Psychology 001
Introduction to Psychology
Christopher Gade, PhD
Office: 621 Heafey
Office hours: F 3-6 and by apt.
Email: gadecj@gmail.com
Class WF 7:00-8:30 Heafey 650
Sleep
• In the first half of today’s class, we’re going
to talk about one type of altered
consciousness… sleep.
• We’ll first discuss theories
about why we sleep.
– Biological theories
– Evolutionary theories
– Cognitive theories
• After that, we’ll discuss the different stages
of sleep.
The Purpose of Sleep
• The Repair and
Restoration Theory:
– The purpose of sleep is
to enable the body to
recover from the
exertions of the day.
– But what needs to
recover???
• Muscles
• Brain systems
– The Randy Gardner
exception
• The Evolutionary Theory:
– Evolution equipped us with a regular pattern of sleeping
and waking for the same reason… to conserve fuel and
to prevent us from walking into dangers.
– What would the purpose of functioning at night be?
• Little visual capabilities
• Scarce resources and opportunity to find food.
• Dangerous predators
• A huge amount of energy is required to maintain alertness and
to function well in the night environment.
– What about today’s world?
• Lighting is available
• Resources are abundant
• Fewer/no predators
• Equal amounts of energy are required in both day and night in
order to maintain alertness and function well in the night
– Does this difference support or refute the evolutionary
theory?
• Information Consolidation Theory:
– Our need for sleep is a result of the
brain’s need to consolidate the
information obtained throughout
the day into memories.
– What’s the proof?
• High levels of brain activity during sleep
• Increased levels of learned responses
• Ferret maze experiment
– Is there any proof against this theory?
• Memories can obviously be established without sleep
• Brain activity measures taken during human sleep
seem extremely random.
What happens while we sleep?
• In the mid 1950’s researchers discovered that
during sleep, people display an extremely
unusual pattern of behavior several times
throughout the night.
• REM (rapid eye movement) or paradoxical sleep.
– Question: 1950’s???
• From this REM discovery, researchers began
observing and defining the different sleep
“cycles” that we go thorough.
Measures of Sleep
• EEG
(electroencephalograph)
• Video recordings
• Intermittent waking
• fMRI
• Polysomnograph
The Stages of Sleep
Awake
Sleep
stages
1
2
3
REM
4
0
1
2
3
4
Hours of sleep
5
6
7
Stage 1
• brain waves patterns that closely resemble
waking patterns.
• Attentive to outside stimuli and can easily
be woken.
• Will report still being awake when woken in
this stage.
• Later replaced by REM sleep after the first
sleep cycle of the night.
Stage 2
• Brain waves begin emitting “sleep spindles”. These
spindles are random bursts of high amplitude EEG
waves. There are also “K complexes” found in this
stage of sleep.
• People woken in this stage report having been asleep.
• Dreams can also occur in this stage, but they were
(are?) considered less rare.
• This stage makes up the majority of our sleep after the
first two sleep cycles that we go through in a night.
Stage 3
• This stage is represented by very slow and
erratic brain waves.
• Believed to have some form of
recuperative effect on the body.
• Dreams???
Stage 4
• The deepest level of sleep that we encounter. It
is represented by long, slow waves on EEG
measures.
• Very difficult to wake people in this stage.
• The stage of sleep that a lot of little children are
in while they sleep walk.
• Occurs only in the first (or first two) cycle(s) of
sleep.
• Considered THE recuperative stage of sleep for
our bodies.
Stage 5 (REM)
• AKA paradoxical sleep
• The majority of our body is paralyzed during this stage. Our
eyes are highly active.
• REM sleep and stage 2 sleep are the two most common
stages of sleep after we experience our first two sleep cycles.
• Neural activity resembles a waking state during REM sleep.
• Associated with memory consolidation and emotion
regulation (new studies have contested this idea).
• Dreams were originally believed to come only from this
stage.
– Waking experiments
Added Notes:
• These sleep cycles and theories of sleep do not
depict an exact replication of everyone’s sleep
patterns.
