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Disorders of Perception.pptx

  1. DISORDERS OF PERCEPTION Perception - (from the Latin perceptio, percipio) is the organization, identification, and interpretation of sensory information in order to represent and understand the environment
  2. Abnormal perception Sensory deceptions Sensory distortions
  3. TYPES  Sensory Distortion - 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
  4. Sensory Distortion Changes in perception that are the result of : 1. Change in the intensity 2. Quality of the stimulus 3. Spatial form of the perception 4. Distortions of the experience of time 5. Splitting of perception
  5. Changes in Intensity • Increased intensity of sensation - Hyperesthesia seen in increasing sensations or lowering of physiological threshold. • Seen in:  anxiety  depressive disorder,  Hangover from alcohol  Migraine  Hypochondria  Increased sensitivity to noise – Hyperacusis is associated with Anxiety and depressive disorders as well as hangover from alcohol and migraine.  Decreased sensitivity to noise – Hypoacusis, occurs in delirium, where the threshold for all sensations is raised. Hypoacusis feature of other disorders associated with attentional deficits such as depression and attention- deficit disorder
  6. Hyperaesthesia
  7. Changes in quality Visual perception • Xanthopsia- Coloring of yellow • Chloropsia - Coloring of green • Erythropsia- Coloring of red •which is result of drugs (poisoning with mescaline or digitalis)
  8. Complete absence of color
  9. Changes in spatial form • Change in percieved shape of an object, can result from  Retinal disease  Disorders of accommodation  Temporal and Parietal Lobe Lesions  Poisoning with Atropine and Hyoscine  Schizophrenia
  10.  Micropsia - a visual disorder in which the patient sees objects Smaller than they really are Farther away than they really are  Macropsia or Megalopsia - opposite to micropsia  Porropsia : Experience of retreat of subjects into the distance without any change in space  Dysmegalopsia: Objects are perceived larger in one side and smaller in the other. Metamorphosia: Irregular in shape.
  11.  Micropsia - a visual disorder in which the patient sees objects Smaller than they really are Farther away than they really are  Macropsia or Megalopsia - opposite to micropsia  Porropsia : Experience of retreat of subjects into the distance without any change in space  Dysmegalopsia: Objects are perceived larger in one side and smaller in the other. Metamorphosia: Irregular in shape
  12. Teleopsia Object appearing far away Pelopsia Object appearing nearer than it should
  13. Distortions in the experience of time • Mania- Time passes quickly • Depression- Time passes slowly • Temporal lobe lesions- feels time either passes slowly or quickly • Schizophrenia- have abnormalities of time judgment, estimating intervals to be less than they are
  14. Splitting of perception Seen sometimes with organic states and with schizophrenia Unable to form usual assumed link between two or more perceptions While watching TV experiencing a feeling of competition between the visual and auditory perception and not coming out of the same source
  15. Illusion Hallucination Misinterpre tations of stimuli from external object Perceptions without external stimulus
  16. Stimuli from perceived object Mental image False perception
  17. Illusions - Stimuli from a perceived object are combined with a mental image to produce a false perception Types of Illusion  Complete Illusion- These depends on misreading words in newspapers or missing misprints because we read the word as if it were capable  Affect Illusion-These arise in the context of particular mood state  Paradolia- vivid illusions occur without the patient making any effort ; are the result of excessive fantasy thinking and a vivid visual imagery
  18. Hallucination A perception without an object A false perception which is not a sensory distortion or a misinterpretation but which occurs at the same time as real perceptions Causes: • Intense emotions • Suggestion • Disorders of sense organs • Sensory deprivation • Disorders of CNS
  19. Disorders of a peripheral sense organ  Hallucinatory voices may occur in ear disease and visual hallucinations in diseases of the eye  Charles Bonnet syndrome (phantom visual images) is a condition in which complex visual hallucinations occur in the absence of any psychopathology and in clear consciousness  It is associated with either central or peripheral reduction in vision
  20. Charles Bonnet syndrome  Features of delirium, dementia, organic affective or delusional syndromes, psychosis, intoxication or neurological disorders with lesion of central visual cortex are absent  Hallucinations are located in external space, much more vivid than the patient’s impaired vision would otherwise permit  May be modifiable by voluntary control  Usually insight is there concerning their unreality  Can be either elementary or complex
