no time delay, both control rats and rats with lesions chose the familiar food. After 24 hours, however, the rats with hippocampal lesions were just as likely to eat both types of food, while control rats chose the familiar food. This can be attributed to the inability to form episodic memories due to lesions in the hippocampus. The effects of this study can be observed in humans with amnesia, indicating the role of the hippocampus in developing episodic memories that can be generalized to similar situations. Henry Molaison, previously known as H.M., had parts of both his left and right medial temporal lobes (hippocampi) removed which resulted in the loss of the ability to form new memories. The long-term declarative memory was crucially affected when the structures from the medial temporal lobe were removed, including the ability to form new semantic knowledge and memories. The dissociation in Molaison between the acquisition of declarative memory and other kinds of learning was seen initially in motor learning. Molaison's declarative memory was not functioning, as was seen when Molaison completed the task of repetition priming. His performance does improve over trials, however, his scores were inferior to those of control participants. In the condition of Molaison the same results from this priming task are reflected when looking at the other basic memory functions like remembering, recall and recognizing. Lesions should not be interpreted as an all-or-nothing condition, in the case of Molaison not all memory and recognition is lost, although the declarative memory is severely damaged he still has a sense of self and memories that were developed before the lesion occurred. Patient R.B. was another clinical case reinforcing the role of the hippocampus in declarative memory. After suffering an ischemic episode during a cardiac bypass operation, Patient R.B. awoke with a severe anterograde amnesic disorder. IQ and cognition were unaffected, but declarative memory deficits were observed (although not to the extent of that seen in Molaison). Upon death, an autopsy revealed that Patient R.B. had bilateral lesions of the CA1 cell region along the whole length of the hippocampus. Amygdala lesion studies Adolph, Cahill and Schul completed a study showing that emotional arousal facilitates the encoding of material into long term declarative memory. They selected two subjects with bilateral damage to the amygdala, as well as six control subjects and six subjects with brain damage. All subjects were shown a series of