Tag Archives: cognitive research

Neuroimaging: What is it and how can it map the brain?

One of the ways psychology has progressed came from the use of various neuroimaging methods. In terms of experimental psychology history, neuroimaging started with the cognitive revolution. Many scientists realized that understanding the brain plays an enormous role in the external behavior.  Scientists also use neuroimaging methods and technique prevention, diagnosis and treatment for different neurological diseases.

Today we still do not have a clear cut picture of the whole brain in itself. Not every network has been mapped, but we have moved forward a substantial amount. The development of non-invasive and invasive neuroimaging methods and their use for research and medical purposes was a definite breakthrough.

Neuroimaging

Neuroimaging-What can we map?

When one thinks about the brain and the nervous system, one can think of many things to map. Of course, we have the brain itself, its parts and the functions of the anatomical functions. We have neuroimaging techniques who deal exactly with that. Despite the anatomy, however, there are many neuroimaging methods that try to look at things on a more microscopic level.

We have methods that can view the cortical areas of the brain. Other techniques look at cortical columns and different layers. We have methods that can record a single cell by itself. Going even further, we can look at the soma of the neuron, the dendrite and, separately the axons. We can even look at the synaptic connections between the two neurons.

Neuroimaging- Method Classification

Neuroimaging methods also do not just encompass the spatial resolution. We try to look into proteins, organelles, bacteria, mammalian cells, the brain of various species and, finally, human brains. Many neuroimaging methods also differ by the temporal resolution. They differ by how quickly they are able to detect an event that happens in the brain. These neuroimaging methods differ by milliseconds, seconds, minutes, hours and days. They also differ by the spatial resolution. Some methods can show anatomical structures well, while others cannot. Apart from that, the variety of the neuroimaging methods differs by how non-invasive and invasive they are.

If one can imagine, scientists use a lot more non-invasive neuroimaging methods in research. Not many regular participants agree to something that can potentially alter their brain functions. Medical practitioners are a lot more likely to use invasive neuroimaging methods in an attempt to treat certain diseases. Various patients with neurological diseases benefit on a daily basis from the invasive neurological methods. In some cases, the patients themselves are able to control the stimulating method.

Electrophysiological techniques

For many years now we know that neurons are able to generate electric potentials. We also know that the synaptic activity of the nervous matter is similar to a battery. It acts as an electric generator.

If we recall the first class in physiology we took, we can roughly remember the structure of the neuron. Words like the cell body or the soma, dendrites and an axon come to mind. Dendrites seem to be able to receive electrical signals. Axon sends electrical signals to the dendrite of the next neuron. The cell body combines the signals from the previous neurons. Then it sends another signal along the axon for the next neuron.

Within the neurons themselves, we are able to distinguish two different types of electrical activity.

1-Action potentials

The action potential is a very common concept that many students learn in their first class on the nervous system. The entire process happens for about 1 ms and culminates with the release of neurotransmitters in the end of the axons.

  • The stimulus from a previous neuron activates the voltage gates on sodium channels which will cause the influx of positively charged sodium to the cell.
  • This depolarizes the membrane. Sometimes the depolarization of the membrane is able to reach the threshold.
  • If that happens, a series of events happen in order to send the signal along the axon to the next neuron. This is what we call an action potential.
  • The potassium channels are still closed and since we have an influx of sodium, the membrane becomes more positive on the inside then it does on the outside.
  • After that, the channels for sodium close and, therefore, the influx of sodium stops as well.
  • That’s when the potassium channels stay open and the potassium comes out of the cell and makes the inside of the cell negative one more time. This repolarization of the neuron can lead to the overall voltage to be below the original resting potential
  • This happens due to the fact that the potassium channels stay open a little longer. This ends in hyperpolarization. During this period a new action potential cannot happen and this is what we call a refractory period of the neuron.
    • Scientists cannot record action potentials via surface electrodes. As of today, we are not able to record potentials from a single neuron. What we can record is the second type of electrical activity. We can, however, use intracranial electroencephalography (EEG) to measure them which happens to be an invasive technique.

