Neuro Science  

  

 

 

 

 

Brain Energy Consumption

 

This note is motivated mostly by personal experience. I clearly senses that a certain type of mental work exhaust myself comparing other types of mental activity. Among all those mental activities that I am doing, it seems writing something in my own words (e,g, writing notes like this) trains my mental energy much faster than other things (e.g, watching YouTube video etc). Then I thought it would be good to do some formal investigation on this topic.

 

 

 

What comsumes more energy ?

 

I am constantly thinking of what kind of brain activity (mental activities) consumes most of my mental energy. To some degree, it would depends on the specific types of mental activities and to some degree it would depends on each individuals. First, I am listing various types of mental activities we may perform in our daily life (of course, we would not do all of these everyday) and this is not the exhaustive list. I just tried to collect as many as possible. Check these out and think which consumes the most in your case.

    1) Solving complex mathematical problems

    2) Playing challenging video games

    3) Learning a new skill or language

    4) Analyzing and interpreting data

    5) Planning and decision making

    6) Performing multiple tasks simultaneously (multi-tasking)

    7) Reading and comprehending complex texts

    8) Developing and implementing a complex strategy

    9) Problem solving under time pressure

    10) Performing complex manual tasks, such as surgery or aircraft piloting

    11) Public speaking or presenting in front of an audience

    12) Taking an advanced level exam

    13) Designing and implementing a complex project

    14) Solving complex puzzles or games

    15) Programming or writing complex software

    16) Performing intricate manual tasks, such as playing a musical instrument

    17) Making a high-pressure business or financial decision

    18) Navigation or finding your way in a new place

    19) Participating in a high-stakes negotiation or conflict resolution

    20) Driving in heavy traffic or in hazardous conditions.

    21) Creative writing or composing music

    22) Analyzing complex financial or economic data

    23) Participating in complex team sports

    24) Performing complex surgical procedures

    25) Designing and constructing complex mechanical or architectural structures

    26) Developing and executing a marketing strategy

    27) Participating in high-stakes legal negotiations

    28) Conducting scientific research or experiments

    29) Participating in complex military operations

    30) Performing complex software or hardware maintenance and repairs.

    31) Any task that requires real time response.

NOTE : I think the energy consumption even for the same task would vary widely with person or situations. For example, let's think of the case of 'complex mathematical problems'. For most of the persons, it would be the biggest energy drainer. But some people would say it does not require much energy. It may be one of the two possible cases. It may be because he is so good at math and those problem would be so easy for him. Another possible reason would be that he is so poor at math and give up right away when he is given any math problem. For sure, I fall into the second category :).

 

 

 

What are the physiological factors for the neural energy consumption ?

 

Are there any specific physiological background that consumes the energy for a specific mental activity ?  There can be tons of physiological process that cause the energy consumption. Some of those processes are listed below. Roughly speaking, we can say all of these processes are involved in every mental activities at least to some degree, but there are a few dominant factors for a certain types of mental activities.

    1) Neural activity: Increased neural activity, such as during periods of high cognitive workload, requires more energy to support the increased activity.

    2) Glucose metabolism: The brain relies on glucose as its primary energy source, and the rate of glucose metabolism can increase during periods of high cognitive workload.

    3) Synaptic transmission: The transmission of signals between neurons requires energy, and the amount of energy required increases with the number of synapses activated during periods of high cognitive workload.

    4) Neuronal signaling pathways: The activation of specific signaling pathways in the brain can affect energy consumption. For example, the activation of the hypothalamic-pituitary-adrenal (HPA) axis, which is involved in stress response, can lead to increased energy consumption.

    5) Blood flow: Increased blood flow to the brain during periods of high cognitive workload can contribute to increased energy consumption.

    6) Neurotransmitter release: The release of neurotransmitters during periods of high cognitive workload can increase energy consumption.

    7) Synaptic plasticity: The formation and strengthening of new synapses, a process known as synaptic plasticity, requires energy and can contribute to increased energy consumption during periods of learning and memory formation.

