Perceptual illusions arise from how the brain encodes and decodes sensory information, optimizing performance for tasks. Gestaltists were interested in illusions and ambiguous figures as they suggest the mind actively interprets perceptions rather than passively recording input. Examples of illusions discussed are the Ebbinghaus illusion of circle size and the Herring-Helmholtz illusion of parallel lines. Ambiguous figures can lead to different representations from the same input. Consciousness involves being awake and aware of one's environment, in contrast to sleep states. The stages and functions of sleep including dreams are described.

1. Group 4
Perception (Part 2) and
Consciousness

2. Perceptual Illusion – The
Deception of Perceptions
Usually thought to arise from the
way sensory signals are encoded by
the brain
Also results from the way the brain
decodes sensory
information, reflecting strategies
that optimize in performance in
particular task.

3.  Perceptual illusion and ambiguous figures
were of special interest to the Gestaltists
because:
 Illusions seem to indicate that our mind
does not always accurately represent the
perpetual input. For Gestaltists, this suggest
that mind was ‘actively’ involved in
interpreting the perceptual input rather
than passively recording the input.

4.  Ebbinghaus Illusion
You probably perceived that the middle circle as smaller in
the figure on the left than the center circle in the figure on
the right. Actually, they are of the same size.

5.  Herring-Helmholtz Illusion
The perception would tell us that the first figure has
middle lines bowing in, while the second figure has
middle lines bowing out. But actually they are parallel
lines.

6.  Ambiguous figures exemplify the fact
that sometimes the same perpetual
input can lead to very different
representations.

8. Completion figures are figures
in which the mind rather
unambiguously interprets in a
particular way despite the
fact that the input is
incomplete relative to what is
typically ‘seen’.

10. Consciousness
being awake and aware
responsive to the
environment
contrast to being asleep or
in a coma

11. Sleep
 A natural state of bodily rest observed in
humans and other animals.
 Common to all mammals and birds
(warm-blooded animals)
 Essential for survival, but the reason why it
is (sleep) and not any other way is still
vague and under intense research
 Undergoes stages, namely 1, 2, 3, 4 and
REM

12. Stages of Sleep
 First four stages of sleep is under NREM
(non-rapid eye movement), the last is
known as REM (rapid eye movement)
 A complete sleep cycle takes an average
of 90-110 minutes.
 The cycle continues after every other, but
REM periods lengthen in every cycle and
deep sleep time decreases.

13. NREM Stage 1
 NREM stage 1 lasts for 5-10 minutes
 Alpha waves disappear and theta waves
appear
 Also known as light sleep
 Eye moves slowly and muscle activity
slows down
 Some feel sudden muscle contraction
preceded by the sensation of falling
(hypnic jerk)

14. NREM Stage 2
 Lasts for about 20 minutes
 Eye movement stops and brain waves
become slower with occasional burst of
rapid brain waves

15. NREM Stage 3
 This was previously two separate stages, 3 &
4, but was combined last 2007 by American
Academy of Sleep Medicine (AASM)
 Also known as slow-wave sleep (SWS) and
deep sleep
 Delta waves start to appear (stage 3
before), then continues to spike (stage 4
before)
 In this stage, waking someone up is difficult.
 Occurrence of parasomnias (sleep disorders)

16. REM stage
 Breathing becomes more rapid, irregular
and shallow
 Eyes jerk rapidly
 Limb muscles are temporarily paralyzed
 Occurrence of dreams
 Infants spend almost 50% of their time in
this stage, 20% for adults
 Most experience 3 to 5 intervals of REM
sleep each night

17. Stages of Sleep

19. Parasomnias/Sleep Disorders
Parasomnias is a medical
disorder of the sleep patterns of
a person or an animal. A test
used to confirm sleep disorder is
the use of polysomnogram to
observe brain activity during
sleep.