  21. Sensory Deprivation  If all incoming stimuli are related to minimum in a normal subject they will begin to hallucinate after few hours  Usually these are changing visual hallucinations and repetitive phrases  BLACK PATCH DISEASE delirium following cataract extraction in the aged result of sensory deprivation and mild senile brain changes
  22. Hallucinations and senses Hearing Vision Smell Taste Touch Pain and deep sensation The sense of presence
  23. Hearing Hearing may be elementary or unformed • Elementary – noises, bells or undifferentiated whispers ; in organic states • Partly organized- music • Completely organized –”Voices” are characteristic of schizophrenia (also occurring in organic states: delirium, dementia and sometimes in severe depression or mania)
  24. Hearing Auditory hallucinations Adverse Neutral Helpful Incomprehensible nonsense Thought echo - hearing one’s own thoughts being spoken loud, voice may come from inside or outside the head GEDANKENAUTWERDEN - thoughts are spoken at the same time or before they are occurring ECHO DE LA PENSES - thoughts are spoken just after they occurred
  25. Hearing Imperative/Command hallucination: • Voices sometimes act upon individuals and give instructions. • may or may not act upon them • Voices speak about the person in the third person and may give a running commentary on their actions, although this was one thought to be diagnostic of schizophrenia, this is no longer the case since these symptoms have also been described in mania • This kind of hallucinations are usually abusive
  26. Vision • Elementary- flashes of light • Partly organized- patterns • Completely organized- visions of people animals or objects • Scenic hallucinations- whole scenes are hallucinated like a cinema film More commonly seen in delirium Also seen in psychiatric disorders associated with epilepsy
  27. Vision • Visual hallucinations are more common in acute organic states with clouding of consciousness than in functional psychosis • Patients with temporal-lobe epilepsy may have combined auditory and visual hallucinations • Some patients with schizophrenia may see and hear people being tortured, murdered and mutilated
  28. Smell (olfactory) Seen in • Schizophrenia • Organic states like temporal lobe epilepsy are often ushered in by an aura involving an unpleasant odour such as burning paint or rubber with or without fit • Depression (uncommon) • PADRE PIO PHENOMENON- religious people can smell roses around certain saints
  29. Taste (gustatory) • Seen in • Schizophrenia • Organic states • Depressed patient often describes loss of taste
  30. Touch (Tactile) • Formication- a feeling that animals are crawling over the body (organic states) • Cocaine bug – formication occurring with delusion of persecution in cocaine psychosis • Sexual Hallucinations- seen in acute and chronic schizophrenia • Types of tactile hallucination 1. Superficial, 2. Kinaesthetic, 3. Visceral
  31. Superficial  Thermic (cold wind blowing across the face)  Haptic (feeling a hand brushing against the skin)  Hygric (feeling fluid )  Paraesthetic (feeling pins and needles) Kinaesthetic  Affects muscles and joints  Patient feels their limbs are being twisted pulled or moved  Seen in schizophrenics  Organic states such as alcohol intoxication and benzodiazepine withdrawal
  32. Pain and deep sensation • Visceral hallucinations • Twisting and tearing pains • Very bizarre complaints- organs being ripped out and flesh ripped from his body • Seen in chronic schizophrenia • Delusional zoopathy in which delusional belief that there is an animal crawling about in the body and also a hallucinatory component since the patient feels it & can describe it
  33. Sense of presence • vivid sensation that somebody (distinct from oneself) is present nearby • Organic states • Schizophrenia • Hysteria • Normal people – Reverently religious
  34. Special kinds of hallucination • Reflex hallucinations • Synaesthesia is the experience of a stimulus in one sense modality producing a sensory experience in another • Can occur under the influence of hallucinogenic drugs such as LSD or mescaline when the subject might describe feeling, tasting and hearing colours simultaneously
  35. Special kinds of hallucination • Autoscopy is the experience in which an individual perceives the surrounding environment from a different perspective, from a position outside of their own body. • Autoscopy comes from the ancient Greek αὐτός ("self") and σκοπός ("watcher")  Internal Autoscopy – Experience of seeing or vividly describing one’s internal organs  External Autoscopy - Person sees an image of himself outside his own body Negative Autoscopy: patients look in the mirror and see no image
  36. Hypnagogic and hypnopompic hallucinations • Hallucinations occur when the person is falling asleep or waking up • Hypnagogic hallucinations is about three times more common than hypnopompic hallucinations. • Hypnopompic a better indicator of narcolepsy. • Commonest is auditory. His name being called • May be geometrical designs , abstract shapes , faces, figures or scenes from nature
