Chapter 4: Building a Mind That Lasts

Chapter Introduction

You have spent three chapters learning how your brain works from the inside out. You understand attention — how it filters, focuses, and wanders. You understand emotions and decisions — how fast and slow systems interact, how biases shape judgment, and how regulation widens the space between impulse and action. You understand sleep, dopamine, and development — the forces shaping your brain right now.

This chapter asks the final question: what do you do with all of that?

Knowledge without application is trivia. Coach Brain did not teach you neuroscience to fill a test. Coach Brain taught you neuroscience so you can use it — to build habits that serve you, to design a relationship with technology that is intentional rather than reactive, to develop a cognitive wellness practice you can carry through college, career, relationships, and the decades of life ahead.

This is the capstone. You will learn how habits form at the neurological level. You will examine your relationship with digital technology through the lens of everything you have learned about attention, dopamine, and the adolescent brain. You will encounter the research on long-term cognitive health — what protects the brain across a lifetime. And you will design your own cognitive wellness protocol, grounded in evidence and tailored to your life.

The turtle is patient. The turtle builds slowly. The turtle's shell lasts a lifetime. That is the lesson.

---

Lesson 4.1: How Habits Form (And How They Change)

Learning Objectives

By the end of this lesson, you will be able to:

• Describe the habit loop (cue → routine → reward) and its neurological basis in the basal ganglia
• Explain how habits become automatic — moving from PFC-controlled to basal ganglia-controlled behavior
• Understand why habit change is hard at the neurological level and why willpower alone is insufficient
• Apply the "habit stacking" and "environment design" strategies to build new habits or modify existing ones
• Distinguish between identity-based habits and outcome-based habits

Key Terms

The Loop That Runs Your Life

Approximately 40-45% of your daily actions are habitual — performed without conscious decision. You do not decide to brush your teeth every morning; the cue (waking up, entering the bathroom) triggers the routine automatically. You do not decide how to tie your shoes; the motor pattern runs from the basal ganglia without PFC involvement [1].

This automation is not laziness. It is efficiency. If your PFC had to consciously manage every action — walking, chewing, typing, driving — it would be overwhelmed before breakfast. Habits free the PFC for novel decisions and complex reasoning by delegating routine behaviors to the basal ganglia.

The habit loop has three components:

Cue: A trigger that tells the brain to initiate a behavior. Can be a time (morning), a location (entering the kitchen), an emotional state (feeling bored), a preceding action (finishing a meal), or a social context (being with certain people).

Routine: The behavior itself — the action that follows the cue.

Reward: The reinforcement that tells the brain this loop is worth remembering. Can be physical (a pleasant taste), emotional (relief from boredom), social (a like on a post), or neurochemical (a dopamine hit) [2].

Why Willpower Is Not Enough

If you have ever tried to break a bad habit through sheer determination and failed, neuroscience explains why.

Habits are stored in the basal ganglia — a region that operates below conscious awareness. The PFC can override a habit temporarily (that is what willpower is), but the PFC fatigues. It has limited capacity. When you are tired, stressed, or depleted, the PFC's override weakens and the basal ganglia's automatic program takes over [3].

This is why most people cannot sustain habit change through willpower alone — and why New Year's resolutions have an approximately 80% failure rate by February. The resolution relies on PFC override of a basal ganglia program, and the PFC cannot maintain that override indefinitely.

Effective habit change works with the neurological architecture instead of against it:

Change the cue: Remove the trigger for unwanted habits. If your phone on the nightstand triggers pre-sleep scrolling, charge it in another room. If walking past the vending machine triggers snacking, take a different route.

Replace the routine: Keep the same cue and reward, but substitute a different behavior. If boredom (cue) triggers phone scrolling (routine) for stimulation (reward), replace scrolling with a 2-minute walk or a brief conversation — same cue, same reward category, different routine.

Design the environment: Make desired behaviors easy and undesired behaviors hard. Pre-commitment from Chapter 2 is an environment design strategy. Putting running shoes by the door, pre-packing a lunch, or using website blockers are all examples of designing your physical environment to support the behavior you want [4].

Identity-Based Habits

Researcher James Clear distinguishes between outcome-based habits ("I want to lose weight") and identity-based habits ("I am a person who moves every day"). The neurological difference is significant.

Outcome-based habits rely on external motivation — which fluctuates. Identity-based habits rely on self-concept — which is self-reinforcing. Every time you act consistently with the identity, you accumulate evidence that the identity is true. "I am a person who reads" gets stronger every time you read, regardless of whether you hit a specific book count [5].

