2/7 Brain Fingerprints & Images of the Brain
Video:
Miss the lesson? Want to hear more? Listen as Bridget Wright delivers a lesson on Brain Fingerprints and brain scans. Click here to access.
Follow-up from Zoom sessions
The Wednesday evening class discussed the MUSE headphones which may assist in meditation and sleep. You can find more information on this site: choosemuse.com.
(We are not promoting the use. This is for informational purpose only. )
Introduction to the lesson
Did you know that our brains are as unique to us as our fingerprints? In our first topics lesson of Spring 2022, we are going to look inside the brain. We are going to look at how the brain looks in a brain scan, and what studying these images can be revealed. We will see how these images may help to understand neurological conditions such as Alzheimer’s. We will view some of the beautiful graphics found in brain scans, electron microscope images and videos. And we will discuss the sometimes controversial research behind brain fingerprints which reflect memories. Prepare to be dazzled!
Introduction to brain scans
(Reynolds, 2022) (Lovering, 2021)
A brain scan is an image of the brain. It is often used by medical professionals to diagnose abnormalities in the brain, such as a stroke or tumor. There are two main types of brain scans, computed tomography (CT) and magnetic resonance imaging (MRI).
CT Scan
The CT scan would be the first ordered if a person has experienced a brain trauma like a stroke. A contrast might be injected into the vein to highlight abnormal areas of the brain. The scan uses ionizing radiation (x-rays) to capture images. The professional will then view the images in “slices” to detect abnormalities. The brain on the CT scan will look gray, while abnormalities will show up as darker or white areas in the brain or tissues. Below, you can see two CT scans. One is a normal one, which the other CT scan is on a person with a brain tumor. The brain tumor is identified as a large white mass.
MRI
If additional screening is needed, an MRI may be performed. In this case, detailed pictures of the brain are taken using magnets along with radio waves to transport an image from inside the brain to the computer screen. The machine will take images of the brain from all angles. The MRI provides a more detailed image, so these pictures can provide a much clearer image of the soft tissue of the brain. The MRI can often see abnormalities not seen in a CT scan. The main difference between the CT scan and the MRI machine is that the MRI uses magnets and radio waves for images, while the CT scan uses ionizing radiation (X-rays).
Other scan options
Apart from the CT and MRI scans, there are additional scans which may be used in the brain. They include:
· Positron emission tomography (PET): Uses a radioactive tracer that attaches to the glucose in your bloodstream. Since the brain uses glucose for fuel, the tracer accumulates in the areas of higher brain activity. The PET scan can see these tracers, observe the movement and how they build up in the brain. They can also see areas where the glucose isn’t moving correctly.
· Electroencephalography (EEG): Measures your brain waves as small electrodes are attached to the scalp with wires. The electrodes detect electrical activity in the brain and send it to a computer where it is seen as a graph-like image. It provides information about your brain activity.
· Magnetoencephalography (MEG): Measures the magnetic field from neuron electrical activity. It can locate and identify malfunctioning neurons in the brain. It is used to evaluate spontaneous brain activity as well as neuronal responses which are triggered by stimuli. The images produced by the MEG shows the electrical currents related to neuronal activity, with low activity red to high activity yellow. In the MEG illustration on the right, the top row is at rest, while the bottom row reflects small movements of the hand.
· Near-infrared spectroscopy (NIRS): Measures the oxygen saturation in the brain using infrared light which detects changes in hemoglobin oxygen levels in your blood. Since oxygen is so important for brain functioning, it can help assist where brain oxygen levels may fluctuate such as during surgery.
Summary of scans:
CT scan uses x-rays to highlight abnormalities following a brain trauma.
An MRI scan uses magnets and radio waves to capture a more detailed image of the brain including all angles
The PET uses a radioactive tracer to locate glucose accumulation in the brain, indicating brain activity
The EEG measures brain waves which detect electrical activity in the brain, providing information about brain activity.
NIRS measures oxygen saturation and detects changes in hemoglobin oxygen levels in the brain, which is useful during times when brain oxygen levels may fluctuate.
