Alcohol consumption has significant consequences on the brain. While short-term effects include impaired memory, mood swings, and decreased coordination, long-term use can lead to more severe cognitive problems. Understanding the neural mechanisms is crucial for public health progress. How does alcohol affect the human brain when consumed? Using a bunch of different resources, we are going to attempt to figure out the exact process in which the human brain goes through when even the tiniest bit of alcohol is consumed. 

The method of this research project involved :

Making an observation : We noticed on TV and in real life that people act/behave differently under the influence of alcohol.

Forming a hypothesis : Alcohol affects the human brain when consumed.

Conducting research : Look at research section

Analyzing the final results : Alcohol affects the human brain more than people think. The tiniest amount of alcohol could stay in the body for up to 3 hours. Moderately drinking can damage the brain and shrink the neurons. There is no safe level of drinking.

 

 

 

Our research question is how does alcohol affect the brain ?

The brain has many different parts. This includes the cerebrum, the cerebellum, the frontal lobe, the parietal lobe, occipital lobe and the brain stem.

The Cerebrum 

The cerebrum is the front of the brain and consists of both the right and left hemispheres and controls coordination, temperature, touch, hearing, reasoning, judgment, learning and problem solving.

The Cerebellum

The cerebellum is the portion of the brain that coordinates the voluntary muscle movements and it maintains the posture, balance and equilibrium. New studies are exploring the cerebellum’s roles in thought, emotions and social behavior, as well as its possible involvement in schizophrenia, addiction and autism. 

The Frontal lobe

The frontal lobe is the largest part of the brain. It is involved in personality characteristics, decision making and movement. Recognition of smell usually involves parts of the frontal lobe too. The frontal lobe has Broca’s Area which is connected with speech abilities.

The Parietal lobe

The middle part of the brain, the parietal lobe helps one identify objects and understand spatial relationships. It is also involved with interpreting pain and touch. The parietal lobe also has Wernicke’s area which helps the brain understand spoken language. 

Occipital lobe

Back part of the brain is involved in vision.

Temporal lobe

Temporal lobes- that are on the sides of the brain - are involved in short-term memory, speech, musical rhythm. They also play a small role in smell recognition.

Brainstem

The middle of the brain, The brainstem connects the cerebrum and the spinal cord. The brainstem consists of the midbrain, the pons and the medulla.

Midbrain - The midbrain (or mesencephalon) is a very complex structure with a range of different neuron clusters (nuclei and colliculi), neural pathways and other structures. These features facilitate various functions, from hearing and movement to calculating responses and environmental changes. The midbrain also contains the substantia nigra, an area affected by Parkinson’s disease that is rich in dopamine neurons and part of the basal ganglia, which enables movement and coordination.

Pons. The pons is the origin for four of the 12 cranial nerves, which enable a range of activities such as tear production, chewing, blinking, focusing vision, balance, hearing and facial expression. Named for the Latin word for “bridge,” the pons is the connection between the midbrain and the medulla.

Medulla - At the bottom of the brainstem, the medulla is where the brain meets the spinal cord. The medulla is essential to survival. Functions of the medulla regulate many bodily activities, including heart rhythm, breathing, blood flow, and oxygen and carbon dioxide levels. The medulla produces reflexive activities such as sneezing, vomiting, coughing and swallowing.

Spinal cord

The spinal cord extends from the bottom of the medulla and through a large opening in the bottom of the skull. Supported by the vertebrae, the spinal cord carries messages to and from the brain and the rest of the body.

Temporal lobe

The temporal lobe is located on the sides of the brain and contributes to memory, speech and smell.

 

 

Stage 1

Subliminal Intoxication

This is the first stage of intoxication. The consumer now has a BAC (Blood Alcohol Content) of about 0.01 to 0.05. They may not seem like they have been drinking but their reaction time, behavior and judgment have been slightly altered. 

 

Stage 2

Euphoria

During early stages of drinking, the body releases more dopamine, the chemical connected to pleasure. The consumer will feel more relaxed and confident. However, their memory and reasoning may be slightly impaired. When the consumer is in the Euphoria stage, they most likely have a BAC of 0.03 to 0.12.

 

Stage 3

Excitement

At this stage, the consumer is now legally intoxicated. With a BAC of 0.08 to 0.25, this stage affects the occipital lobe, the frontal lobe and temporal lobe. Drinking excessively can cause side effects such as blurred vision, slurred speech and lack of control. The parietal lobe, which processes information is now also affected. The consumer will now have a slower reaction time and a loss of fine motor skills. 

Stage 4 

Confusion. A BAC of 0.18 to 0.3 often looks like disorientation. The consumer's cerebellum, which helps with coordination, is now impacted. As a result, they may need help walking or standing. Blackouts, or the temporary loss of consciousness or short-term memory, are also likely to happen at this stage. This is a result of the hippocampus, the region of the brain that is responsible for making new memories, not working well. They may also have a higher pain threshold, which may increase their risk for injury. 

