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New Year, New Me: A guide to rewiring your brain

April 24, 2026

Although it’s been about 4 months since the New Year, the start of summer is another perfect opportunity to get back on track with your new year’s resolutions. And this time, you’re going to stick to it because I’m going to explain the science behind your habits and how you can change your brain to change your habits. 

Scientifically, a habit is a routine, behavior, or cognitive process that starts spontaneously but is repeated automatically as a result of prior experience (Mendelsohn, 2020). It essentially means that it’s something you do without really thinking because you’ve done it before. For example, brushing your teeth as soon as you wake up, showering before bed, or grabbing a snack as soon as you get back to your apartment even if you’re not hungry. Habits are context dependent which means they are strengthened through repetition and use cues from the surrounding environment. When you perceive a cue, it automatically triggers a response without much cognitive input (Mendelsohn, 2020). In the example above, the cue is getting back to your apartment and your habit is grabbing a snack, because you’re normally hungry when you get back. But today, you ate a bigger lunch and even though you aren’t hungry you carried out your habit, why? 

The relationship between the cue and the response is strengthened by dopamine, the same molecule that keeps you scrolling on tiktok even though you have to wake up in 5 hours. This means that habits are strengthened and rewarded, urging you to carry them out over and over again. When you do something for the first time, your prefrontal cortex is highly active, aiding in carrying out complex cognitive behavior, attention, and decision making. As you continue to carry out the response, dopamine is released by two other brain regions known as the Ventral Tegmental Area (VTA) and Substantia Nigra (SNc). Here, dopamine helps facilitate learning by spiking the exact neural pathway carried out if an action is worth carrying out again or repeating. This strengthens the firing of those neurons in relation to one another, a process known as neuroplasticity (more on that later). Once the response has been reinforced with dopamine, it’s tagged for repetition which is facilitated by the corticostriatal loop which connects the cortex to the striatum, the part of the brain responsible for motor control and decision making. Over time, the brain starts to correlate the cue not the action with the reward leading to the automatic nature of habits. Finally, the striatum translates dopamine release into motor encoding so the output is not reliant on cognitive input and the prefrontal cortex but associations with contextual cues (Wyatt, 2024). 

This makes it seem like once a habit is formed, it’s an automatic response wired into us for good. Luckily, our brains are constantly evolving, rebuilding, and restructuring, a process known as synaptic plasticity. This means even though it may be hard, we can restructure, rebuild, and begin new habits. Neuroplasticity is the way the brain changes its activity in response to a stimulus by reorganizing its structure, functions, or connections. This can be carried out through a mechanism known as synaptic plasticity in which long-lasting changes are made to the connections between neurons. In order for this to occur, neurons must “fire together to wire together”(Puderbaugh & Emmady, 2023). At the cellular level, this change happens through synaptic plasticity. When neurons repeatedly fire together, they strengthen their connections, a concept known as “neurons that fire together wire together.” When one neuron activates another, it releases glutamate, an excitatory neurotransmitter. With repeated activation, receptors like AMPA and NMDA work together to increase the sensitivity of the receiving neuron. Over time, this makes the connection stronger, meaning the same signal produces a bigger response. This is how repeated behaviors become more efficient and automatic in the brain. This is obviously really cool science, but how do you use this to form new habits? 

It’s clear that habits require repetition whether it’s strengthening the synapses between neurons or the control of actions shifting from the prefrontal cortex to the striatum. But repetition can be hard when your brain has already been wired to do something different so here’s some tips to get your brain to repeat actions that aren’t yet habits until they become one. 

  • Write down why your new habit made you feel good 

The reward pathway and dopamine are key players in why we carry out habits but unfortunately actions don’t feel like a reward until it’s been repeated over and over again. Taking time to think about why your new habit was a good one, and how it made you feel can release some of the “feel good” neurotransmitters and activate the same reward pathways that led to habit formation initially. 

