Evaluating the multi-store model

RESEARCH SUPPORT (STRENGTH): One strength of the multi-store model is that there is substantial laboratory-based research supporting its different components. For example, Baddeley found that STM primarily encodes information acoustically, whereas LTM primarily encodes information semantically. Jacobs found that STM has a limited capacity, while Peterson and Peterson found that its duration is approximately 18 seconds when rehearsal is prevented. Each of these highly controlled studies supports a different feature of the memory stores described by Atkinson and Shiffrin. Taken together, this research increases the credibility of the multi-store model as an explanation of memory.

CLIVE WEARING (STRENGTH): Another strength of the multi-store model comes from case studies, like Clive Wearing. Wearing contracted herpesviral encephalitis, which attacked his central nervous system, causing damage to his hippocampus: an area believed to be involved in the transfer of memories from the STM store to the LTM store. Wearing was still able to recall information from his past (before his virus); however, he was unable to form new memories and could retain new information for only 20-30 seconds. This case supports the multi-store model, as it shows that memory comprises unitary stores and that specific processes are required to transfer information from one store to the next. In Wearing's case, his ability to ‘transfer’ information from the STM store to the LTM store was impaired, while the other components of the multi-store model remained intact.

FLASHBULB MEMORIES (LIMITATION): One issue with the multi-store model centres on the process of rehearsal. According to Atkinson and Shiffrin, rehearsal is required to transfer information from the STM to the LTM. However, it is commonplace for humans to recall information without rehearsal. Furthermore, Brown and Kulik (1977) documented a specific type of memory, known as flashbulb memories, that are triggered by an event of special importance. Flashbulb memories are permanent memories formed without rehearsal. For example, many people who were alive in 1997 will recall where they were when they first heard the news about Princess Diana’s death; likewise, people who were alive in 2001 will recall where they were when they heard about the Twin Towers attack on 11th September. This highlights a weakness of the multi-store model, as certain memories are stored in the LTM store without rehearsal, contradicting the model’s linear nature.

EXAM HINT: The following evaluation point (Patient KF) can serve as both a limitation of the multi-store model and support for the working memory model.

PATIENT KF (LIMITATION): Another issue with the multi-store model comes from the case study of Patient KF, which was reported by Shallice and Warrington (1970). Patient KF suffered a head injury following a motorcycle accident; after his accident, Patient KF showed significant memory impairments. In particular, his short-term memory for auditory/verbal information (e.g. recalling letters/digits) was worse than his short-term memory for visual information. Furthermore, Patient KF’s issues with auditory information were limited to verbal information and not meaningful sounds (e.g. he could still recognise a ringing phone). This case study demonstrates a limitation of the multi-store model because it shows that short-term memory is not made up of one unitary store that processes acoustic information but at least two different stores: one for auditory and one for visual information.