20. The following is the list of the most
common sleep disorders:
o insomnia
o bruxism/teeth grinding
o sleep apnea
o hypopnea
o narcolepsy
o cataplexy
o sleep paralysis
o sleepwalking

21. Insomnia
a sleeping disorder characterized
by persistent difficulty falling asleep
or staying asleep despite the
opportunity
it is due to the inadequate quality
or quantity of sleep
causes functional impairment while
awake and active

22. Types of Insomnia
1. Transient insomnia
• lasts for days to weeks
• caused by another disorder, change in
sleep environment, changes in the time
of sleep, severe depression, and stress
• effects include sleepiness and impaired
psychomotor performance

23. 2. Acute insomnia
• inability to constantly sleep well for a
period of three weeks to six months
3. Chronic insomnia
• last for years
• it can be caused by another disorder
or a primary disorder itself
• effects vary, including
sleepiness, muscle
fatigue, hallucinations, and mental
fatigues, double visions
• people experiencing this sees things in
slow motion, and moving objects
tends to blend together

24. Bruxism
 grinding of the teeth, typically
accompanied by clenching of the jaw
 an oral parafunctional activity that occurs
in most humans at some time of their lives
 caused by the activation of reflex
chewing activity
 its etiology is unknown

25. Sleep Apnea
 suspension of external breathing
 during this, there is no movement of the
respiratory muscles and lungs’ volume
initially remains unchanged
 this can be voluntarily achieved
(holding one’s breath), drug-induced
(opiate toxicity), mechanically induced
(strangulation), trauma, or
consequence of a neurological disease

26. Hypopnea
 overly shallow breathing or an abnormally
low respiratory rate
 differs in apnea in that there remains
some flow of air
 causes a drop in blood oxygen level,
which typically disrupts the stages of sleep
 symptoms are loud and heavy snoring
that is interrupted with choking sounds or
loud snorts, followed by a period of
silence

27. Narcolepsy
 a chronic sleep disorder characterized by
overwhelming drowsiness, sudden attacks
of sleep and EDS (excessive daytime
sleepiness)
 narcoleptics experience disturbed
nocturnal sleep, and REM within 5 minutes
 often confused with insomnia

28. Cataplexy
 sudden and transient episodes of loss of
muscle tone, and is triggered by emotions
such as laughing, crying, terror, etc
 a rare disorder, but is mostly associated to
people with narcolepsy
 manifests itself as a muscular weakness
which may range from a barely perceptible
slackening of the facial muscles to the
dropping of the jaw or the head, weakness
at the knees or total collapse
 slurred speech, double vision and inability
to focus

29. Sleep Paralysis
a condition that may occur in
normal subjects or be associated
with narcolepsy, cataplexy, and
hypnagogic hallucination
the pathophysiology of this
condition is closely related to the
normal hypotonia that occurs
during REM sleep

30. Sleepwalking
 also called somnambulism or noctambulism
 a sleep disorder characterized by engaging
in activities that are associated with
wakefulness while sleeping, or in a sleep-
state
 is performed by getting out of the sleeping
position, then walks around and performs
actions as if he is awake
 it is more common to people experiencing
high level of stress, anxiety, psychological
distress or to people with genetic history of it

31. Dreams
 are series of images, sounds, and
feelings occurring during a person’s
sleep, accompanied with REM
 typically last in the range of 5-50
minutes
 like consciousness and sleep, dreams
are still one of the Holy Grail of science
 scientific study of this is known as
oneirology

32. Why people dream
 psychoanalyst Sigmund Freud
referred to it as ‘the royal road to the
unconscious’
 interpreted dreams as manifestation
of desires, especially sexual urges
 form of fulfilling suppressed wishes by
transforming dissatisfaction to visual
fantasy.

33.  dream is a respond to our daily thoughts,
activities and sensations
 they are often a reflection of what
consumed our minds in the preceding day
or two
 apparently a necessary part of our being,
but still a mystery why we have it in the first
place
 experiments were conducted to test the
purpose of dream by depriving subjects in
having a REM sleep (drug-induced) and the
results were: personality change (abrasive
and angry) and difficulty in concentration
 also shown that the younger a person is,
the more important dreams are to their well
being

34.  dreams are achieved during REM, and
every full sleep cycle, REM sleep
lengthens, causing longer dreams (first
REM is 5 minutes, then can reach up to 50
minutes)
 are easily forgotten, or gradually fleets
from the person’s memory, being woken
up from a REM sleep
 the only dream we can remember is the
last one that we have, and the dream is
always seemingly meaningless in relation
to daily lives

35. Theories on Dreaming
Psychoanalytic Perspective by
Sigmund Freud
Dream Theory by Alfred Adler
Jungian Theory by Carl Jung

36. Psychoanalytic Perspective
a disconnection from reality by
extinguishing all external stimuli (door
closed, curtains drawn, covering
blanket, turning off lights), then the
brain will protect the person from
being disturbed by other external
stimuli (noise, temperature, light, the
need to urinate, etc), and internal
stimuli (fear, dissatisfaction, desire)

