4. • Sensory distortions – There is a constant real
perceptual object, which is perceived in a
distorted way
• Sensory deceptions – new perception occurs
that may or may not be in response to an
external stimulus
5. • Sensory distortions
• Changes in perception due to changes in the
intensity, quality of the stimulus or spatial
form
6. • Changes in intensity
• Hyperaesthesia - due to intense emotions or
lowering of physiological threshold.
• Eg- anxiety, depression, alcohol
withdrawal,LSD , hypomanic may see colours
as bright intense
• Hypoacusis- delirium, threshold for sensations
is raised
7. • Changes in quality
• Mainly visual perceptions are affected
• Caused by toxic substances
• Xanthopsia, chloropsia, erythropsia
• Derealisation – everything appears strange
and unreal
• Mania- appears perfect and beautiful
8. • Changes in Spatial form ( Dysmegalopsia)
• Changes in perceived shape of an object
• Micropsia: Lilliputian hallucinations
• Macropsia
• Dysmegalopsia – retinal disease,
accomodation and convergence disorders, TL
or parietal lesions
• Rarely seen in schizophrenia
9. • Distortions of experience of time
• Physical and personal time
• Personal time – decided by the personal
judgment of the passage of time
• This is effected in Psychiatric disorders
10. Sensory deceptions
• Illusions
• Hallucinations
• Illusions
• Misinterpretation of stimuli arising from an
external object
• Visual illusions are most common
11. • Illusions can occur in normal, Delirium
• Not in themselves indicative of pathology
12. Hallucinations
• ‘Perception without an object’
• Jaspers- “ a false perception which is not a
sensory distortion or misinterpretation , but
which occurs at the same time as real
perceptions”
• Come from ‘within’ but reacts to them as if
they were true perceptions.
• Objective space
13. True perceptions Mental images
• Substantial • Incomplete
• Objective space • Not clearly delineated
• Clearly delineated • Dependent on will
• Constant • Subjective space
• Independent of will • Inconstant
• Sensory elements are full • Have to be recreated
and fresh
14. • Pseudo hallucinations
Mental image though clear and vivid , lack the
substantiality of perceptions, seen in full
consciousness, known to be not real
perceptions and located in subjective space
• Insight
Presence of PH do not indicate pathology
21. Delusion
• A delusion is a false unshakeable idea or belief
which is out keeping with the patient’s
educational , cultural and social background. It
is held with extraordinary conviction and
subjective certainty.
22. Case Vignette
• Christina , a 44 year old woman, was arrested after harassing a local
television newscaster with telephone calls and letters asserting that
he had fathered, then absconded with her child. She denied any
wish to harm him but steadfastly pursued him with demands that
he give her “visitation rights” to “their” child. She said she
understood that he would be unable to marry her, or even to
outwardly acknowledge his love for her, because of his delicate
public position.
• There was no indication that the newscaster had ever had a
relationship with Chris, although evidence from her files and from
her apartment indicated that her fantasized relationship with him
had existed for several years. There was no indication of
hallucinations, disturbance of affect, significant Mood Disorder, or
organic illness, and the woman had never been treated for a
psychiatric disorder.
23. • English word “ delude” means - to mock, to
cheat, defrauding etc
• The decision to call a belief as a DELUSION is
not made by the person holding the belief ,
but by an external observer.
24. • The person who is holding the delusion holds
the belief with the same conviction as he
holds his other non delusional belief about
himself .
25. • Jaspers regarded delusion as a perverted view
of reality, incorrigibly held so giving delusion 3
components
C.They are held with unusual conviction
D.They are not amenable to logic
E. The absurdity or erroneousness of their
content is manifest to other people.
26. Primary delusions
• Delusion is not occurring in response to
another psychopathology
• “ apophany”
• New meaning arises in connection with some
other psychological event
• Arises ‘ de novo
27. • Core feature of a primary or autochthonous
delusion is that it is ultimately “
Ununderstandable” - Jaspers
• Eg: a female patient with schizophrenia
believes that men enter her flat anesthetize
her and gang rape her every night.
28. Secondary delusions
• Arising from some other morbid experience
• Are Understandable
• Systematization
• Completely systematized delusion- there is
one basic delusion and the remainder of the
system is logically built on this error
30. Delusional misidentification
• The capgras syndrome– familiar person is
been replaced by stranger
• Syndrome of Fregoli- stranger is familiar
31. Overvalued ideas
• Thought that ,because of the associated
feeling tone ,takes precedence over other
ideas and maintains this precedence
permanently for a long period of time.
• Less fixed and have some degree of basis in
reality
• Can occur in normal individuals also
32. • Overvalued idea is an acceptable,
comprehensible idea pursued by the patient
beyond the bounds of reason.
• It becomes so dominant that all other ideas
are secondary and relate to it.
• This term was introduced by Wernicke ( 1906)
34. obsessions
• A thought that persists and dominates an
individuals thinking despite that individual’s
awareness that the thought is either entirely
without a purpose or else has persisted and
dominated their thinking beyond the point of
relevance.
35. • It is a thought, idea, imagery or impulse
which is repetitive , intrusive, irrational,
recognised as ones own thought and ego
dystonic.
• Compulsions- are repetitive ritualistic motor
or cognitive acts which are used to control
anxiety secondary to obsessions
37. Thought alienation
• Thoughts are under the control of an outside
agency
• Others are participating in their thinking
38.
39. DISORDERS OF CONTINUITY
• Perseveration: mental operations persist
beyond the point at which they are relevant
progress of thinking, found in organic
disorders
• Thought Block: sudden arrest of the train of
thought, leaving a “blank”
- Terrifying experience, highly indicative of
schizophrenia
