The Multitasking Mind

One area of concern for neuroscientists is the effect of multitasking on the brain. Computers allow unprecedented opportunities for multitasking. In the following video, teens check their Facebook, their text messages, or play games while they do homework or answer interview questions.

The researchers in this video by PBS are optimistic about the effects technology can have on our brains and are not discouraged by the prevalence of multitasking. Other experts are more cautious in embracing technology.

In the 2008 article "The Myth of Multitasking," senior editor Christine Rosen expresses her concern about multitasking and how it negatively affects the brain's ability to focus and store information. Rosen presents multitasking as one of the most dangerous products of technology use today because it has created what Rosen quotes from Linda Stone as "continuous partial attention." Our brains are never truly focused on one task if we are always sitting with a computer or phone that will alert us to Facebook notifications, emails, breaking news stories, and other distractions. All of this multitasking leads to diminished mental capacity. Rosen cites research done by psychologist David Meyer that shows that multitasking can trigger the release of stress hormones, which affects the brain's short-term memory and physically harms us.

Another alarming point is raised by the research done by psychology professor Russell Poldrack that used brain scans to demonstrate how multitasking affects what parts of the brain are activated. Rosen quotes Poldrack's explanation that the brain scans of multitasking subjects showed activation in their striatum, which is a region of the brain responsible for learning new skills. However, the brain scans of the people who were not multitasking showed activity in the hippocampus; the hippocampus is one area of the brain responsible for storing and recalling information. This research indicates that when people multitask, they do not store information because their brain is busy processing the multiple ongoing tasks instead.

If the brain is consistently stimulated by multitasking, then the conclusions drawn from my previous posts about neural plasticity and the cerebral activation during Internet searches imply that our brains could be currently adjusting to multitasking. This would mean that we might eventually get better at performing simultaneous tasks, but an improvement in the ability to multitask would not necessarily mean an improvement in the ability to store information while multitasking if the same parts of our brain are always activated by multitasking. Until more research is done, people are faced with the choice to keep multitasking and see what consequences await them, or play it safe and minimize their multitasking behavior.

Googling for a better brain

Neuroscientists agree that the brain is healthier when people perform mentally challenging tasks. The variety of tasks that can be performed using a computer or smartphone provides new opportunities for mentally challenging tasks. A quick Google search for "brain exercises" offers up "about 3,430,000 results" that provide users access to articles about how to exercise their brain as well as games to play online to challenge the brain. But, what if the search for brain exercises is actually a mentally challenging and healthy task in itself?

This is what a 2009 study entitled "Your Brain on Google: Patterns of Cerebral Activation during Internet Searching" conducted by Gary W. Small, Teena D. Moody, Prabba Siddarth, and Susan Y. Bookheimer suggests. While my previous post examined how the brain changed due to traditional studying, Small et al. set out to examine how performing internet searches activated and impacted different parts of the brain. The team performed MRI scans on 24 subjects aged 55-78 while they used simulated search engines to learn about various topics; the subjects were told they would be assessed on the topic they were researching afterwards. The groups were divided into "Net Naive" and "Net Savvy" depending upon their prior experience with computers. The researchers also had the subjects view their information in two different formats: one was identical to a web page (called Internet search task in the study), while the other was formatted like a page from a book (called text reading task in the study). The informative content was the same in both.

This is an example of the types of searches the subjects did. The top two images are for people who saw a book page format. The bottom two are what people saw if they were viewing an simulated Internet search engine and web page.

Researchers found that, during the text reading task, the Net Naive group's brains were activated mostly in the left hemisphere in their frontal, temporal, and parietal regions; there was also activation of the visual cortex, hippocampus, and posterior cingulate. These same regions were activated during the Internet search task, with the exception of the hippocampus and posterior cingulate. The Net Savvy group showed activity in the same areas of the brain as the Net Naive during the text reading task. However, during the Internet search task, there was additional activity in the frontal pole, right anterior temporal cortex, the anterior and posterior cingulate, and the right and left hippocampus.

The top images represent the Net Naive group; the bottom represent the Net Savvy. The images on the left are activation patterns during the text reading task; those on the right are during the Internet search task.

What does all of this mean? Small et al. note that the Net Savvy group experienced a more than twofold greater spatial extent than did the Net Naive group; essentially, more of the brain is activated in order to perform Internet searches than to research questions using books. Also, the Net Savvy group showed greater activation in areas that control complex reasoning and decision making. The implication of these findings is that the Net Savvy of the world have developed additional skills in order to use the Internet effectively. Another key aspect of this study is that it was only those with substantial experience with computers experienced greater brain activation. This reemphasizes the findings of Draganski et al. in my previous entry because it shows how the brain adapts to consistent practice of an activity.

So, habitual Googlers unite and celebrate; our internet search habits may be exercising the brain's ability to reason effectively.

What is a cyberliterate brain?

The cyberliterate brain is one that has been affected by the prevalence and use of technology such as computers, tablets, and smart phones. All brains have the ability to change and grow depending upon the stimulus in an individual's environment. This is because of the brain's neuroplasticity. When a person learns a new skill, their brain structures changes. 

For example, in the 2006 study "Temporal and Spatial Dynamics of Brain Structure Changes during Extensive Learning," Draganski, et al. studied medical students in the months prior to and immediately after an important medical exam. The team performed brain scans on the medical students versus students who were not preparing for an exam and had not taken any major exams in the last 6 months. The initial brain scan showed no significant regional differences between the two groups, but later scans showed that the medical students who were preparing for an exam had significant increases of gray matter in their posterior parietal cortex and inferior parietal cortex; these parts of the brain are associated with the transference of information from short-term to long-term. The first two scans also showed a decrease in gray matter, but an increase in white matter, in the occipital parietal lobes of the students who were preparing for exams. The group of students who did not have exams to prepare for showed no significant changes in gray matter. 

The Draganski et al. study suggests that the structure of the brain can change depending upon what (and how intensely) an individual is learning. Although this study does not speak to the impact of technology on the brain, it does provide a clear example of how the repetition of an activity can change the brain. The parts of the brain that were key in retaining the information that the students were studying grew, while other areas converted gray matter to white matter. The students' brain structures noticeably changed to adapt to the intense amount of studying they were doing and the stress they were enduring.

This photo, taken from the 2006 Draganksi, et al. study, illustrates the gray matter increase that occurred in the students studying for the exam. A larger version and a more in-depth explanation can be found here.

 If our brains are affected by our environments, what type of effect could technology be having on our brains? This is what I hope to address in the rest of this blog.