To Brainstorm or Not to Brainstorm

1. Introduction

When developing new systems, we require creative ideas – not only to be one step ahead of our competitors. In consequence, requirements engineering needs tools for eliciting innovative requirements, the so-called delighters in the Kano model ^[Kano]. The IREB CPRE Foundation Level ^[IREB] suggests using creativity techniques to elicit such delighters.

Anyone who has tried to employ creativity techniques within a development project will most probably have encountered resistance or disapproving looks from at least some of the participants.

Techniques used to elicit satisfiers (e.g. interview) and dissatisfiers (e.g. field observation) are fact-based and as such widely accepted. When it comes to creativity, though, not only the outcome but also the process to get there is not as clear.

In Greek mythology, the secret of creativity was explained by the muses’ kiss, which was thought to explain why some were lucky and others strived in vain. Modern science shows that that perception is not far from the truth.

This article, based on neuropsychological insights, clarifies which variables of creativity can be influenced. It explains four "secrets of creativity" and shows modern ways of charming the muses. It also explains, however, why their kiss can never be taken for granted.

In this article we use the term "creative idea" as defined by Alice Flaherty: "A creative idea will be defined simply as one that is both novel and useful (or influential) in a particular social setting." ^[Flaherty]

2. Scientific Basis

To understand creativity, we need to understand the basic purpose of our brain. This can be reduced to the performance of one task: Checking if things that are going on inside and outside of our body are good or bad for us, and then creating an adequate response. To execute this task, specialized brain areas and neurotransmitters have developed.

If an incoming stimulus is rated as positive, a brain area called the reward system releases the neurotransmitter dopamine, and we experience pleasant emotions such as joy, satisfaction or relief. If the stimulus is not only positive, but also novel or better than expected, there is an additional dopamine release in the reward system. The emotional equivalent of this extra dopamine is surprise, joy again, and, if the stimulus is a result of our own actions, pride. The released dopamine activates the hippocampus, a brain area responsible for memory. In this way, actions and thought patterns that have led to the positive stimulus are stored in long-term memory as templates for similar events in the future.

If the stimulus is rated as negative, the brain reacts with decreased dopamine release and the release of stress hormones. Consequently, the event causing the stress will be memorized as something to avoid in the future, and the thought and action patterns that had led to the negative experience won’t be stored for further use ^[Yager].

If a stimulus is neutral, the brain won’t be further occupied with it and has capacity for doodling: daydreaming, reflecting, ruminating and randomly jumping from one thought to another ^[Mason].

2.1. Chance

Incoming sensory stimuli and also thoughts created by the brain itself are transmitted electrically and chemically between 86 billion neurons, which in turn form an estimated number of almost quadrillion synapses ^{[Herculano-Houzel]}.

This allows countless permutations of signaling; and once a neuronal network is activated, there is no predefined outcome. Also in the absence of external stimulation, when our brain is in the doodling mode, new connections between neurons can emerge and become novel thoughts or actions. Thus, our brain and the environment form an unpredictable system, where unexpected new links happen by chance.

Therefore, the first secret of creativity is, simply, chance.

2.2. Knowledge

Brain activity, however, is not totally random. There are preexisting congenital and acquired patterns that help us to process information systematically. New sensory input is linked with information that is already stored, so that they can be recalled and used together. This is realized by building new synapses between neurons, and the more new information we get, the more synapses we build. With more synapses again, there will be more electrical and chemical activity between neurons when another new stimulus hits the brain. Thus, by storing more and more information, we increase the chance for spontaneous links between neurons and thus the emergence of a new idea ^{[Rakic] [Ganguly]}. We can conclude that the second secret of creativity is "knowledge". The more information we have stored in our brain, the more likely is a new and useful neuronal connection: a creative idea. Or, as Louis Pasteur put it: "Chance favors the prepared mind."

2.3. Motivation

Storing and processing information cost time and energy. The human brain needs one fifth of the body's absorbed oxygen, and about two thirds of the circulating blood glucose for this task ^[Krieger]. So, why would the brain do that?

