Each day, millions of people around the world wake up desiring a hot cup of fresh coffee. In the United States, seven in ten Americans consume coffee weekly, and 62 percent drink coffee daily (National Coffee Association, 2023). Is it a decision based on a learned condition by our brain and bodies in response to what coffee provides us? What exactly does coffee offer us and why has this substance become a household staple the world over?
For this paper, we will examine in detail the decision-making process involved in the choice to make a cup of coffee. Our aim will be to also address the substance within the coffee, caffeine, which is most connected to the desire to drink coffee mainly because of the energizing effects of caffeine, (Coffee.org, 2023). This paper will discuss the decision-making process involved in making a cup of coffee and contrast that decision with the effects the first cup of coffee has on our brain and neurological function. This paper aims to conduct an in-depth investigation into our brain and body’s desire for caffeine.
Understanding the relationship between coffee and the brain requires a few moments of clarification to effectively scope two conditions: first, the decision-making and choice to brew a cup of coffee in the morning, and second, the psychoactive properties of caffeine. To deepen our understanding of the substance investigated, we must understand that a cup of coffee, comprised of 8 fluid ounces of water, contains 40 mg of caffeine. This is the composition of coffee made at most restaurants and commonly brewed at home (U.S. Department of Agriculture, 2023). Caffeine is rapidly absorbed and distributed throughout the body. Peak concentrations of caffeine are typically reached within an hour of consumption. Caffeine is also thought to be a reinforcer, having both positive and negative effects. Finally, caffeine is one of the most consumed psychoactive substances (Evatt & Griffiths, 2013).
The desire to make coffee could be investigated first from a cytoarchitectonic approach. Selecting that approach, we must first determine the brain structure involved with initiating the task in question. Alongside this study, we will also make a short correlation to the effects of caffeine on neural pathways and why the substance may have addictive properties.
From our lectures and shared learning, we understand that the prefrontal cortex (PFC) is one of the main structures of the brain involved in decision-making. The PFC is located in the anteriormost portion of the frontal lobe. The idea that the PFC plays a critical role in decision-making is evidenced by scientists’ investigation of human patients having damage to the PFC. In patients with damage to the PFC, researchers have concluded that poor judgment and decision-making are highly correlated to PFC damage (Struss & Benson, 1986). The PFC is understood to be responsible for maintaining representations in the context of working memory. Interestingly, the PFC receives dopaminergic signaling from the ventral tegmental area, accordingly the dopaminergic reward systems may also be a cornerstone factor in the decision to consume caffeine. The phasic release of dopamine in the PFC may enhance or inhibit learning and, therefore, decision making (D’Ardenne et al., 2012). Essentially, activities that promote a positive dopaminergic reward response may be likely to be remembered and recalled by working memory more effectively, whereas those not receiving a dopaminergic response are not as readily recalled. Furthermore, dopaminergic neurons are important components in the reinforcement of learning and motivation (Dreyer, Herrik, Berg, & Hounsgaard, 2010).
The role of the hippocampus is another structure involved in the decision-making process, especially from the standpoint of sequential memory. Building upon that connection, the author has chosen to make a cup of coffee in the morning. The sequence of my morning activities includes, among other things, rolling around in bed, delaying the inevitable task of getting out of it. Usually following the last silence of the alarm, I finalize my decision about getting out of bed and solidify the next one: brewing a cup of coffee. The coordination of these events together culminates in a sequence of events. Sequential memories are accessed by the hippocampus (Fortin, Agster, & Eichenbaum, 2023).
Understanding basic research methodologies is required to understand the study of research initiatives completely. In the most basic form, we must realize that biology, in a somatic intervention, is the independent variable, and the resulting behavior is the dependent variable. Generally, researchers aim to measure outcomes by manipulating some component of a biological system (the independent variable) and then measure the outcome of the manipulation on behavior (the dependent variable).
