DISORDER OF PERCEPTION

1. Disorder Of Perception
NIDHIL NARAYANAN
TBILISI STATE MEDICAL UNIVERSITY

2. Perception
• The process of transferring physical
stimulation into
psychological information, mental process
by which sensory
stimuli are brought to awareness.

3. Abnormal
Perception
Abnormal perception
Sensory distortions
Sensory deceptions

4. TYPES
Sensory Distortion- Constant real
perceptual object which is perceived in a
distorted way.
Sensory Deception- new perception that
may occur that may or may not be in
response to external stimuli.
• Disorders in the experience of time.

5. Distortion
Color, intensity
uniqueness
Shape and sizeLocation
Motion/general
quality

6. Sensory distortion
Changes in Intensity - Increased intensity of
sensation
Hyperesthesia seen in increasing sensations or
lowering of physiological threshold .
Eg. Hyperacusis
Seen in
anxiety
depressive disorder,
Hangover from alcohol
Migraine
hypochondria cal personalities

7. • Hypoesthesia
• Eg - Hypoacusis
• Seen in
 Delirium
 Depression
 Attention deficit disorder

8. Hyperaesthesia

9. Achromatopsian
Complete absence of color

10. Changes in Quality
•Visual perception – toxic drugs
i. Xanthopsia
ii. Chloropsia
iii. Erythropsia
•Derealization- Everything looks unreal and strange
•Mania- looks perfect and beautiful

11. CHANGES IN SPATIAL FORM
• Change in perceived shape of
an object
 Retinal disease
 Disorders of accommodation
 Temporal and Parietal Lobe
Lesions
 Poisoning with
Atropine and Hyoscine
 SCHIZOPHRENIA

12. Macropsia
• Seeing objects larger than they
really are
• Eg . Alice in Wonderland syndrome is
a rare condition that causes temporary
episodes of distorted perception and
disorientation. Patient may feel larger
or smaller than you actually are

13. MICROPSIA
A visual disorder in which the
patient sees objects
• Smaller than they really are
• Farther away than they
really are.

14. METAMORPHOPSIA
• Distorted vision in which
a grid of straight lines
appears wavy and parts
of the grid may appear
blank

15. • Teleopsia Object appearing far away
• Pelopsia: Object appearing nearer than it should

16. DISORDERS IN THE EXPERIENCE OF TIME
• Psychopathological point of view
Physical- Determined by physical events
Personal- Personal judgement of passage of time
• Mania- Time passes quickly Depression-
Time passes slowly
• Acute Schizophrenia- personal time goes in fits and starts
• Acute organic states (temporal disorientation)

17. SENSORY
DECEPTION
• Illusion :Misinterpretations of
stimuli from external object.
• Hallucination:
Falls perception in the absence of
any object or stimulus .

18. ILLUSIONS
STIMULI FROM
PERCEIVED OBJECT
MENTAL IMAGE FALSE PERCEPTION

19. TYPES OF ILLUSIONS
• Complete Illusion –
These depends on inattention,
misreading words in newspapers
• Affect Illusion- These arise in
the context of particular
mood state
• Pareidolia – vivid illusions
without the patient making
any effort ; result
of excessive fantasy thinking
and a vivid visual imagery.

20. Pareidolia

21. HALUCINATIONS
False perception in absence of any object or stimulus .
• Essential criteria for an operational definition
1. Hallucination occur in the absence of any object/stimulus
2. Hallucination are vivid (detailed/clear) as a real perception
3. Hallucination occur in outer and objective space
4. Hallucination are not under willful control of patient .

22. CAUSES
 Intense emotions
 Suggestion
 Disorders of sense organs
 Sensory deprivation
 Disorders of CNS
 Psychiatric disorders

23. Types of hallucination
Hallucinations can be described in terms of
their complexity and their sensory modality
According to complexity
• Elementary hallucination
• Complex hallucination
According to sensory modality
• Auditory hallucinations
• Visual hallucinations
• Olfactory and gustatory hallucinations
• Tactile hallucinations
• Hallucinations of deep sensation

25. Hearing
• Hearing (auditors) may
be elementary or unformed.
 Elementary – noises,
bells or undifferentiated whispers ,
in organic states.
 Partly organized- music
 Completely organized- hallucinatory
voices- schizophrenia-
persecutory in nature.
 Severe depression ,voices heard,
less well formed than schizophrenia.
1. Second-person hallucinations or third
person hallucinations
2. Gedankenlautwerden or écho de la pensée

26. Imperative Hallucination
• Voices sometimes act upon
individuals and give
instructions.
• may or may not act upon
them
• Second-person hallucinations
:They may seem to address
the patient directly .
Eg. voices with derogatory
content ,suggest severe
depressive disorder.
• Third person hallucinations: t
alk to one another referring to
the patient as ‘he’ or ‘she’.
Eg. Voices may be experienced
as commenting on the
patient’s intentions
,associated strongly with
schizophrenia.