Like every other living being, we are motivated to survive as an individual, and as a species. We have to maintain homeostasis (the chemical and physical equilibrium in the body), so we have to make sure that we have enough to eat and drink, keep our body temperature stable, and so on. With animals practicing parental care and living in social groupings, we additionally share the need for stable relationships. The better we are integrated in a social group, and the higher our status within the group, the higher is our individual chance of survival. To maintain homeostasis and to rise in rank, we need strategies. These can be basic like knowing where to find food, or elaborate like making financial investments or gaining awards and decorations.

Creativity is the brain's essential tool to create new strategies to meet our needs better - and trying new things is the basis for developing new strategies.

That is why, as mentioned above, our reward system releases more dopamine when there is a new stimulus, even if it is objectively no better than a familiar one. We even experience the lack of new stimuli as discomfort: boredom. Our brain then craves for another dopamine kick and urges us to seek new stimuli, an experience we know as "curiosity" or "sensation seeking" ^[Baxter].

Through this mechanism, we have an innate system that drives us to explore and experiment. But we will only do so if there really is a true need we want to fulfill, and the development of a new strategy is promising to get there. Thus, the third secret of creativity is "motivation".

2.4. Safety

Although creative processes are the basis for advance and improvement, there is no guarantee of success. On the contrary, the chance to fail with a strategy never tested before is higher, and the potential losses are harder to predict. To prevent us from becoming dopamine-driven daredevils, our brain has an efficient risk management program. A brain region called amygdala checks sensory stimuli for their potentially negative impact on our well-being. If the stimulus is classified as a threat, the amygdala triggers the emotional and physical fear and stress reaction ^[Maren].

The stress reaction includes physical arousal and adaption of brain function with one common characteristic: functions that are not directly related to immediate survival are shut down.

This also means that cortical functions that would be necessary for creative thinking are suspended in favor of fast automated fight, flight or fright-reactions.

Besides managing the immediate stress reaction, the amygdala is embedded in a wider risk assessment network. One of the main players in this network is the orbitofrontal cortex ^[Barbas]. The orbitofrontal cortex is responsible for predicting future events and planning actions accordingly. It weighs the desired reward, the costs of new and old strategies and the potential damage in case of failure. This judgment is based on memories of previous actions and outcomes and on input from the amygdala about the current threat situation. It decides whether we explore new environments, follow the new idea we have, or just stick to our old strategies, because they are foolproof and safe ^[Schoenbaum].
Thus, the fourth secret of creativity is “safety”.

2.5. Individual differences

To a certain extent, our brain structure is determined by genetic factors, intrauterine conditions and events around birth ^[Pinker]. Further on, environmental stimulation ^{[Eluvathingal]}, observational learning ^[Bandura] and stress experience influence the development of our individual neuronal structure and function.

2.5.1. Influence of Stress

While short term stress has an impact on our current creative performance, long term stress can impair our ability to be creative for a longer period or even permanently ^[Sandi]. The stress hormone cortisol suppresses the release of neurotrophic factors (substances that promote the growth of synapses and prevent cell death), thus inhibiting new connections between neurons and learning ^[Mcauley]. The longer the period of stress, and the earlier in life it occurs, the more irreversible is the impact of this effect on the brain structure ^[Pagliaccio].

2.5.2. Influence of Past Experiences

How motivated we feel and how much uncertainty we tolerate strongly depends on our individual experience in the past. If we are repeatedly exposed to aversive events without being able to escape them or influence them in a positive way, our amygdala becomes oversensitive to threatening stimuli and we acquire a self-concept of being helpless and living in a dangerous world. Consequently we then stop exploring ^[Seligman]. On the other hand, if we repeatedly master problems successfully, our orbitofrontal cortex will acquire a more optimistic risk perception and we are motivated to take on more and more difficult tasks ^{[Luszczynska]}.

