Brief History of Neurotechnology

Magnetic Resonance Imaging (MRI)

1938

Isidor Isaac Rabi first detects the phenomenon of nuclear magnetic resonance (NMR), the underlying principles used in MRI, in a beam of lithium chloride through a complex experimental procedure (Link to original paper).

1946

Felix Bloch & Edward Mills Purcell extend the work done by Rabi by developing new methods for obtaining precise measurements from nuclear magnetization in solids and liquids. Bloch & Purcell shared the Nobel Prize in Physics for this work in 1952.

1971

Raymond Damadian shows MR relaxation time could be used to distinguish cancer from healthy tissue, being the first to identify the clinical use of NMR (Link to original paper).

1973

Paul C. Lauterbur develops the theory for MRI by proposing the use of magnetic field gradients to encode spatial information from the NMR signal (Link to original paper). He recieved the Nobel Prize in Physiology or Medicine in 2003 jointly with Peter Mansfield.

1974

Damadian designs and builds the first full-body MRI machine, called 'Indomitable'.

1977

Damadian, Larry Minkoff, and Michael Goldsmith perform the first MRI scan on a live animal to visualize a tumour (Link to original paper), and MRI body scan of a human (Link to original paper).

Peter Mansfield invents an MRI acquisition method that makes scan times suitable for clinical use, called echo planar imaging (EPI) (Link to original paper). He recieved the Nobel Prize in Physiology or Medicine in 2003 jointly with Lauterbur.

1978

Damadian founds FONAR corporation, which produced the first commercially available MRI machine in 1980 (Summary article).

1986-1987

Charles Dumulin & Howard Hart develop MR angiography, where vasculature can be imaged using MRI. Additionally, Denis Le Bihan obtained the first diffusion MR images.

1990

Seiji Ogawa recognizes deoxyhemoglobin and oxyhemoglobin have different magnetic properties, and discovered the technique that underlies functional MRI (fMRI) (Link to original paper).

2012

Animal studies are performed using a magnet strength of 21.1 Tesla (Link to original paper).

2019

For the first time, human studies were performed using a magnet strength of 10.5 Tesla (Link to original paper).

2020

Hyperfine's portable MR imaging system becomes the first FDA approved portable MRI system capable of providing neuroimaging at the bedside, eliminating the need for patients to be moved to a specialized MR suite.

X-ray & Computed Tomography (CT)

1895

Wilhelm Roentgen finds that cathode rays are able to pass through human tissue and visualize underlying anatomy, giving rise to clinical X-ray imaging or radiography (Link for more details). For this work he recieved the Novel Prize in Physics in 1901.

1913

William David Coolidge designs a high vacuum X-ray tube that was a reliable sources of X-rays and could operate at energies up to 100,000 volts. This work overcame technological issues in previous X-ray tubes that often broke down at high voltages.

1917

Johann Radon develops the mathematical theory behind CT by showing an object can be reconstructed based on an infinite set of its projections, known as the Radon transform.

1961

William Oldendorf theorizes the ability to scan a head through the use of a transmitted beam of X-rays in conjunction with the Radon transform, creating an apparatus that has a rotating source and coupled detector that could get X-ray images of various materials.

1967

Godfrey Newbold Hounsfield extends the theory for CT by taking several X-ray images at different angles followed by computer reconstruction, also inventing the first commercially available CT scanner. For this work he recieved the Nobel Prize in Physiology or Medicine in 1979.

1971

In London, England, a CT scanner is used clinically to image a women suspected to have a brain tumour.

Electro- & Magneto-encephalogram (EEG & MEG)

1849

Hermann von Helmholtz measures the speed at which electrical impulses are conducted along nerve fibres.

1875

Richard Caton measures electrical phenomena from exposed cerebral hemispheres in monkeys.

1924

Hans Berger invents the electroencephalogram (EEG) and was the first to record large-scale electrical activity in the brain. The first EEG trace obtained from a human brain was published in 1929 (Link to read more).