27. • Thought echo - hearing one's own thoughts being spoken loud, voice
may come from inside or outside the head.
i. GEDANKENLAUTWERDEN-
thoughts spoken at the same time or before they are occurring.
ii. ECHO DE LA PENSES- thoughts are spoken just after
they occurred.
• Running commentary hallucinations are usually abusive.

30. VISION
Elementary- flashes of light
Partly organized- patterns
Completely organized-
people, animals, objects.
• Scenic hallucinations- like
a cinema common in delirium
• in psychiatric disorders with epilepsy.
Temporal lobe epilepsy
Late onset of
schizophrenia (protracted)

32. • Visual Hallucinations - organic states
• +clouding of consciousness
>functional psychoses
• Small animals –delirium
• rare -schizophrenia
• Occasionally without
any psychopathology
• CHARLES BONNET SYNDROME :
i. CBS is not thought to be related to
psychosis or dementia .
ii. people with CBS are aware that their
hallucinations are not real.
• Produced by drugs of abuse.

34. SMELL
• Seen in
 Schizophrenia
 Organic states like temporal lobe epilepsy
 Depression (uncommon)
• PADRE PIO PHENOMENON- religious
people can smell around certain saints

36. TASTE
• Occurs most
often in temporal
lobe epilepsy as with sa
livation and chewing
and sniffing
• Seen in
 Schizophrenia
 Organic states
• Depressed patient often
describes loss of taste.

38. Tactile
Hallucinations
• Formication- animals
crawling over the body;
• in organic states
• Cocaine bug –
formication + delusion of p
ersecution -
cocaine psychosis
• Sexual Hallucinations- acute
and chronic schizophrenia

39. Tactile Hallucinations
• Almost exclusively the result of
lesion which produces sensory
defect
• PHANTOM LIMB
 Most
common organic somatic hallucination
 95% of amputation after 6 yrs of age
 Pt feels he sees the limb from which in
fact he is not receiving
any sensations either because limb has
been amputated or
sensory pathway destroyed.

41. Hallucinations of
deep sensation
• Classified into 3 types
1. Superficial
2. Kinesthetic
3. Visceral

42. Superficial
• Thermic: a cold wind blowing
across the face
• Haptic: feeling of hand
brushing against the skin
• Hygric: feeling fluids such as
water running from head into
the stomach
• Paraesthetic : pins and
needles mostly organic .

43. Kinesthetic Hallucination
• affects muscles and joints
• Patient feels limbs twisted pulled or moved
• schizophrenia
• Organic states-
alcohol intoxication benzodiazepine
withdrawal

44. Visceral
Hallucination
• Visceral hallucinations
• Twisting and tearing pains
• Very bizarre complaints- organs
ripped out , flesh
ripped from his body
• chronic schizophrenia

45. PSEUDOHALLUCINATION
• mental image ,clear and vivid, lack
the substantiality of perceptions
Full consciousness
subjective space
Definite outlines
Constancy retained, insight preserved
Relevant to emotions, needs and actions
Depends on the observer for existence
• Hysterical
• Attention seeking personalities

46. SPECIAL KINDS OF HALLUCINATION
• Functional hallucinations : stimulus in one modality
produces hallucination in same modality
Chronic schizophrenia
• Reflex Hallucination : a stimulus
in one sense modality produces hallucination in another.
Morbid variety of synaesthesia.
• Eg.Seen in cannabis and LSD intoxication .

48. Autoscopic
(phantom mirror image)
• – experience of seeing one’s own body
projected into external space, usually in
front of oneself, for short periods.
• Normal subjects- emotionally
disturbed, tired and exhausted
• Out-of-body experience or a near-
death experience.

49. HYPNAGOGIC HALLUCINATION
Occur when the subject is falling
asleep or during drowsiness
• Are discontinuous
• Appears to force themselves on the subject
• Do not form part of
an experience in which the subject participates
unlike DREAM
• Commonest is auditory.
• geometrical designs , abstract shapes , faces
• figures or scenes from nature
• EEG shows alpha rhythm

50. HYPNOPOMPIC
HALLUCINATION
• Occurs when the subject is waking up
• Hallucinations persisting
from sleep when the eyes are open
• More in narcolepsy.

51. REFERENCE
• Fish‟s Clinical Psychopathology-
Patricia Casey and Brendan Kelly
• SIMS‟ Symptoms in the Mind-
Femi Oyebode
• Synopsis Of Psychiatry-
Benjamin James Sadock, Virginia
Alcott Saddock

52. Compared to the
brilliance of the
evening sun, reflecting
on the beautiful sea,
we humans are
NOTHING,
but SHADOWS…

53. “You see, but you do not
observe. The distinction is clear.” – Sherlock Holmes

54. Thank you