Memory Span Capacity

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The memory span experiment tested the theory that there is a short term memory system that is limited in capacity and is influenced by different processes. The memory span experiment included different stimuli, which were numeric, letters that sound different, and letters that sound the same. 10 undergraduate students recalled stimuli in the same order that was presented to them. It is hypothesized that short term memory is a limited capacity system that is influenced by verbal processes. Furthermore, participants would be able to recall items, 7±2 where number recall be more successful. From the results, this study indicates that that there is a limit to short-term memory and that verbal processes partially influence verbal processes.

Short term memory or working memory is a system that provides temporary storage and usage of the information necessary for such complex cognitive tasks as language comprehension, learning, and reasoning. The decay in memory is a cause of how the memory system is structured. To test these processes, a presentation on the role of working memory would be incomplete without an understanding of Braddely’s model. It is divided into three components: the phonological loop, the central executive, and the visual sketchpad. This model shows that the central executive controls both the phonological loop and the visuo-spatial sketchpad. They are generally referred to as slaves to the central executive. It coordinates the activity within working memory and controls the transmission of information between other parts of the cognitive system. The central executive has a limited capacity, therefore tasks that seem to deal specifically with either of the slave systems require processing by the central executive. The phonological loop’s functions include providing temporary storage of phonological information for about two seconds; refreshing material in the phonological loop as needed. The visual-spatial sketchpad plays a role in providing temporary storage of visual and spatial information, refreshing images to the sketch pad and generating images. One scientist that initiated the exploration of this phenomenon was Miller. Miller (1956) launched experimentation on short term memory, he initiated by measuring participants’ recall of a list of items by identification of an item from an ordered series, and the ability to know very quickly how many objects are in a display. He concluded that one can recall lists of at most about 7 items, one can identify items with at most about 7 category choices, and one can tell very quickly how many objects are in a display of no more than about 7 objects. This paper impressed upon researchers how very limited the capacity for simultaneously-held information is within cognitive activities. Further studies have analyzed how storage of information depends on the features of it. Cowan and Morey (2007) further demonstrated that the modality-independent capacity limit is in maintenance, not encoding. The evidence for separate phonological and visuospatial stores replaced that interference between items in short-term storage depends on the similarity of their features, or (the terminology of Miller)”chunks” that can then be entered into long-term memory as newly-learned items. For example, if visualizing a cat and a hat you could form the image of a cat wearing a hat and in the future remember that image as a single chunk, rather than as two items. This example explains how the central executive processes can search long-term memory and use it to enter new information into the focus of attention, or to replace items in the focus with other items. In this approach, the term working memory was used to indicate a functional level at which activated memory, the focus of attention, and central executive processes worked together in order to keep items temporarily in mind. However, the effects of chunking are modality...
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