Chapter 5 Exercises: Your Brain Online

These exercises are organized into five tiers of increasing depth and demand. Tier 1 exercises build foundational comprehension. Tier 5 exercises require extended research, synthesis, and original analysis. Complete them in order or select by level of challenge.

Tier 1: Comprehension and Application (Exercises 1–7)

Exercise 1: Attentional Modes Identification

For each of the following activities, identify which attentional mode (focused attention, diffuse attention, or default mode network) is most likely active. Briefly explain your reasoning for each.

a) Writing a first draft of a difficult email b) Sitting on a park bench, watching people walk by c) Daydreaming during a bus ride d) Solving a math problem under time pressure e) Walking home on a familiar route while your mind wanders f) Monitoring a group chat for updates during a work meeting

Exercise 2: Working Memory Capacity Demonstration

This exercise demonstrates working memory limits directly.

Part A: Read the following sequence of digits once, then cover the page and write them from memory. Do not practice in advance.

Sequence: 7 3 9 1 4 8 2 6 5

How many did you recall correctly? How does your performance relate to Miller's (1956) and Cowan's revised estimates?

Part B: Now read this sequence once and recall it:

Sequence: FBI CIA JFK USA GDP NFL

Most people recall all six items effortlessly. Why? What does this tell you about the role of chunking in working memory capacity?

Exercise 3: The Ward et al. Phone-on-Desk Study — Thought Experiment

You cannot replicate the Ward et al. (2017) study without lab equipment, but you can think through it carefully.

a) The study found that phone presence reduced cognitive performance even when the phone was face-down and silent. What mechanism does the chapter propose for this effect?

b) Design a simple personal experiment you could run over one week that would let you observe (if not measure precisely) whether phone presence affects your own studying performance. What would you measure? What would you need to control for?

c) The study found that people with high smartphone dependence showed the largest performance decrements. Propose two explanations for why this relationship might exist.

d) A critic argues that people with lower cognitive ability are both more likely to be smartphone-dependent and more likely to perform poorly on cognitive tasks — making the relationship spurious. How would you respond to this critique? How did Ward et al.'s methodology address it?

Exercise 4: Cognitive Load Classification

For each feature or design element listed below, classify it as primarily creating intrinsic load, extraneous load, or germane load in the context of a student trying to learn from content. Explain each classification.

a) A complex mathematical proof b) An autoplay video that begins when a study article finishes loading c) A well-designed diagram that illustrates a concept from multiple angles d) Red notification badges visible in the browser tab e) A quiz at the end of a chapter that asks you to apply concepts to new examples f) Background music with lyrics playing during reading g) An emotionally upsetting news headline visible in the browser h) A worked example that explicitly shows each step of a solution process

Exercise 5: Negativity Bias Inventory

Over two days, keep a brief log of your social media exposure and your emotional responses to content.

For each session: - Record the approximate duration - Note how many items made you feel positive, neutral, or negative - Note which items you paused on longest or returned to - Note any lingering emotional states after closing the app

After two days: What pattern emerges? Does the content that captures your attention disproportionately represent any emotional valence? What does this tell you about the negativity bias in your own experience?

Exercise 6: Cue-Routine-Reward Mapping

Choose one habitual phone-checking behavior you recognize in yourself (or someone you know well). Map it onto the cue-routine-reward framework:

a) What is the cue? (Environmental trigger? Emotional state? Time of day?) b) What is the routine? (Exactly what action sequence follows the cue?) c) What is the reward? (What does the brain receive? Is it reliable or variable?) d) What does the investment component look like? (What does the behavior produce that makes future engagement more likely?)

Now consider: what would it take to interrupt this loop? At which stage would interruption be most feasible, and why?

Exercise 7: DMN Deprivation Estimate

Think about a typical day in your life. Estimate, as accurately as you can:

a) How many minutes of genuine mind-wandering do you experience — periods with no task demands, no screens, no music, no podcast? b) How does this compare to what you believe your baseline might have been before you owned a smartphone? c) What activities in your life most reliably produce mind-wandering states? d) What activities most reliably prevent them?

Based on your estimates, is your default mode network getting the engagement time it needs? What would change if you protected 20 unstructured minutes per day?

Tier 2: Analysis and Synthesis (Exercises 8–15)

Exercise 8: Cognitive Load Audit of a Social Media Feature

Choose one specific feature of a social media platform you use regularly (examples: Instagram Stories, TikTok's For You Page, Twitter/X's trending topics, Snapchat's streaks, Reddit's front page, YouTube's sidebar recommendations).

