| 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. |
| Episodic memory refers to the memory of an event or 'episode'. |
| Episodic memories allow us to mentally travel back in time to an event from the past. |
| Episodic memories include various details about these events, |
| for example, when an event happened |
| and other information such as the location. |
| To help understand this concept, |
| try to remember the last time you ate dinner at a restaurant. |
| The ability to remember where you ate, |
| who you were with and the items you ordered are all features of an episodic memory. |
| Episodic memory is distinct from another type of memory called semantic memory. |
| This is the type of factual memory that we have in common with everyone else - |
| that is your general knowledge of the world. |
| 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. |
| Unlike episodic memory, semantic memory isn't dependent on recalling personal experiences. |
| Episodic memory can be thought of as a process with several different steps of memory processing: |
| encoding, consolidation and retrieval. |
| The initial step is called encoding. |
| This involves the process of receiving and registering information, |
| which is necessary for creating memories of information or events that you experience. |
| 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. |
| Being distracted can make effective encoding very difficult. |
| Encoding of episodic memories is also influenced by how you process the event. |
| For example, if you were introduced to someone called Charlie, |
| you might make the connection that your uncle has the same name. |
| Future recollection of Charlie's name is much easier |
| if you have a strategy to help you encode it. |
| 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. |
| Consolidation is most effective when the information being stored |
| can be linked to an existing network of information. |
| Consolidation makes it possible for you to store memories for later retrieval indefinitely. |
| Forming strong memories depends on the frequency with which you try to retrieve them. |
| Memories can fade or become harder to retrieve if they aren't used very often. |
| The last step in forming episodic memories is called retrieval, |
| which is the conscious recollection of encoded information. |
| Retrieving information from episodic memory depends upon |
| semantic, olfactory, auditory and visual factors. |
| These help episodic memory retrieval by acting as a prompt. |
| For example, when recalling where you parked your car |
| you may use the colour of a sign close to where you parked. |
| You actually have to mentally travel back to the moment you parked. |
| There are a wide range of neurological diseases |
| and conditions that can affect episodic memory. |
| These range from Alzheimer's to schizophrenia to autism. |
| An impairment of episodic memory can have a profound effect on individuals' lives. |
| For example, the symptoms of schizophrenia can be reasonably well controlled by medication; |
| however, patients' episodic memory may still be impaired |
| and so they are often unable to return to university or work. |
| Recent studies have shown that computer-assisted games designed to keep the brain active |
| can help improve their episodic memory. |
| Episodic memories can help people connect with others, |
| for instance by sharing intimate details about their past; |
| something individuals with autism often have problems with. |
| This may be caused by an absence of a sense of self. |
| This is essential for the storage of episodic memory, |
| and has been found to be impaired in children with autism. |
| Research has shown that treatments that improve memory |
| may also have a positive impact on children's social development. |
| One study... |