Memory

Memory related to procedural memory such as developing new skill and habit can sometime be formed without the hippocampus…

The frontal cortex is involved with planning and foresight, it also selects actions and behaviour. The basal ganglia is involved in guiding and directing voluntary movement. There are connections from basal ganglia to the thalamus that send information to the prefrontal cortex. Every time a complex motor action is executed by the prefrontal cortex that was guided by the basal ganglia, particularly the caudate nucleus and putamen, the loop via the thalamus back to the prefrontal cortext help to strengthen the activity of those circuits. This then lead the process were practiced movement become habits whereas they are able to be performed automatically without conscious effects such as playing the piano, which was initially a conscious effect at first then became automatic as it was directed by the prefrontal cortex. This system works independently from the limbic forms of learning and memory. Therefore someone that has bilateral damage to the hippocampus, that is similar to the case of H.M., can be taught to play the piano by practising everyday but they would not have memories of practising, but if you were to ask them if they can play the piano they would say no.  However if you asked them to try they would be able to play, but would not be able to explain how and why they are playing this is because the frontal cortex and the basal ganglia circuit would have learned independently and separately from the damaged limbic system circuit.

Hippocampus  

  The hippocampus is a brain structure that I located under the medial temporal lobes in both hemispheres. The hippocampus plays an important role in the formation of new autobiographical and factual memories it can be identified as a path way in which new memories need to go through before being sorted in the long term memory. Damage to this area can lead to anterograde amnesia; this is the loss of ability to form new memories while previous memory before injury may still be intact.