  • Habit stacking 

Stack new habits into a routine you already have. For example, if you always brush your teeth right when you wake up but forget to take your vitamins, start taking them right after you brush your teeth. This helps link the new behavior to already existing neural pathways making it easier to reinforce through repetition. 

  • Start small 

Because your brain has wired your habits rendering them automatic, it takes a large cognitive load to override them. By starting small, you lessen the cognitive load and reduce the demand on the prefrontal cortex making it easier to start the task. For example, instead of saying you need to workout, start by saying you’ll go to the gym for 20 minutes. 

  • Pay attention to cues 

Habit formation is highly cue dependent so start paying attention to the cues that trigger certain habits. The next time you see the cue, you are more likely to break the automatic control of the striatum and engage the decision making and cognitive processing of your prefrontal cortex. 

Although habit formation may seem hard, your brain is built to be changed if you let it. Now that you know the science behind changing your brain, the summer is a great time to start! 

Sources: 

Exploring the brain’s relationship to habits | nsf—U. S. National science foundation. (2013, January 14). https://www.nsf.gov/news/exploring-brains-relationship-habits

Mendelsohn, A. I. (2019). Creatures of habit: The neuroscience of habit and purposeful behavior. Biological Psychiatry, 85(11), e49–e51. https://doi.org/10.1016/j.biopsych.2019.03.978

Puderbaugh, M., & Emmady, P. D. (2026). Neuroplasticity. In StatPearls. StatPearls Publishing. http://www.ncbi.nlm.nih.gov/books/NBK557811/

Wyatt, Zoe. (2024). The Neuroscience of Habit Formation. Neurology and Neuroscience. 5. 3. 10.33425/2692-7918.1063. 

 

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  Timothy Durham was convicted of rape when a test showed his DNA genotype matched the DNA recovered from the crime scene. Eye witnesses testified that Durham was in a different state at the time of the incident, but he wasn’t exonerated from his 3000 year sentence until follow up DNA analysis showed that the preliminary forensic analysis used in the trial was misinterpreted (Thomas et al.). DNA testing serves an invaluable part in our criminal justice system, but it comes with complications and bias that can lead to wrongful convictions and misinformed juries.  

Background:

Forensic genetics aims to identify the origin of a biological sample. It can be traced back to Karl Landsteiner who discovered human ABO blood groups. With blood groups, suspects could be eliminated based on their blood type. For example, if a suspect had type A blood and there was type B blood left at the scene by the perpetrator, the investigators could rule out the suspect. Unfortunately, the reverse didn’t work. If the suspect and perpetrator both had the same blood type, it can’t be concluded that the suspect was guilty. Blood identifiers evolved into 8 distinct categories which improved the ability to eliminate suspects, but could only conclude that (if the system matched) it might be the perpetrator or this person might be related to the perpetrator (Jobling and Gill). The field evolved in the 1980s with the discovery of Minisatellites, lines of repetitive DNA that don’t encode proteins. Minisatellite patterns in DNA create what we know today as the DNA fingerprint, and it has a much higher accuracy rate than previous methods (Augustyn et al.). Around the same time, a breakthrough for victims of sexual assault was discovered. In the case of assault, bodily fluids of both the victim and the assaulter can get mixed. A process called differential lysis was created which could selectively increase the concentration of sperm in a fluid sample thereby allowing for accurate DNA testing (Jobling and Gill). Forensics evolved to use single-locus probe testing after several years because of its ease of interpretation. It looked at specific minisatellites that had high variability between subjects. This was the first DNA-based method to be used in a criminal investigation. Two murder homicides from several years apart were connected using DNA evidence. The evidence was then used to exonerate an innocent man, and the guilty party was found when he tried to evade mandatory DNA testing for all men in the small town. His guilt was then reinforced when the DNA profiles matched, and he gave a confession (Jobling and Gill). Finding DNA at a crime scene doesn’t guarantee that you’ll find a murderer. There are issues with non-pure samples and limited samples that make DNA work difficult, and accreditation of facilities and new techniques and take time (Jobling and Gill).  