2- Post-synaptic potentials

They last for hundreds of milliseconds and it is the addition of the potential from various neurons that happen at the same time. We are able to record the potentials together. Researchers can easily record these potentials from surface electrodes. Electroencephalography (EEG) can measure these types of potentials.

So, in the end, we are able to distinguish two principal types of neuroimaging methods that measure the electrical activity of the neuron.

Two principal types of electrophysiological techniques

  • Single-cell recordings
    • These recordings are able to measure a number of different action potentials every second. The electrodes will be place inside a single cell or nearby a neuron which makes the technique invasive.
    • This technique can be useful for researchers who want to understand how single cells work.
    • Due to the fact that this technique allows measuring single neurons, we are able to see how specific these cells are.
    • A paper published saying that single neurons were firing to Jennifer’s Aniston’s face and nobody else’s. This level of object recognition falls under very high-level vision neurons and the paper gained a lot of attention due to such a strange working of a single neuron. (1)
  • Event-related potentials (ERP)
    • These recordings get the summation of different electrical potentials for a variety of neurons (millions of them). This technique places electrodes on the skull, therefore, they are surface electrodes.

Electroencephalography & Event-Related Potentials (ERP)

Since we now know that the brain produces electrical potentials, we are able to measure them. Electroencephalography helps us do that. Scientists can place various electrodes on the surface of the scalp and then measure the bio-electrical activity that the brain produces. Event-related potentials (ERP) are the potentials from various neurons that happen as a result of different stimuli given by the scientist to the participant. Stimuli and the tasks that the researchers assign can range from motor, to sensory and cognitive.

So the scientists are able to measure where and when the neurons will spike as a result of a certain assigned stimuli. Researchers have been able to find various ERP components or similarly distributed neurons that fire at the same time. They found various ERP components related to language, visual attention, auditory components (famous concepts like the mismatch negativity) and many others.

Other neuroimaging methods

Magnetoencephalography (MEG)

Neuroimaging methods don’t just stop at measuring the electrical activity of the neurons. Another famous brain imaging technique is MEG – it records magnetic fields. Electrical currents that already occur in the brain generate magnetic fields. MEG is able to directly measure the brain function which is a huge advantage when comparing it with other techniques. Apart from that, it has very high temporal resolution and high spatial resolution which is one of the rarest things when it comes to brain research. Usually, neuroimaging methods are either higher in spatial resolution or in temporal resolution, not both.

MEG is non-invasive. Scientists are able to use it with other neuroimaging methods at the same time – like EEG. One big disadvantage of MEG comes from the fact that in order to get the magnetic fields, a special room that gets rid of other types of magnetic interference needs to be built. Due to this, the machine is quite costly, but one of the best methods for measuring brain activity as of today.

Other famous types of brain imaging do not measure direct brain activity, however, they have quite good spatial resolution and are often used for clinical and diagnostic purposes.

Positron Emission Tomography (PET)

This technique gives an image of brain activity, however, in order to produce that image radioactive material needs to be either inhaled or injected by the participant. The image will then be produced due to this radioactive material going to the areas of the brain that are active.

Computed Tomography Scan (CT Scan)

This technique is able to produce brain images as well. It is able to show the anatomy of the brain, however, not the functions themselves which are a serious drawback especially if we consider the fact that X-ray lights need to go through the head to produce the image.

Magnetic Resonance Imaging (MRI)

MRI – Neuroimaging

One of the most common techniques nowadays. It gives an image of anatomical structures in the brain. It is non-invasive, but the patient must remain still in the MRI chamber which could prove to be quite painful for those suffering from claustrophobia. Apart from that, any type of metallic devices cannot be put in the chamber so many patients and subjects are not able to get a scan.