For a teenager, this distinction is powerful. Your identity is actively forming right now (Lesson 3.3). The habits you build are not just behaviors — they are votes for who you are becoming. Each repetition is a vote. No single vote is decisive, but the pattern over time becomes your identity.

Lesson Check

1. What are the three components of the habit loop, and where in the brain are established habits stored?
2. Why does willpower alone typically fail to sustain habit change?
3. Describe the "replace the routine" strategy and give an original example.
4. What is the difference between outcome-based and identity-based habits? Why is the identity-based approach more sustainable?

---

Lesson 4.2: The Five Pillars of Cognitive Longevity

Learning Objectives

By the end of this lesson, you will be able to:

• Identify the five research-supported pillars of long-term brain health
• Understand cognitive reserve — why building neural complexity now protects against decline later
• Recognize that brain health is not a future concern — the foundations are laid during adolescence
• Frame cognitive wellness as a lifelong practice, not a one-time achievement

Key Terms

The Five Pillars

Decades of longitudinal research — studying people over 20, 30, even 40 years — have identified five factors that consistently predict long-term brain health. These are not exotic interventions. They are ordinary practices that, when sustained over time, build the cognitive reserve that protects your brain across a lifetime [6].

1. Physical movement. Exercise is the single most powerful intervention for brain health that exists. Aerobic exercise increases hippocampal volume, boosts BDNF production, improves blood flow to the brain, enhances executive function, and reduces neuroinflammation. A 2011 study found that one year of moderate aerobic exercise increased hippocampal volume by 2% in older adults — effectively reversing 1-2 years of age-related shrinkage [7].

You do not need intense training. Walking 30 minutes per day produces measurable cognitive benefits. The minimum effective dose is remarkably low — far lower than most people assume.

2. Sleep. Everything you learned in Lesson 3.1 applies here: memory consolidation, glymphatic waste clearance, synaptic pruning, emotional processing. Chronic sleep deprivation is one of the strongest predictors of cognitive decline in later life. The foundation you build now — consistent sleep habits, circadian rhythm maintenance — pays dividends for decades [8].

3. Social connection. The human brain evolved to be social. The Social Brain Hypothesis proposes that our large neocortex evolved primarily to manage complex social relationships — not to solve abstract problems [9]. Longitudinal studies consistently show that social isolation is associated with accelerated cognitive decline, while strong social networks are protective — even more protective than most cognitive training programs.

4. Continuous learning. The brain maintains plasticity throughout life — but only if it is challenged. Learning new skills, studying unfamiliar topics, engaging with complex material, and exposing yourself to novel experiences all build cognitive reserve. The principle is the same as synaptic pruning: use it or lose it. A brain that stops learning starts declining [10].

5. Stress management. Chronic stress (Lesson 1.4) elevates cortisol, damages the hippocampus, weakens the PFC, and accelerates neuroinflammation. Sustained stress management — through any effective method (meditation, exercise, social support, professional help) — is protective over the long term [11].

Why This Matters Now

Cognitive reserve is not something you start building at 60. The research is clear: the cognitive habits established during adolescence and young adulthood create the foundation that determines resilience decades later. Education level — a proxy for early cognitive engagement — is one of the strongest predictors of cognitive reserve in old age [12].

The habits you build now are not just for now. They are architectural decisions about the brain you will inhabit at 40, 60, and 80. The turtle thinks in decades, not days.

Lesson Check

1. Name the five pillars of cognitive longevity and briefly describe why each matters.
2. What is cognitive reserve, and how is it built?
3. Why is exercise described as "the single most powerful intervention for brain health"?
4. Why does cognitive longevity matter during adolescence, not just in old age?

---

Lesson 4.3: Your Brain in the Digital World

Learning Objectives

By the end of this lesson, you will be able to:

• Analyze your relationship with technology using the attention, dopamine, and habit frameworks from previous chapters
• Distinguish between intentional technology use and reactive technology use
• Understand the research on social media and adolescent mental health — what it shows and what it does not
• Design a personal technology practice that is informed by neuroscience rather than driven by fear or compulsion

Key Terms

The Honest Picture

The research on social media and adolescent mental health is more nuanced than most headlines suggest.

