A model of hysterical and hypnotic blindness: Cognition, motivation, and awareness.

Abstract

Clinical and experimental analyses of hysterical conversion reactions of blindness are reviewed. A model is offered to account for the visually controlled behavior of the psychogenically blind. The model attributes a central role to motivational factors in determining selective nonawareness of cognition, A case study of hypnotic blindness is presented that illustrates the utility of the model. The model has implications for interpretations of other hypnotic phenomena and for views concerning the relations between cognition and awareness.There have been long-standing debates in psychology and philosophy concerning the relations between cognition and awareness (e.g.,

Hypnosis and Conversion Hysteria: A Unifying Model

“…Despite the change in performance this patient reported no change in his experience of blindness. In contrast, under less highly motivated conditions hysterically blind patients, like those with visual cortical lesions who displaỳ`b lindsight' ' (W eiskrantz, 1997), tend to show com pletely accurate performance on visual discrimination tasks whilst m aintaining their professions of blindness and having no insight into the basis for their accurate visual perform ance (Sackeim et al, 1979).…”

“…In a further demonstration of im plicit knowledge, hysterically blind individuals under high motivational conditions tend to do worse on visual discrimination tasks than would be expected by chance (Bryant & M cConkey, 1989 ;Grosz & Zim merman, 1956, 1970Sackeim et al, 1979). M oreover, in the Grosz and Zimm erman (1965) study the patient' s perform ance rose to chance level when the patient overheard a confederate of the experim enters say (p. 259)``the doctors reckon that the patient can see because he makes fewer correct responses by chance than a blind m an would make' ' .…”

“…The feeling of involuntariness in hypnosis and hysteria m akes the relevant phenom ena subjectively``real' ' to the subject or patient, although an onlook er m ay gain the impression that they are the products of outright faking or m alingering (Sackeim et al, 1979), especially when there is evidence that physiologically the effects are anything but``real' ' (see Kihlstrom , 1994;Pincus & Tucker, 1985). In the case of both hysterical and hypnot ic paralysis, for example, there is com monly no evidence of abnormal m uscle tone and when the patient attem pts to m ove the``paralysed' ' limb a classic observation is that both agonist and antagonist m uscles contract (K ihlstrom , 1994 ; Y ealland, 191 8).…”

“…In hysteria, la belle indiffe rence shown by many patients to their symptoms has long been recognised and is still regarded by some as a diagnostic feature of the (M erskey, 1995;Sackeim, Nordlie, & Gur, 1979). In hypnos is also, it is predom inantly the case that, although they may recognise the discrepancy between reality and the suggested hypnoti c effects, subjects experiencing a phenomenon, such as arm levitation or eyelid catalepsy, express interest, surprise, and m ild amusement at these experiences rather than the anxiety, concern, and fear which might be expected if these or similar changes occurred in other contexts.…”

Brain circuits implicated in psychogenic paralysis in conversion disorders and hypnosis

“…For example, Pavlov (best known for his work on associative conditioning) proposed that emotional arousal arising in subcortical centers requires inhibitory control from cortical centers (especially in the frontal lobe), such that in some situations of strong arousal, [67]. An active inhibition of motor, sensory, or even cognitive processes preventing their integration into conscious awareness was also proposed by more recent authors [10,64,78]. Other accounts have built on the notion that conversion symptoms may more often affect the left than right hemibody, on the one hand, and evidence that the right hemisphere might be dominant for emotion processing, on the other hand, to suggest a role for impaired communication or integration between the two hemispheres [29,34,90].…”