37. Freud believe that dreams are
composed of two parts – the
manifest and the latent content
manifest content can be thought as
what a person would remember as
soon as he wakes or what he would
consciously describe to someone
else when recalling the dream
Freud said that manifest content
are superficial and meaningless,
and it masks the true thought of
dream

38. on the other hand, latent content
hold the true meaning of a dream –
forbidden thoughts and unconscious
desires
appears in manifest content, but is
disguised and highly recognizable
in rare cases, manifest and latent
contents can be
indistinguishable, and Freud called it
as ‘infantile dreams’

39. the process by which latent content is
transformed to manifest content is
known as ‘dream work’, and this
distorts the latent thoughts in four
ways
1. Condensation – two or more latent
thoughts are combined to make up one
manifest dream image or situation
2. Displacement – instead of directing the
emotion or desire toward the intended
person or subject, it is transferred onto a
meaningless/unrelated object in a
manifest dream

40. 3. Symbolism – where complex or vague concepts
are transformed into dream images
 mind uses images similar sounding word instead
of what the real word
 use a similar, less intrusive object/s
 mostly, symbols have sex correlation
 for example, he suggested that objects such as tree-
trunks, ties, swords, rockets and other elongated
objects refer to male genitalia; while objects such as
boxes, cups, vases, suitcases and other hollow objects
refer to female genitalia
 sexual acts are symbolized by walking up a
staircase, ladder, or steps
 castration are represented by baldness or of cutting
of hair
 genitalia can also be represented by other body
parts (for male, hand; for females, eyes or mouth)

41. 4. Secondary Revision – the final stage of
dream work where in the dreams, according
to Freud, loses the ‘appearance of absurdity
and incoherence’.
• in essence, this can be thought of as ways in
which the dream work covers up the
contradiction and attempts to reorganize the
dream into a pattern in sync with the
dreamers’ experience in everyday lives
• used the method of ‘free association’ to
discover the underlying meaning behind the
dream (latent content) by letting the patient
describe the dream as accurately as possible
(manifest content), then let him focus on
specific elements on the dream and form as
many association as they could

42. Dream Theory by Alfred Alder
 according to this theory, dreams are ways of
addressing our insecurities
 we can try out strategies for overcoming or
shortcomings or compensate via wish fulfillment
 it involves looking at the parts of a dream and
analyzing what problems or inferiorities they
might represent, then the reaction from that
elements represent the way of overcoming the
issue

43. Jungian Theory
 Carl Jung, the proponent of this
theory, stated that dreams are dramas on
one’s inferior stage
 it has steps, namely: the opening scene
(settings, characters, initial situation of the
main character), development of
plot, emergence of a major conflict, and
lastly the response of the main character
to the conflict
 but this theory falls on the account that
dreams are too fragmented to be
explained by this

44. Types of Dreams
a. ordinary dream
• occurs during REM sleep
• In this type of dream, it is the thoughts that
triggers them, based on stored
knowledge, impressions, information and
experiences of the day
• This type of dream lacks any real story or
straight interpretation, but cascades as
images
• This kind of dream usually occurs every 3 to
5 times per night, and can be easily
forgotten

45. b. Lucid dreams
• in this type of dream, you are aware
that you are dreaming
• In addition to this, the person
experiencing this can also explore
the possibilities or ‘what ifs’, giving
him the power to control what
would happen next
• lucidity may also help you bolt out a
bad dream by realizing it

46. c. Day dream
• it happens when you are awake (i.e. in a
class, in a meeting or in a car)
• it is the way of imagination to wander
• in a conscious state, but feels drowsy and
relaxed
d. False awakening dream
• this happens when a person experiences
waking up, but remembering he just
performed some things already (going to
the bathroom, playing video games,
drinking water, etc)

47. e. Nightmares
• a disturbing type of dream, for the
person experiences terror, fear,
sadness and anger
• this will usually happen to people
under stress or is deeply worried

48. Hypnosis
 a mental state or set of attitudes usually
induced by a procedure known as a
hypnotic induction, which is commonly
composed of series of preliminary
instructions or suggestions
 hypnosis or hypnotism are both derived
from the term ‘neuro - hypnotism’
(nervous sleep) coined by James Braid to
distinguish his theory and practice

