Other sections will examine input devices, output devices, and secondary memory. The Central Processing Unit The computer does its primary work in a part of the machine we cannot see, a control center that converts data input to information output. This control center, called the central processing unit CPUis a highly complex, extensive set of electronic circuitry that executes stored program instructions. All computers, large and small, must have a central processing unit.
History[ edit ] The term "working memory" was coined by MillerGalanterand Pribram  and was used in the s in the context of theories that likened the mind to a computer. InAtkinson and Shiffrin  used the term to describe their "short-term store".
What we now call working memory was formerly referred to variously as a "short-term store" or short-term memoryprimary memory, immediate memory, operant memory, and provisional memory. Most theorists today use the concept of working memory to replace or include the older concept of short-term memory, marking a stronger emphasis on the notion of manipulating information rather than mere maintenance.
The earliest mention of experiments on the neural basis of working memory can be traced back to more than years ago, when Hitzig and Ferrier described ablation experiments of the prefrontal cortex PFC ; they concluded that the frontal cortex was important for cognitive rather than sensory processes.
Of those, the two that have been most influential are summarized below. The multicomponent model[ edit ] Main article: Baddeley's model of working memory Baddeley and Hitch's model of working memory InBaddeley and Hitch  introduced the multicomponent model of working memory.
The theory proposed a model containing three components: A "central executive" is responsible for supervising the integration of information and for coordinating "slave systems" that are responsible for the short-term maintenance of information.
One slave system, the phonological loop PLstores phonological information that is, the sound of language and prevents its decay by continuously refreshing it in a rehearsal loop. It can, for example, maintain a seven-digit telephone number for as long as one repeats the number to oneself again and again.
It can be used, for example, for constructing and manipulating visual images and for representing mental maps. The sketchpad can be further broken down into a visual subsystem dealing with such phenomena as shape, colour, and textureand a spatial subsystem dealing with location.
InBaddeley extended the model by adding a fourth component, the episodic bufferwhich holds representations that integrate phonological, visual, and spatial information, and possibly information not covered by the slave systems e.
The episodic buffer is also the link between working memory and long-term memory. The episodic buffer resembles Tulving's concept of episodic memorybut it differs in that the episodic buffer is a temporary store. In this way, parts of long-term memory effectively function as working memory.
In a similar vein, Cowan does not regard working memory as a separate system from long-term memory. Representations in working memory are a subset of representations in long-term memory.
Working memory is organized into two embedded levels. The first consists of long-term memory representations that are activated.
There can be many of these—there is theoretically no limit to the activation of representations in long-term memory. The second level is called the focus of attention. The focus is regarded as having a limited capacity and holds up to four of the activated representations.
The one-element focus is embedded in the four-element focus and serves to select a single chunk for processing. For example, four digits can be held in mind at the same time in Cowan's "focus of attention".
When the individual wishes to perform a process on each of these digits—for example, adding the number two to each digit—separate processing is required for each digit since most individuals cannot perform several mathematical processes in parallel. An early quantification of the capacity limit associated with short-term memory was the " magical number seven " suggested by Miller in Later research revealed this number depends on the category of chunks used e.
For instance, span is lower for long than short words.How Memory Works and 6 Tips to Improve It. The way our memory works is a complicated process, the details of which neuroscientists are still trying to understand.
In this paper we will explore how memory works, such as sensory registration, short term memory and long term memory. Things that can improve one's memory like mnemonics, rehearsal, and chunking.
Losing your memory, such as amnesia. The effects that leading questions can have on your memory. Flash memory is an electronic (solid-state) non-volatile computer storage medium that can be electrically erased and reprogrammed..
Toshiba developed flash memory from EEPROM (electrically erasable programmable read-only memory) in the early s and introduced it to the market in  The two main types of flash memory are named after the NAND and NOR logic gates.
The following table summarizes the characteristics of the various kinds of data storage in the storage hierarchy. Storage: see the How Stuff Works pages on computer memory.. How the CPU Executes Program Instructions Let us examine the way the central processing unit, in association with memory, executes a computer program.
We will be. characteristics of memory are capacity and performance • Three performance parameters: —Access time —Cycle Time • The reason that this works well is called • Another way to organize this system is to. Since time immemorial, humans have tried to understand what memory is, how it works and why it goes wrong.
It is an important part of what makes us truly human, and yet it is one of the most elusive and misunderstood of human attributes.