3. Analysis of Selected Creativity Techniques

In the past decades, many techniques and methods have been developed to "make" creative ideas. They usually address one or several of the "secrets of creativity" from chapter 2. In order to select the best technique for your current situation, it makes sense to analyze the situation itself as well as the creativity techniques considered concerning those criteria (secrets of creativity). In the following we will show for two examples whether and how they meet the neurological requirements for creativity. We have chosen Brainstorming, as it is one of the oldest techniques, and the Design Thinking method, as it is not only one technique but a whole process designed to create innovation.

3.1. Brainstorming

What is it?

Brainstorming was invented by Alex F. Osborn. As co-founder of an advertising agency, he faced the challenge of having to come up with new ideas every day. In 1939, he organized the first "group-thinking". As it was very successful, he continued using such "Brainstorm Sessions" and finally published the technique ^{[Osborn 1948]}.

He suggests a group of 5-10 people to sit together for about an hour. The problem to be solved must be outlined clearly ("single target") and the group needs one person to lead the session, who makes sure the following rules are adhered to ^{[Osborn 1948]}:

1. Judicial judgment is ruled out.
2. "Wildness" is welcomed.
3. Quantity is wanted.
4. Combination and improvement are sought.

In addition, every idea is written down and all participants receive a copy of the result.

Chance

This technique improves the chance of a creative idea by going for quantity, allowing for sufficient time (about an hour) and by bringing together different people who inspire each other. Osborn himself put it like this: "'HE WAS LUCKY-he just stumbled on that idea.' Quite often there's a grain of truth in such a comment; but nearly always the truth is that the inspiration would not have come to him if he had not been on the hunt for ideas at the time." ^{[Osborn 1948]}

Knowledge

The technique itself does not include any explicit step to acquire knowledge. Nonetheless, Osborn emphasizes: "To develop creativeness, the mind needs not only to be exercised, but to be filled with material out of which ideas can best be formed. The richest fuel for ideation is experience." ^{[Osborn 1953]}

Motivation

The main motivational aspect of brainstorming is fun. As the technique aims for quantity and does not allow criticism, laughter is almost inevitable when "silly ideas" are voiced. Osborn writes: "The proof of a good brainstorm session is the number of ideas produced and the way the participants feel afterward. If, as they go back to their regular tasks, they tell each other, 'Gee, but that was fun!' the session was probably a success." ^{[Osborn 1948]} He also advises that "Brainstorm sessions should always be kept informal" and to "create the atmosphere of a picnic". Also, when somebody comes up with an idea and the others build on it, this creates further motivation (= being valuable for the group, see 2.3).

Safety

Brainstorming does not allow criticism. Any idea, any thought is allowed, such creating a safe environment. For Osborn, this is a key success factor of brainstorming: "Why is group-brainstorming productive? The main reason is that it concentrates solely on creative thinking and excludes the discouragement and criticism which so often cramp imagination." He also points out that it is the session leader's job to create that safety: "The few fiascoes have been due to failure of leadership [...] The leader who allows criticism to creep into the proceedings likewise fails to get the best out of his brainstormers." ^{[Osborn 1948]}.

Conclusion

Properly applied, brainstorming can help to spark creative ideas. It mainly helps to increase chance and safety. If, however, safety is absent in the everyday business of the company, it may not be enough to proclaim safety in the brainstorming session for the participants to relax. If group members distrust each other outside a Brainstorming session, they will not start trusting each other inside one.

Having sufficient knowledge of the topic to be discussed is a prerequisite for a good Brainstorming session. The technique itself does not provide tools to increase knowledge of the topic.

Motivation can be drawn from Brainstorming if it takes place in a relaxed environment where Brainstorming is fun (= increase of comfort, see 2.3). But if the topic itself is of no relevance to the participants and if they do not benefit themselves in any way from the solution of the problem at hand, Brainstorming cannot help to increase motivation.

Put in a nutshell, a Brainstorming session only makes sense, if

• There is enough time (about an hour),
• The participants benefit from a solution to the problem to be discussed,
• The participants have sufficient knowledge of the topic at hand,
• There is a general sense of safety and trust among the group.

