basic perception disorders

1. DISORDER OF
PERCEPTION
SEMINAR BY : MOHD AHSAN
MODERATOR : PROFESSOR R.K. GAUR
DEPARTMENT OF PSYCHIATRY, JNMCH,AMU

2. SENSATION AND PERCEPTION
SENSATION:
 Sensation is simple awareness due to stimulation of a sense organ.
 First stage in receiving information from outside the self
 It is basic registration of light, sound, pressure, odour or taste as
parts of our body interact with the physical world.
 Sensation involves three steps:
1.Sensory receptors detect stimuli.
2.Sensory stimuli are transduced into electrical impulses (action potentials) to be decoded by the
brain.
3.Electrical impulses move along neural pathways to specific parts of the brain wherein the impulses
are decoded into useful information (perception)

3. PERCEPTION
 Perception(from the Latin word perceptio) is the organization,
identification and interpretation of sensory information in order to
represent and understand the presented information , or the
environment.
 Perception Is not a passive process, but an active one that involves
construction of an external world that depends on internal templates i.e.
transformation of raw sensory stimuli from sensory information is
decoded into meaningful perception at cortical level which involves active
processes,influenced by attention,affect,cultural expectation,context,prior
experiences, memory and most importantly, prior concepts.

4. Perception can be split into two processes
(1) processing the sensory input, which transforms this low-level information to higher-level information
(e.g., extracts shapes for object recognition)
(2) processing which is connected with a person's concepts and expectations (or knowledge), restorative
and selective mechanisms (such as attention) that influence perception.
Example- In visual system, light sensation is received by retina and transformed into a neural code that is
transmitted from retinal ganglion cells to primary visual cortex via lateral geniculate nucleus of thalamus.
Perception occurs when a stimulus has undergone processing according to its form, colour, motion and
meaning.

5. Difference between perception and sensation

7. Difference between imagery and normal
perception?
1. Perception are of concrete reality Images are figurative and have a character
of subjectivity
2.Perception occur in external objective space Images appear in inner subjective space
3.Perceptions are clearly delineated Images are incomplete and poorly delineated
4.The sensory elements are full and fresh The sensory elements are relatively
insufficient
5.Perceptions are constant and remain
unaltered
Image dissipate and have to be recreated
6. Perceptions are independent of our will Images are dependent on our will

8. ABNORMAL PERCEPTIONS
 1. SENSORY DISTORTION- constant real perceptual object, which is
perceived in a distorted way.
 2.SENSORY DECEPTION- a new perception occurs which may or may not
be in response to external stimulus
 Disturbance of the mental state, with or without organic brain pathology,
may cause sensory distortion. This portion may involve any of the
components of elementary aspects of perception, such as
uniqueness,size,shape,colour,location,motion or general quality. What is
significant that the perceived object is correctly recognized and identified
yet there is a deviation from its customary appearance without
prejudicing the knowledge of the kind of thing that is it

9. Sensory distortions: changes in perception that are the result of:
1)change in the intensity of stimulus.
2)quality of the stimulus
3)spatial form of the perception
4)distortions of the experience of time
5)splitting of perception

10. SENSORY DISTORTIONS
 1.CHANGE IN INTENSITY
 (A) HYPERAESTHESIA- Increased intensity of sensations due to intense
emotions or lowering of physiological threshold. Seen in
 anxiety
 Depressive disorder
 Hangover from alcohol
 Migraine
 Hypochondriacal personalities
(B) HYPOAESTHESIA- Decreased intensity of sensations due to heightened
physiological threshold. Seen in
 Generalized anxiety disorder
 Major depressive disorder
 Increasedsensitivityto noise–Hyperacusis
 Decreasedsensitivityto noise–Hypoacusis,seenin:
 Delirium
 Depression
 Attention deficitdisorder.

