years for whatever effects to take hold. If you can show later on that the
experimental group did, indeed, have higher rates of sexual deviance than did the control group, you’ve got some proof to
back up your causal claim.
Not an easy study to accomplish, you say? Well, the logistics of trying to make some boys see the materials during their
adolescence while ensuring that other boys never see such stuff are certainly monumental, but what is the larger
difficulty? Ethics! Of course it would be unethical to deny boys their right to see smut. O.K., I‘m kidding, it would of course
be unethical (& impractical), and so the study really cannot be done. To some, that means that we must simply be
satisfied with whatever evidence we do have, for example a study showing a high positive correlation (detailed in your
text) between interest in porn and sexual deviance, and so off they go lobbying for anti-pornography laws. I need to point
out, however, that practical and ethical barriers are no excuse for acting as though you have proof backing your causal
claim when in fact you don’t.
You see, the problem with correlational research, as an example, is that you have no way of knowing whether the high
positive correlation between interest in pornography and sex offensive behavior is because the first causes the second or
vice-versa. Oh, I know that anti-pornography groups may claim it is “common sense” that smut causes rape, but it could
be argued that the rapist, sitting around waiting for his next opportunity, immerses himself in smut. Or, maybe some other
characteristic of the rapist (such as upbringing or neurological disorder) may cause BOTH the raping and the interest in
smut. Again, many will use common sense or public outcry as a very poor substitute for actual scientific evidence of the
kind that is required to prove a causal relationship—to back up a causal inference.
4 Examples of Issues in Physiological Psychology:
1. Coolidge Effect – Given access to a receptive female, male mammals will engage in sex until they are exhausted,
but when a new female is made available, the male will suddenly engage in sexual behavior again. Experimental
studies have shown this phenomenon over and over with males, but there was no such parallel demonstration
with females. Evolutionary psychology might be satisfied with this asymmetry – fits in with the general idea that
the best reproductive strategy for males is to spread their genes far and wide…Still, it would be best to show
experimental evidence that the Coolidge Effect does or does not apply to females as well. Be sure to study your
text’s point about a particular confound that has befuddled experimenters – and also the creative solution that 2
researchers devised.
2. Perception of Movement – common sense doesn’t always make sense!
3. Jose & the Bull
 Anthropomorphize – infer human qualities in nonhumans – like believing beavers are “busy” or lions are
“proud”
 Morgan’s Canon, Occam’s Razor, Law of Parsimony – essentially the same principle
4. Prefrontal Lobotomies
 Inference based on a single – nonhuman -- case study
 Inference relying on validity of testing—Patients were followed up, but the interviews and psychological
tests were actually invalid. For example, when asked “What should you do if you smelled something
burning in a movie theatre?”, the frontal lobe patient might answer correctly (e.g., “quietly inform the
manager”), but in the actual situation, the patient might very well jump up & shout, “Fire! We’re all going to
die!”
 Unbridled spread of “treatment” in both number and diagnosis – basically a fad – if it erases disabling
anxiety, then why not moderate anxiety? If it erases anxiety, then why not depression? Schizophrenia?
Chapter 2
False Dichotomies:
Physiological or Psychological? AKA: the Mind-Body Problem; Nature-Nurture Debate.
 The Mind-Body Problem is only a problem for Dualists because they must explain how a mental event (e.g., a
“thought” or “feeling”) in the nonphysical world can influence a behavioral event (e.g., action) in the physical world.
What kind of thing links the physical with the nonphysical?
 Your professor, for example, has no mind and so no mental events – only behavioral ones. Sure, some are covert
– hidden in his head – but they are behaviors nonetheless. So, no mind-body problem!
Evolution:
 Natural Selection
Physiological Psychology Chapter 1 & 2 -- Dr. Mascolo
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 both Nature & Nurture
 cannot pass on “acquired characteristics” (but see Epigenetics at the end of these notes!)
“Survival of the Fittest” – a catchy phrase but also misleading – not enough to survive – but also to reproduce –
that is, pass their genes on to next generation.
Structural (physical) and also Functional (behavioral) – for example:
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Social Dominance in Males – for example, the #1 Bull Elephant Seal
accounts for 37+% of copulations, #2, almost 20%, …#10 just 1%
Mating Relationships – again, more opportunity….
 Promiscuity – males & females mate indiscriminately – safety in large
numbers
 Polygyny – males mate with multiple females (each devoted to raising
young)
 Polyandry – females mate with multiple males (not seen in mammals)
 Monogamy – males & females mate with a single partner for life
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8 Misunderstandings about Evolution: Study your text’s answers to these questions:
1. does it run along a single line?
