Seven or eight times now I have emerged from a brain-imaging device and looked at the inner workings that make me: the folds and lobes and pathways that determine my thinking, my whole way of seeing the world.
— Temple Grandin, The Autistic Brain

Neuroscience Research: the history and multidisciplinary nature of neuroscience research makes studying and understanding the brain relevant to all fields of human endeavor. Improvements in brain-imaging techniques in the past decade have made it possible for changes in brain activity to be measured without direct access to the brain. (Kolb, 571)

The history of neuroscience is the history of the techniques we employ to delve into the brain. Our very ability to pose questions about this organ … depends on the tools and methods we have conceived to interact with them. (Schoonover, 8) Educators can now relate the powerful discoveries of learning brain research to classrooms and curriculum by incorporating research-based learning strategies to help students learn more effectively and joyfully. (Willis, vii)


Algorithm: a procedure or method that, when followed step by step, always produces the correct solution. For example, mathematical formulas. (Hockenbury, 265) A problem-solving procedure requiring repetition in order to eliminate possible answers until only the correct one remains. (Cardwell, 7) Vernon Mountcastle suggests that since all regions (of the “cerebral cortex”) look the same, perhaps they are actually performing the same basic operation. He proposes that the cortex uses the same computational tool to accomplish everything it does. He concludes that there is a common function, a common algorithm, that is performed by all the cortical regions. Vision is no different from hearing, which is no different from motor output. In my opinion it was, is, and will likely remain the most important discovery in neuroscience. (Hawkins, 50-53)

Animal Model: a non-human species used in medical research because it can mimic aspects of a disease found in humans. Animal models are used to obtain information about a disease and its prevention, “diagnosis,” and treatment. By using animals, researchers can carry out experiments that would be impractical or ethically prohibited with humans. (NHGRI)

Aplysia: foot-long, six-pound California sea slug made famous by Eric Kandel who studied its brain to build the foundations of modern neuroscience. (SAM, Oct/Nov 2007, 33) Not only are there few cells involved in generating the behavior, but in Aplysia one encounters the largest nerve cells in the animal kingdom. (Kandel Brain and Mind, 4)

Blue Brain Project: computer model being designed to take on the human brain. Henry Markram developed. Model will electronically mirror the real brain’s biological behaviors. IBM has custom tailored one of its most powerful supercomputers for the project, capable of processing more than 22 trillion operations per second. (Discover, Dec. 2007, 51)

Brain-Machine Interface (BMI): demonstration that (primates and humans) can learn to control voluntarily the movements of extraneous artificial devices, such as robotic arms and legs, using only their raw electrical brain activity. (Nicolelis, 8)

Electroencephalograph (EEG): an instrument that produces a graphic record of the brain’s electrical activity by using “electrodes” placed on the scalp. (Hockenbury, 59) A recording of electrical activity in the brain. It is made by placing electrodes on the skin covering the top of the head, and impulses are sent to a special machine. An EEG may be used to diagnose brain and sleep disorders. (NCIt)

God Helmet: created by Michael Persinger. Generates weak “electromagnetic” fields and focuses them on particular regions of the brain’s surface. An experiment focused on the “temporal lobes.” Most research subjects either 'sensed' a presence in the room with themselves, although they were alone, or had a profound state of 'cosmic bliss.' Each subject translated the perception into their own cultural and religious language, terming it ‘God’, Buddha', or the 'wonder of the universe.' (SAM Oct/Nov 2007, 41)

Hippocampal Slice: thin slice of “hippocampus” removed from the brain and submerged in a saltwater bath, with electrodes placed in relevant regions. A major advantage of hippocampal slice preparations is that the (cell architecture) and “synaptic” “circuits” of the hippocampus are largely retained. Hippocampal slices have mostly been used for investigating the effects of "neurotoxic" chemicals on synaptic function. More recently, hippocampal slice cultures, which can be maintained for several weeks to several months "in vitro," have been employed to study how neurotoxic chemicals influence the structural and functional "plasticity" in hippocampal neurons. (PubMed, 21815062)

Microelectrodes: pin-shaped electronic devices that are so small and sensitive that they can be inserted inside or beside a single neuron and can detect when an individual neuron fires off its electrical signal to other neurons. The neuron’s signal passes from the microelectrode to an amplifier and then to an “oscilloscope” where it appears as a sharp spike. (Doidge, 50) “Action potentials” from “ganglion cells” can be picked up by placing a microelectrode near their cell bodies in the "retina" or in the “optic nerve” outside the eye. (Koch, 55)

Micromapping: a technique using microelectrodes to map a specific area of the brain. It is still about a thousand times more precise than the current generation of brain scans. Yet micro mapping hasn’t replaced brain scans because it requires an extremely tedious kind of surgery, conducted under a microscope with microsurgical instruments. Michael Merzenich and his colleagues did thousands of these laborious surgeries to make their important discoveries. (Doidge, 50)

Nano: very small; specifically used in names of units of measurement to denote a factor of 10 -9 (one billionth), as nanogram, “nanometer,” nanosecond, etc. (Oxford) A unit prefix indicating a quantity of 10E-9 or one one-billionth. (NCIt)

Neuroanatomical Tract-Tracing Techniques: methods used to label and follow the course of neural pathways by axonal transport of injected neuronal “tract-tracers.” (MeSH)

Tract-Tracers: substances used to identify the location and to characterize the types of “neural pathways.” (MeSH)

