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Snap Out of It!

by Jesha Harlalka

art by Ariel Brown-Ogha

The room is brightened with the sunrise, and your eyes fly open with the blaring sound of your alarm. Soon enough, you make your way through the bustling morning commute to your local cafe only to find that your usual—a blueberry muffin—is sold out. You’re then forced to make a conscious decision: what would you like to order instead? Which other muffins are around the same price? Do any of them have ingredients that you are allergic to? Which one will taste good with your coffee? Typically, you do not need to think about these factors because you are ordering your usual, but now they are all things you need to consider. If you were ordering your usual muffin, it would have been an unconscious decision. You are said to be conscious when you are aware of sensations, feel emotions, form mental imagery, and experience overall higher cognitive functioning [1]. So in which situations do you switch from unconscious to conscious? What is the mechanism for this switch?

The shift from unconscious to conscious decision-making underscores the intricate nature of consciousness in our daily choices. To explain this difference in states, psychologists Tversky and Kahneman introduced the Dual Processing Model, which delineates two systems: System 1 and System 2 [2]. To better understand the differences between these systems, we will refer to System 1 as the ‘Instinctive System’ and System 2 as the ‘Deliberate System.’ System 1 is unconscious, fast, automatic, and intuitive, based on instincts and past experiences. On the other hand, System 2 is conscious, slow, and rational— and thus less prone to mistakes [2]. In unfamiliar situations, such as ordering a different muffin or navigating new roads, we employ the Deliberate System. However, once we practice a task enough, it shifts from the Deliberate System to the Instinctive System. For example, daily activities like brushing teeth and tying shoelaces may have initially been dependent on the Deliberate System, but over time, have shifted to the Instinctive System due to practice.

Furthermore, Tversky and Kahneman theorize that we tend to rely on the Instinctive System rather than the Deliberate System because we often resort to taking mental shortcuts rather than thinking our actions through [3]. However, this reliance on the Instinctive System often leads to mistakes. This happens because we base our decisions on past information rather than the information immediately available to us. For instance, before leaving your house, Apple Maps alerts you that your usual route to the local cafe is blocked. Despite this information, you still take the same path you have taken daily, just to reroute when you inevitably encounter the block. In this situation, you have based your decision on the fact that this route is the shortest and most accessible, prioritizing prior information over more recent and relevant information such as the road being blocked. It is our Instinctive System that causes this reliance on previous information. This dependence on the Instinctive System is further evidenced by the Wason selection task, a study first run by Peter C. Wason in which participants were presented with a logical, abstract puzzle containing four cards [4]. The puzzle was relatively easy to solve if the participant was paying attention—in other words, doing it consciously. At its simplest, this was a test of logic similar to the one described below.

The statement “If there is an A on one side of the card, then there is a 4 on the other

side” is provided alongside four cards showing A, D, 4, and 7. The subject is told that each card has a letter on one side and a number on the other, and then asked to select only the cards that need to be turned over to determine whether

the rule is true or false. While the correct answer was turning over the cards A and 7 (since it is the only combination that can falsify this rule) the two most common errors were failing to select the 7 or unnecessarily selecting 4. Wason found that despite the ease of the puzzle, participants repeatedly selected wrong answers that they were unable to explain later [4].

A potential explanation for these errors is that participants were relying on the Instinctive System to make decisions during the task, and were therefore unable to solve the puzzle correctly despite repeated attempts. The fact that the participants could not explain their answers suggests that they were not thinking logically or rationally. While the participants’ shortcuts made the process quicker, it also led to biases and errors due to their reliance on past experiences and preconceived notions rather than a thorough analysis of information currently present. The puzzle required careful logical reasoning and conscious thought—it required use of the Deliberate System—but the participants relied predominantly on the Instinctive System, leading to poor decision-making [4].

Now that we have established that we do use two different systems when making decisions, it leads us to the question: what is the neuroscientific evidence for the dual processing mod- el? Which neural regions are involved? Fink et al. established connections between the Instinctive System, the Deliberate System, and the frontal regions of the brain, which are active during conscious decision-making [5].

Fink et al. based their study on the assumption that creative activity uses the Deliberate System because it requires conscious effort, unlike mundane activity which is done routinely through the Instinctive System. In order to investigate this hypothesis, researchers created a test composed of four tasks—two were said to be creative while the two others were centered around verbal intelligence.

With the help of an electroencephalogram (EEG)—a non-invasive method of measuring the brain’s electric fields—the study found that frontal regions of the brain were active while engaging in creative tasks [5]. The frontal regions of the brain are integral to voluntary movement, expressive language, and the management of higher-level executive functions, and therefore can be attributed to the Deliberate System. Furthermore, individuals with more creative answers had greater synchronization in the right than in the left hemisphere of their posterior parietal brain regions. These regions are related to spatial perception, maintaining an alert state by directing attention, and hand-eye coordination—all of which fall under the characteristics of the Deliberate System [5]. Hence, this study presents us with a stronger understanding of which brain regions play a role in conscious thinking utilizing the Deliberate System.

