剑桥雅思13听力test2section4原文答案解析+文本精讲

[01:11.38]Today, we'll be continuing the series of lectures on memory by focusing on what is called episodic memory and what can happen if this is not working properly.
[01:25.32]Episodic memory refers to the memory of an event or ‘episode’.
[01:31.94]Episodic memories allow us to mentally travel back in time to an event from the past.
[01:40.11]Episodic memories include various details about these events, for example, when an event happened and other information such as location.
[01:54.37]To help understand this this concept, try to remember the last time you ate dinner at a restaurant.
[02:03.13]The ability to remember where you ate, who you were with and the items you ordered are all features of an episodic memory.
[02:14.42]Episodic memory is distinct from another type of memory called semantic memory.
[02:22.61]This is the type of factual memory that we have in common with everyone else.
[02:29.86]That is our general knowledge of the world.
[02:34.59]To build upon a previous example, remembering where you parked your car is an example of episodic memory, but your understanding of what a car is and how an engine works are examples of semantic memory.
[02:55.17]Unlike episodic memory, semantic memory isn't dependent on recalling personal experiences.
[03:06.02]Episodic memory can be thought of as a process with several different steps of memory processing: encoding, consolidation and retrieval.
[03:21.32]The initial step is called encoding.
[03:25.11]This involves the process of receiving and registering information, which is necessary for creating memories of information or events that you experience.
[03:39.35]The degree to which you can successfully encode information depends on the level of attention you give to an event while it's actually happening.
[03:52.63]Being distracted can make effective encoding very difficult.
[03:58.81]Encoding of episodic memories is also influenced by how you process the event.
[04:07.33]For example, if you were introduced to someone called Charlie, you might make the connection that your uncle has the same name.
[04:19.11]Future recollection of Charlie's name is much easier if you have a strategy to help you encode it.
[04:28.11]Memory consolidation, the next step in forming an episodic memory, is the process by which memories of encoded information are strengthened, stabilised and stored to facilitate later retrieval.
[04:47.65]Consolidation is most effective when the information being stored can be linked to an existing network of information.
[05:00.38]Consolidation makes it possible for you to store memories for later retrieval indefinitely.
[05:08.88]Forming strong memories depends on the frequency with which you try to retrieve them.
[05:18.05]Memories can fade or become harder to retrieve if they aren't used very often.
[05:25.37]The last step of forming episodic memories is called retrieval, which is the conscious recollection of encoded information.
[05:38.24]Retrieving information from episodic memories depends upon semantic, olfactory, auditory and visual factors.
[05:50.82]These help episodic memory retrieval by acting as a prompt.
[05:57.76]For example, when recalling where you parked your car you may use a colour of a sign close to where you parked.
[06:08.92]You actually have to mentally travel back to the moment you parked.
[06:19.58]There are a wide range of neurological diseases and conditions that can affect episodic memories.
[06:29.44]These range from Alzheimer's to schizophrenia to autism.
[06:36.78]An impairment of episodic memory can have profound effect on individuals' lives.
[06:45.90]For example, the symptoms of schizophrenia can be reasonably well controlled by medication;
[06:55.30]However, patients' episodic memory may still be impaired and so they are often unable to return to university or work.
[07:07.30]Recent studies have shown that computer-assisted games designed to keep the brain active can help improve their episodic memory.
[07:19.75]Episodic memories can help people connect with others.
[07:26.07]For instance by sharing intimate details about their past;
[07:31.55]Something individuals with autism often have problems with.
[07:37.32]This may be caused by an absence of a sense of self.
[07:43.79]This is essential for the storage of episodic memory, and has been found to be impaired in children with autism.
[07:55.06]Research has shown that treatments that improve memory may also have a positive impact on children's social development.
[08:07.00]One study looked at......