What the research shows:

• Heavy social media use (3+ hours per day) is associated with increased risk of depression and anxiety symptoms in adolescents — particularly in girls [13].
• Social comparison on image-heavy platforms is associated with decreased body satisfaction and self-esteem [14].
• Notification-driven interruptions impair sustained attention and academic performance (Chapter 1).
• Variable-ratio reinforcement designs exploit the adolescent dopamine system (Lesson 3.2).

What the research does not show:

• That social media causes mental illness in most users. The associations are correlational, not causal, and the effect sizes are moderate.
• That all technology use is harmful. Video calls with friends, creative tools, educational content, and collaborative platforms have measurable social and cognitive benefits.
• That the solution is abstinence. Research on complete technology removal shows mixed results — social isolation can be as harmful as compulsive use [15].

The honest answer is that technology is a tool. Like all tools, its effects depend on how it is used. The neuroscience you have learned gives you a framework for evaluating your own use — not through guilt, but through understanding.

Intentional vs. Reactive — The Only Distinction That Matters

The most useful question about your technology use is not "how much?" but "who is driving?"

Intentional use: You pick up your phone to message a friend about plans tomorrow. You open it, send the message, put it down. The PFC directed the action. Duration: 2 minutes.

Reactive use: You pick up your phone because you felt a notification buzz. You check the notification (3 seconds). You see the social media icon. You open it (no conscious decision). You scroll for 25 minutes. You put it down feeling vaguely dissatisfied. The habit loop and dopamine system directed the action. You barely used your PFC.

Both interactions involved a phone. One was a tool serving your goals. The other was a cue-routine-reward loop serving the platform's engagement metrics.

The practice is not to eliminate technology. It is to shift the ratio toward intentional use — and that starts with noticing which mode you are in. Meta-awareness (Chapter 1, Lesson 1.3) is the foundational skill. Notice. Then choose.

Designing Your Digital Practice

Based on everything you have learned across four chapters:

Protect your attention architecture. Notifications are involuntary attention hijacks (Lesson 1.1). Turn off all notifications except from actual humans who need to reach you. Move social media apps off your home screen. Use grayscale mode to reduce visual dopamine cues.

Protect your dopamine baseline. Extended variable-ratio reinforcement sessions (scrolling, gaming) produce spike-and-crash dopamine patterns (Lesson 3.2) that lower your baseline motivation. Front-load your day with sustained-effort activities (exercise, creative work, learning) before engaging with high-stimulation digital content.

Protect your sleep. Screen light in the final hour before bed delays melatonin onset (Lesson 3.1). Charge your phone outside your bedroom. Use a physical alarm clock.

Build friction for reactive use, remove friction for intentional use. This is environment design (Lesson 4.1) applied to technology. Make the mindless behavior harder to access. Make the intentional behavior easier.

Lesson Check

1. What is the difference between intentional and reactive technology use? Give one example of each.
2. What does the research on social media and adolescent mental health actually show — and what does it not show?
3. Design two specific changes to your phone or digital environment using concepts from this curriculum.
4. Why is meta-awareness (from Chapter 1) the foundational skill for healthy technology use?

---

Lesson 4.4: Capstone — Your Cognitive Wellness Protocol

Learning Objectives

By the end of this lesson, you will be able to:

• Synthesize everything you have learned across four chapters into a personal cognitive wellness protocol
• Support your protocol choices with evidence from the curriculum
• Design a practice that is realistic, sustainable, and tailored to your actual life
• Present your protocol as a living document — something that evolves as you do

The Capstone Assignment

Design a personal cognitive wellness protocol (500-800 words) covering five domains.

For each domain, describe one specific, realistic practice you will implement — and cite the evidence from this curriculum that supports it.

The five domains:

1. Attention — One practice for strengthening or protecting your attention system.
2. Emotional regulation — One strategy for widening the gap between stimulus and response.
3. Sleep — One change to your current sleep practice based on what you learned about circadian biology.
4. Dopamine management — One adjustment to how you engage with high-stimulation activities (technology, social media, gaming, etc.).
5. Long-term investment — One habit that builds cognitive reserve for your future brain.

For each domain, include:

• The specific practice (what you will do, when, and how)
• The evidence (cite the lesson, concept, or study that supports it)
• The identity statement (who this practice helps you become — identity-based framing from Lesson 4.1)

Example entry (do not copy — write your own):

Domain: Attention. Practice: 5 minutes of focused-attention meditation each morning before checking my phone. Evidence: Hölzel et al. (2011) found measurable PFC gray matter increases after 8 weeks of practice; Zeidan et al. (2010) found improvements in sustained attention within 2-4 weeks of 10-minute daily sessions. Identity: "I am a person who trains their attention deliberately."