49. Meditation
 a mental discipline by which one
attempts to get beyond the
reflexive, ‘thinking’ mind into a deeper
relaxation or awareness
 often involves turning attention into a
single point of reference
 is believed to calm the mind, increase
alertness, and bring the person into a
state of physical and psychological
balance

50. Psychoactive Drugs
a chemical substance that
acts primarily upon the central
nervous system where it alters
the brain function, resulting in
temporary changes in
perception, mood, consciousn
ess, and behavior

51. Types of Psychoactive Drug
a. depressants
• drugs that inhibit the function of the central
nervous system and are among the widely
used drugs in the world
• causes drowsiness, relaxation, decreased
inhibition, anesthesia, sleep, & coma
• potentially addictive

52. examples of drugs that are classified as
depressants:
• ethyl alcohol – second most widely used
psychoactive drug in the world
• barbiturates – also known as
‘downers’, type of CNS depressant that
causes euphoria and relaxation; has a
dramatic effect on sleep patterns, resulting
in the suppression of REM sleep
• benzodiazepines – a CNS depressant that is
used to treat anxiety and sleep
disorders, but long-term usage causes
dependency resulting to addiction

53. b. stimulants
• drug that increases brain activity, resulting to
elevated alertness, mood and awareness
examples of drugs that are classified as stimulants:
• caffeine – the most widely used psychoactive drug
in the world; abuse causes insomnia or anxiety
• nicotine – third most used psychoactive drug in the
world, despite the fact that very few medical
purpose can be benefitted from the drug
• Cocaine – an illegal psychoactive drug that is
extracted from the leaves of the coca tree; can be
absorbed rapidly from any administration point
(snorting, inhaling, injecting or swallowing)
• Amphetamines – known as ‘uppers’; causes
tremors, vasoconstriction, restlessness, tachycardia,
insomnia, agitation and loss of appetite

54. c. hallucinogen
• comprise a unique collection of
substances that are ingested to
induce alteration of
consciousness
• are usually visual, auditory and
tactile, depending on the
subject ingested, the setting
and the experience of the user

55. examples of drugs that are classified as
hallucinogens
• Lysergic acid diethylamide – also known as
LSD, was used to cure alcoholism and was
believed to enhance creativity and well-
being; heavy doses cause delusions and
visual hallucination; also causes the ‘cross-
over’ of senses (seeing sounds, hearing colors,
etc.)
• Peyote – also referred as crown (for it came
from the top part of the peyote cactus);
effects are similar to LSD, including increase in
body temperature, elevated heart rate,
ataxia, profound sweating and flushing

56. • psilocybin – also known as magic
mushrooms; effects are similar to LSD, but
also causes altered perception of time, and
inability to discern fantasy from reality; can
also cause panic and psychosis, memory
impairment and tolerance
• phencyclidine – also known as PCP, is a
white crystalline powder that is readily
soluble in water or alcohol; once used as
an intravenous anesthetic, but was
discontinued in 1965 because of its adverse
effects like delusions, paranoia,
hallucinations, disordered thinking, and
sensation of distance from one’s
environment

57. • marijuana – (scientific name: Cannabis
sativa) is a plant that is widely used as a
hallucinogen; can cause relaxation and
elevation of mood, but abuse of it (which is
often the case) causes
hallucinations, paranoia, and euphoria; also
causes dry mouth, swollen eyelids, bloodshot
eyes, loss of coordination and accelerated
heart rate

58. d. Narcotics – refers to any psychoactive drugs
that has sleep-inducing properties
examples of drugs that are classified as narcotics
• heroin – semi-synthetic opioid drug
synthesized from morphine; regular
administration causes tolerance, moderate
physical dependence and severe
psychological dependence
• opium – formed from the latex of the
immature seed pops of opium poppies
(scientific name: Papaver somniferum); has
been widely used since antiquity and has
been quoted by famous personalities
(Friedrich Nietzsche, Jose Rizal, etc.)

59. • morphine – a highly potent
analgesic drug, effects are similar to
opium
• codeine – an
analgesic, antitussive, and
antidiarrheal drug, and most widely
used medication according to World
Health Organization (WHO)
• barbiturates – a
depressant, affecting the CNS and
has effects like sedation and
anesthesia; are also
anxiolytics, hypnotics, and
anticonvulsant

60. Depressants

61. Stimulants

62. Hallucinogens

63. Narcotics