11. HYPERAESTHESIA

12. 2.Changes in Quality
1.XANTHOPSIA Colouring of yellow
2.CHLOROPSIA Colouring of green
3.ERYTHROPSIA Colouring of red
 It is mainly visual perceptions that are affected by this brought about by toxic substances
 These are mainly the results of drugs (for example santonin,poisoning with mescaline or
digitalis) used in the past to treat various disorders
 Perceptual distortions of colour occurs in schizophrenia
 EXAMPLE JASPERS describe as ‘I ONLY SEE BLACK, EVEN WHEN THE SUN IS SHINING, IT IS
STILL ALL BLACK’
 In organic conditions ACROMATOPSIA which is the complete absence of colour, has been
described as U/L or B/L occipital lesion, usually of lingual and fusiform gyrus
 Dyschromatopsia refers to perversion of colour perception and occurs after unilateral
posterior lesion

13. 3.Change in spatial form- change in
perceived form of an object
seen in:
 Retinal disease
 Disorder of accommodation/convergence
 Temporal/parietal lobe lesion(posterior)
 Poisoning with atropine/hyoscine
 Secondary to chronic arachnoiditis(due to involvement of nerves
controlling accommodation)
 Schizophrenia
 Person flying at high altitude

14. Micropsia-visual disorder in which patient sees objects as
 Smaller then they really are
 Farther than they really are.
Seen in
 Organic conditions a/w partial paralysis of accommodation example retinal
edema,macular degeneration or CSR
 Organic conditions of brain such as TBI, epilepsy or migraine
 Drug use such as mescaline,long term use of cocaine and also rarely with
zolpidem

15.  Macropsia/Megalopsia- visual disorder in which objects within an affected
section of the visual field appear larger than normal. Seen in
 Organic conditions associated with Complete paralysis of
accommodation,vitreomacular traction, macular edema
 Illicit drug use of cocaine, also reported with zolpidem and citalopram
 Migraine
 Temporal lobe/frontal lobe epilepsy
 Miscellaneous such as endogenous hypoglycaemia and virus such as EBV
and IM

16. MACROPSIA

17.  Hemimicropsia- apparent reduction in only one hemifield of vision seen in temporal lobe epilepsy
 Metamorphopsia-alteration of customary shape of perceived objects. When metamorphopsia affect faces, it
is referred as PARAPROSOPIA example one woman saw people upside down,on their heads. Perceptual
disorders of face are rapidly fluctuant and dynamic
 Teleopsia-object appearing far away than it should be
 Pelopsia-object appearing nearer than it should be
 Alloaesthesia-perceived object in a different position from what it is expected, so that the patient
experience transposition of objects from left to right. Seen in right sided vascular lesions of the putamen
characterized by sensory stimulus on one side of body being perceived on contralateral side. Cause include
spinal cord lesions such as cervical tumors or disc herniation and multiple sclerosis.
 Akinetopsia- impairment of visual perception of motion. Following B/L posterior cortical damage
 Dysmegalopsia- objects perceive to be larger on one side and smaller on the other side. Seen in
 Retinal disease
 Disorder of convergence/accommodation
 Atropine/hyoscine poisoning
 Chronic arachnoiditis

18. Metamorphopsia in left half field of vision

19. PORROPSIA
 Experience of retreat of subjects into the distance without any change in
space(seeing things being carried away).
 Visual distortion in which stationary objects appear to be moving away
from the observer.
 Seen in
I. Edema of retina
II. Partial paralysis of accommodation
III. Disease affecting the nerves controlling accomodation

20. 4.DISTORTIONS IN THE EXPERIENCE OF
TIME
 MANIA: time passes quickly
 DEPRESSION: time passes slowly
 TEMPORAL LOBE LESIONS: feels time passes quickly or slowly either
 SCHIZOPHRENIA: have abnormalities of time judgement.
In acute organic states, disorders of personal time are shown in temporal
disorientation. Temporal lobe lesion can show that either time passes slowly or
quickly
in recent years, there is evidence to suggest that patients with schizophrenia have
abnormalities of time judgement, estimating intervals to be less than they are i.e.
age disorientation is another feature of it,even in absence of any other features
of confusion.

