Dr. Nirmal Nair

One practical use of neuroscience is to discover functionalities of the brain in order to unlock and hack previously inaccessible parts of our mind. There have been quite a few applications developed in the recent past. Elon Musk’s Neuralink is one more famous example. Another device claims, via electrodes, to translate the brain’s electrical activity into words.

It is interesting to note how this device was initially trained. A brain-to-computer interface connects electrodes to a computer program designed to translate electrical activity into words. A region of the brain known as the supramarginal gyrus was identified as the prime location for detecting this activity. This region is known for processing subvocal speech and is active in verbal activities such as determining if words rhyme.

While previous brain-to-computer interfaces had been trained to translate partially vocalized speech, this was the first time in which completely mental speech was translated. But what the researchers found was intriguing. In one subject, the BCI was able to translate internal speech with 79 percent accuracy, while in another, this accuracy dropped to just 23 percent—suggesting a vast difference in how individuals process their own thoughts at a neural level.

If our thoughts can vary so widely that some brains can translate mental speech with near-perfect accuracy while others struggle, then it follows that other subconscious processes—like hunger, cravings, and impulse control—are equally variable. Just as no two people’s inner speech is processed the same way, no two people experience hunger, satiety, or self-control in exactly the same way. Neuroscience has shown that the drive to eat is shaped not only by physical hunger but by deep-seated neural pathways governing motivation, impulse control, and reward processing (1).  In much the same way that BCIs attempt to map individual differences in internal speech, brain imaging allows us to decode how different people experience food cravings and what might lead some to struggle with overeating more than others.

At the fundamental level, when we are hungry, we seek satiation of that hunger through food. The actual act of eating food is therefore associated with a certain reward, or else we would not bother finding and eating something. Yet, if hunger and eating were that simple, we would expect that all individuals exposed to the same environment would have similar body compositions. However, in everyday life, we see dramatic differences in body size and eating behaviors. The emotional reaction to food, the inhibitory sense that a certain food will set us back in terms of our health, and social cues around meals all play a role in shaping how we process our internal dialogues around food. Much like our language model above, there is a huge variation in how our brains—or minds—seek food.

This difference in how we seek food is deeply connected to how our brains process hunger, reward, and self-control. Brain scans show that people with obesity tend to have stronger activity in areas like the medial prefrontal cortex (MPFC) and anterior cingulate cortex (ACC)—regions that help us weigh decisions and respond to rewards (3,4).  Interestingly, while most people’s brains naturally adjust after eating, signaling that they’re full, those with obesity often continue to show high activity in these areas, as if their brains are still motivated by food even after a meal (9). This persistent activation suggests that, for some individuals, the neural mechanisms that regulate satiety do not function as efficiently, reinforcing a cycle of cravings and overconsumption (5,6). In particular, lower ACC activation has been linked to reduced impulse control, meaning that those who struggle with cravings may be more vulnerable to continued eating even when they are no longer physically hungry (9). To make matters worse, these brain activities are heightened the more obese the individual.

Just like how different people’s brains process internal speech in unique ways, the way we experience hunger and food cravings is not the same for everyone. Studies show that some people will work harder for food rewards, feel stronger cravings, and have a harder time controlling their eating (1,9). Brain areas like the orbitofrontal cortex (OFC), which determines how rewarding food is, and the insula, which links hunger and taste, light up more in response to food cues in those who are more prone to overeating (7). At the same time, obese individuals show heightened MPFC activity even postmeal, meaning that their food motivation remains active despite satiety (4,5). This suggests that the brain is not just responding to hunger but is also engaged in habit-driven or emotionally reinforced food-seeking behaviors (2,8). Much like the brain-to-computer interface struggled to accurately translate mental speech for different individuals, the way our brains handle food motivation varies widely from person to person. This could explain why some people can stop eating when they’re full, while others struggle with cravings even after a meal. If we can better understand these subconscious processes, we may be able to develop new ways to “retrain” the brain to make healthier choices—personalized to how each person’s mind responds to food. By identifying the neural pathways responsible for persistent food motivation, we could target interventions that strengthen impulse control, reduce reward sensitivity to unhealthy foods, and ultimately help reshape eating behaviors at a fundamental level (8)

Citations Used

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8. Tataranni PA, Gautier JF, Chen K et al. (1999). Neuroanatomical correlates of hunger and satiation in humans using positron emission tomography. Proceedings of the National Academy of Sciences, 96(8), 4569-4574.
9. Martin, L. E., Holsen, L. M., Chambers, R. J., Bruce, A. S., Brooks, W. M., Zarcone, J. R., Butler, M. G., & Savage, C. R. (2012). Neural mechanisms associated with food motivation in obese and healthy weight adults. Obesity, 18(2), 254–260.