    8) Ion transport: The transport of ions across the neuronal membrane requires energy and can be increased during periods of high cognitive workload.

    9) Maintenance of ion gradients: The maintenance of ion gradients, such as the sodium-potassium pump, also requires energy and can contribute to increased energy consumption during periods of high cognitive workload.

    10) Mitochondrial activity: The activity of mitochondria, which are the cellular powerhouses that produce energy, can be increased during periods of high cognitive workload.

As you may notice from the list above, in general high cognitive workload cause high energy consumption.

 

 

 

Is there any correlation between dominant physiological factors and the type of mental task ?

 

For sure, there is a certain correlation, but it is not easy to pin point out exactly which type of physilolgical factors are dominantly associated with which type of mental activities. It can depend on a number of factors, such as the specific task demands, the individual's experience and expertise, and the level of motivation. Various physiological factors interact with each other and can be influenced by a number of factors, such as stress, sleep, and individual differences, making it challenging to make generalizations about the relationship between specific physiological factors and types of mental tasks.

 

Even though it is not easy to clearly define the correlation between the two, it would be possible to provide a few general examples as below :

  • Tasks that require high levels of attention, such as public speaking or complex problem solving, may be associated with increased glucose metabolism, blood flow, and neurotransmitter release.
  • Tasks that involve learning and memory formation, such as participating in a training program, may be associated with increased synaptic plasticity and mitochondrial activity.

 

NOTE : Which of the mental task listed above requires more energy consumption in terms of the amount of total energy ?

    Again, It is difficult to determine which type of mental task (there is no simple thing in neurosciene :), those that require high levels of attention or those that involve learning and memory formation, requires more energy in terms of total energy consumption as it can vary depending on several factors such as the specific task demands, individual differences, and environmental factors.

     

    For example, a task that requires high levels of attention, such as public speaking, may require a large amount of energy to sustain attention and processing, but this energy consumption may be brief in duration. On the other hand, a task that involves learning and memory formation, such as participating in a training program, may require a lower level of energy for a longer period of time as the brain adapts and incorporates new information.

     

    It is also possible that different types of mental tasks may result in different patterns of energy consumption across brain regions, which can affect overall energy consumption.

 

 

 

Does the same mental task always consumes the same amount of energy ?

 

Based on both common sense and your personal experiences, you may say 'NO'.  I think it is right answer. I am more interested in why the same mental task consumes different amount of energy and what are the factors to make such a difference.

  • Level of Experties : Even with the similar task and complexities, the task which you have higher level of experties tend to consume less energy.
  • Cognitive load: The amount of information that must be held in working memory at once can also impact energy consumption. Tasks that require more information to be held in working memory at once may be more mentally demanding and require more energy to complete.
  • Emotional state: An individual's emotional state can also impact energy consumption during a mental task. For example, if someone is feeling anxious or stressed, they may require more energy to complete the task due to increased cognitive demands.
  • Fatigue: Mental fatigue can also impact energy consumption during a task. If an individual is mentally fatigued, they may require more energy to complete a task compared to when they are well-rested and alert.
  • Motivation: Motivation and engagement with a task can also impact energy consumption. If an individual is highly motivated and interested in a task, they may require less mental effort

NOTE : Impact of Level Experties on Mental Energy Consumption.  I am specifically interested in how the level of experties can impact on the amount of energy consumption. There are several reasons behind this as listed below.

  • Selective attention: With greater expertise, individuals can focus their attention more selectively on the most important aspects of a task. This can reduce the amount of distracting information that needs to be processed and ultimately reduce energy consumption.
  • Neural efficiency: As individuals gain expertise in a task, they may develop more efficient neural networks and pathways in the brain for processing information related to that task. This can lead to less overall brain activity being required to complete the task, which can also reduce energy consumption.and energy to complete it compared to if they are disengaged and uninterested. In some researches, it is shown that people would use different part of brain even for same/similar task depending on level of experties.
  • Efficiency: With more expertise in a task, an individual can become more efficient in completing it. This means that they can complete the task more quickly and accurately, using less mental effort and consuming less energy.
  • Automaticity: As individuals become more proficient in a task, they can develop automaticity, meaning they can complete the task with less conscious thought and effort. This can reduce the amount of energy required to complete the task.