21. 5.SPLITTING OF PERCEPTION
 Seen sometimes with organic states and in schizophrenia
 Unable to form usual assumed link between two or more perceptions
 For example in schizophrenia, while watching tv experiencing a feeling of
competition between visual and auditory perception and not coming out
of the same source.

22. Todds syndrome/ALICE IN
WONDERLAND SYNDROME
Alice in wonderland syndrome (AIWS), also known as Todd's
syndrome or Dysmetropsia, is a neuropsychological condition that distorts perception.
people may experience distortions in visual perception such as micropsia (objects
appearing small), macropsia (objects appearing large), pelopsia (objects appearing to be
closer than they are), or teleopsia (objects appearing to be further away than they are).
Size distortion may occur in other sensory modalities as well.
Alice in wonderland syndrome is often associated with migraines, brain tumors,
and psychoactive drug use. it can also be the initial symptom of the epstein–barr
virus. It can be caused by abnormal amounts of electrical activity resulting in abnormal
blood flow in the parts of the brain that process visual perception and texture.

23. Sensory deceptions
 Illusion
 Hallucination
 Pseudohallucination

24. ILLUSION
 Misinterpretation of stimuli arising from external object
 In illusion, stimuli from a perceived object are combined with a mental image to produce
a false perception
 Illusion in themselves are not indicative of any psychopathology since they can also
occur in absence of psychiatric disorder
 EXAMPLE- a person walking along a dark road may misinterpret innocuous shadows as
threatening attackers
 Visual illusions are most common followed by auditory illusions(example-when a person
hear words in a conversation that resemble their own name and believe they are being
talked about)

25.  derived from set and lack of perceptual clarity
SEEN IN
 DELIRIUM(where perceptual threshold is raised and an anxious and
bewildered patient misinterpret stimuli)
 SEVERE DEPRESSION WITH DELUSION OF GUILT
 PATIENT WITH DELUSION OF SELF REFERENCE

26. TYPES OF ILLUSION
A. COMPLETE ILLUSION- these depend on inattention such as misreading words
in newspapers or missing misprints because we read the word as if it were
complete
Example - _ook might be misread as book to a person with interest in reading
even though the faded letter was L
B. AFFECT ILLUSION-arise in the content of particular mood state
Example-(a) A bereaved person may momentarily believe they ‘see’ the deceased
person.
(b) A delirious person in a perplexed and bewildered state may perceive the
innocent gestures of others as threatening.
C. PAREIDOLIA- vivid illusions occurs without patient making any effort. These
are as a result of excessive fantacy thinking and a vivid visual imagery.

28. Hallucination
 DERIVED FROM A LATIN WORD ALUCINARI MEANING TO WANDER IN THE MIND.
 A PERCEPTION WITHOUT AN OBJECT( ESQUIROL,1817)
 A HALLUCINATION IS AN EXTEROCEPTIVE OR INTEROCEPTIVE PERCEPT THAT DOES NOT
CORRESPOND TO AN ACTUAL OBJECT(SMYTHIES,1956)
 A HALLUCINATION IS A PERCEPTION WITHOUT AN OBJECT(WITHIN A REALISTIC
PHILOSOPHIC FRAMEWORK) OR THE APPEARANCE OF AN INDIVIDUAL THING IN THE WORLD
WITHOUT ANY CORRESPONDING MATERIAL EVENT(CUTTING,1997)
 AFALSE PERCEPTION WHICH IS NOT A SENSORY DISTORTION OR A MISINTERPRETATION
,BUT WHICH OCCURS AT THE SAMETIME AS REAL PERCEPTIONS(JASPERS,1962).