Functional Magnetic Resonance Imaging (fMRI)

An upgrade from the MRI – this technique detects the blood-oxygen-level dependent contrast imaging (BOLD) levels in the brain which are the changes in the blood flow and it not only gives the anatomical structures but the functions as well. Various colors will change depending on which part of the brain is active. The big drawback with this technique is the fact that it does not directly measure brain activity, but BOLD signal so we cannot for sure say that the activity that we find via fMRI studies is fully accurate and is produced by neurons.

Diffusion Tensor Imaging (DTI)

A technique based on MRI and it measures the way the water can travel through the white matter in the brain. It can show the activity as the colored area on the image. It’s very good in detecting concussions so can be used in clinical applications which is a huge advantage. Again, it does not measure direct brain activity which is a huge disadvantage and sometimes it also distorts the images. DTI has a quite low spatial resolution.

Transcranial Magnetic Stimulation (TMS)

The electric field that TMS is able to generate is able to interfere with the action potentials that are happening in the brain. It’s a highly invasive technique and is able to be used in research applications for the workings of many diseases and pathologies. What we do know is that repetitive TMS is able to produce seizures so, obviously, it has some sort of side effects and needs to be used with caution.

Neuroimaging- New Developments in Neuroscience

New neuroimaging methods and brain imaging techniques are being developed nowadays and, perhaps, soon enough we will be able to not only map the entire anatomical structures of the brain but functions as well. As of right now, these are the majority of the neuroimaging methods that are used in cognitive neuroscience. Maybe, in a few years, we will be able to develop a low-cost neuroimaging technique that has both high spatial and temporal resolution and is non-invasive to the participants!

References

Quiroga RQ, Reddy L, Kreiman G, Koch C, Fried I. Invariant visual representation by single neurons in the human brain. Nature [Internet]. 2005;435(7045):1102–7. Available from: http://www.nature.com.zorac.aub.aau.dk/nature/journal/v435/n7045/abs/nature03687.html%5Cnhttp://www.nature.com.zorac.aub.aau.dk/nature/journal/v435/n7045/pdf/nature03687.pdf

Experimental methods: how to create a successful study

Various rules govern every science and it uses different experimental methods. It does so in order to achieve the results. These results have to be able to be ready for publishing in scientific articles. In order to come up with a successful, publishable material a researcher needs to follow specific guidelines. He needs to arrange the experiments in an understandable, easily replicable way. Every future experiment needs to be able to replicate an already published scientific one. Without this ability to replicate, we couldn’t know whether the experiments are valid and transferable to a bigger population. Scientists need to have a clear view of all the guidelines in their mind before beginning a project.

Experimental Methods

Researchers need to have as much control as possible over all of the variables. They need to try and avoid confounding. Striving for objectivity and clearness in every step of the way is the goal of science. There is no worse thing for a scientist to miss a significant contributing factor to their study. This is due to the fact that this factor could have been able to change the results greatly.

If that happens, in a lot of cases, the research will have to start again. If you are lucky, maybe re-doing one or two experiments will be enough. In many cases, the scientist needs to run the entire set of experiments again. He does that in order to reach statistical significance with the results. Re-gathering all of the data again can sometimes turn research into a walking living nightmare!

Can you imagine running 200 infant participants between the ages of 5-7 months? And then you find out that the entire design of your study is faulty and you need to start over? You will have to rethink the entire design again but also recruit the 200 infants of the required age again! That is the reason why research takes time, patience, serious dedication and on occasion job stress.

In order to prevent these types of mashups, scientists have created guidelines and sets of rules. They aim to help speed the process along and make sure that it is running smoothly.

Experiments – the key to success in experimental methods

As mentioned before, an important part of every scientific study is the experiment itself. An experiment has certain prerequisites. A scientist needs to formulate a clear and concise hypothesis and the objectives of the study.

The hypothesis predicts what your study is attempting to find – the result of the study itself. It’s a statement. There are two different types of hypotheses in research.

  1. The null hypothesis states that the two variables that you are studying do not have a relationship. That means that one of them does not affect the other in any way, shape or form.
  2. Alternative hypothesis states the variables you are studying have a relationship and do affect one another. They do so in a significant fashion.