Now let’s take a break and do a fun task to test whether you’re conscious right now! State the color of the following words: BLACK, GREEN, WHITE. If your replies were black, green, and white, you were unconscious of what you were doing. However, if your answers were blue, red, and green, congratulations on making a conscious decision!

The test you completed was developed by John Ridley Stroop, whose findings led to the formulation of the Stroop Effect [6]. According to this theory, our ability to focus is limited to one source of information at a time. When faced with multiple sources of information at once, it is critical to make conscious decisions, as unconscious ones will lead to inaccuracies.

While Tversky and Kahneman’s Dual Processing Model explores the Instinctive and Deliberate systems, the Stroop Effect delves into our inability to process multiple sources of infor- mation at a time, which Stroop classifies as selective attention. This leads to a delay in reaction time when we are presented with incongruent stimuli (conflicting sources of information presented at once), compared to congruent stimuli (no conflicting information) [6]. The Stroop Effect suggests that we are only able to focus on one aspect of complex problems and ignore other aspects. The delay in processing incongruent stimuli contributes to our understanding of how cognitive processes shape decision-making outcomes.

J. Ridley Stroop measured the time participants took to verbally report the color of the ink given in equal-sized lists [7]. The findings revealed that participants took approximately 47 seconds longer to identify the colors in the incongruent condition compared to the congruent condition [7]. During the congruent condition, the influence of the Instinctive System was predominant, characterized by automatic and unconscious processing. In contrast, the incongruent condition, which in- volved identifying the color of the words rather than the words themselves, required the Deliberate System, classified as a more cognitive and conscious effort. Participants encountered greater difficulty with the second task, often reading the word instead of its color, indicating the automatic response of the Instinctive System where participants answered unconsciously rather than consciously. Stroop concluded that the 74% increase in reaction time was due to interference, in which participants had to consciously use the Deliberate System to override the Instinc- tive System [7]. The automatic, unconscious nature of the Instinctive System creates tensions when individuals consciously attempt to engage the Deliberate System, resulting in inter- ference and an observable increase in reaction time. This offers insights into the dynamics of cognitive processes during tasks that require selective attention and conscious decision-making.

However, in order to be fully convinced of the Stroop effect, we can look at the neuroscientific evidence. A recent experi- ment by Song and Hakoda helps to deepen our understanding of Stroop’s observations on the cognitive mechanisms involved in processing incongruent stimuli by demonstrating how the Stroop Effect affects the neurobiology of certain parts of the brain [8]. Stroop Interference (SI) refers to the extended time taken to recite the color of the ink in the incongruent list, while Reverse Stroop Interference (RI) refers to the extent to which it takes longer to read a word written in an incongruent color. The researchers conducted four tests. Test 1, the control condition for the SI test, involved a color patch shown in the middle of the screen. The participants were asked to choose the matching color from five color words written in black ink. Test 2, the SI test, was the same procedure as the original Stroop study. Test 3 was the control test for the RI condition, where the color word combination was written in black ink and the participants were asked to choose which one matched the color patch (e.g. RED). Test 4 was the RI test, in which the color-word combi- nation was written in incongruent ink (e.g. RED). The participants were once again asked to choose which one matched the color patch. Theoretically, if the correspondence between the semantic meaning of the word and the ink color did not affect semantic processing, participant results from Test 3 and Test 4 should not have differed [8].

After carrying out the test, the researchers concluded that RI interference must be closely related to activity in the prefrontal and cingulate cortices [8]. These regions relate to the activity of memory and reward. During Test 4, certain brain regions had

to exert more cognitive control compared to Test 2, leading to the conclusion that the RI test is a better tool than the SI test. The left middle frontal gyrus (which plays a key role in the de- velopment of literacy), left inferior frontal gyrus (related to language, executive function and social cognition), and prefrontal lobe (which regulates our thoughts, actions and emotions) are all prefrontal regions commonly activated by the SI and the RI tasks [8]. Hence, the researchers were able to biologically prove the stimulus’ effect during the Stroop test.

Now, after all that effort, what if I told you that according to some scientists, the Deliberate System does not exist? That you have no free will such that decisions are made in your brain before you think you’ve made them? You are probably puzzled and shocked, so let me explain. Let’s suppose I ask you to flex your wrist at any point over a period of five minutes and then ask you to record the time at which you decided to flex your wrist. You may believe that you decided to flex your wrist at a particular time—let’s say the two-minute mark. However, according to scientist Benjamin Libet, it was decided in your brain sometime before that mark.

