1Today, we'll be continuing the series of lectures on memory
2by focusing on what is called episodic memory
3and what can happen if this is not working properly.
4Episodic memory refers to the memory of an event or 'episode'.
5Episodic memories allow us to mentally travel back in time to an event from the past.
6Episodic memories include various details about these events,
7for example, when an event happened
8and other information such as the location.
9To help understand this concept,
10try to remember the last time you ate dinner at a restaurant.
11The ability to remember where you ate,
12who you were with and the items you ordered are all features of an episodic memory.
13Episodic memory is distinct from another type of memory called semantic memory.
14This is the type of factual memory that we have in common with everyone else -
15that is your general knowledge of the world.
16To build upon a previous example,
17remembering where you parked your car is an example of episodic memory,
18but your understanding of what a car is and how an engine works are examples of semantic memory.
19Unlike episodic memory, semantic memory isn't dependent on recalling personal experiences.
20Episodic memory can be thought of as a process with several different steps of memory processing:
21encoding, consolidation and retrieval.
22The initial step is called encoding.
23This involves the process of receiving and registering information,
24which is necessary for creating memories of information or events that you experience.
25The degree to which you can successfully encode information
26depends on the level of attention you give to an event while it's actually happening.
27Being distracted can make effective encoding very difficult.
28Encoding of episodic memories is also influenced by how you process the event.
29For example, if you were introduced to someone called Charlie,
30you might make the connection that your uncle has the same name.
31Future recollection of Charlie's name is much easier
32if you have a strategy to help you encode it.
33Memory consolidation, the next step in forming an episodic memory,
34is the process by which memories of encoded information are strengthened,
35stabilised and stored to facilitate later retrieval.
36Consolidation is most effective when the information being stored
37can be linked to an existing network of information.
38Consolidation makes it possible for you to store memories for later retrieval indefinitely.
39Forming strong memories depends on the frequency with which you try to retrieve them.
40Memories can fade or become harder to retrieve if they aren't used very often.
41The last step in forming episodic memories is called retrieval,
42which is the conscious recollection of encoded information.
43Retrieving information from episodic memory depends upon
44semantic, olfactory, auditory and visual factors.
45These help episodic memory retrieval by acting as a prompt.
46For example, when recalling where you parked your car
47you may use the colour of a sign close to where you parked.
48You actually have to mentally travel back to the moment you parked.
49There are a wide range of neurological diseases
50and conditions that can affect episodic memory.
51These range from Alzheimer's to schizophrenia to autism.
52An impairment of episodic memory can have a profound effect on individuals' lives.
53For example, the symptoms of schizophrenia can be reasonably well controlled by medication;
54however, patients' episodic memory may still be impaired
55and so they are often unable to return to university or work.
56Recent studies have shown that computer-assisted games designed to keep the brain active
57can help improve their episodic memory.
58Episodic memories can help people connect with others,
59for instance by sharing intimate details about their past;
60something individuals with autism often have problems with.
61This may be caused by an absence of a sense of self.
62This is essential for the storage of episodic memory,
63and has been found to be impaired in children with autism.
64Research has shown that treatments that improve memory
65may also have a positive impact on children's social development.
66One study...