Which memory store is characterized by a duration of approximately 12-20 seconds?

Short-term memory is indeed characterized by a duration of approximately 12-20 seconds. This phase of memory is where information is temporarily held for processing and can be lost if not actively maintained through practices like rehearsal. It's the stage where we are consciously aware of the information and it is easily accessible for tasks such as following a conversation or recalling a short list of items.

In contrast, sensory memory only holds information for a fraction of a second to a few seconds, allowing for the initial processing of sensory stimuli. Long-term memory is designed for the retention of information for extended periods, potentially a lifetime. Working memory, while it involves short-term storage and manipulation of information, refers more specifically to the active management of information needed for cognitive tasks rather than just the storage duration. Thus, the defining feature of short-term memory is its limited duration of about 12-20 seconds, making it the correct answer in this context.