The method of loci [loh-sahy] (plural of Latin ‘locus’ for ‘place’ or ‘location’), also called the ‘memory palace,’ is a mnemonic device introduced in ancient Roman and Greek rhetorical treatises. The items to be remembered in this mnemonic system are mentally associated with specific physical locations. It relies on memorized spatial relationships to establish, order and recollect memorial content.
The method of loci is also commonly referred to as the journey method. In basic terms, it is a method of memory enhancement which uses visualization to organize and recall information. Many memory contest champions claim to use this technique in order to recall faces, digits, and lists of words. These champions’ successes have little to do with brain structure or intelligence, but more to do with their technique of using regions of their brain that have to do with spatial learning. Those parts of the brain that contribute most significantly to this technique include the medial parietal cortex, retrosplenial cortex, and the right posterior hippocampus.
O’Keefe and Nadel refer to ”the method of loci’, an imaginal technique known to the ancient Greeks and Romans and described by Yates (1966) in her book ‘The Art of Memory’ as well as by Luria (1969). In this technique the subject memorizes the layout of some building, or the arrangement of shops on a street, or any geographical entity which is composed of a number of discrete loci. When desiring to remember a set of items the subject literally ‘walks’ through these loci and commits an item to each one by forming an image between the item and any distinguishing feature of that locus. Retrieval of items is achieved by ‘walking’ through the loci, allowing the latter to activate the desired items. The efficacy of this technique has been well established, as is the minimal interference seen with its use.’ ‘The ment’al maps we have of our home town, our neighborhood, and our house are all examples of the kinds of spatial contexts within which events occur, can be coded internally, and can subsequently be effectively retrieved or recalled
In a classic study in cognitive neuroscience O’Keefe and Nadel proposed ‘that the hippocampus is the core of a neural memory system providing an objective spatial framework within which the items and events of an organism’s experience are located and interrelated.’ This theory has generated considerable debate and further experiment. It has been noted that ‘[t]he hippocampus underpins our ability to navigate, to form and recollect memories, and to imagine future experiences. How activity across millions of hippocampal neurons supports these functions is a fundamental question in neuroscience, wherein the size, sparseness, and organization of the hippocampal neural code are debated.’ ‘Using neuropsychological, structural, and functional brain imaging measures, we found that superior memory is not driven by exceptional intellectual ability or structural brain differences. Rather, we found that superior memorizers used a spatial learning strategy (the method of loci) while preferentially engaging brain regions critical for memory and for spatial memory in particular, including the hippocampus.’
The medial parietal cortex is most associated with encoding and retrieving of information. Patients who suffered from medial parietal cortex damage had troubles linking landmarks with certain locations. Many of these patients were unable to give or follow directions and often got lost. The retrosplenial cortex is also greatly linked to memory and navigation. In Pothuzien HH’s study on the effects of cortex lesions in rats, the researcher found that damage to the retrosplenial cortex lead to impaired spatial learning abilities. Rats with damage to this area failed to recall which areas of the maze they had already visited, rarely explored different arms of the maze, almost never recalled the maze in future trials, and took longer to reach the end of the maze, as compared to rats with a fully working retrosplenial cortex. The ‘mental walk’ originated from the idea that you can best remember things that you are familiar with. Therefore, by associating a certain object with a familiar landmark, you increase your chances of remembering that object. Since the mental walk revolves around the idea of visualizing a familiar place and associating certain ideas or items with landmarks within that familiar place, the medial parietal cortex plays a huge role in this technique. Without the ability to mentally ‘walk’ through a familiar route, this method cannot work.
All top memorizers today use the ‘method of loci’ to a greater or lesser degree. Contemporary memory competition was initiated in 1991 and introduced to the USA in 1997. Part of the competition requires committing to memory and recalling a sequence of digits, two-digit numbers, alphabetic letters, or playing cards. In a simple method of doing this, contestants, using various strategies well before competing, commit to long-term memory a unique vivid image associated with each item. They have also committed to long-term memory a familiar route with firmly established stop-points or loci. Then in the competition they need only deposit the image that they have associated with each item at the loci. To recall, they retrace the route, ‘stop’ at each locus, and ‘observe’ the image. They then translate this back to the associated item. Memory champions elaborate on this by combining images. Eight-time World Memory Champion Dominic O’Brien advocates this technique. His name for it is ‘The Journey Method.’ The 2006 World Memory Champion, Clemens Mayer from Germany, used a 300-point-long journey through his house for his world record in ‘number half marathon,’ memorising 1040 random digits in a half hour. One individual has used the method of loci to memorize pi to 65,536 digits.
Using this technique a person with ordinary memorization capabilities, after establishing the route stop-points and committing the associated images to long-term memory, with less than an hour of practice, can remember the sequence of a shuffled deck of cards. The world record for this is held by Simon Reinhard at 21.19 seconds. The ‘Rhetorica ad Herennium’ and most other sources recommend that the method of loci should be integrated with elaborative encoding (i.e., adding visual, auditory, or other details) to strengthen memory. However, due to the strength of spatial memory, simply mentally placing objects in real or imagined locations without further elaboration can be effective for simple associations. A recent variation of the involves creating imaginary locations (houses, palaces, roads and cities) to which the same procedure is applied. It is accepted that there is a greater cost involved in the initial setup, but thereafter the performance is in line with the standard loci method. The purported advantage is to create towns and cities that each represent a topic or an area of study, thus offering an efficient filing of the information and an easy path for the regular review necessary for long term memory storage. Something that is likely a reference to the ‘method of loci’ techniques survives to this day in the common English phrases ‘in the first place,’ ‘in the second place,’ and so forth.
During the mental walk, people remember lists of words by mentally walking a familiar route and associating these objects with specific landmarks on their route. An example of this would be to remember your grocery shopping list in a mental walk from your bedroom to kitchen in your house. Let’s say the first item on your list was bread; then mentally you can place a loaf of bread on your bed. As you continue mentally walking you can place the next item, assume it is eggs, on your dresser. The mental walk continues like this as you place consecutive items along a familiar route that you walk. So when you are at the grocery store, you can then think about this walk and ‘see’ what you placed at each location. In your head you will remember bread being on your bed, and eggs being on the dresser. This can continue for as many items as you want to place on your path as long as the route continues. The more dramatic the images, the more vivid the memory. For instance: instead of ‘bread,’ try to visualize a baker rising through an elevator pod in your bed, serving fresh bread; instead of ‘eggs,’ imagine a golden hen dropping rainbow eggs on the dresser.
The Daily Omnivore 