1930s

Wilder Penfield develops a technique that obtains EEG recordings directly from pial matter in the brain, now known as electrocorticography (ECoG).

1968

David Cohen discovers magnetoencephalography (MEG) (Link for original paper).

Near-Infrared Spectroscopy (NIRS)

1876

Karl von Vierordt observes changes in the spectrum of visible light when it passes through human fingers which were predominated by either oxy- or deoxy-hemoglobin, being the first to demonstrate the potential for a non-invasive method for monitoring tissue oxygenation.

1930-1939

Based on findings from von Vierordt, Kramer & Matthes find that near-infrared light can also be used to determine levels of oxy- and deoxy-hemoglobin in human tissue, laying the ground for the discovery of near-infrared spectroscopy (NIRS).

1977

Frank Jobsis, known as the pioneer of medical applications of NIRS, theorizes the use of near-infrared light to study brain activity continuously and led to the invention of NIRS (Link for original paper).

1985

The first clinical NIRS studies are conducted on newborns by Jobsis & Brazy (Link for original paper), and adults by Marco Ferrari (Link for original paper).

1992

Based on the development of fMRI by Seiji Ogawa, studies carried out by Chance, Kato, Hoshi, and Villringer led to the discovery of functional NIRS (fNIRS).

1996

Kleinshmidt carries out the first simultaneous recording of brain activation using both fMRI and fNIRS (Link for paper)

Neuroelectronic Recording & Stimulation

1963

Hodgkin & Huxley become the first to use an electrode to record an action potential in an axon.

1937

Physicians Ugo Carletti & Lucio Bini develop and use electroconvulsive therapy (ECT) that electrically induces a seizure as a treatment for mental illness. In the following decades, this became overused and resulted in public backlash.

1980

Merton & Morton develop transcranial electrical stimulation (TES) whereby an electrical current is passed through the skull to stimulate the cortex of the brain (Link for original paper).

1985

Anthony Barker develops transcranial magnetic stimulation (TMS), whereby a changing magnetic field is used to induce current in a specific region of the brain.

1987

Alim Benabid discovers electrical stimulation of the basal ganglia improves symptoms of Parkinson's disease, the first use of what is now known as deep brain stimulation (DBS).

1997

DBS is approved by the FDA for tremors and Parkinson's disease. DBS is now approved in the treatment of dystonia (2003), obsessive-compulsive disorder (OCD)(2009), and epilepsy (2018).

2008

TMS is approved by the FDA for treatment of medication-refractory depression.

Positron Emission Tomography (PET)

1911

George Hevesy demonstrates the use of radioactive isotopes for labelling. For this work he recieved the Nobel Prize in Chemistry in 1943.

1934

Irene & Frederic Joliot-Curie produce an artificial isotope that could be formed and made safe for humans.

1953

Gordon Brownell & William Sweet invent and demonstrate the first large-scale use of a positron imaging device, with Brownell going on to develop the first positron emission tomography (PET) imaging device in 1972.

1976

Louis Sokoloff, Alfred Wolf, and Joanna Fowler synthesize 2-[¹⁸F]fluoro-2-deoxy-D-glucose (FDG), which is used to measure cerebral glucose utilization and is still widely used for PET imaging today.

Brain-Computer Interfaces (BCI)

1875

Richard Caton records the first ever electrical activity in the brain of living rabbits.

1924

Hans Berger first measures EEG signals and leads to the identification of alpha and beta brain waves. This discovery was a preclude to the development of brain-computer interfaces (BCIs).

1961

Otologist William House implants the first cochlear implant into a patient with sensorineural hearing loss (See here for in depth review, Image of the first cochlear implant prototype).

1965

Jose Delgada implants his 'stimoceiver' in a bull's brain and shows that by sending a radio signal to this device, he can stop the bull from charging at him. Watch this video to learn more about this wild demonstration.

1968

Brindley & Lewin demonstrate that direct electrical stimulation of the occipital lobe in a patient with blindness can result in the patient experiencing sensations of light ('phosphenes'), being the first to show the use of a visual cortex implant. They also demonstrate that stimulating specific regions of the visual cortex results in phosphenes in a specific region of the patients visual field (Link for original paper).