Write a 400-500 word cognitive load analysis of that specific feature covering: - What intrinsic load it places on users - What extraneous load it creates (identify at least three specific sources) - Whether it creates any conditions for germane load, and under what circumstances - How the feature's design choices affect the balance between extraneous and germane load - What the designers might have prioritized when making these choices

Exercise 9: Attention Residue in Your Own Work

Design a personal experiment to observe attention residue in your own cognitive performance.

For one week: - On alternating study sessions, either (a) check your phone briefly mid-session or (b) leave your phone in another room for the entire session - Rate your perceived ability to focus after each session on a 1-10 scale - Note how long it takes to feel "back in" the work after a check - Record any instances of your mind returning to content you saw on your phone

Analyze your results: Do you observe attention residue effects? How does your subjective experience compare to what Leroy's research would predict?

Exercise 10: Evolutionary Mismatch Analysis

The chapter argues that social media exploits attentional systems that evolved for a very different environment. Select three specific features of social media design (e.g., the infinite scroll, the like button, notification systems, story formats, comment sections) and for each:

a) Identify the evolved attentional or social cognitive system it targets b) Describe the ancestral environment in which that system would have been adaptive c) Explain the mismatch between the ancestral context and the modern context d) Predict what behavioral or psychological outcomes you would expect from this mismatch, based on the chapter

Exercise 11: Comparing Multitasking Claims

Find two popular articles or opinion pieces (from mainstream media, productivity blogs, or popular psychology sources) that make claims about multitasking and technology use.

For each article: a) Summarize the central claim about multitasking b) Evaluate the claim against David Meyer's research and the evidence reviewed in this chapter c) Identify any inaccuracies, oversimplifications, or unsupported assumptions d) Note what the article gets right

Write a 300-word synthesis: What patterns do you notice in how popular media represents the science of multitasking?

Exercise 12: Personal Attention Audit Design

Design a rigorous personal attention audit — a system for tracking your own attentional patterns over a two-week period. Your audit should:

a) Define what you are measuring (attention quality? fragmentation? device use? DMN availability?) b) Specify how you will measure it (self-report scales, screen time data, task completion metrics, timed focus sessions, or some combination) c) Identify potential confounds (mood, sleep, stress, academic demands) and describe how you will account for them d) Specify what insights you hope to gain e) Describe how you would analyze the data to test specific hypotheses derived from this chapter

Exercise 13: The Salience Network and Platform Design

Consider the following data: across multiple studies, content featuring faces outperforms content without faces on engagement metrics by substantial margins. Angry and fearful content generates more sharing than content of equivalent quality with positive or neutral valence. Content that triggers social comparison responses generates longer dwell times.

a) Explain each of these findings using the salience network framework from this chapter. b) If you were designing a social media platform with engagement maximization as your primary objective, what content types would you algorithmically amplify based on these findings? c) If you were designing the same platform with user wellbeing as your primary objective, how would your design choices differ? d) What tensions exist between these two objectives, and how do real platforms navigate them?

Exercise 14: Social Comparison and Self-Model Distortion

Social comparison is described as an automatic cognitive process that updates the self-model based on available reference points.

a) Describe three specific ways in which the reference points available on social media differ from the reference points available to humans in ancestral environments. b) For each difference, predict the direction of self-model distortion it would likely produce. c) What psychological outcomes would you predict from systematic self-model distortion over months or years of heavy social media use? d) Are there any circumstances in which social media comparison could produce accurate or positive self-model updates? Describe them.

Exercise 15: The Dopamine Prediction Error Model

The chapter describes dopamine's function as signaling prediction error rather than pleasure. Apply this model to explain the following observations:

a) People continue checking social media even when they rarely find content they genuinely enjoy b) Getting a lot of likes on a post feels less rewarding over time c) The first scroll of the day often feels more compelling than subsequent scrolls d) Turning off notifications often produces an initial period of anxiety before users adjust e) People sometimes feel worse after using social media but immediately reach for it again

For each observation, construct a dopamine-based explanation. Where the model does not fully explain the observation, note the gaps.