Video:
Need to know more? This Ted video discusses three of the methods above (EEG, fMRI and PET). It also highlights the importance of each, and suggests new directions of scanning.
Video:
Another excellent lesson, this time from Khan Academy. It categorizes the different scans into brain structure and brain function, and scans that look at both. Easy to understand!
Seeing scans: The brain as a neural network
(Bassett, 2017) (Fornito, 2019)
The various methods of scanning the brain will result in a variety of pictures of the brain (structural as well as metabolic) which can then create a model of how the brain works. This can then be used to design therapies for brain health. This technology has been used in several projects including the Human Connectome Project [1], the Brain Initiative Project [2] and the Human brain project [3].
Network neuroscience is a wiring diagram of the brain. It can locate the networks in the brain, including networks of molecular interactions, neuronal connections, synapse connections and even mapping of the white and gray matter within the brain. It uses the imaging data from the various scans described above to make a map of the connections and a diagram of how the areas fit together.
After the data is made available, algorithms are used to process the data and affect the results. Various algorithms will produce different results from the data.
[1] http://www.humanconnectomeproject.org/
[2] https://braininitiative.nih.gov/
[3] https://www.humanbrainproject.eu/en/
Images from the Human Connectome project
Videos which depict neural networks
The Human Brain:
Starting at the whole brain, it reduces to the parts of the brain, the neuron makeup (gray and white matter), the connections in a portion of the brain (hippocampus) and finally to the individual neurons.
Neurons & Synapses:
This video uses data to reconstruct the images highlighting the behavior of neurons and synapses. Connectivity between neurons is used to predict behavior. In this video, neurons are seen within the amygdala by using special dyes. Mathematics are then used to isolate neurons to further understand structure and function.
Neurodegeneration from Alzheimer’s:
The process of neurodegeneration from Alzheimer’s disease takes place over a period of years. In this video, a condensed time frame illustrates the evolution of the disease.
Fingerprints of the brain
(Your brain has its own fingerprint, and doctors can pinpoint it in under 2 minutes, 2021) (Our brains have a fingerprint too, 2021) (Patel, 2021)
For years, fingerprints have been used to identify people. Now, emerging data suggests that our brain has a unique fingerprint as well.
Using data on connectomes (the brain’s neural networks), it has been seen that these connectomes can produce a unique “fingerprint”. They could then be used to identify a certain individual based on their brain scan. This technology resembles the way that you can use you fingerprint to turn on your phone. Using MRI scans, scientists examine the networks and connections within the brain, including the links between different areas to understand how the brain works. This data is then processed to generate graphs which summarize activity in the brain. These graphs are represented by colorful matrices that summarize activity in the brain and is commonly known as functional brain connectomes. Below view the neural networks of the brain (source).
Neuroscientists have identified brain fingerprints using MRI scans taken over a fairly long period of time. These MRI scans would last several minutes and were done over several days. But scientists were wondering if this data could be obtained in less time. They wondered whether the fingerprints could occur in a few seconds, or do they take longer? And they also wondered if fingerprints in different areas of the brain appear in different moments of time?
Enrico Amico, a scientist at the Swiss Federal Institute of Technology in Switzerland wanted to find how much time in an MRI scan would detect useful data. This is important because his research has suggested that features that make a brain fingerprint unique will disappear as a disease (such as Alzheimer’s) progresses. It is then harder to use connectomes to identify people. The key finding was that with brain trauma, the brain identity (fingerprint) is lost. Using a variety of scans over time, he found that these brain fingerprints could be achieved in about 1 minute and 40 seconds, much less than the 5 minutes or more used in the past.
Amico also found that the fastest brain fingerprints start to appear from the areas associated with more primitive functions, such as sensory areas of the brain, and especially in the areas related to eye movement, visual perception and visual attention. With time, the areas in the frontal cortex regions associated with more complex cognitive function to reveal the unique information to each of us.
His next task will be to compare the brain fingerprints of healthy patients with those with brain disease. Given that the diseases of the brain will change the unique fingerprint of the brain, having a baseline may help to detect neurological conditions where the brain fingerprints will disappear.