Experimental methods for every experiment include a set of variables that will help to formulate that hypothesis. The two sets of variables include an independent and a dependent variable. Independent variable is the one that the scientist manipulates.  The dependent variable is the one that the scientist is trying to find out. The researcher needs to also control for confounding or extraneous variables. These variables can compromise the results of their study.

Experimental methods: Hypothesis example

Let’s try to create a hypothesis ourselves. We can have a theory that video game players have better reflexes compared to non-video game players. That is an alternative hypothesis that tries to predict whether video games have an effect on reflexes in human participants. The independent variable, in this case, would be the video games themselves. The dependent variable is the speed of the reflexes.

Now, we need to take into an account the confounding and extraneous variables. For example, there are many video games in this world. Is there a difference, let’s say, between strategy and action games? We further define our hypothesis saying that action video game players will have better reflexes compared to non-video game players.

Extraneous variables

Other extraneous variables come to mind. If we do find an effect, is there a subsequent gender difference or an age difference? That could potentially lead to a new series of experiments. In the first experiment, we test whether video game players have better reflexes than non-players. In the second experiment, we compare male and female video game players. We try to eliminate the possibility for gender to be a confounding variable. In the third experiment, we could compare adults to teenagers.

We can see how a simple question can turn into a lengthy study with many different participants and variables. This is by no means a well-thought out hypothesis. If we were to spend some more time on it, we’d probably find more variables that we need to control for. We’d find ourselves in front of at least four or five different experiments with the use of many experimental methods.

The experiments themselves can be classified into different categories.

Experimental methods categories

Experimental Methods

Experimental methods: Experiments

Experimental methods: Field experiments

These types of experiments happen in participant’s real life situation. The scientist here will manage the independent variable but in a setting outside of the laboratory environment.

There are certain advantages to field experiments. Due to the setting being realistic the participants will behave in a more normal and ordinary way than they would in a laboratory. This brings higher ecological validity to the experiment compared to a lab experiment.

  • Ecological validity: how can the outcome of your study apply to real life?

Due to the fact that the participants usually do not know that they are being studied, they will not change their behavior subconsciously or consciously. Participants tend to do that when they think they know the purpose of the study that the researcher is conducting. That can seriously compromise the results of any experiment due to them not being genuine and create outliers in the further statistical analysis.

Experimental methods: Drawbacks of field experiments

We can see some challenges this set of experiments can produce due to the inability of the experimenter to control the confounding and extraneous variables that will for sure appear on the horizon during the study. Due to the inability to control for extraneous variables, there is a lesser likelihood to replicate the study which could be quite damaging for the project overall.

Experimental methods: Quasi/Natural experiments

The main difference between ‘Natural experiments’ and ‘Field experiments’ is that in the first one the scientist has no control over any variables that occur during the experiment. Because the experiment occurs in even more real-life settings than the field experiment, the participants are a lot more likely to act genuinely and naturally. This is one of the main strengths of these type of experiments. The ecological validity of them is quite high when compared to laboratory experiments and, even, field experiments. Because the participants do not know about the study or they might not suspect they are being studied, they will not try to subconsciously or consciously sabotage the results of the study which is a huge advantage in itself.

Experimental methods: Drawbacks of quasi/natural experiments

The scientist can go virtually anywhere and observe any situation. A big and obvious limitation of these types of experiments is the serious lack of control over any variables so it is either very difficult or sometimes virtually impossible for a future researcher to conduct a study in a similar way.

Experimental methods: Laboratory experiments

Laboratory experiments are the most controlled ones out of the three and they can use a variety of experimental methods for data collection due to the fact that they are the most objective ones. They allow the scientist to measure things and control for everything that he can possibly control for due to the fact that the researcher himself decides the place of the experiment, the time, the participants and the circumstances.