Variant Brainstorming Paradox

A variant of brainstorming is Brainstorming Paradox. It applies the same rules as Brainstorming, only the topic is inverted. Instead of asking for positive results (e.g. How can we improve our software?), negative results are sought for (e.g. How can we decrease the quality of our software?). This twist helps to increase safety as well as motivation. As the question itself is "silly", only "silly ideas" can be the answer. Thinking about them is absurd and as such creates a relaxed and fun atmosphere. In addition, this negative thinking benefits from our brain's constant risk assessment: It is trained to answer the question "what could go wrong?" (See 2.4).

3.2. Design Thinking

What is it?

In contrast to Brainstorming, Design Thinking has neither one clear inventor nor one universally defined process. The term "design thinking" is used to describe a mindset as well as a process. We will look at the process as taught at the Stanford University Institute of Design ^[d.school] as one example of the Design Thinking approach and look at it in the context of requirements engineering.

The Stanford Design Thinking process is divided into five modes: Empathize, Define, Ideate, Prototype, and Test. The modes can be used in the sequence as shown in Figure 2 as well as in a non-linear way, depending on which approach suits best: The Design Thinking Process is meant to be adapted.

In Empathize mode, the requirements engineer learns to understand the stakeholders' needs, way of thinking and what is important for them. They can do so by observation, engagement, interaction or other means.

In Define mode, the requirements engineer builds on what they have learned in Empathize mode and define a "meaningful and actionable problem statement" ^[d.school].

In Ideate mode, the goal is to push "for a widest possible range of ideas from which you can select" ^[d.school]. Here, Brainstorming or other idea generating techniques can be used.

In Prototype mode, artifacts are created with which the stakeholders can interact. In the early stages, they should be quick and cheap to make.
The Test mode brings the prototype to the stakeholders. The objective of this mode is to learn how the prototype can be improved and to learn more about the stakeholders (see Empathize mode).

The Test mode brings the prototype to the stakeholders. The objective of this mode is to learn how the prototype can be improved and to learn more about the stakeholders (see Empathize mode).

Chance

Chance is invited throughout the whole Design Thinking process. The Ideate mode is designed to produce many ideas, thus improving the probability of a "lucky" creative idea. Also, the Test mode is prone to lead to unexpected insights as new input is received from the stakeholders. The knowledge acquired in Empathize mode increases the probability of a suitable idea coming up in any of the other phases.

Knowledge

The whole point of the Empathize mode is to acquire knowledge, not only on a cognitive but also on an emotional level.

Motivation

By generating quick results in Prototype and Test mode, Design Thinking helps to motivate the participants. Here, the dopamine release in the reward system comes into play, leading to a feeling of pride when our idea is perceived positively by the stakeholders.

Safety

The Test phase is designed to deliver quick feedback. Thus, the Design Thinking process helps to shorten phases of uncertainty, resulting in a feeling of safety.

Conclusion

The Design Thinking process and mindset is well designed to create an environment for our brain to become creative. It should not be understood as a vending machine or magic wand for creativity, though. Only if the mindset behind Design Thinking is understood and adopted can the process realize its full potential.

4. Conclusion

4.1. Recommendations to Improve Chances of Creative Ideas

For a creativity session to be successful, we recommend the following:

• Do not fixate on one single creativity technique; ideally use several different techniques that care for different individual needs.

• Be prepared to change course mid-session and use a different technique if the original one does not help the participants to engage in creative thinking. But do not give up too quickly, either.

• Always make sure, no matter which technique you are using, that the four neurological aspects are cared for during your session:

4.1.1. Chance

The factor of chance is the hardest one to influence. Even in the best-prepared creativity session with the best people, who feel safe, have the right knowledge and are motivated, chance may still not happen. What we can do before, during and after creativity sessions is to improve the probability of chance occurring.

The major influencing factor for chance is knowledge (see 2.2, 4.1.1). Additionally, neuronal activity (and as such the probability of the lucky thought happening) can be enhanced by repeating the process in new constellations (e.g. new participants, new environment), thus creating new input.

Lastly, be aware that creativity doesn't stop the moment a creativity technique ends. Whenever the brain switches to "doodle mode" (see 2), it may come up with a new idea. Suddenly, the problem intensely thought about the week before is solved while taking a shower.