Stage 5

Stupor

If the consumer reaches a dangerously high BAC of 0.25, they may start to show concerning signs of alcohol. At this point, all mental, physical and sensory functions are severely impaired. The risk for injury, suffocation and passing out are high. 

 

Stage 6

Coma

At a BAC of 0.35, the consumer is now at risk of going into a coma. This occurs due to compromised respiration and circulation, motor responses and reflexes. The consumer also faces the risk of death.

Stage 7

Death

With a BAC of or over 0.45, the consumer may die due to the lack of control the brain has over the body’s vital functions or due to alcohol poisoning. 

 

 

Long-term drinking causes alterations in the neurons. This can reduce their size.

Misuse of alcohol can lead to blackouts. A blackout is a gap in the consumer's memory when they are Intoxicated. These gaps happen when the consumer drinks enough alcohol that it temporarily blocks the transfer of memories from short-term to long-term storage - known as memory consolidation - in a brain area called the hippocampus. 

Continuing to drink despite clear signs of obvious impairments can result in an alcohol overdose. An alcohol overdose occurs when there is so much alcohol in the bloodstream that areas of the brain controlling basic life-support functions—such as breathing, heart rate, and temperature control—begin to shut down. Symptoms of alcohol overdose include mental confusion, difficulty remaining conscious, vomiting, seizure, trouble breathing, slow heart rate, clammy skin, dulled responses (such as no gag reflex, which prevents choking), and extremely low body temperature. Alcohol overdose can lead to permanent brain damage or in extreme cases, death.

 

Alcohol Use Disorder

The consumer continues to drink alcohol over time, progressive changes can occur in the structure and function of their brains. These changes can compromise brain function and drive the transition from controlled, occasional use to chronic misuse, which can be difficult to control and lead to alcohol use disorder (AUD). Individuals with moderate to severe AUD may enter a cycle of alcohol addiction. The extent of the brain’s ability to return to normal following long-term sobriety is not fully understood, but a growing number of studies indicate that at least some AUD-induced brain changes—and the changes in thinking, feeling, and behaving that accompany them—can improve and possibly reverse with months of abstinence from drinking. 

 

 

 

 

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We found that the amount of alcohol that is consumed really affects what stage someone may be at. For example, a BAC of 0.08 is when the consumer enters the first stage.

We have gathered the following information based on a study by Oxford University. 

A team of researchers from University of Oxford looked at data from 424 men and 103 women who are participating in the 10,000-person Whitehall Study, an ongoing investigation of the relationship of lifestyle and health among British civil servants. At the beginning of the study in 1985, all of the participants were healthy and none were dependent on alcohol. Over the next 30 years, the participants answered detailed questions about their alcohol intake and took tests to measure memory, reasoning, and verbal skills. They underwent brain imaging with MRI at the end of the study.

When the team analyzed the questionnaires, the cognitive test scores, and the MRI scans, they found that the amount of shrinkage in the hippocampus — the brain area associated with memory and reasoning — was related to the amount people drank. The ones who had the equivalent of four or more drinks a day had almost six times the risk of hippocampal shrinkage as did nondrinkers, while moderate drinkers had three times the risk. However, the only link between drinking and cognitive performance was that heavy drinkers had a more rapid decline in the ability to name as many words beginning with a specific letter as possible within a minute.

 

We came to the conclusion that alcohol, whether consumed regularly or once in a while, can have an affect on the brain. It can cause massive damage that could be irreversible. It also has a huge impact on the body itself, staying in the system for almost 3 days before its completely gone. This means that while alcohol can be consumed, for those who want to know the safe level of drinking, there is no safe level of drinking.*

*Our research does not mean that people can't drink, this was simply meant for a science project. 

 

 

"[Brain Anatomy and how the brain works]." [John Hopkins Medicine], n.d., https://www.hopkinsmedicine.org/health/conditions-and-diseases/anatomy-of-the-brain.

"[How Alcohol Impacts the Brain]." [Northwestern Medicine] n.d., https://www.nm.org/healthbeat/healthy-tips/alcohol-and-the-brain

"[This is your brain on alcohol]." [Harvard Health], n.d., https://www.health.harvard.edu/blog/this-is-your-brain-on-alcohol-2017071412000

"[Alcohol's Effects on Health]." [Nation Institute on Alcohol Abuse and Alcohol], n.d., https://www.niaaa.nih.gov/publications/alcohol-and-brain-overview

 

We acknowledge our teachers, our peers, the websites we used information from and our parents. Without them, we might not have been able to do this project. Thank you.