Participants: Random assignment

Usually, for the best outcome, the researchers try to get a random assignment of the participants to avoid a bias of only picking females over the age of 35 of higher-middle class. That would be quite a significant confounding variable that would surely compromise the results of any study. Sometimes, however, a certain population needs to be used, for example, if the scientists are testing a new drug for schizophrenia. Clearly, the participants of that study would have to have been diagnosed with schizophrenia beforehand.

Drawbacks of laboratory experiments

Laboratory experiments are easily replicable due to the fact that everything that happens in the experiment needs to follow a concise step-by-step procedure that the researcher will then share in his methods section. Avoidance of the extraneous variables becomes easier due to this controlled environment. A big limitation of laboratory controlled experiments in the field of psychology is the control itself.Due to the fact that many studies in psychology deal with human participants, the artificial environment may encourage the participants to act in a way that is not genuine or normal for them. On top of that, the participants usually know that they are a part of the experiment and, therefore, might subconsciously or consciously sabotage the results.

Experimental methods: Data collection

There are various different experimental methods of collecting data and two different types of data can be distinguished.

Experimental methods: Two types of data

Qualitative data is mainly a part of an exploratory research. It is less objective than quantitative data. Some common types of qualitative analysis include interviews, focus groups, participation/observation and case studies. In case studies, in particular, researchers are able to look into one specific problem or one particular participant that is of their interest.

Quantitative data usually generates data that is numerical and is able to be statistically analyzed. Quantitative data is the type of data that is mainly used in laboratory research because it allows structure and standardization. Scientists use quantitative research to study behaviors, opinions and other variables that are clearly defined. Usually, researchers will use a small sample and then attempt to generalize the results to a larger population.

Quantitative data can come in the form of surveys, interviews and questionnaires and longitudinal studies. During the experiments, other various scientific and experimental methods are used in the form of eye-tracking and neuroimaging methods.

Experimental methods: Patience, hard work, and dedication

This is by far not all that there is to know about the experimental methods in the field of psychology. People become statisticians for the sole purpose of analyzing data and clinical lab technicians that help with the experiments themselves. Despite that, it gives an insight of what it is like to be a researcher in the modern society and how many different variables need to be taken account of. Just to think that completely different ethical guidelines are used for animal and human research and different countries have distinct guidelines for both! It is important not to despair because only through research we are able to find out about ourselves. Only through research, we can look for prevention, diagnosis, and treatment of various diseases. It’s important to follow the guidelines and the rules for the society’s benefit.

How We Listen: Is It Just The Ears That Play A Role?

We listen with our hands, not only our ears. Some researchers even suspect we may listen with our hands and other body parts too.

We listen

Ever been in a car and a good song pops on the radio and before you know it your fingers are tapping to the rhythm of the music without you even noticing? Ever felt compelled to clap at a certain part of a song because it follows the beat?  We could say that we listen with our hands. Listening happens thanks to our auditory perception that allows for sounds to be processed by our ears.

Julian Treasure made a short Ted talk explaining how we listen and what can we do to listen better.

However, it is possible that we listen with other body parts.

We listen with our hands

Cognitive research and scientists managed to get solid evidence that the sensorimotor systems are involved in language processing. This suggests that comprehending verbal descriptions of actions rely on an internal simulation of the described action.

Several scientists decided to see if this was true. They got a group of people, ages ranging from 18-34-year-olds, to participate in a study. The scientists prepared thirty-five action words into affirmative and negative context sentences.

The participants listened to the spoken sentences, each in the third person and present tense, such as “John walks to work.” to measure their motor grip as they listened and pinched a grip-force sensor.

The researchers found that subjects increased their grip when listening to action words that involved hands or arms. Some of the verbs hand or arm related were: scratch, grate, throw, etc. But this response depended on context, meaning the grip force was unchanged when the action was negative, as in “Laura did not lift her luggage.”

This suggests that when the person hears the sentences of hand verbs happening at the exact moment the brain sends impulses to the motor neurons and the grip becomes tighter. If the action is not happening the grip does not tighten therefore it understands that it’s not happening. We could say that we listen with our hands because it’s our hands that respond to the words being spoken.