Tier 3: Extended Analysis and Personal Research (Exercises 16–22)

Exercise 16: Interview Study — Phenomenology of Social Media Use

Conduct brief structured interviews with three people about their subjective experience of social media use. Ask each person:

1. Can you describe what it feels like to scroll through your feed for an extended period?
2. What do you feel immediately after closing a social media app?
3. Have you ever intended to check your phone briefly and spent significantly longer than planned? What happened?
4. What do you notice about your ability to concentrate after a period of heavy phone use?
5. Are there times when you use your phone without wanting to, or when you find it hard to stop?

Analyze your interviews: What common themes emerge? How do participants describe the experiences this chapter explains neurologically? Where do their self-reports align with the scientific account, and where do they diverge?

Exercise 17: Case Study — Designing for Cognitive Respect

Identify a digital product, service, or feature (it does not have to be a social media platform) that you believe was designed with users' cognitive wellbeing in mind. It should minimize extraneous cognitive load, avoid exploiting habit loops, or actively support rather than suppress DMN function.

Write a 500-word case study analyzing: - What specific design choices reflect cognitive respect - What mechanisms from this chapter the design avoids exploiting - What tradeoffs the designer likely accepted in making these choices - What measurable outcomes (engagement, wellbeing, learning) you would predict from this design compared to a less considerate alternative

Exercise 18: Literature Review Mini-Project — Working Memory and Digital Media

Find three peer-reviewed empirical studies (not popular summaries or news articles) that examine the relationship between digital media use and working memory performance. For each study:

a) Summarize the methodology and key findings b) Evaluate the strength of the evidence (sample size, controls, replication status) c) Note how the finding relates to the mechanisms described in this chapter

Write a 500-word synthesis: What does the current empirical evidence say about digital media's effect on working memory? Where is the evidence strong? Where are the gaps?

Exercise 19: The Transition Cost Experiment

This exercise requires two separate study sessions, ideally on consecutive evenings at the same time.

Session A: Study for 45 minutes without any phone use (phone in another room). After 45 minutes, rate your focus quality, progress made, and sense of mental clarity.

Session B: Study for 45 minutes with your phone accessible and allowing yourself to check it up to three times. After 45 minutes, rate the same measures.

Immediately following each session, attempt the same 10-minute standardized cognitive task (a timed set of arithmetic problems, a vocabulary test, or any standardized online working memory test works).

Analyze your results. Consider: How large were the differences, if any? What factors might explain any differences you found? What factors might have confounded your results? What would a well-controlled scientific study need to control for that your informal experiment could not?

Exercise 20: The Habit Loop Disruption Project

Select one digital habit you would like to change — a specific pattern of phone use that you consider excessive, unwanted, or counterproductive.

Week 1: Observe and document the habit. Map the cue, routine, and reward in detail. Note the frequency and circumstances of the behavior. Do not attempt to change it yet.

Week 2: Attempt one specific intervention targeting a single component of the habit loop (replacing the routine, modifying the environment to reduce cue exposure, or interrupting the reward). Document your attempts, successes, and failures daily.

At the end of week 2, write a 400-word reflection: What did you learn about habit change from attempting it? How does your experience compare to what the chapter predicts about the difficulty of changing basal ganglia-encoded routines?

Exercise 21: Platform Comparison — Cognitive Load by Design

Choose two social media platforms you are familiar with and compare them systematically on cognitive load dimensions.

Create a comparison table covering at least eight specific design elements (examples: notification density, visual complexity of the feed, content format variety, user interface element density, autoplay settings, content valence distribution, scrolling mechanics, comment visibility). For each element, rate each platform on the extraneous cognitive load it creates (1 = minimal, 5 = very high) and provide a brief justification.

Based on your analysis: Which platform do you predict would produce more cognitive fatigue per unit of time? More attention residue? More disruption to DMN function? Support your predictions with reference to specific design elements and the mechanisms described in this chapter.

Exercise 22: Reflective Synthesis — Maya's Brain, Your Brain

This chapter uses Maya as a running example. Now write your own account.

Choose a specific episode from your own experience — a period when you spent significantly longer on social media or your phone than you intended, followed by difficulty focusing on something important.

Write a 600-800 word narrative account of that episode from both a phenomenological perspective (what it felt like, what you noticed) and a neuroscientific perspective (what was happening in your attentional systems, working memory, salience network, habit loop, and DMN based on this chapter's framework).

The goal is not self-criticism but scientific self-understanding: can you map your own experience onto the mechanisms the chapter describes? Where does the fit feel accurate? Where does it feel incomplete or inaccurate?