29.  According to Slade (1976) ,3criteria are essential (a) percept like experience
in the absence of external stimuli, (b) percept like experience that has the full
force and impact of a real perception (c ) percept like experience that is
unwilled ,occurs spontaneouslyand cannot be readily controlled by the
percipient.

30. Causes of
hallucination
 INTENSEEMOTIONS
 DISORDERS OFSENSEORGANS
 SUGGESTION
 SENSORYDEPRIVATION
 DISORDERS OFCNS
 PSYCHIATRICDISORDERS

31. (A)EMOTIONS
 Indepressedpatients with delusionsof guilt; hallucinationtendsto bedisjointed
orshort phases.
 Occurrenceof continuous persistent hallucinatory voicesin severedepression
shouldarousethesuspicionof schizophrenia orsomeintercurrentphysicaldisease.
 Inschizophreniahallucinationsareofpersecutorynatureorandmayconsistofvoices
givingcommentaryonperson’sactionsanddiscussinghiminahostilemanner

32. (B) SUGGESTIONS
 Normalsubjectscanbepersuadedtohallucinate,forexamplewhenaskedtowalk
downadimlylitcorridorandstopwhentheysawafaintlightoverthedoorattheend,
mostsubjectsstoppedwalkingatsometimeduringthestudysayingthattheycould
seealighteventhoughnonewasswitchedon.
 Similarlysubjectscanbepersuadedtohallucinatevisuallyorauditorily,eitherby
hypnosisorbybrieftaskmotivatinginstructions

33. (C) SENSORY DEPRIVATION
 Ifallincomingstimuliarereduced to minimum in a normal subject they will begin
to hallucinateafterfewhours.
 These hallucinationsareusuallychanging visual hallucinations and
repetitive words and phrases.
 BLACK PATCH DISEASE following cataract extraction in the agedasa
result of sensorydeprivation andmild senilebrain changes.

34. (D) DISORDERS OF CNS
 Lesionsof diencephalon andcortex can producehallucinationthatarenot only
visual but canbe auditory

35. (E)Hallucination of individual senses
 Hearing
 Vision
 Smell
 Taste
 Touch
 Pain and deep sensation
 Vestibular sensations
 Sense of presence

38. 1.HEARING
 Hearing(auditors) may be elementary or unformed.
 Usually unstructured sounds-ELEMENTARY HALLUCINATION, example
patient hears noises or rattles,whistling or machinery.
 Partly organized-music
 Completely organized-hallucinatory voices-schizophrenia
 In severe depression, ‘voices’ heard are less well formed than those
described in schizophrenia.
 They can be heard also in organic states like delirium or
dementia,occasionally in severe depression but ‘VOICES’ are characteristic
of schizophrenia, can occur at any stage of the illness.

39. A paracusia, or auditory hallucination, is a form of hallucination that involves perceiving sounds without
auditory stimulus.
Hearing voices, which are characteristic of schizophrenia,also known as PHONEMES, in association with
organic states,are simple words or short sentences,spoken to patient in second person as
peremptory(insisting on immediate attention) orders or abusive remarks, but in schizophrenia more often
complicated speech is heard,voices are single/multiple,male/female or both,people known to patient or not
known, patient’s own thought loud,which give a running commentary on patient’s actions or voices.
SECOND PERSON
HALLUCINATION
any voice in your ears
Example- COMMAND
HALLUCINATION
TYPES OF
AUDITORY
HALLUCINATIONS
THIRD PERSON
HALLUCINATION
>= 2 voices in ears
Example running
commentary
(MOST COMMON/MOST
SPECIFIC/MOST
PATHOGNOMIC)
FIRST PERSON
HALLUCINATION
(AUDIBLE
THOUGHTS)
Own thoughts as
hallucination

