PSY 402 Topic 5 DQ 1: Four Types of Memory

Start by fixing which four your chapter means, because the phrase is used for two different sets. One reading is the stages — sensory, short-term, working and long-term — and the other divides long-term memory into episodic, semantic, procedural and priming. Say which you are using in your first sentence, since a marker reading the chapter will notice a mismatch immediately. Then compare on axes rather than describing each in turn. Duration separates them sharply: sensory memory holds a rich trace for well under a second, short-term memory for seconds without rehearsal, long-term memory potentially for decades. Capacity separates them again, from very large but instantly decaying at the sensory end to functionally unlimited at the long-term end. Code is the third axis — sensory memory holds a modality-specific trace, short-term memory is largely phonological, and long-term memory is organised by meaning. Add a fourth axis if your chapter supports it: how information is lost.

The strongest thing you can add is dissociation evidence, because it is what turns a description into an argument that these really are different systems. Patients with hippocampal damage can lose the ability to form new episodic memories while retaining intact short-term span and unimpaired procedural learning, so they improve at a motor task across sessions they cannot remember attending. That single pattern demonstrates independence more convincingly than any list of properties. Working memory deserves particular care if it is one of your four: it is not simply short-term memory renamed, because it adds manipulation to storage and is usually modelled with separable components and an executive that coordinates them. Finish with a use — why the distinctions matter for study technique, for interviewing a witness, or for assessing a patient — since a comparison with no consequence reads as bookwork. Choose the use from your own field, since testimony and revision technique read very differently.