Tier 4: Critique and Synthesis (Exercises 23–29)

Exercise 23: Evaluating the Evolutionary Psychology Framework

This chapter makes extensive use of evolutionary psychology — arguing that human attentional vulnerabilities exist because our brains evolved in environments with very different stimulus profiles. Evaluate this explanatory approach.

Write a 600-word critical analysis covering: - What the evolutionary framework explains well in the context of social media effects - The limitations and potential problems with evolutionary just-so stories - What alternative frameworks (social learning theory, developmental psychology, cognitive neuroscience without evolutionary framing) might explain the same phenomena - Whether the practical implications of the chapter change if the evolutionary framing is weakened or dropped

Exercise 24: The Replication Crisis and Working Memory Research

Cognitive psychology has been significantly affected by the replication crisis — the finding that many published results in psychology fail to replicate when studied again by independent labs.

Research the replication status of at least two key findings cited in this chapter (suggestions: the Ward et al. phone-presence study, Leroy's attention residue findings, working memory capacity estimates, or multitasking research). For each:

a) Summarize what the original finding claimed b) Describe the replication evidence (has it replicated? partially replicated? failed to replicate?) c) Note any important methodological differences between the original and replication studies d) Assess what the replication status implies for the chapter's arguments

Write a 500-word synthesis: How should we calibrate our confidence in the chapter's claims given replication considerations?

Exercise 25: Counter-Argument Construction

The chapter argues that social media use impairs cognitive performance through multiple mechanisms. Construct the strongest possible counter-argument to this position.

Your counter-argument should address: - Alternative explanations for the correlations between social media use and cognitive measures - Whether the effects described might be temporary or adaptable - Whether heavy social media users might develop compensatory cognitive strategies - Whether there are cognitive benefits of social media use that the chapter underemphasizes - Whether the effects differ substantially across individuals, contexts, or platforms

After constructing your counter-argument (400 words), write a 200-word response explaining where the chapter's position holds despite your critique and where it should be genuinely qualified.

Exercise 26: Cognitive Vulnerability Across the Lifespan

The chapter focuses primarily on adolescents like Maya. Consider how the cognitive vulnerabilities described might differ across the lifespan.

Compare the likely cognitive vulnerability profiles of: a) A 12-year-old beginning social media use b) A 17-year-old like Maya c) A 25-year-old in an intensive knowledge work job d) A 45-year-old parent with limited tech background e) A 70-year-old new to smartphone use

For each group, consider: How do developmental factors affect working memory capacity, prefrontal inhibitory control, and habit formation? How does prior digital media exposure affect attentional calibration? What unique vulnerabilities or relative protections does each group have?

Cite specific mechanisms from the chapter in your analysis.

Exercise 27: Design Ethics — The Responsibility Question

This chapter describes specific cognitive mechanisms that social media platforms exploit, whether intentionally or through algorithmic optimization. This raises a design ethics question: to what extent are platform designers morally responsible for the cognitive effects their products produce?

Write a structured ethical analysis (700-800 words) that: - Distinguishes between intentional exploitation and emergent exploitation through optimization - Considers what it means to "know" about cognitive effects for the purpose of assigning responsibility - Engages with at least two different ethical frameworks (consequentialist, deontological, virtue ethics, or others) in assessing platform responsibility - Arrives at a position on where the line of responsibility should be drawn and why

Exercise 28: Neuroplasticity and Long-Term Effects

The chapter focuses primarily on acute effects — what happens cognitively during and immediately after social media use. Consider the neuroplasticity implications of sustained, long-term use patterns.

Research and write a 600-word analysis addressing: - What neuroplastic changes might result from years of high-frequency, high-intensity social media use based on known principles of synaptic plasticity - What the evidence says about whether the attention and working memory effects of heavy digital media use are temporary or show signs of lasting structural change - Whether the neuroplastic changes associated with heavy digital media use are reversible, and what the evidence shows about recovery timelines - What this implies about the importance of attentional habits developed during adolescence

Exercise 29: Cross-Cultural Considerations

Most of the research cited in this chapter was conducted with participants from WEIRD (Western, Educated, Industrialized, Rich, Democratic) populations. Critically assess the generalizability of the chapter's claims.

a) Which mechanisms described (working memory limits, the negativity bias, salience responses to faces, habit formation via the basal ganglia) are likely to be universal, and which might vary across cultures? b) Are there cultural factors that might moderate the effects of social media on attention and cognitive load? c) What would a well-designed cross-cultural study of social media's cognitive effects need to include? d) What should change in the chapter's claims if cross-cultural variation turns out to be substantial?