Scoring

Total: 30 points

A Final Word from Coach Brain

You now know more about how your brain works than most adults will ever learn.

You know that attention is trainable. You know that emotions are data. You know that your dopamine system can be directed rather than exploited. You know that sleep is the foundation everything else stands on. You know that your brain is still under construction — and that the construction is both a vulnerability and the greatest opportunity you will have.

What you do with this knowledge is yours. Coach Brain taught you the science. The application is your life.

Sit still with me for a moment. Breathe. Notice what you notice.

Then go build something that lasts.

Lesson Check

This lesson has no separate lesson check. The capstone protocol is the assessment.

---

End-of-Chapter Activity

The capstone protocol (Lesson 4.4) serves as the end-of-chapter activity. Students should be given 2-3 class periods for research, drafting, and revision.

---

Vocabulary Review

---

Chapter Quiz

Multiple Choice:

1. Approximately what percentage of daily actions are habitual? A) 10-15% B) 25-30% C) 40-45% D) 75-80%

2. The habit loop consists of: A) Motivation → Action → Satisfaction B) Cue → Routine → Reward C) Thought → Decision → Outcome D) Stimulus → Processing → Response

3. Research on habit formation shows the median time to automaticity is approximately: A) 21 days B) 66 days C) 7 days D) 365 days

4. BDNF (Brain-Derived Neurotrophic Factor) is most potently stimulated by: A) Meditation B) Physical exercise C) Social media use D) Caffeine consumption

5. The difference between intentional and reactive technology use is: A) The amount of time spent B) Whether the PFC or the habit/dopamine system is directing the behavior C) Whether you are on WiFi or cellular data D) The type of device used

6. Cognitive reserve is built through: A) Avoiding all stress B) Education, complex mental activity, social engagement, and physical fitness C) Sleeping more than 12 hours per day D) Using brain-training apps

7. Identity-based habits are more sustainable than outcome-based habits because: A) They require less effort B) Each repetition reinforces the identity, creating a self-reinforcing cycle C) They produce faster results D) They do not require any practice

8. The Social Brain Hypothesis proposes that: A) Social media is good for the brain B) The human neocortex evolved its large size primarily for managing complex social relationships C) Social isolation has no cognitive effects D) Intelligence is determined by social status

9. The most effective approach to changing a habit is: A) Using willpower to override it indefinitely B) Working with the neurological architecture — changing the cue, replacing the routine, or redesigning the environment C) Punishing yourself when you fail D) Ignoring the habit until it goes away

10. "When I get home from school, I will put my phone in the drawer and read for 15 minutes" is an example of: A) Cognitive reappraisal B) An implementation intention with habit stacking C) A cognitive bias D) Variable ratio reinforcement

Short Answer:

1. Explain why willpower alone is neurologically insufficient for sustained habit change. Reference the PFC and basal ganglia.

2. Design a habit stack for building a new daily practice. Identify the existing habit, the new habit, and the reward.

3. A friend spends 4 hours per day on social media and says "I could stop any time, I just don't want to." Using concepts from Lessons 3.2 and 4.3, evaluate this claim.

4. Explain why the five pillars of cognitive longevity matter during adolescence, not just in old age. Use the concept of cognitive reserve.

5. Write the attention domain entry for your capstone protocol. Include the specific practice, the evidence, and the identity statement.

---

Teacher's Guide

Pacing Recommendations

Quiz Answer Key

1. C, 2. B, 3. B, 4. B, 5. B, 6. B, 7. B, 8. B, 9. B, 10. B

2. Habits are stored in the basal ganglia, which operates below conscious awareness. The PFC can temporarily override habits (willpower), but the PFC fatigues — it has limited capacity that depletes with use, stress, and fatigue. When the PFC's override weakens, the basal ganglia's automatic program resumes. Effective habit change works with the architecture (changing cues, replacing routines, designing environments) rather than relying on sustained PFC override.

3. Accept any well-structured example. Format: "After I [existing habit], I will [new habit], which gives me [reward]." Example: "After I brush my teeth (existing), I will read one page of a book (new), which gives me a moment of calm before sleep (reward)." Key: the existing habit provides a reliable cue, the new habit is small enough to not require willpower, and the reward reinforces the loop.

