Imagery without perception—A case study of anosognosia for cortical blindness

doi:10.1016/0028-3932(95)00070-J

Neuropsychologia

Volume 33, Issue 11, November 1995, Pages 1373-1382

https://doi.org/10.1016/0028-3932(95)00070-J Get rights and content

Abstract

A patient with complete cortical blindness after bilateral posterior cerebral artery infarctions denied her blindness. Her pretended visual experiences could frequently be traced back to synaesthetic translations of acoustic or tactile perceptions into mental visual images. Possibly, the belief to see resulted from a confusion of mental visual images with real percepts. The patient manifested preserved visual imagery also by correct responses to questions concerning the shapes of letters and the shapes and colours of objects. MRI showed an almost complete destruction of primary visual cortex with sparing of only small remainders of cortex at the occipital tip of the left upper calcarine lip. In the literature there are a few cases of denial of blindness with similarly severe damage to primary visual cortex but none with unequivocal evidence of complete destruction of primary visual cortex. We conclude that severe damage to primary visual cortex is compatible with visual imagery but that there is a possibility that islands of visual cortex must be spared to permit the generation of mental visual images.

References (36)

CharlotV. et al.
Different mental imagery abilities result in different regional cerebral blood flow activation patterns during cognitive tasks
Neuropsychologia
(1992)
GoldenbergG.
Loss of visual imagery and loss of visual knowledge—A case study
Neuropsychologia
(1992)
GoldenbergG. et al.
Visual imagery and knowledge about the visual appearance of objects in patients with posterior cerebral artery lesions
Brain Cognit.
(1991)
GoldenbergG. et al.
Contributions of occipital and temporal brain regions to visual and acoustic imagery
Neuropsychologia
(1991)
GoldenbergG. et al.
Regional cerebral blood flow patterns in visual imagery
Neuropsychologia
(1989)
GoldenbergG. et al.
Regional cerebral blood flow patterns related to verification of low- and high-imagery sentences
Neuropsychologia
(1992)
LevineD.N.
Unawareness of visual and sensorimotor defects: A hypothesis
Brain Cognit.
(1990)
PereninM.T. et al.
Residual visual capacity in a case of cortical blindness
Cortex
(1980)
RolandP.E. et al.
Visual imagery and visual representation
Trends Neurosci.
(1994)
AldrichM.S. et al.
Cortical blindness: Etiology, diagnosis and prognosis
Ann. Neurol.
(1987)

AntonG.

U¨ber die Selbstwahrnehmung der Herderkrankungen des Gehirns durch den Kranken bei Rindenblindheit und Rindentaubheit

Arch. Psychiat. Nevenkrankh.

(1899)

BeckU. et al.

Prosopagnosie und Farberkennungssto¨rung bei Ru¨ckbildung der Blindheit

Arch. Psychiat. Nervenkrankh.

(1978)

BergmanP.S.

Cerebral blindness

Arch. Neurol. Psychiat.

(1957)

CelesiaG.G. et al.

Visual function of the extrageniculocalcarine system in man

Arch. Neurol.

(1980)

CohnR.

Phantom vision

Arch. Neurol.

(1971)

della SalaS. et al.

Anton's (-Redlich-Babinski's) syndrome associated with Dide-Botcazo's syndrome: a case report of denial of cortical blindness and amnesia

Arch. Suisses Neurol. Psychiat.

(1988)

FarahM.J. et al.

Electrophysiological evidence for a shared representational medium for visual images and percepts

J. exp. Psychol.: Gen.

(1988)

FarahM.J. et al.

Visual angle of the mind's eye before and after unilateral occipital lobectomy

J. exp. Psychol.: Hum. Percept. Perform.

(1992)

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Imagery without perception—A case study of anosognosia for cortical blindness

Abstract

Neuropsychologia

Neuropsychologia

Brain Cognit.

Neuropsychologia

Neuropsychologia

Neuropsychologia

Brain Cognit.

Cortex

Trends Neurosci.

Cortical blindness: Etiology, diagnosis and prognosis

Ann. Neurol.

U¨ber die Selbstwahrnehmung der Herderkrankungen des Gehirns durch den Kranken bei Rindenblindheit und Rindentaubheit

Arch. Psychiat. Nevenkrankh.

Prosopagnosie und Farberkennungssto¨rung bei Ru¨ckbildung der Blindheit

Arch. Psychiat. Nervenkrankh.

Cerebral blindness

Arch. Neurol. Psychiat.

Visual function of the extrageniculocalcarine system in man

Arch. Neurol.

Phantom vision

Arch. Neurol.

Anton's (-Redlich-Babinski's) syndrome associated with Dide-Botcazo's syndrome: a case report of denial of cortical blindness and amnesia

Arch. Suisses Neurol. Psychiat.

Electrophysiological evidence for a shared representational medium for visual images and percepts

J. exp. Psychol.: Gen.

Visual angle of the mind's eye before and after unilateral occipital lobectomy

J. exp. Psychol.: Hum. Percept. Perform.