Patients with Alzheimer’s disease often lose their sense of proper timing. Many of my physician friends often complain that their dementia patients will therefore come in long before their appointment time. Dementia, such as Alzheimer’s disease, can gradually destroy a patient’s cognitive abilities, impairing memory, planning and the ability to function on a daily basis, making it very difficult to perform routine actions such as shopping and cleaning. In our modern society, an accurate sense of time is a very necessary skill. Therefore this misjudgment of time can seriously affect people with dementia as well as their families and caregivers. In Australia today, the aging of the population has become a clear social phenomenon. This has been accompanied by a gradual increase in the incidence of dementia, the most prevalent of which is Alzheimer’s disease. In Australia, one in ten people over the age of 65 and one in three people over the age of 85 have dementia. Neurological research has largely explained why people with dementia have a different sense of time and why they can recall experiences from decades ago, but not events that occurred within the last few hours. Time perception in people with dementia People with dementia have a faster than normal sense of the passage of time. This refers to prospective time perception, which allows people to anticipate the length of a time interval in advance; whereas retrospective time estimation requires people to judge the length of the experience after the event is over. To give a practical example: people with dementia often underestimate the amount of time they will wait at a bus stop (backward time estimation) and the amount of time they will ride on the bus (forward time estimation). The reason why people with dementia are unable to judge the length of time may be that they have difficulty recalling all the events that occurred in the short past, which can create a relatively blank window of time. Patients without dementia may recall meeting a young boy on a bicycle on the way to the bus stop, the yellow car parked next to the store, the noisy lawn mower, the couple playing tennis, etc.; whereas people with dementia have poor recall of these events, thus creating the illusion that since nothing happened, that time must have been short. Living in the past In people with dementia, there is a link between time perception and memory function. Family members of patients often complain that their loved ones sometimes act as if they are surviving in the past, even all the way back to their native language stage. This is because in the brain, memory is not just one type of processing, but also a collection of different systems. Patients with Alzheimer’s disease usually have impaired short-term memory capacity, yet their long-term memory is guaranteed to be relatively intact. Thus they are able to recall various events from decades ago, but are unable to recall what happened yesterday. An interesting case study reveals the reason why long-term memory cannot be linked to short-term memory. A retired cab driver diagnosed with Alzheimer’s disease was able to recall precisely a street map of downtown Toronto, Canada – where he had worked for 45 years. Yet this did not affect the fact that his short-term memory and cognitive function were impaired. Yet even though Alzheimer’s patients’ long-term memory was much less impaired than their short-term memory, they actually had much worse long-term memory levels than non-patients of the same age or even older. Interestingly, the stories that patients most often recall are mostly about events that occurred in the later years of their disease, rather than events at other ages in their lives. This phenomenon manifests itself as a mirror image of memory in patients who speak both languages. A friend once said that his grandmother, who emigrated from Greece to Australia 50 years ago, gradually became predominantly Greek-speaking since her recent illness (and this caused much distress to their English-only speaking friends). People with dementia will always revert to their native language. This usually occurs when the person is communicating in a second language and suddenly speaks in the native language. This phenomenon occurs more often in people who are not sufficiently proficient in the second language, independent of the age of exposure to the second language. What is the reason for this phenomenon? It may be because familiar memory storage relies more on the cortex – the outer layer of the brain – while short-term memory relies more on a structure called the hippocampus. The hippocampus is the first area to be damaged by the onset of Alzheimer’s disease, while damage to the cerebral cortex occurs later. How is it treated and managed? Family and friends of people with dementia are often overwhelmed when their loved one can only remember the distant past and live with memories of the past. Of course, these past memories should not be ignored or repressed just because of this. Family members and caregivers should try to enter their reality, build trust and empathy, and reduce the patient’s anxiety, rather than trying to find ways to bring them into the so-called reality of our world. This is also known as confirmation therapy, a name many families do not understand but are using for treatment and care in this way. Some studies also claim that reminiscence therapy is also effective in restoring the patient’s emotional, performance and behavioral abilities. This therapy involves talking with the patient about past experiences and events (usually with the aid of photos, music, some memorabilia). Building recovery. There is no completely effective method about stopping the onset of dementia. But regular, long-term cognitive stimulation can be effective in delaying the onset of dementia. This means that you need to exercise your memory and other cognitive skills as often as possible, such as performing challenging tasks, spelling words, and participating in more social activities. The more often we exercise our memories in our lives, the better our chances of being able to find them easily in our older years.