In the second part, the narrator’s mother is 85 years old and lives in her hometown. She repeatedly iterates the same thing as something new and the extraordinariness of her utterances explains the progress of her dementia. At this stage, an example of her dementia is the hallucination of the woman who asked for directions one summer in Karuisawa. There is also the episode where she wanders away on a moonlit night to look for her son. As her dementia advances to a medium degree of severity, communication with her becomes difficult.
The narrator’s mother turns the advanced old age of 89 years in the third part. In one incident, she wakes up, turns on a flashlight, and enters the room. She whispers to her granddaughter Yoshiko, that “she can’t go out anymore.” She thinks she is confined to the room. Immediately after she has had her breakfast, she assumes evening has come. The family is also pulled into her increasing wandering episodes. Her dementia becomes very serious and the life of her family is brought to the brink of collapse.
The neuron nerve fibers in the brains of patients with dementia atrophy and the information cannot be transferred smoothly. In time, the neurons of the receptors will be damaged and information cannot be adequately communicated. The dietary intake of acetylcholine essentially becomes insufficient and communication areas and other symptoms of the disease manifest themselves. The type of dementia suffered by the author/narrator’s mother is Alzheimer’s disease. This is the most common form of dementia and the memory defects of not being able to remember experiences is often accompanied by abnormal behavior.
花村嘉英訳（2018）「シナジーのメタファーの作り方」より translated by Yoshihisa Hanamura