the task. This effect is more apparent if the information is familiar. The person with Alzheimer's must also be guided through the task and prevented from making errors. Alzheimer's also has an effect on explicit spatial memory. This means that people with Alzheimer's have difficulty remembering where items are placed in unfamiliar environments. The hippocampus has been shown to become active in semantic and episodic memory. The effects of Alzheimer's disease are seen in the episodic part of explicit memory. This can lead to problems with communication. A study was conducted where Alzheimer's patients were asked to name a variety of objects from different periods. The results shown that their ability to name the object depended on frequency of use of the item and when the item was first acquired. This effect on semantic memory also has an effect on music and tones. Alzheimer's patients have difficulty distinguishing between different melodies they have never heard before. People with Alzheimer's also have issues with picturing future events. This is due to a deficit in episodic future thinking. There are many other reasons why adults and others may begin to have memory loss. In popular culture Amnesiacs are frequently portrayed in television and movies. Some of the better-known examples include: In the romantic comedy 50 First Dates (2004), Adam Sandler plays veterinarian Henry Roth, who falls for Lucy Whitmore, played by Drew Barrymore. Having lost her short-term memory in a car crash, Lucy can only remember the current day's events until she falls asleep. When she wakes up the next morning, she has no recollection of the previous day's experiences. These experiences would normally be transferred into declarative knowledge, allowing them to be recalled in the future. Although this movie is not the most accurate representation of a true amnesic patient, it is useful for informing viewers of the detrimental effects of amnesia. Memento (2000) a film inspired by the case of Henry Molaison (H.M.). Guy Pearce plays an ex-insurance investigator suffering from severe anterograde amnesia caused by a head injury. Unlike most amnesiacs, Leonard retains his identity and the memories of events that occurred before the injury, but loses all ability to form new memories. This loss of ability to form new memories indicates that the head injury affected the medial temporal lobe of the brain resulting in the inability for Leonard to form declarative memory. Finding Nemo features a reef