40.  In 2015 a small survey reported voice hearing in persons with a wide variety of DSM-5 diagnoses, including:
 Bipolar disorder
 Borderline personality disorder
 Depression (mixed)
 Dissociative identity disorder
 Generalized anxiety disorder
 Major depression
 Obsessive compulsive disorder
 Post-traumatic stress disorder
 Psychosis (NOS)
 Schizoaffective disorder
 Schizophrenia
 TRANSIENT CAUSES:
Auditory hallucinations have been known to manifest as a result of intense stress, sleep deprivation, drug use, and errors
in development of proper psychological processes. Genetic correlation has been identified with auditory
hallucinations, but most work with non-psychotic causes of auditory hallucinations is still ongoing.
High caffeine consumption has been linked to an increase in the likelihood of experiencing auditory hallucinations. A
study conducted by the La Trobe University School of Psychological Sciences revealed that as few as five cups of coffee a
day could trigger the phenomenon

41. Imperative hallucination
 Voices sometimes act upon individuals and give instructions
 May or may not act upon them
 In some cases voices speak about the person in the third person and may give
a running commentary on their actions. They are among SCHNEIDER First rank
symptoms,previously diagnostic of schizophrenia,this is no longer the case as
these symptoms have also been described in mania(GONZALEZ-PINTO et
al,2003)
AUDITORY HALLUCINATIONS
 Adverse
 Neutral
 Helpful
 Incomprehensible nonsense
 Neologism

42. THOUGHT ECHO/THOUGHT SONORIZATION- hearing one’s own thought
spoken aloud,voices may come from outside/inside the head.
 Gedankenlautwerden- thoughts are spoken at the same time or just before
as they are occurring.
 Echo de la pensée- thoughts are spoken just after they occurred.
Auditory hallucination occurs when there is a combination of vivid mental
imagery and poor reality testing in the auditory modality

44. 2.VISUAL HALLUCINATION
 Characteristically occur in organic states rather than functional psychosis
 May be elementary in the form of flashes of light,partly organized in form of
patterns,or completely organized in form of visions of people,objects or animals.
 SCENIC HALLUCINATION: whole scenes are hallucinated rather like a cinema film.
Seen in delirium and psychiatric disorder associated with epilepsy.
 Often visual hallucination are isolated and do not have any accompanying
voices.Sometimes,however, visual and auditory hallucination co-occur to form a
coherent whole. EXAMPLE
 IN TEMPORAL LOBE EPILEPSY
 IN SCHIZOPHRENIA OF LATE ONSET(may see and hear people being
tortured,murdered and mutilated)

45. LILLIPUTIAN HALLUCINATION
 Often micropsia affects visual hallucinations so that they may see tiny people or objects,so-called
LILLIPUTIAN HALLUCINATION.
 Unlike the usual organic visual hallucination,they are accompanied by pleasure and amusement.
 There is bizzare intermingling of affect so that the patient experiences stark terror and at the same
time, a humorous response to absurd experiences especially common with these disorders.
 Seen in DELIRIUM TREMENS(alcohol withdrawal syndrome)

46. Charles bonnet syndrome(PHANTOM VISUAL IMAGES)
 Sometimes,visual hallucination do not appear to be associated with any other psychiatric
abnormality.
 It is a condition in which individual experience complex visual hallucinations in association with
impaired vision without demonstrable pathophysiology or disturbance of normal
consciousness(SCHULTZ AND MELZACK,1991)
 Features of this syndrome are:
 Elderly people with normal consciousness experience visual hallucination.
 None of the following is present:delirium,dementia,organic affective or delusional
syndromes,psychosis,intoxication or neurological disorder with lesions of central visual cortex
 There is reduced vision,resulting from eye disease in most cases
 Hallucination in this condition are always located in external space,are usually coloured and are much
more vivid and distinct than patient’s impaired vision would otherwise permit
 Content is elementary in about 1/3rd cases
 Percepts may be modified by voluntarily control, for example closing the eyelids, and there is insight
concerning their unreality