We listen with our hands

We listen with oher parts of the body, too

We listen not only with our hands but we can listen with our whole body. The human brain has the capacity to amaze us each time with what it can accomplish and with all the body parts involved for cognitive abilities to develop.

Susanne Poulette came up with a concept called whole body listening. It consists of breaking the abstract concept of listening by explaining how each body part other than the ears is involved. She explains that the parts involved go as follows; the brain thinking about what is being said; the eyes looking at or toward the speaker; the mouth closed and quiet; the body facing toward the speaker; and the hands and feet quiet and kept to oneself.

Truesdale, later stressed that the most critical part of whole body listening takes place in the brain but we couldn’t forget about the heart which is a way of caring and feeling empathy with those we listen to.

“When we are asking someone to think about what we are saying, we are, in essence, asking for the listener’s brain to be connected and tuned-in.”

Truesdale establishes that whole body listening is a tool, meaning that adults need to think flexibly about how best to use it and there is no one way to teach it.  Gradually, other professionals have come to terms that we listen with our whole body and this helps listening become a less abstract concept and more a concrete concept, easier to understand, teach and practice.

Teaching children

We listen with our whole body, however, teaching children to understand this concept might be abstract. Many parents, teachers, and other professionals have used tips from these professionals to break down the abstract concept of listening into more manageable, concrete actions.

Parents and teachers tend to claim that children have a hard time listening to instructions, stories, etc. When explained into more depth how we listen with our body and what is expected of each body part. Many children claimed that they found listening much easier. Step by step brain training and body training to listen intently and retain the information.

Parts of the body we listen with:

  •        eyes to look at the person talking
  •        ears to hear what is being said
  •        mouth by remaining quiet
  •        hands by keeping them by their side or in lap
  •        feet by placing them on the floor and keeping them still
  •        body by facing the speaker or sitting in chair
  •        brain to think about what the speaker is saying
  •        heart to care about what the speaker talks about

To listen we need to…

Ears: Limit auditory distractions.

Eyes: Look toward the speaker, maybe not directly but checking in for facial expressions to “read” emotions and others’ intentions. Limit distractions and visual clutter. People can hear what is being said even if they are not looking directly at the speaker. Therefore, try to modulate direct eye-contact.

Mouth: Try not to interrupt. Chewing gum can help regulate impulse control.

Hands:  Use a fidget or doodle. Squeeze hands together. Sit on hands or put them in pockets. This helps to concentrate on what the other person is saying.

Feet: Cross or sit on feet to help keep them still. Some people need to move their body to stay regulated, enhance attention, and feel comfortable.

Heart: It’s important to understand why we listen to others. We listen to create rapport, share and experience, and always consider the other person’s feelings.

Brain: We should know how the brain works and how our cognitive abilities and cognitive skills help us to listen with our whole body. Mindfulness can a good asset in being aware of the present moment. This can help to know when to pause and reflect before acting, and knowing how and when to listen with our whole body.

 

Music and the Brain

6 Ways Music Affects the Brain

Music and the Brain

A lot of people listen to music. However, many people do not know the effects music has on the mind. Since music plays such an integral part of our daily lives, we decided to write about the ways music affects the brain functions. Here are 6 ways music affects the brain.

1. The Type of Music You Listen to Reflects Your Personality: Research has shown that your music preferences may have a reflection on your personality. For example, people who listen to pop music tend to have extroverted personalities. People who prefer pop music tend to have high self-esteem. However, they tend to be less creative and more stressed out than other people. Rap listeners tend to be more confident and gregarious. Rock music fans tend to be more easy going, introverted and creatively inclined. Indie listeners are also shown to be introverted and creative. However, they may suffer from low self-esteem. People who listen to dance music are often more assertive and outgoing. Classical music aficionados tend to be more laid back and quiet. Jazz listeners are often extraverted and confident. Keep in mind this is not applicable to everyone. In other words, it is a general rule.