NOTE : Now I am interested in the 'Neural Efficiciency', especially about 'using different part of the brain for the similar task depending on level of experties'. Followings are some of examples :

  • Individuals become more proficient in a mathematical task, they may rely less on the prefrontal cortex and more on other brain regions, such as the parietal cortex.
  • Individuals who were highly trained in mental calculation tasks showed decreased activity in the prefrontal cortex and increased activity in the parietal cortex compared to those who were less trained. The researchers suggested that this shift in brain activity patterns may reflect the development of more efficient and automatic neural networks for mental calculation with increased expertise.
  • When solving algebraic equations, experts in algebra showed greater activation in the intraparietal sulcus, a region of the brain associated with spatial and numerical processing, compared to novices. The researchers suggested that this increased activation may reflect more efficient and automatic processing of algebraic rules with increased expertise.
  • The brain activity of expert violinists, novice violinists, and non-musicians while they listened to violin music. The study found that expert violinists showed increased activity in the left inferior frontal gyrus, a region of the brain associated with processing and producing language, compared to the other two groups. The researchers suggested that this increased activation may reflect the expert violinists' ability to use musical syntax to understand and interpret the music they were listening to.
  • The brain activity of expert violinists and non-musicians while they played the violin. The study found that expert violinists showed increased activity in the somatosensory cortex, a region of the brain that processes sensory information, specifically related to the left hand, which is used to finger the strings. The researchers suggested that this increased activation may reflect the expert violinists' ability to integrate sensory and motor information to produce highly precise and coordinated movements.

 

 

 

Is mental Fatigue same as too much consumption of mental energy ?

 

For long time (even until the start of writing this page), I thought 'mental fatigue' is direct result of too much consumption of mental energy. In orther words, I thought metal fatigue and mental energy consumption are based on the same physiological background. Sometimes I enjoyed feeling fatinque mentally because I took it as more energy consumption which may imply burning calories. I thought I might lose weight just by doing complicated mental task without going to gym :).

However as I read further while writing this note, I start thinking that mental fatigue and mental energy consumption may not be the same. The conclusion that I found was 'they would be related but not same'.

  • Mental energy consumption refers to the amount of mental effort or resources required to perform a cognitive task. This can include processes such as attention, working memory, and decision-making. The brain requires energy in the form of glucose to perform these processes.
  • Mental fatigue, on the other hand, refers to the feeling of exhaustion or tiredness that can result from prolonged cognitive activity or stress. It is often associated with a decreased ability to concentrate or perform mental tasks, and can be accompanied by physical symptoms such as headaches or eye strain.

NOTE : While mental energy consumption and mental fatigue are related, they are caused by different physiological processes. Mental fatigue can be the result of a depletion of mental energy resources, but it can also be caused by factors such as stress, boredom, or lack of motivation. Additionally, mental fatigue can be influenced by factors such as sleep quality, nutrition, and physical exercise, which can impact the body's ability to recover and replenish mental energy resources.

 

NOTE : Then how mental consumption and mental fatigue are related ? can I say "mental task requiring more energy consumption would lead to faster mental fatigueness' ?

  • It is generally true that mental tasks requiring more energy consumption can lead to faster mental fatigue. The brain uses glucose as its primary energy source to perform cognitive tasks such as thinking, learning, and decision-making. When the brain is working hard to complete these tasks, it can deplete its energy stores more quickly, leading to mental fatigue.
  • Some studies have suggested that the amount of mental energy required to perform a task can be a predictor of mental fatigue. Tasks that require more mental energy may be more likely to lead to mental fatigue than tasks that require less energy.

 

 

 

Does emotion affects brain energy consumption ?

 

Yes, for sure. You would know this by your own experience. When we experience intense emotions, various regions of the brain are activated, and this increased neural activity requires more energy.