4.1.2. Knowledge

We can influence the factor knowledge before and during creativity sessions. E.g.:

• Make sure you have teamed up the right participants with the right knowledge in your creativity session (i.e. stakeholder analysis).
• Provide knowledge input some time before the creativity session takes place. This has two positive effects:
  1. Participants have the possibility to brush up their knowledge of the topic and become more valuable members in the session
  2. Participants get involved with the topic and, consciously as well as unconsciously, start thinking about the topic of the creativity session, improving the probability of a new neuronal connection (see 2.1)
• Start the creativity session by collection and exchange of knowledge on the session’s topic or by a short introduction or video on the topic.

4.1.3. Motivation

Make sure you have the right participants for the right problem. The participants who are required to come up with creative ideas for a problem need to benefit themselves in some way from the ideas they are expected to have. Such benefit could include an improvement of social rank or an improvement of their working environment. Always bear in mind that our brain will not waste energy on creative thinking if it itself has no prospect of benefitting from the investment.

4.1.4. Safety

Security of "Homeostasis" and Basic Needs

Our body's homeostasis must be secured for our brain to work properly. That includes the right level of blood sugar and body heat as well as not being hungry or thirsty. The following recommendations may sound very obvious. We list them anyway, as dissatisfiers are easy to forget.

Make sure:

• To provide food and drink, accessible before and during the workshop.
• The participants know where to find the next restroom and feel free to use it as required.
• To adjust the climate of the room to fit most participants (heating, air conditioning).
• To open the window about once an hour to air the room (if not equipped with an automated ventilation system)
• To plan for regular breaks: 10-15 minutes after each 60-90-minute block is a good rule of thumb.

Security of Self Esteem, Inter-Individual Relationships and Social Rank

Do not team up people in a creativity session who have a history of not getting along with each other. Depending on company and group culture, it may also not be a good idea to team up people with different levels in the hierarchy. Both constellations will most probably reduce social security.

But even with the best creativity techniques and the most carefully selected group of participants you can only influence safety-issues in the work context. You cannot influence individual long-term stress (e.g. caused by health issues, relationship problems, or low self-esteem).

4.2. Summary

Although there is a huge industry built around the creation of creativity, we still have not found the formula to guarantee creative ideas. If we are aware of the influencing factors (chance, knowledge, motivation, safety), we can analyze the current situation as well as the creativity techniques we consider suitable and choose the techniques consciously. This will improve the probability of a truly creative idea coming up.

5. Useful Links

If you would like to improve the probability of selecting a suitable creativity technique even more, it helps to know many different creativity techniques. In the following we list some websites on creativity we find very inspiring. If you have further links you would like to share on the topic, please add them in the feedback section below.

• www.gamestorming.com
• www.creativethinking.net
• www.mycoted.com/Category:Creativity_Techniques
• dschool.stanford.edu/use-our-methods