  37. Phantom Limb • Most common organic somatic hallucination. • 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 rare cases with thalamo−parietal lesions the patient describes a third limb
  38. Thought disorder A thought disorder is any disturbance in cognition that adversely affects language and thought content, and thereby communication  Content-thought disorder thought disturbance in which a person experiences multiple, fragmented delusions, typically a feature of schizophrenia  Formal thought disorder also known as disorganized speech – evident from disorganized thinking, and is one of the hallmark features of schizophrenia
  39. Types • Alogia – A poverty of speech, either in amount or content • Blocking or thought blocking – An abrupt stop in the middle of a train of thought • Circumstantial speech - An inability to answer a question without giving excessive, unnecessary detail. • Clanging – A severe form of flight of ideas whereby ideas are related only by similar or rhyming sounds rather than actual meaning. • Derailment -Thought frequently moves from one idea to another which is obliquely related or unrelated, often appearing in speech but also in writing • Echolalia– Echoing of another's speech that may only be committed once, or may be continuous in repetition • Flight of ideas - a form of formal thought disorder marked by abrupt leaps from one topic to another
  40. Types • Illogicality– Conclusions are reached that do not follow logically • Incoherence (word salad)– Speech that is unintelligible because, though the individual words are real words, the manner in which they are strung together results in incoherent gibberish • Neologisms – forms completely new words or phrases whose origins and meanings are usually unrecognizable • Perseveration– Persistent repetition of words or ideas even when another person attempts to change the topic • Pressured speech - Rapid speech without pauses, difficult to interrupt. • Self reference – Patient repeatedly and inappropriately refers back to self • Tangential speech – Wandering from the topic and never returning to it or providing the information requested
  41. Delusions Fixed, false beliefs that conflict with reality. Despite contrary evidence, a person can’t let go of their convictions Delusions are categorized into four different groups: • Bizarre delusion: Delusions which are clearly not understandable to same- culture peers and do not derive from ordinary life experiences Example: a belief that someone replaced all of one's internal organs with someone else's without leaving a scar • Non-bizarre delusion: A delusion that, though false, is at least technically possible Example: the affected person mistakenly believes that they are under constant police surveillance • Mood-congruent delusion: Any delusion with content consistent with either a depressive or manic state Example: a depressed person believes that news anchors on television highly disapprove of them, or a person in a manic state might believe they are a powerful deity • Mood-neutral delusion: A delusion that does not relate to the sufferer's emotional state Example: a belief that an extra limb is growing out of the back of one's head is neutral to either depression or mania
  42. Themes • Delusion of control: False belief that another person, group of people, or external force controls one's general thoughts, feelings, impulses, or behaviors • Cotard delusion: False belief that one does not exist or that one has died • Delusional jealousy: False belief that a spouse or lover is having an affair, with no proof to back up • Delusion of guilt or sin (self-accusation): Ungrounded feeling of remorse or guilt • Delusion of mind being read: False belief that other people can know one's thoughts • Delusion of thought insertion: Belief that another thinks through the mind of the person • Delusion of reference: False belief that insignificant remarks, events, or objects in one's environment have personal meaning or significance. Usually the meaning assigned to these events is negative
  43. Themes • Erotomania: False belief that another person is in love with them (usually famous one) • Religious delusion: Belief that the affected person is a god or chosen to act as a god • Somatic delusion: False belief is that the body is somehow diseased, abnormal or changed. A specific example of this delusion is delusional parasitosis: Delusion in which one feels infested with insects, bacteria, spiders, lice, fleas, worms, or other organisms • Delusion of poverty: Person strongly believes they are financially incapacitated • Grandiose delusions: False beliefs that one is famous, omnipotent or otherwise very powerful • Persecutory delusions: In which the affected person wrongly believes that they are being persecuted, spied on, attacked, poisoned or drugged The individual thinks that the persecutors have the intention to cause harm