1969

Eberhard Fetz conducts an experiment where he shows monkeys can control the deflection of a meter arm through consciously controlling the firing rate of their cortical neurons, being the first to show what is now known as 'neurofeedback' (Link for original paper).

1973

Jacques Vidal coins the term 'BCI' and produces the first academic papers on the topic (1, 2). He is now regarded as the inventor of BCI's.

1978

William Dobelle implants a single-array BCI into a man with adulthood blindness that when accompanied with the use of specialized glasses, allowed the man to see shades of grey within a limited field-of-vision (Read more).

1988

Philip Kennedy builds the first intra-cortical BCI in monkeys by implanting neurotrophic-cone electrodes. He continued this work in humans and even used himself as a test subject for BCI implantation (Read more, Interview).

1996

Mark Humayun is the first to use a retinal implant in humans and demonstrates that electrical stimulation of electrodes implanted on the surface of the retina can evoke phosphenes in patients sufferring from photoreceptor degeneration Interview).

1998

Kennedy & Bakay become the first to implant a BCI in the human brain. The patient suffered from 'locked-in syndrome' and in the years following implant surgery he was able to control a computer cursor using his thoughts (Read more)

1999-2000

Miguel Nicolelis develops and implants a BCI which decodes brain activity in monkeys allowing them to control a robotic arm through thought, being the first to accurately predict movement through recording of neuron ensembles (Link for original paper).

2006

Hochberg reports on the first person with tetraplegia being able to control an artificial hand using an implanted BCI (Link for original paper). This was the first BrainGate trial that used Blackrock's Utah Array.

2021

Neuralink, founded by Elon Musk, shows that its BCI chip allows monkeys to play video games in real-time solely with their thoughts (Link to read more).

Willett & Moses separately use BCIs implanted in the motor cortex of paralyzed patients to allow them to communicate 15-18 words per minute. Willett did so by recording from neurons active when thinking about writing words (Link to paper), Moses did so by recording from neurons active when thinking about vocalizing words (Link to paper).

Synchron becomes the first company to recieve FDA approval to conduct a clinical trial of a permanently implanted BCI that uses endovascular electrodes to record/stimulate neurons from within blood vessels (Learn more).

General Neuroscience

Before Christ (BC)

Both Herophilus & Galan propose the brain as the control center of the body and cognition, although they incorrectly believed this was the responsibility of the ventricular system specifically.

1860-1865

Paul Broca is the first to make progress in the theory of cerebral localization, the belief that different aspects of cognition are localized to certain regions of the brain. This work marked the onset of carefully studying deficits in patients with brain damage of specific regions to determine the regions function.

1906

Ramon y Cajal, known as 'The father of Modern Neuroscience', discovers an imaging method called Golgi staining using which he discovered that neurons are the structural units that make up the brain and they are separated by small junctions called synapses through which they directionally communicate with other neurons. Based on this work, Cajal and Sherrington were the first to vocalize the 'neuron doctrine', stating the neuron is the structural and functional unit of the nervous system (Link for review paper).

Brief History of Neurotechnology

Magnetic Resonance Imaging (MRI)

Isidor Isaac Rabi first detects the phenomenon of nuclear magnetic resonance (NMR), the underlying principles used in MRI, in a beam of lithium chloride through a complex experimental procedure (Link to original paper).

Felix Bloch & Edward Mills Purcell extend the work done by Rabi by developing new methods for obtaining precise measurements from nuclear magnetization in solids and liquids. Bloch & Purcell shared the Nobel Prize in Physics for this work in 1952.

Raymond Damadian shows MR relaxation time could be used to distinguish cancer from healthy tissue, being the first to identify the clinical use of NMR (Link to original paper).

Paul C. Lauterbur develops the theory for MRI by proposing the use of magnetic field gradients to encode spatial information from the NMR signal (Link to original paper). He recieved the Nobel Prize in Physiology or Medicine in 2003 jointly with Peter Mansfield.