2. are we humans at the “end point”?
3. is the process always slow (like thousands or millions of years)?
4. what percentage of species are alive today?
5. what’s the difference: “function” versus “purpose” & “design”
6. is every characteristic of a species today “adaptive”?
7. did every characteristic evolve because of its current function?
8. do similar functions mean common ancestors?
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Evolution of the Brain (why are we the smartest?)
 Brain Size?
 Brain Size relative to Body Size?
 Brain Size of the “impressive parts”?
 Brain Complexity?
Behavioral Development – Nature-Nurture Interactions
• Selective Breeding – “Maze-Bright” vs. “Maze-Dull” Rats
 Was it really possible to separate rats into 2 strains based simply on mazerunning errors?
 Was maze-running error the only difference between the 2 strains?
 Was maze running ability the true difference between the 2 strains?
 Finally, the maze-bright – maze-dull difference is seen only in rats raised in an
impoverished environment. When the 2 strains are raised in an enriched
environment, the maze-bright superiority all but disappears.
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PKU Syndrome – the damaging effects of this purely genetic disorder (Nature) can
be mitigated by restricted diet (Nurture)
Development of Birdsong – an important paragraph details 3 “remarkable” points
about Canary song neural circuits – remarkable because they may link Canary
song to Human speech—including the possibility of neurogensis (though Pinel is less explicit about this
possibility compared to previous editions).
Human Studies – 4 groups based on all possible combinations of 2 variables:
 Fraternal (DZ) twins vs. Identical (MZ) twins – Genetic (“Nature”) variable
 Twins raised together vs.Twins raised apart – Environmental (“Nurture”) variable
 How are the results from Human studies similar to/different from the “Maze-Bright” vs. “Maze-Dull” study
above?
Physiological Psychology Chapter 1 & 2 -- Dr. Mascolo
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Heritability Index is a statistic estimating the degree to which genetics contibutes to a particular psychological
characteristic or ability in a particular sample of subects.
 Like all statistical estimates, the results vary across studies.
 Also, statistical estimates apply to the groups, not individuals
 Studies done with samples who are genetically similar but environmentally diverse will tend to produce a
lower heritability index --- Studies done with samples who are environmentally similar but genetically
diverse will tend to produce a higher heritability index.
Epigenetics – A True Paradigm shift?
The advances in genetics are undeniable – I say this because the field has extended way beyond esoteric scientific
inquiry; it has revolutionized our lives – medical technology is just one example.
Still, genetics isn’t everything, and so there remains the challenge of identifying other (presumably environmental) factors
that are also significant in explaining human experience.
One example: the prevalence of Schizophrenia in the general population is about 1%. That is, any of us has a 1% risk of
developing Schizophrenia just by being human. This risk increases considerably to the extent that family members have
been diagnosed with the disorder. At its peak, the risk rises to almost 50% if an MZ twin has been diagnosed with
Schizophrenia. This seems to confirm genetics is a significant factor in Schizophrenia, because 50% is much larger than
1%. However, 50% is also much smaller than 100%. So unlike PKU Syndrome, genetics are not necessary & sufficient
for Schizophrenia. So research has focused on accounting for the other 50%.
The challenging Nature-Nurture issue has been made even more challenging by advances in the field of Epigenetics. I
have a lot of catching up to do, and so I’m not going to say much more about this. I can tell you that this field has been
around a while, but it always seemed just an interesting little area of research flirting around the margins of the field.
Not any more – it seems clear now that textbooks in the life sciences will have to be rewritten to accommodate epigenetic
findings.
Pinel’s textbook is no exception; see Chapter 2’s Modern Genetics: Growth of Epigenetics.
So here’s all I’m going to say for now: The field of Epigenetics focuses on inheritable characteristics that change over an
organism’s lifetime that are not the result of changes in DNA. So far as I can tell, the phenomenon is this: we inherit out
DNA from our parents, but some genes are “buried” and so do not affect our development – BUT – environmental factors
can “unearth” these genes in such a way that they do affect our development – so these are inheritable factors that do not
involve actual changes in the DNA we inherited from our parents.
So to illustrate the principle – and this is pure speculation solely for illustration – maybe Schizophrenia is 100% genetic,
but our studied examine MZ twins who are, say 20 years old, and the reason the concordance rate is only 50% is that
epigenetic changes have taken place over the 20 years – that is, inheritable factors may have changed even though the
twins still share the exact same DNA.
OK – that’s all I’m going to say on this topic – it’s back to school for me!