4. "I could stop any time" is likely inaccurate at the neurological level. Social media uses variable ratio reinforcement (Lesson 3.2), which produces the highest dopamine anticipation and is the most compelling reinforcement schedule. The adolescent dopamine system is hypersensitive (Lesson 3.2), making the behavior more neurologically compelling than it would be for an adult. The behavior pattern (4 hours daily, cue-driven, reactive) suggests basal ganglia-driven habit, not PFC-directed intentional use. The friend may genuinely believe they could stop — but the neurological mechanisms suggest the habit loop is stronger than conscious will predicts.

5. Cognitive reserve — the brain's resilience against decline — is built cumulatively. Education level during adolescence is one of the strongest predictors of cognitive reserve in old age. The neural complexity built through learning, exercise, social connection, and sleep during the sensitive period of adolescence creates the foundation for decades of brain health. Starting at 60 is still beneficial, but the returns are smaller than starting at 16.

6. Accept any well-structured entry with specific practice, accurate evidence citation, and identity statement. Example provided in lesson as reference. Key evaluation: Is the practice specific and actionable? Does the evidence actually support it? Is the identity statement framed as becoming, not achieving?

Common Student Questions

Q: Is it realistic to meditate and exercise and sleep 9 hours AND limit screen time? That sounds like a full-time job. A: The point of the capstone is not to do everything — it is to choose one practice per domain that is realistic for YOUR life. Five minutes of meditation, walking to school, a consistent bedtime, and charging your phone outside your bedroom is a complete cognitive wellness protocol. Simple, sustainable, and grounded in evidence. The enemy of good habits is not laziness — it is trying to do too much at once.

Q: What if I tried to build a habit and failed? A: Every behavior you perform is a vote for your identity. A missed day is one vote, not a verdict. The research on habit formation shows wide variation (18-254 days to automaticity) — which means it is normal for some habits to take months. The relevant question is not "did I do it perfectly?" but "am I doing it more often than not?"

Q: Aren't some people just born with better brains? A: Genetics matter — they influence processing speed, working memory capacity, and temperament. But neuroplasticity means the brain you are born with is not the brain you are stuck with. The cognitive habits you build — especially during the sensitive period of adolescence — have measurable effects on brain structure and function. The five pillars work regardless of your starting point.

Parent Communication Template

Dear Parent/Guardian,

Your student is completing Chapter 4: Building a Mind That Lasts — the final chapter of CryoCove's brain science curriculum. This chapter covers:

• How habits form at the neurological level and evidence-based strategies for building beneficial habits
• The five pillars of lifelong cognitive health: movement, sleep, social connection, learning, and stress management
• Digital wellness: an honest examination of technology's effects on the adolescent brain, with practical strategies based on neuroscience rather than fear
• A capstone protocol where students design their own cognitive wellness practice

Key things to know:

• The technology lesson presents research honestly — including what the data does and does not show. We avoid both "screens are destroying your brain" alarmism and "technology is fine" dismissiveness
• The capstone asks students to design a personal protocol. Each student's protocol will be different — there is no single correct answer
• This chapter explicitly frames brain health as a lifelong practice, not a teenage concern

This marks the completion of Coach Brain's curriculum. Thank you for supporting your student through all four chapters.

---

Illustration Briefs

Illustration 1: Lesson 4.1 — The Habit Loop

• Placement: After habit loop explanation
• Scene: Circular loop diagram: Cue → Routine → Reward → (repeat). Below: brain showing basal ganglia highlighted. Coach Brain tracing the loop.
• Mood: Clear, educational, kinetic
• Aspect ratio: 16:9 web, 4:3 print

Illustration 2: Lesson 4.2 — The Five Pillars

• Placement: After five pillars overview
• Scene: Five columns supporting a brain structure. Each labeled: Movement, Sleep, Connection, Learning, Stress Management. Coach Brain standing among the pillars.
• Mood: Architectural, stable, long-term
• Aspect ratio: 16:9 web, 4:3 print

Illustration 3: Lesson 4.3 — Intentional vs. Reactive

• Placement: After intentional/reactive comparison
• Scene: Split image. Left: a person calmly using phone with a clear thought bubble ("message friend about tomorrow"). Right: same person slumped, glazed, scrolling with dopamine symbols around them and a clock showing 25 minutes. Coach Brain in the middle holding a mirror.
• Mood: Honest, relatable, not judgmental
• Aspect ratio: 16:9 web, 4:3 print

