Models of Memory

• The multi-store model was devised by Atkinson and Shiffrin, it conceptualizes a linear process, or flow, by which memories are encoded and stored via storage facilities. It emphasizes the notion that information is either retained in the memory or lost due to lack of rehearsal.
• The multi-store model consists of three storage units: the sensory register, short term memory (STM), and long term memory (LTM)
• The sensory register is where your five senses pick up environmental stimuli. This information is held onto for a fraction of a second (a very short duration). Any information that's noticed from the SR is passed onto the STM. In other words, if we ignore or don't pick up items of sensory information, they won't be transferred to the STM.
• The short term memory is a temporary storage facility that holds onto information for a limited duration of time before it either gets forgotten or transferred to the LTM. It has a capacity of 7 items and duration limit is 30 seconds.
• New information entering the short term memory from the sensory register may push existing information out due to its low capacity, hence rehearsal is required for it to be passed on to the LTM.
• There are two types of rehearsal for the short-term memory - maintenance (a shallow form of rehearsal that involves repeating information verbally until you don't need the information anymore) or elaborate (a deep form of rehearsal that involves actually learning and embedding information through reframing it, writing it down). Short-term memory can be improved by chunking.
• Long term memory like a library holding a vast number of memories, with a possibly limitless capacity and duration. There are multiple types of memories in the LTM: episodic memories (personal experiences), semantic memories (facts and knowledge), and implicit memories (skills and memories we're not aware of).
• Information may decay in the long term memory if not rehearsed or visited frequently.
• The existence of separate memory stores as hypothesized by the multi-store model was supported by Glanzer & Cunitz (1966)
• The working memory model was devised by Baddeley and Hitch (1974) in response to Atkinson and Shiffrin's multi-store model, but more dynamic and flexible. The WMM only focuses on short-term memory, not so much as long-term memory.
• The working memory model consists of four units - the central executive, the phonological loop, the visuospatial sketchpad, and the episodic buffer.
• The central executive is the driving force of the working memory model. It decides with tasks are to be assigned to which slave system, deciding which information to pay attention to and which to ignore. It is difficult to test though.
• The phonological loop organizes acoustic information in the form of spoken or written information, it can be divided into the phonological store (stores acoustic information) and the articulatory control system (translates written words into speech, like a phone number).
• The visuospatial sketchpad attends to visual and spatial information, like the color of a flower or how to get around town. It can be divided into the visual cache (form and color, like a purple triangle) and the inner scribe (movement-related information).
• The episodic buffer was added recently in 2000, it acts as a messenger that communicates between the slave systems and the long-term memory, arranging information into packets and moving them to slave systems accordingly.
• Baddeley and Hitch (1974) provides support for the working memory model.