References

• [Bandura] Bandura, A. (2004). Observational Learning. Learning and Memory. Ed. John H. Byrne. 2nd ed. New York: Macmillan Reference USA, 482-484.
• [Barbas] Barbas, H. (2007, 08). Flow of information for emotions through temporal and orbitofrontal pathways. Journal of Anatomy, 211(2), 237-249.
• [Batey] IREB (2015). Syllabus of the IREB Certified Professional for Requirements Engineering, Foundation Level, Version 2.2., retrieved January 08, 2017, available at: https://www.psychologytoday.com/blog/working-creativity/201102/is-creativity-the-number-1-skill-the-21st-century
• [Baxter] Baxter, A., & Switzky, H. (2008). Exploration and Curiosity. Encyclopedia of Infant and Early Childhood Development, 460-470.
• [Bechara] Bechara, A., Damasio, A. R., Damasio, H., & Anderson, S. W. (1994, 04). Insensitivity to future consequences following damage to human prefrontal cortex. Cognition, 50(1-3), 7-15.
• [Beckett] Beckett, C., Maughan, B., Rutter, M., Castle, J., Colvert, E., Groothues, C., . . . Sonuga-Barke, E. J. (2006, 05). Do the Effects of Early Severe Deprivation on Cognition Persist Into Early Adolescence? Findings From the English and Romanian Adoptees Study. Child Development, 77(3), 696-711.
• [Bernstein] Bernstein, D. (2010). Essentials of psychology. Cengage Learning, 123–124.
• [Berridge] Berridge, K. C. (2012, 04). From prediction error to incentive salience: Mesolimbic computation of reward motivation. European Journal of Neuroscience, 35(7), 1124-1143.
• [Best] Best, B. (2004). The Amygdala and the Emotions. Retrieved 08 January 2017, from http://www.benbest.com/science/anatmind/anatmd9.html
• [Buzsáki] Buzsáki, G. (1989, 01). Two-stage model of memory trace formation: A role for “noisy” brain states. Neuroscience, 31(3), 551-570. doi:10.1016/0306-4522(89)90423-5
• [d.school] HASSO PLATTNER Institute of Design at Stanford (n.d.). An Introduction to Design Thinking PROCESS GUIDE. Retrieved January 08, 2017, from https://dschool.stanford.edu/sandbox/groups/dresources/wiki/welcome/attachments/8e447/d.school%27s%20Design%20Thinking%20Process%20Mode%20Guide.pdf; link not available anymore.
  Alternative document with similar content: HASSO PLATTNER Institute of Design at Stanford (n.d.). Bootcamp bootleg. Retrieved August 21, 2017, from: https://static1.squarespace.com/static/57c6b79629687fde090a0fdd/t/58890239db29d6cc6c3338f7/1485374014340/METHODCARDS-v3-slim.pdf
• [Eluvathingal] Eluvathingal, T. J., Chugani H. T., Behen M. E., et al. (2006, 06). Abnormal Brain Connectivity in Children After Early Severe Socioemotional Deprivation: A Diffusion Tensor Imaging Study. Pediatrics, 117(6), 2093-2100.
• [Flaherty] Flaherty, A. W. (2005). Frontotemporal and dopaminergic control of idea generation and creative drive. The Journal of Comparative Neurology, 493(1), 147-153. doi:10.1002/cne.20768
• [Ganguly] Ganguly, K., & Poo, M. (2013, 10). Activity-Dependent Neural Plasticity from Bench to Bedside. Neuron, 80(3), 729-741.
• [Gray] Gray, D., Brown, S., & Macanufo, J. (2010). Gamestorming: A playbook for innovators, rulebreakers, and changemakers. Sebastopol, CA: O'Reilly.
• [Henckens] Henckens, M. J., Hermans, E. J., Pu, Z., Joels, M., & Fernandez, G. (2009, 08). Stressed Memories: How Acute Stress Affects Memory Formation in Humans. Journal of Neuroscience, 29(32), 10111-10119.
• [Herculano-Houzel] Herculano-Houzel, S. (2009). The human brain in numbers: A linearly scaled-up primate brain. Frontiers in Human Neuroscience, 3.
• [IREB] IREB (2015). Syllabus of the IREB Certified Professional for Requirements Engineering, Foundation Level, Version 2.2., retrieved January 08, 2017, available at: https://www.ireb.org/content/downloads/2-syllabus-foundation-level/ireb_cpre_syllabus_fl_en_v222.pdf