2. Music Helps Us Exercise: Often we see people listening to music with their headphones at the gym. Listening to music gives the brain attention. In fact, it draws brain’s attention from fatigue. People who listen to faster upbeat music tend to push themselves harder compared to people who do not listen to music.

3. Music Can Be A Reflection of Your Mood: Cognitive research has shown that our brains tend to respond differently to happy and sad music. The way we interpret a piece of music can be expressed through our facial expressions.

4. Music Can Benefit Your Health: A good way to reduce high blood pressure is to listen to relaxing music. Another way music can benefit our health is that it can enhance our immunity. Music has been shown to reduce the amount of cortisol in the body. Cortisol is a stress related hormone. People who have a higher level of cortisol in their body tend to have a weaker immune system.

5. Music Can Increase Productivity at Work: People often listen to music while they are on the job. Did you know that music can help to get more work done? It is important to note that only classical music and rock music increase work efficiency.

6. Music Reduces Stress: How does music relieve stress? It can help relax tense muscles and make you have less negative emotions. Many people consider music to be therapeutic when they are feeling sad and depressed.

Newborn babies’ brains grow one percent a day

Newborn babies’ brains grow one percent a day

Newborn babies’ brains grow one percent a day

A baby’s brain is a mystery whose secrets scientists are beginning to unravel. The first study of its kind shows that newborn babies’ brains are about a third the size of an adult’s at birth, and grow at an average rate of 1% a day to reach just over half the size of an adult’s brain within three months.

The study, carried out by researchers from the University of California, the University of Hawaii and the Norwegian University of Science and Technology, aimed to map newborns’ brains during their first three months of life. This cognitive research was published on August 11th, 2014 in the peer-reviewed medical journal, JAMA Neurology.

For centuries doctors have estimated brain growth using measuring tape to chart a baby’s head circumference over time. Any changes to normal growth patterns are monitored closely as they can suggest problems with development. But as head shapes vary, these tape measurements are not always accurate.

Thus for this study, researchers used a new scanning technique to measure the early development of newborn brains. They set out to map growth trajectories in the brains of newborn babies during the first three months of their life. Using a series of magnetic resonance imaging (MRI) scans, the volume of multiple brain regions and the growth rate of the newborn brain could be calculated. MRI works by executing high-quality images of a range of brain regions, without the use of radiation. One huge advantage of earlier charting of the size and rate of brain growth is that it could help to detect potential signs of developmental disorders in the brain, such as autism. If a developmental disorder is seen to be present, treatment will be more effective than if detected at a later stage.

Researchers scanned the brains of 87 healthy newborns 211 times, starting when the babies were only 2 days old. They found that the newborn brain grows extraordinarily fast right after birth, but slows down to a growth rate of 0.4 percent per day by the end of three months.

Overall, infants’ brains grew by 64 percent in the first 90 days, according to the study. The average brain size was 20 cubic inches (341 cubic centimeters) at birth, and 34 cubic inches (558 cubic cm) at 90 days. In other words, the brains of newborns grew from about 33 percent of the average adult brain size to 55 percent of it in three months.

The researchers noted that the brains of the infants who were born one week earlier than the average in the study (about 38 weeks), were 5 percent smaller than the average. By the end of the three months, the difference between these babies, which the researchers said were preterm, and the full-term babies became smaller, but the preterm babies hadn’t fully caught up, and their brain size was 2 percent smaller than the average, according to the study,

“The brains of premature babies actually grow faster than those of term-born babies, but that’s because they’re effectively younger — and younger means faster growth,” study researcher Dominic Holland, of the University of California, San Diego School of Medicine, said in a statement. The findings suggest that inducing labor early, without a medical reason, may have a negative effect on the baby’s cognitive development, Holland said.

Researchers say using MRI scans will prove to be a much more effective way to track cognitive development. Scans should lead to more exact growth charts, replacing the old method of measuring the skull with measuring tape, and help identify disorders such as autism or brain injury early.

Scientists will now investigate whether alcohol and drug consumption during pregnancy alters brain size at birth.