47. 3.SMELL(OLFACTORY)
 Seen in
 Schizophrenia
 Temporal lobe epilepsy
 Depressive psychosis
There may also be a problem distinguishing olfactory hallucination from
delusion since they are some people who insists that they emit a smell
Difficult to certain whether it is a hallucination or illusion
PADRE PIO PHENOMENON- some religious people can smell roses around
certain saints

48. 4.GUSTATORY HALLUCINATION
Occur in
 Schizophrenia
 Depression
 Temporal lobe epilepsy
 Some psychoactive drugs such as lithium carbonate or disulfiram
 in schizophrenia, they sometimes present with delusion of being poisoned.
 In depression and schizophrenia, the flavour of food may disappear altogether or
become unpleasant.
 A very common condition is BURNING MOUTH SYNDROME, seen in association
with dentistry and maxiofacial surgery,presenting with burning sensation on
tongue,palate,inner aspects of cheeks and gum. Often associated with altered
taste sensation.often difficult to describe how this disturbance of taste is
mediated and , therefore whether it is hallucinatory

49. 5.TACTILE HALLUCINATION
 FORMICATION(Latin:formica,’ANT’)- a sensation of little animals or insects
crawling over body or just under the skin. EXAMPLE- cocaine addiction or
alcohol withdrawal, uncommon in acute organic states.
 COCAINE BUGS- formication occurring with delusion of persecution
 SEXUAL HALLUCINATION- in acute and chronic schizophrenia
 Tactile hallucination is divided into 3 types:
 SUPERFICIAL
 KINAESTHETIC
 VISCERAL

50. SUPERFICIAL
Affecting the skin into 4 types
 Thermic(e.g- a cold wind blowing across the face)
 Haptic, of touch(e.g- feeling a hand brushing against the skin/a dead body
touced me)
 Hygric,a perception of fluid(e.g-all my blood has dropped into my legs and
I can feel a water level in my chest)
 Parasthetic, sensation of tingling(pins and needles)

51. Kinaesthetic
 Affects the muscle and joints and patient feels that their limbs are being
twisted,pulled or moved
 Seen in schizophrenia and are often linked with bizzare somatic delusions.
 Also seen in withdrawal state from benzodiazepine drugs or from alcohol
intoxication
 Can also occur in the absence of any abnormality for example after a week
sailing an undulating feeling may persist for a few days.

52. 6.PAIN AND DEEP SENSATION
 Visceral hallucination(SIMS-2003)
 False perception of inner organs
 Only limited range of possible visceral sensation, example
pain,heaviness,distention,palpitation and various combination of these
such as throbbing. However the possible range of bizzare schizophrenic
false perceptions is limitless.
 Some patients with chronic schizophrenia may complain of twisting and
tearing pains
DELUSIONAL ZOOPATHY- an unusual form of hallucinosis,which may take the
form of delusional belief that there is an animal crawling about in the body.
There is also a hallucinatory component since the patient feels
it(hallucination) and can describe it in detail

53. 7.THE SENSE OF PRESENCE
The sense of presence can occur in-
 Healthy people
 Organic states
 Schizophrenia
 Religious enthusiasm
 Hysteria
 Borderline personality disorder(rare)
EXAMPLE-most normal people have from time to time the sense that someone is
present when they are alone,or a dark street or climbing a dimly light
staircase.Usually this is dismissed as imagination but nevertheless they look
behind them to be certain

54. PSEUDOHALLUCINATION
Typeof mentalimagethat although clearand vividlackthe substantiality of perceptions
 Fullconsciousness
 Located in inner subjective space
 Definite outlines
 Constancyretained
 Relevantto emotions,needsandactions
 Dependsonthe observerfor existence
 Pseudohalliucination are not pathognomic of any particularmental illness.

