The Cognitive Load (Performance) Decreases With Distractions or Events Requiring Multi-Tasking Increase
Cognitive theorists believe that an individual has a limit to their mental capacity and that if too much information is provided at once, the individual runs the risk of a cognitive overload which can lead to errors and reduce learning and performance. In addition, cognitive overload reduces space in working memory (WM) and inhibits learning and problem solving. Cognitive Load Theory (CLT) was developed by John Sweller in the 1980s. CTL refers to the effort of the working memory. This theory does not imply that there is a limit to our capacity of cognition, but there is a limit to how many new elements we can hold in our working memory. In 2010, Sweller along with Van Merriènboer outlined three types of cognitive load, intrinsic, extraneous, and germane.
Doing more than one task at a time, especially more than one complex task, takes a toll on productivity. Although that shouldn't surprise anyone who has talked on the phone while checking E-mail or talked on a cell phone while driving, the extent of the problem might come as a shock. Psychologists who study what happens to cognition (mental processes) when people try to perform more than one task at a time have found that the mind and brain were not designed for heavy-duty multitasking. Psychologists tend to liken the job to choreography or air-traffic control, noting that in these operations, as in others, mental overload can result in catastrophe. Multitasking can take place when someone tries to perform two tasks simultaneously, switch . from one task to another, or perform two or more tasks in rapid succession. To determine the costs of this kind of mental "juggling," psychologists conduct task-switching experiments. By comparing how long it takes for people to get everything done, the psychologists can measure the cost in time for switching tasks. They also assess how different aspects of the tasks, such as complexity or familiarity, affect any extra time cost of switching. In the mid-1990s, Robert Rogers, PhD, and Stephen Monsell, D.Phil, found that even when people had to switch completely predictably between two tasks every two or four trials, they were still slower on task-switch than on task-repeat trials. Moreover, increasing the time available between trials for preparation reduced but did not eliminate the cost of switching. There thus appear to be two parts to the switch cost -- one attributable to the time taken to adjust the mental control settings (which can be done in advance it there is time), and another part due to competition due to carry-over of the control settings from the previous trial (apparently immune to preparation).
The dual channel has bases on the works of Paivolo’s (1986) on the dual coding theory and Baddeley’s (1998) theory of working memory (Mayer and Moreno, 2003, p.44). Twitter pages have images and wording that can provoke mind processing. The second assumption that each channel has limits during the human information processing (Cobb, 1997, p.21). This is at the center of the Cognitive Load theory fronted by Chandler and Sweller (1991). The third assumption is based on generative-learning theory and selecting-organizing-integrating theory of active learning fronted by Wittrock (1989) and Mayer (1999), respectively (Mayer and Moreno, 2003, p.44). The integration of Twitter into learning has the influence as illustrated below.
Finally, some school tasks or assessment situations also require readers to first select and read documents and then perform a specific task with or without access to the texts. In short, solving tasks based on multiple documents presents considerable challenges to an individual's text processing skills, and appropriate training of these skills can be of use in formal education as well as in everyday life and lifelong learning.
Mayer, R. E. and Moreno, R. (2003). Nine Ways to Reduce Cognitive Load in Multimedia Learning. Educational Psychologist 38(1), 43–52.
Cobb, T. (1997). Cognitive Efficiency: Toward a Revised Theory of Media. ETR&D 45, 21-35.
Dawley, L. (2009). Social network knowledge construction: emerging virtual world pedagogy. Emerald Group Publishing Limited 17(2), 109-121.