Fortin et al. illustrated the cause-effect relationship between the brain and behavior well in their somatic approach to their study of the hippocampus and its association with sequential memory in lab rats. Postulating that the hippocampal area of rats was highly responsible for sequential memory, two groups of rats were studied. In one group, the hippocampal region was left intact, and the rats completed a sequence of tasks. This group is known as the control group. Their behavior was recorded. Using a lesion study, the independent variable, researchers aimed to determine if the sequence of a stimulus produced a different sequential outcome for the rats. The outcome, in this case, was the dependent variable, whereas the lesion group was the independent variable. This research approach is classified as a somatic approach due to using a lesion aimed to modify biology and the resulting behavior measured.
The study concluded that rats with damage to the hippocampal region are less likely to remember sequentially inspired events. Relating this to the instant study, it could stand the test of reason that the decision to consume coffee, if taken out of sequence, may not produce a response behaviorally or neurologically that is consistent with previous experiences and, therefore, may not be rewarded by a complex such as dopamine. We understand from previous studies that caffeine is one of the world’s most popular psychoactive substances. Caffeine is similar to a stimulant and enhances dopamine (DA) signaling by antagonizing adenosine receptors (Volkow et al., 2015).
Research Methods
Researchers utilize several methods to study the process of decision-making and brain function. Cognitive neuroscientists utilize positron emission tomography (PET), near-infrared spectroscopy (NIRS), magnetoencephalogram (MEG), electroencephalography (EEG), and functional magnetic resonance imaging (fMRI) as modern imaging techniques to understand the process of decision making on cortical structures of the brain, (Xue, Chen, Lu, & Dong, 2010). From our lecture study, we understand that there are several common methods of analyzing cortical function. They include, among others, histology, modern imaging, lesion studies, histology, and psychophysiological procedures. For our study, we will focus on fMRI as our modern imaging technique and a lesion study as our second form of research into the process of decision-making.
fMRI Selected Study
Developed in the early 1990s, the fMRI has become the primary method to research cognitive neuroscience objectives due to its noninvasive nature and wide availability. The decision to ingest caffeine through coffee is unique due to the nature of coffee’s taste. While this is only moderately relevant, the author believes that the notion that caffeine, by its bitter taste, engages bitter taste receptor-independent pathways and is one reason researchers postulate its popularity among caffeine consumers. In one study, randomly selected participants assigned in a double-blind study to consume 40 mg of caffeine or a placebo exhibited increased attention on a task selected for examination versus those not in the control group (Rao, Hu, & Nobre, 2013).
In a separate study, researchers contended that the most essential function of the prefrontal cortex is the executive function. Among the executive functions in which the PFC participates, decision-making is one of the most important. The decision to consume coffee fits squarely within the context of executive control and decision-making (Struss & Benson, 1986). This is supported by the notion that patients with prefrontal damage exhibit difficulties with decision-making but no difficulty understanding sensation, perception, and motor control (Miller, Erickson, & Desimone, 2000).
Our selected study, however, is scoped narrowly into the cave of consuming coffee in the morning. We have defined the morning as the first activity following getting out of bed. Our underlying theme is that coffee contains caffeine and antagonizes adenosine. Adenosine is known to modulate dopaminergic neurotransmission and, therefore, reward systems antagonistically. Consequently, we shift our focus to the primary choice of study: understanding how the prefrontal mechanisms combine rewards and beliefs in human decision-making, (Rouault, Drugowitsch, & Koechlin, 2019).
In this study, 25 subjects of mixed genders and scoped age, all uniquely right-handed, volunteered to participate.[1] The participants were paid for their participation and tested in three fMRI sessions lasting approximately an hour and a half each. Each session was administrated on separate days. Researchers aimed to understand how the PCF maps reward contingencies into choice options. The connection to our study is the reward of having the first cup of coffee in the morning. Rouault et al. determined that reward beliefs and state values were activated in the PFC regions when state beliefs and reward expectations were in line. Connecting this research to our chosen daily event, the reward expectation associated with the consumption of coffee directly correlates with the decision to the PFC and the stimulation of neuronal activity therein.
