Constraints on selective attention

Attention is intentional, focused awareness of any external or internal stimulation, and involves four key features:

  1. Selectivity — focusing on information relevant to our immediate goals while blocking irrelevant information.
  2. Sustainability – the length of time we can maintain our focus on specific information.
  3. Speed of processing – the amount of time it takes to engage and disengage our attention from a source of information.
  4. Distribution — broadening and narrowing the scope of what we focus on.

Attention is vital for learning. We learn very little unless we can focus and sustain attention on the learning tasks before us. Unfortunately, we have limited capacity and imperfect control of these aspects of attention. For example, even when we attend selectively to a source, we still are susceptible to other sources of information that can grab our attention and distract us from our goal (Gazzaley & Rosen, 2016). Our capacity to sustain or focus attention over time is also limited, especially in situations that we perceive as monotonous or boring.[1] Another limitation is speed of processing. We cannot shift our attention instantaneously. We are apt to miss information during transitions when we engage or withdraw from a task. Finally, the overall scope of our attention is limited. If we distribute our attention too broadly in a situation, we can miss important, relevant information (Gazzaley & Rosen, 2016).

These constraints pose challenges for learning. One prominent attention problem involves media multi-tasking in which students engage in non-class activities such as texting, social media, and scanning websites during class or while studying. Media multitasking is common in college classes. One study reported that 80% of college students admit to texting during class; 15 percent say they send 11 or more texts in a single class period. A study that monitored students’ laptops found substantial multitasking behavior and that non-course-related software applications were open and active about 42% of the class period. Another study found that 58% of second- and third-year law students who had laptops in class were using them for non-class purposes more than half the time (Sovern, 2012).

Why is multi-tasking a threat to learning? A common misconception about multitasking is that people allocate their full attention to carry out two tasks simultaneously.

Research shows that people are not able to attend to and perform two complex tasks simultaneously (Shomstein & Yantis 2004; Clapp, Rubens, & Gazzaley, 2009).

Instead, when students think they are doing two things simultaneously, they actually are shifting their attention back and forth between the two tasks. Task switching is disruptive and inefficient as the individual disengages from one task then engages with another, and then switches back. While the individual is attending to one task, they are not able to attend to the other, i.e., they are not aware of what is going on. Upon switching back they need to re-orient, which not only takes time but may be difficult if the student has missed critical information.

Whenever students’ attention is divided, their learning can suffer. A growing body of research has documented negative outcomes associated with multi-tasking in the classroom and while doing homework. These include:

  • Assignments take longer to complete (Rosen, Carrier & Cheever, 2013).
  • Mental fatigue leads to more mistakes (Levitin, 2014).
  • Memory is impaired when attention is divided (Fried, 2008).
  • Students are less adept at extending and transferring new knowledge to novel contexts (Foerde, Knowlton & Poldrack, 2006).
  • Students get lower grades. Media multitasking is negatively correlated with course grades and college students’ GPAs (Glass & Kang, 2019; Patterson, 2017; Ravizza, Uitvlugt & Fenn, 2017).
  • Heavy media multitaskers are more distractible and have a more difficulty focusing their attention on a single task (Ophir, Nass, & Wagner, 2009; Uncapher, Thieu & Wagner, 2016).

Even when students are not multi-tasking, they may be distracted by other sources. Of course, there are everyday disruptions, a loud talkative student in class, a faulty microphone in a large lecture, etc. These tend to be incidental and inconsequential distractions compared to habitual or recurring ones. For example, some students may be preoccupied with ongoing personal concerns that make it difficult for them to focus attention. Moreover, instructors can introduce distractions inadvertently when their instruction is disorganized or when they present extraneous information unrelated to the topic at hand. Poorly organized instruction may confuse students about what they should attend to. For example, in small group learning episodes students need explicit directions to accomplish complex tasks. Without clear purpose and goals for the activity, they may be uncertain about where to focus their effort. Some studies have shown that instructors’ attempts to pique students’ interest and capture their attention can backfire. When these episodes are unrelated or tangential to the material at hand, students may focus on the “seductive details” rather than the course content (Rey, 2012). The point is that many things can distract students, and a basic teaching challenge is to reduce distractions and help students manage their attention.


[1] A common educational myth is that students can attend to lectures for only 10-15 minutes, as if attention is a single fixed timespan. This is not true. Sometimes students lose focus almost immediately after a lecture starts, and other times they can maintain much longer focus. It is true that people fatigue and lose their attention on repetitive vigilance tasks. But a variety of factors in the classroom influence how long students maintain a singular focus on learning.

Recommendations to support students’ attention in class.

Segment class time. Students may have difficulty sustaining attention during a long class period, especially when presented with large amounts of unfamiliar information. To mitigate this difficulty, take short breaks between topics to allow students to catch up before shifting to the next topic.

Reorient students to topics and material during class. Periodically remind students about the topic, the learning goal, or what they should focus on. If students are struggling to attend, it may help to point directly to what is most important for them to focus on.

Ask students to use the new material. At the end of a segment in class, ask students to use the new material in some meaningful ways such as:

  1. Think-pair-share: a) Instructor poses question, b) students think and write a response, and c) discuss with classmate
  2. Respond to thought-provoking clicker questions
  3. Draw a diagram or picture and then collect and project several of these to the class for discussion

Scaffold in-class small group activities. Working together is not automatically better than working alone. Base group activities on purposeful collaborative learning.