56. HALLUCINATORY
SYNDROMES(HALLUCINOSIS)
 Persistent hallucinations in any sensory modality in absence of other
psychotic features. For example
1. ALCOHOLIC HALLUCINOSIS:
 mostly auditory, occur during periods of relative abstinence.
 May be threatening,reproachful or simply benign voices
 Sensorium is clear and hallucinations rarely persist beyond 1 week
2. ORGANIC HALLUCINOSIS:
 Present in 20-30% of patients with dementia(MCC-ALHZEIMER)
 Most commonly auditory or visual
 Patient is disoriented and memory is impaired

57. SPECIAL KINDS OF HALLUCINATION
FUNCTIONAL HALLUCINATION:
 this is a strange phenomenon in which an external stimulus is necessary to
provoke hallucination,but the normal perception of the stimulus and
hallucination in same modality are experienced simultaneously.
 In other words the hallucination require presence of another real sensation
 Example- a patient with schizophrenia first heard the voices of GOD as clock
ticked, later she heard voices from the running tap and voices coming from
chirping of birds.
 So both noices and voices were audible
 Common in chronic schizophrenia and can be mistaken for illusions

58. REFLEX HALLUCINATION
 A stimulus in one sensory modality producing a hallucination in another
sensory modality is known as synaesthesia
 Reflex hallucination are a morbid form of synaesthesia
 Example- the feeling of cold in one’s spine on hearing a fingernail scratch
a blackboard.
 Another reflex hallucination occurred in a woman who experienced pain
when certain words were mentioned.
 Although rare, synaesthesia can occur under the influence of
hallucinogenic drugs such a LSD or mescaline.

59. EXTRACAMPINE HALLUCINATION(CONCRETE AWARENESS)
 In this patients has a hallucination that is outside the limits of sensory
fields,outside the visual fields or beyond range of audibility.
 Seen in
1. Schizophrenia
2. Organic conditions such as epilepsy
3. Hypnagogic hallucination in healthy people
FOR EXAMPLE- A patient sees someone standing behind them when they are
looking straight, he keeps on hearing them talking about his disease down in the
post office(half a mile away).

60. AUTOSCOPY(PHANTOM MIRROR IMAGE)
 It is the experience of seeing an image of oneself in external space and knowing
that it is oneself
 It is not just a visual hallucination because kinaesthetic and somatic sensation must
also be present to give impression that hallucination is oneself
Seen in
I. Emotionally upset healthy individuals
II. Hysteria
III. Schizophrenia
IV. acute/subacute delirious states
V. Organic conditions:epilepsy,focal lesions(parieto-occipital lesion),toxic infective
states.
VI. Drug addiction
VII. Chronic alcoholism

61.  NEGATIVE AUTOSCOPY-
 Patients look into the mirror and sees
no image at all i.e. lack of perception
of own image in the mirror
 Often associated with
depersonalization
 Seen in organic states
INTERNAL AUTOSCOPY
 Subject sees their own internal organs
 It is very rare
 The description of internal organs is
that which would be expected from a
layperson, with crude knowledge of
anatomy.

62. HYPNAGOGIC AND HYPNOPOMPIC HALLUCINATION
 These are perceptions that occur while going to sleep(hypnagogic) and on
waking(hypnapompic).
HYPNAGOGIC HALLUCINATION- occur during drowsiness,are discontinuous,appear to force
themselves and do not form part of experience in which subject participates unlike dreams.
Patient often asserts that they are fully awake,with EEG showing low alpha wave at time of
hallucination.
HYPNOPOMPIC HALLUCINATION- persist from sleep when eyes are open,occur when subject is
waking up
 Hypnagogic hallucination is more common than hypnopompic(3:1)
 It is known that conscious level fluctuates considerably in different stages of sleep, and both
types of abnormal perception probably occur in a phase of increasing drowsiness:the
structure of thought,feelings,perceptions,fantacies and ultimately, self awareness become
blurred and merged into oblivion
 Both are not necessarily abnormal, even though they may be true hallucinatory

63. ORGANIC HALLUCINATION
 Occursin anysensorymodality andmay occurinvariousneurologicalorpsychiatric
disorders.
 Dependson:
 Generalconditionof thebrain
 Recentexperiences
 Psychodynamicfactors
 Effect of local lesion.