Before we delve into the experiment, it is important to know that electric activity in neurons begins up to a second earlier than the actual movement when dealing with simple movements, and for an even longer time when dealing with a more complex series of movements [9]. This electric change is known as the readiness potential (RP). This RP is measured via EEG. Electrodes placed on the scalp record voltage potentials resulting from current flow in and around neurons [9].

Before we delve into the experiment, it is important to know that electric activity in neurons begins up to a second earlier than the actual movement when dealing with simple movements, and for an even longer time when dealing with a more complex series of movements [9]. This electric change is known as the readiness potential (RP). This RP is measured via EEG. Electrodes placed on the scalp record voltage potentials resulting from current flow in and around neurons [9].

In order to understand the neuroscientific implications, another modified version of Libet’s experiment was conducted [11]. Eight participants were asked to perform a series of tests under EEG and electromyography (which records the electrical activity of muscles via electrodes) scanning, all involving the face of a clock with a revolving dot. In the first (“M”) series, participants were asked to click a button at any point, and report at what moment, according to the position of the dot on the clock, they realized they had begun to click the

button. The second (“W”) series was almost identical except that participants were asked to report when they felt the urge to first move. During the third (“S”) series, the participants had a tactile skin simulator attached to their left wrist and reported the time at which they registered stimulation from the simulator. In the fourth (“P”) series, also known as the pre-set series, the clock face presented the moving dot along with a bright green static “target” point. The participant’s task was to click the button when the moving dot reached the target point. Similar to the W series, only the EEG was recorded. The results of all four series were found to be in accordance with Libet’s theory that the brain decides the activity before an individual can sense that the activity will take place [11].

Hence, Libet’s experiment gives us a lot to think about. Does our free will to do simple actions like flexing our wrists not exist? If it doesn’t exist for these actions, does it also not exist for larger cognitive decisions that would classify as decisions under the Deliberate System?

While Libet leaves us with a lot to ponder, I hope you remember that in all situations, you should not solely rely on your Instinctive System, but remember to switch to the Deliberate System when needed. Either way, the next time your favorite muffin is no longer available in the morning and you’re forced to choose another one, remember that it is your Deliberate System at work.


  1. Liljenström, H. (2022). Consciousness, decision making, and volition: freedom beyond chance and necessity. Theory in Biosciences = Theorie in Den Biowissenschaften, 141(2), 125–140. 021-00346-6

  2. Diederich, A., & Trueblood, J. S. (2018). A dynamic dual process model of risky decision making. Psychological Review, 125(2), 270–292. https://doi. org/10.1037/rev0000087

  3. Evans, J. S. B. T. (2010). Intuition and Reasoning: A Dual-Process Perspec- tive. Psychological Inquiry, 21(4), 313–326. 40X.2010.521057

  4. Wason, P. C. (1968). Reasoning about a rule. Quarterly Jour- nal of Experimental Psychology, 20(3), 273–281. https://doi. org/10.1080/14640746808400161

  5. Fink, A., Grabner, R. H., Benedek, M., Reishofer, G., Hauswirth, V., Fally, M., ... Neubauer, A. C. (2008). The creative brain: Investigation of brain activity during creative problem solving by means of EEG and FMRI. Hu- man Brain Mapping, 30(3), 734–748.

  6. MacLeod, C. M. (1991). John Ridley Stroop: Creator of a landmark cogni- tive task. Canadian Psychology / Psychologie canadienne, 32(3), 521–524.

  7. Cothran, D. L., Larsen, R. J., Zelenski, J. M., & Prizmic, Z. (2012). Do Emotion Words Interfere with Processing Emotion Faces? Stroop-Like Interference versus Automatic Vigilance for Negative Information. Imag- ination, Cognition and Personality, 32(1), 59–73. IC.32.1.e

  8. Song, Y., & Hakoda, Y. (2015). An fMRI study of the functional mecha- nisms of Stroop/reverse-Stroop effects. Behavioural Brain Research, 290, 187–196.

  9. Travers, E., Khalighinejad, N., Schurger, A., & Haggard, P. (2020). Do readiness potentials happen all the time? NeuroImage, 206, 116286.

  10. Fifel, K. (2018). Readiness Potential and Neuronal Determinism: New Insights on Libet Experiment. Journal of Neuroscience, 38(4), 784–786.

  11. Dominik,T.,Dostál,D.,Zielina,M.,Šmahaj,J.,Sedláčková,Z.,& Procházka, R. (2018). EEG data and introspective reports from the Libet’s experiment replication. Data in Brief, 20, 2040–2044. https://doi. org/10.1016/j.dib.2018.09.066

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