 

For example, when we experience fear or anxiety, the amygdala and prefrontal cortex are activated, and this increased activity can lead to higher energy consumption in these regions. Similarly, when we experience positive emotions like joy or excitement, the release of neurotransmitters like dopamine can also impact brain energy consumption.

 

Additionally, experiencing chronic stress or negative emotions over a prolonged period can lead to changes in the brain's structure and function, which can further impact energy consumption and overall brain health.

 

In short, emotions can have a significant impact on brain energy consumption, but it is important to note that this can vary depending on the specific emotion, the intensity and duration of the emotional experience, and the individual's overall emotional and cognitive health.

 

 

 

Which one would spend more of brain energy ? emotion ? or any other cognitive activity ?

 

Generally speaking, cognitive activities that require focused attention and working memory, such as learning, problem-solving, and decision-making, tend to require more brain energy than emotions. This is because cognitive activities typically involve the activation of multiple brain regions, including the prefrontal cortex, hippocampus, and other areas involved in memory and executive functioning.

 

However, it's important to note that the amount of brain energy consumed by emotions versus cognitive activities can vary depending on the specific emotional experience and the complexity of the cognitive task. For example, if a cognitive task is particularly challenging or requires significant mental effort, it may consume more brain energy than a mild emotional experience.

 

Moreover, some emotions can have a significant impact on brain energy consumption, particularly if they are intense and prolonged. Emotions such as fear, anger, and anxiety can activate the amygdala and prefrontal cortex, which are areas of the brain that require a lot of energy to function properly.

 

About this topic, I would suggest you to read through the article : Emotions Are Energy : The bodymind connection and e-motion. A few lines that I want to quote from this article are :

  • Based on neural circuitry, our emotional brain responds faster to incoming information or stimuli than our analytical brain does.
  • The emotional brain has more neural circuits connecting to the analytical brain than the analytical brain has connecting to the emotional brain.
  • The emotional brain is connected to every area of the brain, whereas the analytical brain is not.
  • On the basis of survival, the experience of stress and feelings of worry, fear, or anger take priority over feelings of happiness and peace of mind.

 

 

 

Are there any specific materials leading to mental fatigueness ?

 

It is relatively widely known that there is specific chemical that lead to physical fatigueness (i.e, muscle fatiguness). The most well known chemical for this is lactate. I was wondering if there is any specific chemicals that leads to mental or cogntive fatigueness.

 

There are several chemicals and substances that can contribute to mental fatigue, but none of them work in the same way that lactic acid causes muscle fatigue. It seems that different researches point to different material depending which part of the brain they observe or how to create conditions causing the fatigueness.

 

Mental fatigue is a complex phenomenon that can result from various factors, including lack of sleep, stress, prolonged cognitive activity, and other environmental factors. Here are some chemicals and substances that have been shown to contribute to mental fatigue:

  • Glutamate: Glutamate is an excitatory neurotransmitter that plays a critical role in learning and memory. However, when glutamate levels are too high, it can cause excitotoxicity, leading to mental fatigue and cognitive decline. (Check out the reference this, this)
  • Adenosine: Sustained cognitive activity burns up glucose, particularly in certain regions of the brain associated with “effortful mental processes,” such as the anterior cingulate cortex. This temporary and localized fuel shortage triggers a rise in adenosine levels, which in turn blocks the release of neurotransmitters like dopamine. The result is a rise in perception of effort and a decrease in motivation—in other words, a feeling of mental fatigue (Check out the this reference)
  • Cortisol: Cortisol is a stress hormone that is released by the adrenal glands. When cortisol levels are chronically elevated due to stress, it can contribute to mental fatigue and cognitive decline. (NOTE : I see different researches shows conflicting results about this chemical. Compare this with this).
  • Inflammatory cytokines: Inflammatory cytokines are immune system molecules that can be produced in response to infection or inflammation. When they cross the blood-brain barrier, they can contribute to mental fatigue and cognitive impairment. (Check out this reference)

 

 

 

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