Alzheimer’s disease is a type of neurodegenerative dementia that affects memory. Decreased semantic memory may be an indicator of Alzheimer’s disease. Researchers have examined different types of dementia-related memory loss..
Alzheimer’s disease instills fear in people of not being able to remember even the simple details of their lives, according to a newspaper report neuroscience Scientific Researchers in the Laboratory of Neuropsychology of Aging at the Research Center of the University Institute in Montreal, Canada, studied the types of memories that Alzheimer’s patients forget when they have it.
Alzheimer’s disease affects memory but memory is not a single entity, like a basket in which all our memories accumulate together, so it is important to realize that there are different types of memory, and how they are affected by Alzheimer’s disease.
One type of memory includes personal memories of events from our early years.
A bit like a photo album, episodic memory includes things like our childhood memories, the first time we moved, our best vacation, but also what we did last weekend and what we had for breakfast this morning.
These are the memories that, in order to bring them back to the surface, require us to make a kind of “mental journey” in time to put ourselves in the context of the event we experienced: when was it? where were we? with whom?
Unlike episodic memory, semantic memory collects memories that do not need to be reactivated by putting them in context. We are referring here to general knowledge about the external world, which is not associated with a specific place or time..
separate brain regions
These two types of memory are closely related in our daily lives In order to be able to function we have to constantly rely on our episodic and semantic memories, with new episodic and semantic memories being constantly encoded.
Despite the fact that they are related, these two types of memory are supported by partially distinct regions of the brain that include the production of memories of past events (related to episodic memory) the hippocampus, which are structures in the medial temporal lobe located in the middle of the brain, as well as the frontal lobe, which places these memories in context.
On the other hand, general knowledge memories (related to semantic memory) include the parahippocampal regions, which are the structures around the hippocampus and the anterior part of the temporal lobe (the temporal poles)..
Memories Forgotten When You Have Alzheimer’s
Alzheimer’s disease is usually associated with decreased episodic memory, and patients complain that they cannot remember the events they experienced, the conversations they had, or the things they did. This type of memory is often tested in neuropsychology when assessing dementia, which is also this type of Memory that has been studied in the vast majority of research on Alzheimer’s disease.
Recent studies show that in the progression of Alzheimer’s disease, semantic memory is affected first and patients show a gradual decline in their general knowledge..
Symptoms appear before 12 years
According to a study that evaluated different cognitive functions in several hundred elderly people, individuals who develop Alzheimer’s disease begin to experience semantic memory deficits for up to 12 years before being diagnosed with dementia and semantic memory difficulties occur before past events are forgotten, spatial and temporal confusion or loss Personal belongings or speech difficulties.