Chandra Sadanandavalli Retnaswami, Issac Thomas Gregor
Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
Department of Clinical Neurosciences, National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
Indian J Psychol Med. 2014 Oct;36(4):400-3. doi: 10.4103/0253-7176.140726.
Gnosis is a modality-specific ability to access semantic knowledge of an object or stimulus in the presence of normal perception. Failure of this is agnosia or disorder of recognition. It can be highly selective within a mode. self-images are different from others as none has seen one's own image except in reflection. Failure to recognize this image can be labeled as mirror image agnosia or Prosopagnosia for reflected self-image. Whereas mirror agnosia is a well-recognized situation where the person while looking at reflected images of other objects in the mirror he imagines that the objects are in fact inside the mirror and not outside.
Five patients, four females, and one male presented with failure to recognize reflected self-image, resulting in patients conversing with the image as a friend, fighting because the person in mirror is wearing her nose stud, suspecting the reflected self-image to be an intruder; but did not have prosopagnosia for others faces, non living objects on self and also apraxias except dressing apraxia in one patient. This phenomena is new to our knowledge.
Mirror image agnosia is an unique phenomena which is seen in patients with parietal lobe atrophy without specificity to a category of dementing illness and seems to disappear as disease advances.
Reflected self-images probably have a specific neural substrate that gets affected very early in posterior dementias specially the ones which predominantly affect the right side. At that phase most patients are mistaken as suffering from psychiatric disorder as cognition is moderately preserved. As disease becomes more widespread this symptom becomes masked. A high degree of suspicion and proper assessment might help physicians to recognize the organic cause of the symptom so that early therapeutic interventions can be initiated. Further assessment of the symptom with FMRI and PET scan is likely to solve the mystery of how brain handles reflected self-images.
A new observation involving failure to recognize reflected self-images is reported.
认知是一种特定模态的能力，即在正常感知的情况下获取物体或刺激的语义知识。若此能力缺失则为失认症或识别障碍。它在一种模式内可能具有高度选择性。自我形象与其他形象不同，因为除了在镜子中反射看到的，没有人见过自己的形象。无法识别这个形象可被称为镜像失认症或对反射自我形象的面孔失认症。而镜像失认症是一种广为人知的情况，即一个人看着镜子中其他物体的反射影像时，会想象这些物体实际上在镜子里面而非外面。
五名患者，四女一男，表现出无法识别反射的自我形象，导致患者将镜中的影像当作朋友交谈，因镜中的人戴着鼻钉而与之争吵，怀疑反射的自我形象是入侵者；但对他人面孔、自身上的无生命物体并无面孔失认症，除一名患者有穿衣失用症外也无失用症。据我们所知，这种现象是新的。
镜像失认症是一种独特的现象，见于顶叶萎缩患者，对痴呆疾病类别无特异性，且似乎随着疾病进展而消失。
反射的自我形象可能有特定的神经基质，在后部痴呆尤其是主要影响右侧的痴呆中很早就会受到影响。在那个阶段，大多数患者因认知功能中度保留而被误诊为患有精神疾病。随着疾病蔓延，这个症状会被掩盖。高度怀疑和适当评估可能有助于医生识别该症状的器质性病因，从而能够尽早开始治疗干预。通过功能磁共振成像（FMRI）和正电子发射断层扫描（PET）对该症状进行进一步评估，可能会解开大脑如何处理反射自我形象之谜。
报告了一项关于无法识别反射自我形象的新观察结果。
