environmental stimuli is passed to the sensory register. this is where info is held at each of the senses such as the eyes, ears, nose etc. info is passed into STM by attention, if attention is focused on the sensory register, it will then pass onto STM -has limited capacity and lasts 18-30 seconds. if a person has no attention then the info is decayed. from STM info is passed onto LTM with rehearsal - permanent memory store and has unlimited capacity. if you practice rehearsal then info can be eventually permanently stored in the LTM.