Brain fingerprints (AKA functional brain connectomes)
Video:
A long video, but you can meet Enrico Amico and discover how he came to his area of research. Optional video!
Fingerprints created by memories
(Memories create 'fingerprints' that reveal how the brain is organized, 2020)
New research suggests that there are differences between how people reimagine scenarios in the brain. Because each person has different experiences, they will imagine similar types of events differently as well. Researchers have shown that you can decode the information in the brain related to everyday life and identify neural fingerprints that are unique in that individual’s remembered experience.
Researchers asked participants to recall common scenarios (driving, eating out at a restaurant) which were broad enough to be reimagined differently. The verbal descriptions were mapped to a linguistic model that approximated the meaning of the word and created numerical representation of the context of the description. They were also asked to rate aspects of the experience, such as how strongly it was associated with sound, color, movement and emotions.
They were then placed in a functional MRI and asked to recall the experience while the brain was activated in different areas. Using the data and the subject’s verbal descriptions and ratings, researchers could isolate brain activity patterns associated with the individual experience. An example would be a person driving through a red light, where the areas of the brain associated with recalling motion and color would be activated. This data was then used to create a functional model of each participant’s brain, creating their unique fingerprint of their neuronal activity.
Researchers found several areas of the brain used for processing information across the brain networks, which contributed to recalling information about people, objects, places, emotions and sensations. They were also able to see how it looked at an individual level. Researchers concluded that fMRI could measure brain activity and identify meaningful interpersonal differences in the neurons which imagined the events. They also noted that many of the key regions identified in their research tend to decline as we age and are vulnerable to degradation seen in brain illness and trauma. They suspect that new ways to diagnose and study disorders related to irregular memory deficits could be used to create personal treatments and predict which therapies will be more effective.
Video:
A review of memory in the brain. Review the types of memories, and where in the brain they can be found. How do you think they identified the regions of memory storage? Scans of course!
Fingerprints of the brain used in crimes
(Lauf, 2018) (Meijer, 2012) (Bramdom, 2015)
Steven Avery arrested for murder in 2005. However, he had always said that he did not commit the murder. Furthermore, he attributed the veracity of the prosecution to the fact that just two years earlier, he had been exonerated by DNA testing for a sexual assault and attempted murder conviction. This exoneration provided spirited discussion of Wisconsin’s criminal justice system, and prompted a civil suit against Manitowoc County, its sheriff and its former district attorney for $36 million. With the suit pending, he was arrested for the murder of photographer Teresa Halbach and was sentenced to life imprisonment without possibility of parole.
Avery gained national attention when Netflix featured a ten-episode series entitled “Making a Murderer”. This stirred the public into action, causing a renewed look at the case. Appeals have been ongoing for years. In 2018, his then attorney Kathleen Zellner employed the services of Larry Farwell, an investor of a polygraph-like technique called brain fingerprinting. Zellner maintains that if his brain does not register certain details of the crime, he must be innocent.
Video:
Learn about the Avery case, which will then be discussed as we discuss brain fingerprinting for the purpose of crime.
Brain fingerprinting functions like an advanced lie detector test. It takes EEG readings of brain activities, then tracks responses to specific facts or images to determine whether those details are stored in the brain. For example, during interrogations, a subject is often asked pointed questions about a crime, such as was the victim shot? Stabbed? Strangled? Since there is only one answer, if the subject knows they were shot, they will show a specific response (known as a P300 response).
Farwell maintains that if you show someone information about a crime that only the person who committed the crime would know, their P300 response would determine innocence or guilt.
Video:
Let's meet Larry Farwell in 2007 as he explains the science behind brain fingerprinting.
Farwell presented to Avery words on a computer screen, some of which were related to the murder of Teresa Halbach. These words were either things that officials knew he knows, things that are irrelevant and then probes (a response only if he knows it). At the end of testing, Farwell said that he believed Avery wasn’t involved in the murders.
This method is controversial among scientists. Although brain fingerprinting has been accurate with innocent participants (outpacing the traditional polygraph), but with real crime scenarios, it was often less reliable than a polygraph.
