Specifically, Baddeley and Hitch (974) postulated that working memory represent a significant part in supporting broad range of cognitive activities related to everyday living, such as reasoning skills and language comprehension, long-term learning, and mental arithmetic. The work of Baddeley and Hitch (974) was concerned with whether or not short-term memory could function as a working memory, this was achieved by asking the participants to perform reasoning, comprehension, and learning tasks, while they simultaneously hold 0 and 8 digits in their short-term memory for instant recall. If short-term memory serves as a working memory, then overloading it should interfere with cognitive processing, it does lead to disruption and impacted performance, but not to a great extent. Alan Baddeley and his colleagues have been actively involved in developing the idea that short-term storage is composed of many subsystems, in which around 974 they advocated that the concept of short-term memory should be replaced with that of working memory. A central executive component, a phonological loop, and a spati
al sketch pad are the three components of their model they proposed. Based on the model, working memory consists of a central executive that controls two complementary modules through limited attention, which is a modality-free component with limited capacity, and limited attention is used to control the other two modules.
Bunge et al. (2000) presented evidence for the central executive, where researchers studied the brain activity in participants while they were performing two tasks at once, reading a sentence and recalling the final word in the sentence. They used FMRI (functional magnetic resonance imaging) to see which areas were most active. An increased amount of activation was observed in the dual task condition, indicating that attention increases brain activity that affects the central executive function. Baddeley et al. (975) also provided evidence of a visual sketchpad, where he asked participants to visualize a matrix of numbers in a task given to them at the end. There was a significant impairment in visual perception when this task was combined with the tracking of a moving light.