Memory

           Memory is an umbrella term for functions such as encoding, retrieving, recalling and recognising information. It is commonly divided into two different types, long-term memory (LTM) and short-term memory (STM). STM allows recall for a period of several seconds to a minute without rehearsal, its capacity is very limited. LTM however has a much larger capacity, meaning one can remember a much larger quantity of information and recall can last for an unlimited period of time, sometimes an individuals lifetime. The hippocampus and the frontal lobes are both implicated in memory, another area is the diencephalon consisting of the thalamus and the hypothalamus. Damage to any of these areas can result in memory loss and result in a memory disorder such as Amnesia. Amnesia is a disorder which is characterised by a loss of memory. There are two sub types, Retrograde amnesia refers to individuals who suffer a loss of memory for events that occurred before the trauma (loss of LTM) where as Antrograde amnesia refers to a loss of ability to learn new information and an inability to make long lasting memories post trauma however, memories prior to the trauma are still intact (Loss of STM). END.
           There are a number of other specialised types of memory that can be used to store information, depending on the task. Declarative memory sometimes referred to as explicit memory is one of two types of long term memory and refers to memories that can be recalled such as facts and knowledge, this refers to material that is consciously learnt and retrieved. This type can further be divided into episodic memory which is used to store personal experiences such as a memory from your favourite holiday and semantic memory which stores factual information (such as naming the capital cities of the world). The other type of LTM is procedural memory, often referred to as implicit, because the memory process for learning and recalling such memories is unconscious. This includes memories that are used to perform skills, for example how to drive a car. These sorts of memories are concerned with the ability to perform motor functions in a certain order, these types of memories are called 'proceduralized'.
Working memory actively holds information in the mind in order to perform further processing. For example reading a sentence and then processing the words so you can understand it.
Lateralization of memory
Encoding and retrieval of episodic and semantic memory has been associated with activation in the pre frontal and medial temporal cortex. Activation may be left-sided if the episodic material is verbal, bilateral if non-verbal. Working memory selectively activates the pre frontal cortex.
A model called the HERA model has been proposed to account for the differences in activation seen during memory encoding and retrieval. HERA stands for hemispheric encoding-retrieval asymmetry. This model argues that the left hemisphere is more active during episodic encoding, whereas greater activation in the right frontal cortex is seen during episodic retrieval.