Damadian designs and builds the first full-body MRI machine, called 'Indomitable'.

Damadian founds FONAR corporation, which produced the first commercially available MRI machine in 1980 (Summary article).

Charles Dumulin & Howard Hart develop MR angiography, where vasculature can be imaged using MRI. Additionally, Denis Le Bihan obtained the first diffusion MR images.

Seiji Ogawa recognizes deoxyhemoglobin and oxyhemoglobin have different magnetic properties, and discovered the technique that underlies functional MRI (fMRI) (Link to original paper).

Animal studies are performed using a magnet strength of 21.1 Tesla (Link to original paper).

For the first time, human studies were performed using a magnet strength of 10.5 Tesla (Link to original paper).

Hyperfine's portable MR imaging system becomes the first FDA approved portable MRI system capable of providing neuroimaging at the bedside, eliminating the need for patients to be moved to a specialized MR suite.

X-ray & Computed Tomography (CT)

Wilhelm Roentgen finds that cathode rays are able to pass through human tissue and visualize underlying anatomy, giving rise to clinical X-ray imaging or radiography (Link for more details). For this work he recieved the Novel Prize in Physics in 1901.

William David Coolidge designs a high vacuum X-ray tube that was a reliable sources of X-rays and could operate at energies up to 100,000 volts. This work overcame technological issues in previous X-ray tubes that often broke down at high voltages.

Johann Radon develops the mathematical theory behind CT by showing an object can be reconstructed based on an infinite set of its projections, known as the Radon transform.

William Oldendorf theorizes the ability to scan a head through the use of a transmitted beam of X-rays in conjunction with the Radon transform, creating an apparatus that has a rotating source and coupled detector that could get X-ray images of various materials.

Godfrey Newbold Hounsfield extends the theory for CT by taking several X-ray images at different angles followed by computer reconstruction, also inventing the first commercially available CT scanner. For this work he recieved the Nobel Prize in Physiology or Medicine in 1979.

In London, England, a CT scanner is used clinically to image a women suspected to have a brain tumour.

Electro- & Magneto-encephalogram (EEG & MEG)

Hermann von Helmholtz measures the speed at which electrical impulses are conducted along nerve fibres.

Richard Caton measures electrical phenomena from exposed cerebral hemispheres in monkeys.

Hans Berger invents the electroencephalogram (EEG) and was the first to record large-scale electrical activity in the brain. The first EEG trace obtained from a human brain was published in 1929 (Link to read more).

Wilder Penfield develops a technique that obtains EEG recordings directly from pial matter in the brain, now known as electrocorticography (ECoG).

David Cohen discovers magnetoencephalography (MEG) (Link for original paper).

Near-Infrared Spectroscopy (NIRS)

Karl von Vierordt observes changes in the spectrum of visible light when it passes through human fingers which were predominated by either oxy- or deoxy-hemoglobin, being the first to demonstrate the potential for a non-invasive method for monitoring tissue oxygenation.

Based on findings from von Vierordt, Kramer & Matthes find that near-infrared light can also be used to determine levels of oxy- and deoxy-hemoglobin in human tissue, laying the ground for the discovery of near-infrared spectroscopy (NIRS).

Frank Jobsis, known as the pioneer of medical applications of NIRS, theorizes the use of near-infrared light to study brain activity continuously and led to the invention of NIRS (Link for original paper).

The first clinical NIRS studies are conducted on newborns by Jobsis & Brazy (Link for original paper), and adults by Marco Ferrari (Link for original paper).

Based on the development of fMRI by Seiji Ogawa, studies carried out by Chance, Kato, Hoshi, and Villringer led to the discovery of functional NIRS (fNIRS).

Kleinshmidt carries out the first simultaneous recording of brain activation using both fMRI and fNIRS (Link for paper)

Neuroelectronic Recording & Stimulation

Hodgkin & Huxley become the first to use an electrode to record an action potential in an axon.