64.  Seen in eye disorders,CNS disorders, optic tract lesions
 Temporal lobe lesions-complex scenic hallucination
 Charles bonnet syndrome
 Delirium,dementia and substance abuse-Visual hallucination
 MOST COMMON ORGANIC SOMATIC HALLUCINATION OF PSYCHIATRIC
ORIGIN?
PHANTOM LIMB:
 in this patient feels that they have a limb from which in fact they are not
receiving any sensations either because it has been amputated or because
the sensory pathways from it have been destroyed
 In most phantom limb phenomenon is produced by central and peripheral
disorders,occasionally after lesion of peripheral nerve or medulla or spinal
cord.
 While the experience is related to limb the perception shrinks over
time,with distal parts disappearing more quickly than those that are
proximal.
 If there is clouding of consciousness, patient may be deluded that the limb
is real

65. Drug induced hallucination
 Drug-induced hallucinations are caused by hallucinogens, dissociatives, deliriants including many
drugs with anticholinergic actions and certain stimulants, which are known to cause visual and
auditory hallucinations. Some psychedelics such as lysergic acid diethylamide (lsd)
and psilocybin can cause hallucinations that range from a spectrum of mild to severe.
 Hallucinations, particularly auditory, are known side effects of opioid to various degrees.
 Hallucination have also been described by individuals after sniffing glue and petrol
 The drugs mescaline and LSD are potent causes of visual perceptual change.
 People can experience hallucinations when they're high on illegal drugs such as amphetamines,
cocaine, LSD or ecstasy.
 Abstaining from hallucinogenic drugs can help reduce prevalence of hallucination.

66. BODY IMAGE DISTORTIONS
 HYPERSCHEMAZIA- perceived magnification of body parts.
EXAMPLE: Brown Sequard syndrome, PVD, Multiple sclerosis,thrombosis of PICA
IN PSYCHIATRY- hypochondriasis,depersonalization and conversion disorder
 ASCHEMAZIA- perception of body parts as absent
 HYPOSCHEMAZIA- Perception of body parts as diminished. Seen in parietal lobe lesions such as
thrombosis of right MCA
 PARASCHEMAZIA- distortion of body image,feeling that parts of body are distorted or twisted or
separated from the rest body. Associated with hallucinogenic use,with epileptic aura or rarely
migraine
 HEMISOMATOGNOSIA- unilateral lack of body image in which person behaves as if one side of the
body is missing. Seen in migraine or epileptic aura.
 ANOSOGNOSIA- denial of illness. According to CUTTING,1978 58% of those with right hemispheres
stroke denied their hemiplegia early after stroke and refused to admit weakness in left arm
 SOMATOPARAPHRENIA- bizzare attitude to paralysed limb.(delusional beliefs about the body i.e.
distorted,inanimate,severed)
 Gerstman syndrome- agraphia,acalculia,finger agnosia and right/left disorientation. Seen in lesion
of dominant parietal lobe

67. Summary
 Abnormalities of perception remain some of the most compelling experiences
with which patient present.These experiences speak to the underlying
structures of perceptual world and neural correlates that make perception itself
possible.Illusion, which is misinterpretation of a normal perception and
hallucination, which is perception of an object in the absence of stimulus are
the most frequently encountered false perceptions in clinical practise.

68. REFERENCES
1. SIMS’ SYMPTOMS IN THE MIND(6TH EDITION)
2. FISH’S CLINICAL PSYCHOPATHOLOGY(3RD EDITION)
3. KAPLAN AND SADOCK’S SYNOPSIS OF PSYCHIATRY(11TH EDITION)
4. WIKIPEDIA,THE FREE ENCYCLOPEDIA

69. “Change the way you look at things and the things you
look at change.”
― Wayne W. Dyer