Lesion Studies & the Hippocampal Region of Laboratory Animals
As discussed earlier in this paper, Fortin et al. analyzed the behavior of laboratory rats in their examination of the hippocampal region post-lesion and the outcome of the rat’s ability to sequentially remember a series of orders, leading them to progressive decision-making. In their somatic investigation, researchers tested rats with hippocampal lesions against a control group to determine memory order and elements of episodic memory. The result significantly degraded the rat’s ability to remember sequential ordering (Fortin, Agster, & Eichenbaum, 2023).
Connecting this research to our selected daily activity seems strange and perhaps disconnected at first blush. Consider the sequence of events leading to the decision to make a cup of coffee: first, the alarm, then the decision to silence the alarm (several times), and finally, the decision to stop the alarm and proceed to the kitchen to brew a cup of joe. At each process, the hippocampus was involved in the sequential recollection of stored memories and their association with the event: brewing the cup of coffee. This is supported by the notion that the decision not to make a cup of coffee occurs on certain days. When considering these exceptions, it is relevant to note an internal correlation to interruptions of that sequence, which inhibits the reward that follows.
Conclusion and Reflection
Making a cup of coffee seems on the surface to be a non-event, for most people. We simply aim to ingest a warm substance, loaded with caffeine, to jump-start our day or even at random times when we just need that extra pick-me-up. Once we dive a little deeper, we discover that a wide variety of cortical structures are involved in the highly advanced process of simply, making a cup of coffee. Whether the decision is based on past experiences, the pick-me-up that coffee provides, or routine familiarity is inconsequential to most. To our brain, however, it’s a complicated decision, loaded with options that can change at the drop of a hat. One chance decision can impact our reliance on another. For example, waking up late for an alarm impacts our decision to brew a cup of coffee in the morning. The interruption of that decision, over time, alters reward pathways associated with the consumption of coffee altogether. Perhaps one day, we wake up and desire not, for coffee.
When researching this topic, the author found it particularly interesting that few studies have actually been performed using modern imaging resources, specifically the fMRI, to analyze how the decision to ingest coffee actually occurs. It would be highly interesting to understand how the ventral tegmental region is activated upon consumption of coffee. The obvious correlation, at least to me, is that dopamine is one of the most powerful neurotransmitters. Certainly, more studies could be done involving the activation of the ventral tegmental region upon ingestion of caffeinated substances.
Another interesting component of study would be to determine if enough research participants exist to examine a correlation to the specific decision to consume caffeinated beverages with those having PFC damage or hippocampal damage, as we discussed with Fortin et al, laboratory animals with hippocampal lesions were unable to make sent based decisions as those in the control group could. Is sent, a strong characteristic of coffee, yet another clue interpreted by sequential memory and processed through the hippocampal region and somehow connected to the consumption of coffee? In other words, absent coffee’s aroma, would the coffee experience be the same? If we could no longer taste or smell coffee, would we still ingest the substance?
One final consideration is the DA pathways that could be involved here. As we have discussed, caffeine is an antagonist of adenosine receptors, (Volkow, et al., 2015). Adenosine and dopamine are interwoven. Stimulants such as cocaine and methamphetamine are unique stimulants that act on dopamine. Where stimulants such as cocaine and methamphetamine inhibit DA reuptake causing a flooding effect. Methamphetamine specifically increases extracellular dopamine levels by competing with dopamine uptake and reabsorption or reverse transport of dopamine, (Lin, Sambo, & Khoshbouei, 2016). It would be highly interesting to understand if caffeine acts in the same manner on DA as it seems to have similar properties as stimulants such as cocaine or methamphetamine.
This has been one of the most interesting days in the life of my brain. I have taken a menial task that most take for granted and demonstrated that my decision to make a cup of coffee is much larger than the routine of doing so. Reward pathways are excited, sequential memories accessed and recalled then transmitted into signaling motivating a very real response: actually getting out of bed, excited for the first cup of coffee. Tomorrow, I’ll do a little less thinking about the “how” it all occurs and appreciate the “why” a little bit more.
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French National Ethics Committee (CPP, Inserm protocol #C07-28) ↑
Special thanks to Dr. Nhi Kieu Thai, Professor, The Pennsylvania State University