Furthermore, comments in the journal Cognitive Neurodynamic disputed the process, saying that Farwell’s brain fingerprinting was misrepresented. Farwell had called this a state of the art in forensic science while is actually a variant of another imaging tool, the CIT. The CIT (Concealed Information Test) determines the presence or absence of crime-related information in the subject's memory. It is often used with other measures, such as recording changes in the autonomic nervous system. It focuses on the P300 waveform which assesses recognition of crime details have been developed. This is what Farwell referred to as "brain fingerprinting". Farwell claims that his brain fingerprinting measures recognition of crime details, while the CIT measures deception. These scientists also included reasons why this research was flawed including misrepresentation (suggesting a revolution in forensic science), an oversimplification of the P300 waveform, problems in study protocol and peer review process, selection bias, and lack of consistency is design.
Opponents of brain fingerprinting to resolve guilt or innocence are also concerned about the effect on the legal system. They believe that there is not enough testing behind it to be used as evidence to convict people. There is concern that laboratory testing cannot reliably replicate the brain activity of a suspect being interrogated for an actual crime. (Student volunteers are one thing, but potential murderers like Avery are another.)
At this point, brain fingerprinting has only been admitted into court once in 2003. But the technique is gaining adherents in Australia and India based on the early success in American courts. Time will tell whether it will become another method of defense in crime solving.
Video:
A look at brain fingerprinting in crime. Provides both sides of the story, questioning the methodology as well as the ethical standards of the procedure.
Video:
Compares lie detector tests to brain fingerprinting.
Summary:
The brain is a complex organ which features many components. Brain imaging is a way to diagnose and follow diseases of the brain. The revelation that we have a unique brain fingerprint is a challenge and an opportunity for neuroscientists to better understand our brain, and to detect abnormalities early in the game. And for the rest of us, we can enjoy the beautiful images our brain can render.
Works Cited
Bassett, D. (2017, February 23). Network Neuroscience. Retrieved from Nat Neuroscience: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5485642
Bramdom, R. (2015, February 2). Is 'brain fingerprinting' a breakthrough or a sham? Retrieved from theverge.com: https://www.theverge.com/2015/2/2/7951549/brain-fingerprinting-technology-unproven-courtroom-science-farwell-p300
Fornito, A. (2019, August). An Introduction to Network Neuroscience. Retrieved from OHBM 2019 Annual Meeting: https://www.pathlms.com/ohbm/courses/12238/sections/15846/video_presentations/137536
Lauf, J. (2018, October 19). Why The Brain Fingerprinting Technique In 'Making A Murderer' Part 2 Is So Controversial. Retrieved from bustle.com: https://www.bustle.com/p/how-accurate-is-brain-fingerprinting-the-making-a-murderer-part-2-test-is-controversial-within-the-scientific-community-12603938
Lovering, N. (2021, October 22). Types of Brain Imaging Techniques. Retrieved from psychcentral.com: https://psychcentral.com/lib/types-of-brain-imaging-techniques
Meijer, E. e. (2012, August 14). A comment on Farwell (2012): brain fingerprinting: a comprehensive tutorial review of detection of concealed information with event-related brain potentials. Retrieved from ncbi.nlm.nih.gov: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3595430/
Memories create 'fingerprints' that reveal how the brain is organized. (2020, November 20). Retrieved from medicalxpress.com: https://medicalxpress.com/news/2020-11-memories-fingerprints-reveal-brain.html
Our brains have a fingerprint too. (2021, October 15). Retrieved from neurosciencenews.com: https://neurosciencenews.com/brain-fingerprint-19479/
Patel, N. (2021, October 15). Brain ‘Fingerprints’ Could Unlock Alzheimer’s Early Warning System. Retrieved from dailybeast.com: https://www.thedailybeast.com/brain-connectome-fingerprints-could-be-an-early-warning-system-for-alzheimers
Reynolds, L. (2022, January 28). What is a brain scan. Retrieved from thehealthboard.com: https://www.thehealthboard.com/what-is-a-brain-scan.htm
Your brain has its own fingerprint, and doctors can pinpoint it in under 2 minutes. (2021, November 28). Retrieved from studyfinds.org: https://www.studyfinds.org/brain-fingerprint/