Subjectivity of DNA Interpretation:

In a 2009 publication, the National Academy of Science discusses the possibility for subjective influence in lab based forensics. The interpretation bias happens in complex cases where, for example, there could be a mixture of DNA. A study published in 2011 looked specifically at this issue. A gang rape happened in Georgia, and the mixture in DNA from the case was used to prosecute one suspect after another suspect took a plea bargain to testify against him. With DNA mixtures, there are three possible conclusions: suspect excluded, suspect cannot be excluded, and inconclusive. If the suspect is excluded, it means that there’s little to no possibility that his DNA is part of the sample. If the suspect cannot be excluded, it means that there’s a possibility that his DNA is part of the sample. In the trial, the DNA examiners who knew the context of the case concluded that the suspect being prosecuted could not be excluded. The 2011 study gave the DNA evidence from this case and the DNA profiles of the suspects to 17 forensic examiners. These examiners had no context of the case, and they all worked independently. Of the 17, only 1 came to the same conclusion (suspect cannot be excluded) as the examiners who knew the context of the case. Twelve of the 17 concluded that the suspect who was prosecuted and convicted had no relation to the DNA found in the sample. Not only does this show that subjectivity occurs due to the context of the case, but the 17 examiners came up with different findings based on their past experiences meaning that not all DNA analysis is objective. Some organizations like the Scientific Working Group on DNA Analysis Methods say that quantitative statistical evidence should be presented with every categorical conclusion, but the US doesn’t require this (Dror and Hampikian).

False Positives:

There are two categories that cause wrongful identification in a DNA report: coincidental matches and false positives. Coincidental matches are DNA matches between two unrelated people. The probability of these matches is about 1 to 500,000 for white individuals and about 1 to 350,000 for black individuals. This small probability of coincidental matches makes people feel confident in DNA evidence. False positives, on the other hand, are matches between DNA and test DNA that result from issues in the forensics lab. There have been multiple cases of forensics labs accidentally switching victim and suspected rapist DNA which lead to convictions that were later overturned when the lab realized the error. There are also cases of misreading or misunderstanding a sample. In a case from 1993, a man was convicted of rape because someone interpreted a mixed sample of victim and perpetrator DNA as an individual sample. The conviction was again overturned. To prevent false convictions, retesting DNA is allowed, but it’s not an efficient solution. Many people are pushing for statistical information on the probability of false positives, so that the jurors can make accurate judgements based on DNA evidence (Thomas et al.).  

Conclusion:

DNA analysis is a useful tool for the criminal justice system, but subjectivity can be an issue in forensic testing. To combat wrongful convictions, there are organizations like The Innocence Project who use DNA testing to free the innocent, but reformed forensic testing standards should be put in place to prevent subjectivity and to ensure juries are correctly informed during trials. https://www.innocenceproject.org/    

Citation:

Augustyn , Adam, et al. “DNA Finerprinting.” Encyclopedia Britannica , 26 Apr. 2018, www.britannica.com/science/DNA-fingerprinting#ref153186. Dror, Itiel E., and Greg Hampikian. “Subjectivity and Bias in Forensic DNA Mixture Interpretation.” Science & Justice, vol. 51, no. 4, 2011, pp. 204–208., doi:10.1016/j.scijus.2011.08.004. Jobling, Mark A., and Peter Gill. “Encoded Evidence: DNA in Forensic Analysis.” Nature Reviews: Genetics, vol. 5, no. 10, Oct. 2004, pp. 739–751., doi:10.1038/nrg1455. Thompson, William C, et al. “How the Probability of a False Positive Affects the Value of DNA Evidence.” Journal of Forensic Sciences, vol. 48, no. 1, Jan. 2003, pp. 1–8., doi:10.1520/jfs2001171.