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K C underwent thorough neuropsychological testing in both 1996 and 2003, with scores shown in Table 2. His intellectual and non-mnemonic cognitive function was found to be mostly normal, obtaining Full-Scale, Performance, and Verbal IQ scores of 99 on the Wechsler Abbreviated Scale of Intelligence test in 2003, indicating average intelligence. His language functions were typically well preserved, showing no signs of aphasia on the Western Aphasia Battery test, and no difficulty in naming line drawings of objects on the Boston Naming Test in 1996. Visual impairments were apparent, with borderline tritan colour-blindness seen on the City University Color Vision Test, and difficulties with complex face-matching task that requires the synthesis of multiple visual features on the Facial Recognition Test. Anterograde memory function was found to be severely impaired, with K C showing significantly poor performance on the Wechsler Memory Scale Revised test, the California Verbal Learning Test. On the Warrington Recognition Memory Test for words and faces, K C scored under the 5th percentile for immediate recall, and under the 1st percentile for delayed recall. Retrograde memory function was also severely impaired, where he was unable to produce a single episode from his past that was distinct in time and place on the Autobiographical Memory Inventory test. K C’s physical exam is unremarkable, showing strength, bulk, tone, and reflexes are within normal limits, except for decreased dexterity in the right hand. He suffers mild vision loss in the right eye, and severe vision loss in the left eye as a result of glaucoma. K C underwent three MRI scans in 1990, 1996 and 2002, all of which showed similar results as seen in Figure 1 & 3, where the dark areas indicate tissue damage or death. There is a large posterior occipital–temporal infarction on the left hemisphere, involving the cuneous, lingual and parahippocampal gyri, likely resulting from posterior cerebral artery compression secondary to the increased intracranial pressure caused by the motorcycle accident. This is consistent with K C’s symptoms of impaired colour perception and complex facial matching, whilst preserving other visual functions such as reading and recognition of objects. There is also a smaller anterior lesion in K C’s frontal–parietal cortex, which is limited to the dorsolateral and pre-motor functional areas. This may account for his majority preservation of executive function, with small impairments in phonemic fluency and reduced strategic retrieval of recent and remote memories. The most substantial damage is located in K C’s medial temporal lobes, with pronounced necrosis and atrophy of the hippocampal formation, including the hippocampus, parahippocampus, and associated diencephalic and basal forebrain structures, spreading out into entorhinal and perirhinal cortices. This is theorised to be the cause of his profound impairment in autobiographical memory, as the affected areas are critical for explicit memory and learning. Additionally, damage to K C’s amygdala may account for his personality changes and subdued demeanour. His lateral temporal cortex and occipital structures appear unaffected, which may explain his preservation of semantic memory and implicit learning. The case of K C has played a fundamental role in our understanding of memory and its associated brain structures. After suffering significant head trauma from a motorcycle accident, K C presented with a lack of autonoetic consciousness, in addition to global anterograde amnesia and retrograde episodic amnesia. Neuropsychological testing and diagnostic imaging found substantial atrophy of his hippocampal formation, alongside changes to his amygdala, posterior occipital–temporal cortex, and anterior frontal–parietal cortex, which caused significant impairment of autobiographical memory, without impairing executive or intellectual function. This case challenged the notion that memory was a unified system, demonstrating that explicit and implicit memory can be selectively impaired. It also helped establish the importance of the hippocampal formation as related to learning and memory. This information is crucial for psychological research and the understanding of the human brain. Thank you for listening.