Physicians Ugo Carletti & Lucio Bini develop and use electroconvulsive therapy (ECT) that electrically induces a seizure as a treatment for mental illness. In the following decades, this became overused and resulted in public backlash.

Merton & Morton develop transcranial electrical stimulation (TES) whereby an electrical current is passed through the skull to stimulate the cortex of the brain (Link for original paper).

Anthony Barker develops transcranial magnetic stimulation (TMS), whereby a changing magnetic field is used to induce current in a specific region of the brain.

Alim Benabid discovers electrical stimulation of the basal ganglia improves symptoms of Parkinson's disease, the first use of what is now known as deep brain stimulation (DBS).

DBS is approved by the FDA for tremors and Parkinson's disease. DBS is now approved in the treatment of dystonia (2003), obsessive-compulsive disorder (OCD)(2009), and epilepsy (2018).

TMS is approved by the FDA for treatment of medication-refractory depression.

Positron Emission Tomography (PET)

George Hevesy demonstrates the use of radioactive isotopes for labelling. For this work he recieved the Nobel Prize in Chemistry in 1943.

Irene & Frederic Joliot-Curie produce an artificial isotope that could be formed and made safe for humans.

Gordon Brownell & William Sweet invent and demonstrate the first large-scale use of a positron imaging device, with Brownell going on to develop the first positron emission tomography (PET) imaging device in 1972.

Louis Sokoloff, Alfred Wolf, and Joanna Fowler synthesize 2-[18F]fluoro-2-deoxy-D-glucose (FDG), which is used to measure cerebral glucose utilization and is still widely used for PET imaging today.

Brain-Computer Interfaces (BCI)

Richard Caton records the first ever electrical activity in the brain of living rabbits.

Hans Berger first measures EEG signals and leads to the identification of alpha and beta brain waves. This discovery was a preclude to the development of brain-computer interfaces (BCIs).

Otologist William House implants the first cochlear implant into a patient with sensorineural hearing loss (See here for in depth review, Image of the first cochlear implant prototype).

Jose Delgada implants his 'stimoceiver' in a bull's brain and shows that by sending a radio signal to this device, he can stop the bull from charging at him. Watch this video to learn more about this wild demonstration.

Eberhard Fetz conducts an experiment where he shows monkeys can control the deflection of a meter arm through consciously controlling the firing rate of their cortical neurons, being the first to show what is now known as 'neurofeedback' (Link for original paper).

Jacques Vidal coins the term 'BCI' and produces the first academic papers on the topic (1, 2). He is now regarded as the inventor of BCI's.

William Dobelle implants a single-array BCI into a man with adulthood blindness that when accompanied with the use of specialized glasses, allowed the man to see shades of grey within a limited field-of-vision (Read more).

Philip Kennedy builds the first intra-cortical BCI in monkeys by implanting neurotrophic-cone electrodes. He continued this work in humans and even used himself as a test subject for BCI implantation (Read more, Interview).

Mark Humayun is the first to use a retinal implant in humans and demonstrates that electrical stimulation of electrodes implanted on the surface of the retina can evoke phosphenes in patients sufferring from photoreceptor degeneration Interview).

Kennedy & Bakay become the first to implant a BCI in the human brain. The patient suffered from 'locked-in syndrome' and in the years following implant surgery he was able to control a computer cursor using his thoughts (Read more)

Miguel Nicolelis develops and implants a BCI which decodes brain activity in monkeys allowing them to control a robotic arm through thought, being the first to accurately predict movement through recording of neuron ensembles (Link for original paper).

Hochberg reports on the first person with tetraplegia being able to control an artificial hand using an implanted BCI (Link for original paper). This was the first BrainGate trial that used Blackrock's Utah Array.

General Neuroscience

Both Herophilus & Galan propose the brain as the control center of the body and cognition, although they incorrectly believed this was the responsibility of the ventricular system specifically.

Louis Sokoloff, Alfred Wolf, and Joanna Fowler synthesize 2-[¹⁸F]fluoro-2-deoxy-D-glucose (FDG), which is used to measure cerebral glucose utilization and is still widely used for PET imaging today.