---

Citations

1. Wood, W. & Neal, D.T. (2007). A new look at habits and the habit-goal interface. Psychological Review, 114(4), 843-863. DOI: 10.1037/0033-295X.114.4.843

2. Duhigg, C. (2012). The Power of Habit. Random House. [Book — framework reference for habit loop]

3. Baumeister, R.F. et al. (1998). Ego depletion: Is the active self a limited resource? Journal of Personality and Social Psychology, 74(5), 1252-1265. DOI: 10.1037/0022-3514.74.5.1252

4. Gollwitzer, P.M. (1999). Implementation intentions: Strong effects of simple plans. American Psychologist, 54(7), 493-503. DOI: 10.1037/0003-066X.54.7.493

5. Clear, J. (2018). Atomic Habits. Avery. [Book — identity-based habit framework]

6. Livingston, G. et al. (2020). Dementia prevention, intervention, and care: 2020 report of the Lancet Commission. The Lancet, 396(10248), 413-446. DOI: 10.1016/S0140-6736(20)30367-6

7. Erickson, K.I. et al. (2011). Exercise training increases size of hippocampus and improves memory. Proceedings of the National Academy of Sciences, 108(7), 3017-3022. DOI: 10.1073/pnas.1015950108

8. Walker, M.P. (2017). Why We Sleep. Scribner.

9. Dunbar, R.I.M. (1998). The social brain hypothesis. Evolutionary Anthropology, 6(5), 178-190. DOI: 10.1002/(SICI)1520-6505(1998)6:5<178::AID-EVAN5>3.0.CO;2-8

10. Stern, Y. (2012). Cognitive reserve in ageing and Alzheimer's disease. Lancet Neurology, 11(11), 1006-1012. DOI: 10.1016/S1474-4422(12)70191-6

11. McEwen, B.S. (2007). Physiology and neurobiology of stress and adaptation. Physiological Reviews, 87(3), 873-904. DOI: 10.1152/physrev.00041.2006

12. Valenzuela, M.J. & Sachdev, P. (2006). Brain reserve and dementia: A systematic review. Psychological Medicine, 36(4), 441-454. DOI: 10.1017/S0033291705006264

13. Twenge, J.M. & Campbell, W.K. (2019). Media use is linked to lower psychological well-being: Evidence from three datasets. Psychiatric Quarterly, 90(2), 311-331. DOI: 10.1007/s11126-019-09630-7

14. Fardouly, J. et al. (2018). Instagram use and young women's body image concerns and self-objectification. Body Image, 26, 61-67. DOI: 10.1016/j.bodyim.2018.06.002

15. Orben, A. & Przybylski, A.K. (2019). The association between adolescent well-being and digital technology use. Nature Human Behaviour, 3(2), 173-182. DOI: 10.1038/s41562-018-0506-1

16. Lally, P. et al. (2010). How are habits formed: Modelling habit formation in the real world. European Journal of Social Psychology, 40(6), 998-1009. DOI: 10.1002/ejsp.674

17. Hölzel, B.K. et al. (2011). Mindfulness practice leads to increases in regional brain gray matter density. Psychiatry Research: Neuroimaging, 191(1), 36-43. DOI: 10.1016/j.pscychresns.2010.08.006

18. Zeidan, F. et al. (2010). Mindfulness meditation improves cognition. Consciousness and Cognition, 19(2), 597-605. DOI: 10.1016/j.concog.2010.03.014

19. Balban, M.Y. et al. (2023). Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine, 4(1), 100895. DOI: 10.1016/j.xcrm.2022.100895

20. Posner, M.I. & Rothbart, M.K. (2007). Research on attention networks. Annual Review of Psychology, 58, 1-23. DOI: 10.1146/annurev.psych.58.110405.085516

21. Galván, A. (2010). Adolescent development of the reward system. Frontiers in Human Neuroscience, 4, 6. DOI: 10.3389/neuro.09.006.2010

22. Casey, B.J. et al. (2008). The adolescent brain. Developmental Review, 28(1), 62-77. DOI: 10.1016/j.dr.2007.08.003

23. Arnsten, A.F.T. (2009). Stress signalling pathways that impair prefrontal cortex structure and function. Nature Reviews Neuroscience, 10(6), 410-422. DOI: 10.1038/nrn2648

24. Lupien, S.J. et al. (2009). Effects of stress throughout the lifespan on the brain, behaviour and cognition. Nature Reviews Neuroscience, 10(6), 434-445. DOI: 10.1038/nrn2639