• Each individual’s sleep patters vary from the
population as a whole, and their sleep need vary as
well (some of us need a lot, some of us need a
little).
• Various sleep abnormalities have a strong impact
on the sleep patterns of a number of individuals in
the population at some point in time during their
lives.
• Read up on sleep abnormalities and about different
causes for our becoming “tired” in the text.
Now we’re going to discuss…
• Dreams!
What can we discuss about dreams?
• The meaning of dreams
• The purpose of dreaming (from a more
modern perspective)
• The content of dreams (read about this
one in your text)
• “Dreams are a window to
our unconscious thoughts,
motivations, and desires.”
• Freud believed that dreams
needed to be broken down
into two distinct types of
content.
– Manifest content – the
information in our dreams that
appear on the surface (e.g.
the story, the people, and the
places in our dreams)
– Latent content – the hidden
themes and symbols (which
tell us about the unconscious
thoughts, motivations, and
desires) that can be abstracted
from the manifest content of
the dream
Freud
Freud (cont.)
• Freud also argued
that some manifest
content in our
dreams actually had
no latent content in
it.
– “Sometimes a cigar is
just a cigar.”
• What is the
significance of this
statement?
Cognitive Theory (Activation Synthesis Theory)
• The prominent theory in our day about what
is going on during our dreams.
• While we sleep, our brain is producing large
numbers of random neural firings.
• Our primary cortex (frontal lobe) attempts to
make sense of this information.
• We create a vivid and relevant story from
this.
– Dreams appears meaningful because the majority of our
neural links are from our prevalent thoughts and
common experiences. Thus, we’re more likely to have
dreams about things we know.
The Purpose of Dreaming
• What can our dreaming
actually do?
– Allow us to generate
insights into problems
that we are faced with
– Restore/retrace/establish
neural connections
– Act out
fantasies/obstacles in a
safe manner
What insights can our dreams reveal to us?
• Elias Howe
– Dreamt that he was about to be eaten by
cannibals
– Was taken back by the spears that the cannibals
held, which had a hole at the tip
– Used this design to invent the needle
• Dmitri Mendeleyev (1869)
– Elemental table was thought up through a dream
What does this tell us?
• Dreams might actually be used as a tool to help
us solve problems that we are faced with every
day.
– Question: How many of you have experienced a math
problem, visual-spatial task, or major life question
that was impossible to achieve the day it was
presented to you, but it became easy when you
attempted to overcome the obstacle the next day?
• But is this just the result of an illusionary
correlation?
– Question: How many of you have experienced a math
problem, visual-spatial task, or major life question
that was impossible to achieve the day it was
presented to you, and it was still impossible to
overcome the next day?
• Side note:
– It is important to note that the problems
solved in these examples were problems
that the figures had already been
struggling with. These were not merely
moments of random insight about
unknown topics.
• What can that tell us?
– Maybe our brains are just working through
the stuff that we already know a lot about
during our sleep.
Restore/Retrace/Establish Neural
Connection Theory (same as
Information Consolidation Theory)
• During sleep, almost every part of our brain is
activated at some point in time.
• Studies have shown that specific brain areas in
animals that have been overly active during the
day, display higher activity during dreaming.
– Ferret maze example revisited
• Research has also shown that response time at
newly learned tasks, as well as processing
speed, is greatly increased after just one day’s
sleep.
Problems with the RRE (IC) Theory
• We don’t have sophisticated enough tools, and
we don’t know enough about the brain to
determine with certainty if the firing of neurons
during sleep are random, or if they are truly
restoring, retracing, and establishing new neural
connections.
• Studies have shown that our lack of sleep
doesn’t have a direct impact on REM sleep. In
fact, the percentage of REM sleep we get only
increases when we get an abundant amount of
sleep.
One final possibility...
• Sleep might just have
developed because there’s
nothing to do at night.
• Dreams might actually just be
something that developed
through evolution as a result
of our need to move our eyes
at some point in time during
the night.
– Computer example (from the
text)
And then…
• Next lecture
we’re going to
address other
forms of
consciousness.
• So until then,
keep studying…