  1. Provide coherent, explicit guidelines that describe what students should do.
  2. Monitor groups and intervene when they are off task. If necessary, assign roles to help groups stay focused on their task, e.g., one student in each group monitors off task activity and reminds the group about the purpose and goal of the discussion, one student is timekeeper to keep the group moving toward timely completion of their work
  3. Ask groups to indicate when they are done with their work

Ask each student to hand in an individual product, e.g., summary, reflections, remaining questions, etc. If students are not individually accountable, some will turn their attention elsewhere.

Decide on a class policy to minimize distractions from electronic devises in class.

Help students become aware of how multitasking will make learning harder, not easier.

Take steps to identify and reduce the ways your teaching contributes to distractions in your classes (See recommended reading below, Improving learning by reducing unnecessary mental load.)

Recommended readings

Carl Wieman Science Education Initiative. (2014). Improving learning by reducing unnecessary mental load. Vancouver, Canada: Retrieved from

Multitasking animated video by Dan Willingham

The Distracted Mind lecture by Adam Gazzaley (one-hour video)


Chen, Q. & Yan, Z. (2015). Does multitasking with mobile phones affect learning? A review. Computers in Human Behavior, 54, 34-42.

Clapp, W.C., Rubens, M.T., & Gazzaley, A. (2009). Mechanisms of working memory disruption by external interference, Cerebral Cortex, 20, 859-872.

Foerde, K., Knowlton, B. J., Poldrack, R. A. (2006). Modulation of competing memory systems by distraction. Proceedings of the National Association of Science, 103(1), pp. 1778-1783.

Fried, C. B. (2008). In-class laptop use and its effects on student learning. Computers & Education, 50, pp. 906-914.

Gazzaley, A. & Rosen, L.D. (2016). The distracted mind: Ancient brains in a high-tech world. (pp. 30-80). Cambridge, MA: MIT Press.

Generation M2: Media in the Lives of 8- to 18-Year-Olds. 2010 National Survey by Kaiser Family Foundation.

Glass, A.L. & Kang, M. (2019). Dividing attention in the classroom reduces exam performance, Educational Psychology, 39(3), 395-408, DOI:10.1080/01443410.2018.1489046.

Judd, T. (2014). Making sense of multitasking: The role of Facebook. Computers & Education, 70, 194-202.

Kraushaar, J.M. & Novak, D.C. (2010). Examining the affects of student multitasking with laptops during the lecture. Journal of Information Systems Education. 21(2), 241-251.

Lau, W.W.F. (2017). Effects of social media usage and social media multitasking on the academic performance of university students, Computers in Human Behavior, 68, 286-291.

Levitin, D.J. (2014). The organized mind: Thinking straight in the age of information overload. NY: Dutton.

Martin, C. (n.d.). In-class texting behaviors among college students: A university-wide study to determine the in-class texting attitudes and behaviors of students at the University of New Hampshire.

McCoy, B. (2016). Digital distractions in the classroom phase II: Student classroom use of digital devices for non-class purposes. Journal of Media Education 7(1), 5 – 32.

Ophir, E., Nass, C. & Wagner, A.D. (2009). Cognitive control in media multitaskers. Proceedings of the National Academy of Sciences, USA, 106, 15583-15587.

Patterson, M.C. (2017). A naturalistic investigation of media multitasking while studying and the effects on exam performance, Teaching of Psychology, 44(1), 51-57.

Ravizza, S. M., Uitvlugt, M. G., & Fenn, K. M. (2017). Logged in and zoned out: How laptop internet use relates to classroom learning. Psychological Science, 28, 171–180.

Rekart, J. (2013). The cognitive classroom: Using brain and cognitive science to optimize student learning, pp. 35-53. Lanham, Maryland: Rowan & Littlefield Publishers, Inc.

Rey, G. D. (2012). A review of research and a meta-analysis of the seductive details effect. Educational Research Review, 7, 216–237.

Rosen, L., Carrier, L. & Cheever, N. (2013). Facebook and texting made me do it: Media-induced task-switching while studying. Computers in Human Behavior. 29(3), 948–958.

Rosen, L. D., Lim, A. F., Carrier, L. M., & Cheever, N. A. (2011). An empirical examination of the educational impact of text message induced task switching in the classroom: Educational implications and strategies to enhance learning. Psicologia Educativa, 17, 163–177. doi:

Sana, F., Weston, T. & Cepeda, N.J. (2013). Laptop multitasking hinders classroom learning for both users and nearby peers, Computers & Education, 62, 24–31.

Shomstein, S., & Yantis, S. (2004). Control of attention shifts between vision and audition in human cortex. Journal of Neuroscience, 24, 10702-10706.

Sovern, J. (2012). Law student laptop use during class for non-class purposes: Temptation v. incentives. Paper #11-004, St. John’s University School of Law, June 6, 2012.

Uncapher, M.R., Thieu, M.K. & Wagner, A.D. (2016). Media multitasking and memory: Differences in working memory and long-term memory, Psychonomic Bulletin Review, 23, 483–490. DOI 10.3758/s13423-015-0907-3.