• [Kano] Kano, N., Seraku, N., Takahashi, F. & ichi Tsuhi, S. (1984). Attractive Quality and Must-Be Quality. Journal of the Japanese Society for Quality Control, 14, 147-156.
• [Krieger] Krieger M. (1921). Über die Atrophie der menschlichen Organe bei Inanition [On the atrophy of human organs in inanition]. Z. Angew. Anat. Konstitutionsl. 7, 87–134
• [Kringelbach] Kringelbach, M. L. (2005, 09). The human orbitofrontal cortex: Linking reward to hedonic experience. Nature Reviews Neuroscience, 6(9), 691-702.
• [Kumar] Kumar, V. (2012). 101 design methods: A structured approach for driving innovation in your organization. Hoboken, NJ: Wiley.
• [Luszczynska] Luszczynska, A., & Schwarzer, R. (2005). Social cognitive theory. Predicting health behaviour. Eds. M. Conner & P. Norman. 2nd ed. rev. Buckingham, England: Open University Press, 127–169.
• [Maren] Maren, S. (1999, 12). Long-term potentiation in the amygdala: A mechanism for emotional learning and memory. Trends in Neurosciences, 22(12), 561-567.
• [Mason] Mason, M. F., Norton, M. I., Horn, J. D., Wegner, D. M., Grafton, S. T., & Macrae, C. N. (2007, 01). Wandering Minds: The Default Network and Stimulus-Independent Thought. Science, 315(5810), 393-395.
• [Mcauley] Mcauley, M. T., Kenny, R., Kirkwood, T. B., Wilkinson, D. J., Jones, J. J., & Miller, V. M. (2009). A mathematical model of aging-related and cortisol induced hippocampal dysfunction. BMC Neuroscience, 10(1), 26. doi:10.1186/1471-2202-10-26
• [Michalko] Michalko, M. (2006). Thinkertoys: A handbook of creative-thinking techniques. Berkeley, CA: Ten Speed Press.
• [Osborn 1948] Osborn, A. F. (1948). Your creative power: How to use imagination. New York: C. Scribner's Sons. (Accessed as digital reprint: Read Books Ltd. (epub eBook), April 2013)
• [Osborn 1953] Osborn, A. F. (1953). Applied Imagination - Principles and Procedures of Creative Writing. New York: C. Scribner's Sons. (Accessed as digital reprint: Read Books Ltd. (epub eBook), April 2013)
• [Pagliaccio] Pagliaccio, D., Luby, J. L., Bogdan, R., Agrawal, A., Gaffrey, M. S., Belden, A. C., . . . Barch, D. M. (2014). Stress-System Genes and Life Stress Predict Cortisol Levels and Amygdala and Hippocampal Volumes in Children. Neuropsychopharmacology, 39(5), 1245-1253.
• [Pinker] Pinker, S. (2004) Why nature & nurture won't go away. Dædalus
• [Rakic] Rakic, P. (2002, 01). Neurogenesis in adult primate neocortex: An evaluation of the evidence. Nature Reviews Neuroscience, 3(1), 65-71.
• [Rolls] Rolls, E. T. (2000, 03). The Orbitofrontal Cortex and Reward. Cerebral Cortex, 10(3), 284-294.
• [Salamone] Salamone, J., & Correa, M. (2012, 11). The Mysterious Motivational Functions of Mesolimbic Dopamine. Neuron, 76(3), 470-485.
• [Sandi] Sandi, C., & Pinelo-Nava, M. T. (2007). Stress and Memory: Behavioral Effects and Neurobiological Mechanisms. Neural Plasticity, 2007, 1-20.
• [Schoenbaum] Schoenbaum, G., Takahashi, Y., Liu, T., & Mcdannald, M. A. (2011, 12). Does the orbitofrontal cortex signal value? Annals of the New York Academy of Sciences, 1239(1), 87-99.
• [Seligman] Seligman, M. E. (1975). Helplessness: On depression, development, and death. San Francisco: W.H. Freeman.
• [Spitzer] Spitzer, M., Fischbacher, U., Herrnberger, B., Grön, G., & Fehr, E. (2007, 10). The Neural Signature of Social Norm Compliance. Neuron, 56(1), 185-196.
• [Verweij] Verweij, B., Amelink, G., & Muizelaar, J. (2007). Current concepts of cerebral oxygen transport and energy metabolism after severe traumatic brain injury. Progress in Brain Research Neurotrauma: New Insights into Pathology and Treatment, 111-124.
• [Yager] Yager, L., Garcia, A., Wunsch, A., & Ferguson, S. (2015, 08). The ins and outs of the striatum: Role in drug addiction. Neuroscience, 301, 529-541.

Picture Credits

PeopleImages: "Baking some goodies", iStockphoto
RomoloTavani: "idea of innovation", iStockphoto