Tier 5: Original Research and Extended Projects (Exercises 30–35)

Exercise 30: Systematic Literature Review

Conduct a systematic literature review of the relationship between social media use and one cognitive variable (suggestions: sustained attention, working memory capacity, mind-wandering frequency, creative performance, or task-switching efficiency).

Your review should: - Search at least two academic databases (PsycINFO, PubMed, Google Scholar) using systematic search terms - Include at least eight peer-reviewed empirical studies - Summarize each study's methodology, sample, findings, and limitations - Assess the overall quality of the evidence - Identify the direction, magnitude, and consistency of effects - Identify significant gaps in the current literature - Arrive at an evidence-based conclusion about the current state of knowledge

Target length: 1,500-2,000 words plus a reference list and summary table.

Exercise 31: Quasi-Experimental Study Design

Design a quasi-experimental study to test one specific hypothesis derived from this chapter. Your design must be feasible to implement with limited resources (no neuroimaging, no large grants required).

Your design document should include: - A clearly stated hypothesis derived from a specific mechanism in the chapter - Participant selection criteria and recruitment approach - Independent and dependent variables with operationalization - Procedure and materials - Control conditions and potential confounds addressed - Statistical analysis plan - Expected results if the hypothesis is correct - Limitations of your design - How you would interpret null results

Target length: 800-1,000 words.

Exercise 32: Platform Audit and Cognitive Harm Report

Conduct a systematic audit of one social media platform with a focus on features that create cognitive vulnerability based on the mechanisms in this chapter.

Your audit should: - Systematically document every notification type the platform generates, their frequency, and their content framing - Map the platform's content recommendation system against the salience network triggers described in this chapter - Identify specific design elements that create or exploit habit loops - Evaluate the platform's stated user wellbeing policies against its actual design features - Produce an evidence-based harm profile describing the specific cognitive costs the platform imposes - Make three specific, feasible design recommendations that would reduce cognitive harm without eliminating the platform's core functionality

Target length: 1,200-1,500 words with supporting documentation.

Exercise 33: Longitudinal Self-Study

Over a four-week period, systematically vary your social media use and track your cognitive and psychological state.

Week 1 (baseline): No change to your normal behavior. Track daily screen time, mood, sleep, focus quality, and complete a brief standardized attention task each morning.

Week 2 (reduction): Reduce social media use by 50% from baseline. Continue all tracking.

Week 3 (elimination): Eliminate social media use entirely. Continue all tracking.

Week 4 (return): Return to normal use. Continue all tracking.

Analyze your results across all four weeks. Write a 1,000-word structured report of your findings, including: - Your hypotheses at the start - Your data - What the data shows about the relationships between social media use and your cognitive/emotional state - Where your experience confirmed or contradicted this chapter's predictions - Methodological limitations of your self-study

Exercise 34: Comparative Analysis — Two Theories of Attention

This chapter draws primarily on a cognitive neuroscience framework to explain social media's effects. Research at least one alternative theoretical framework that addresses the same phenomena (suggestions: Attention Restoration Theory, Self-Determination Theory, Uses and Gratifications Theory, or Media System Dependency Theory).

Write a 900-word comparative analysis that: - Summarizes each framework's core claims and mechanisms - Identifies what each framework explains that the other does not - Identifies where the frameworks make conflicting predictions - Evaluates which framework has stronger empirical support for the specific phenomena this chapter addresses - Proposes how the frameworks might be integrated into a more comprehensive account

Exercise 35: Intervention Design and Pilot

Design, implement (on yourself or with willing participants), and evaluate a brief cognitive protection intervention — a set of evidence-based practices aimed at reducing the attentional costs of social media use.

Phase 1 (Design): Based specifically on the mechanisms in this chapter, design an intervention with at least four specific components. For each component, cite the specific mechanism it is designed to address and the evidence base supporting the approach.

Phase 2 (Implementation): Implement the intervention for two weeks. Document adherence, challenges, and modifications.

Phase 3 (Evaluation): Assess outcomes using at least two measures (subjective focus quality, screen time data, task performance, mood measures, or others). Compare to pre-intervention baseline.

Phase 4 (Report): Write a 1,000-word intervention report including your design rationale, implementation notes, outcome data, interpretation, and recommendations for refinement.