Neuroimaging: includes techniques such as positron-emission tomography (“PET”) scans and functional magnetic resonance imaging (“fMRI”) scans that allow scientists to go beyond snapshots and see the brain at work. (Ratey, 129) Used for both descriptive and experimental research. Used in “cognitive neuroscience.” Most brain-imaging studies involve a small groups of subjects. Most involve simple aspects of behavior. Knowing what brain area is involved may tell us little about the psychological process being investigated. (Hockenbury, 60) Neuroimaging allows us to ask two fundamental questions about every part of the brain: What does it look like? What does it do? (Grandin, 22)

Functional Magnetic Resonance imaging (fMRI): imaging technique that tracks the flow of "oxygenated" blood by virtue of its magnetic properties, which differ from those of non-oxygenated blood. Because oxygenated blood preferentially flows to where it is in high demand, fMRI highlights brain areas that are most active when someone is thinking or doing something. (SAM, Oct/Nov 2007, 42) In fMRI, magnetic fields in the brain produced by changes in blood flow are measured while the subject is doing or looking at something. (RamachandranTTB, 61) Images are called 'functional' because they measure how the brain performs tasks rather than simply mapping out the structure of the brain. (Spinks) Technique yields the equivalent of a video showing what parts of the brain light up during different inputs, or imagery. (Goleman, 10) It is possible to use fMRI non-invasively to track the activity of the whole brain while subjects are performing a variety of tasks. It has good, although not ideal, “spatial” and temporal resolution, but not down to the single cell achieved with implanted electrodes in experiments with monkeys. (Iacoboni, 60) Provides moment to moment images of the brain’s changing activity using the same scanning hardware as an MRI. Compared to PET scans, fMRI produces a much sharper picture and can detail much smaller brain structures. Another advantage of fMRI is that it provides a picture of brain activity averaged over seconds rather than the several minutes required by PET scans. (Hockenbury, 60) Noninvasive brain imaging. Allows experimentation with human subjects that combines with the single-cell research on monkeys to yield results and insights. (Iacoboni, 23)

Magnetic Resonance Imaging (MRI): a noninvasive imaging technique that produces highly detailed images of the brain using electromagnetic signals generated by the brain in response to magnetic fields. MRI is very versatile, producing 'thin-slice' images of body tissue from virtually any angle. Tissues with high concentrations of water, such as fat, appear lighter in color, while bone and other tissues with less water appear darker. (Hockenbury, 60)

Diffusion Tensor Imaging (DTI): new MRI approach that tracks water “diffusion” along nerve fibers, exposing the micro architecture of the brain. Can show physical connections between brain structures. (SAM, Dec 2007/Jan 2008, 8) Also referred to as ‘diffusion MRI.’

Magnetocephalography (MEG): modern neuroimaging technique which relies on the principle that if you touch different body parts, the localized electrical activity that results can be measured as changes in magnetic fields on the scalp. The major advantage of the technique is that it is noninvasive; one does not have to open the patient’s scalp to peer inside the brain. Using MEG is relatively easy in just a two-hour session to map out the entire body surface on the brain surface of any person willing to sit under the magnet. (Ramachandran, 31)

Positron Emission Tomography (PET scan): an imaging test of the brain. It uses a radioactive substance called a ‘tracer’ to look for disease or injury in the brain. A PET scan shows how the brain and its tissues are working. Other imaging tests, such as MRI and CT scans only reveal the structure of the brain. (PubMedHealth2) An invasive imaging technique that provides color-coded images of brain activity by tracking the brain’s use of a radioactively tagged compound, such as “glucose,”  “oxygen,” or a drug. The PET scan measures the amount of the radioactively-tagged-substance used in brain areas while the person engages in some type of mental activity. Over the course of several minutes, the information is collected, analyzed, and averaged by computer. (Hockenbury, 60)

Single Photo Emission Computerized Tomography (SPECT scan): research technique where a patient is injected with a radioactive isotope that is carried by the blood to active brain areas. A special camera is then used to photograph the isotope's distribution. (SAM, Oct/Nov 2007, 41)

Neuromodulation: a therapeutic alteration of activity either through stimulation or medication, both of which are introduced by implanted devices. Can include treatments that involve the stimulation of various nerves in the "central nervous system," "peripheral nervous system," "autonomic nervous system," or deep cell nuclei of the brain that lead to the “modulation” of its activity. (NANS, About Neuromodulation)

Neuroprosthetics: devices the size of a modern heart “pacemaker” that harvest healthy brain electrical activity to coordinate the contractions of a silk-thin wearable robot, a vest as delicate as a second skin but as protective as a beetle’s exoskeleton — a suit capable of supporting a paralyzed person’s weight and making formerly immobile bodies roam, run, and once again exult in exploring the world freely. (Nicolelis, 8)

Nonsense Syllable: three-letter combination, made up of two consonants and a vowel, such as WIB or MEP. It almost sounds like a word, but it is meaningless. (Hockenbury, 234)

Oscilloscope: an electronic instrument in which the position of a moving spot on a screen represents the relationship between two variables, usually a signal voltage and time. (Oxford) An electronic device designed to display electrical measurements, typically as a waveform on a cathode ray tube. (NCIt) Allows neuroscientists to see neuronal activity. (Chudler, 73)

Oscillate: swing or move to and fro in a regular rhythm. (Oxford) Noun - ‘oscillation.’

Pupil Dilation: pupils are sensitive indicators of mental effort. They dilate substantially when people multiply two-digit numbers, and they dilate more if the problems are hard than if they are easy. The pupil is a good measure of the physical arousal that accompanies mental effort. (Kahneman, 32-34)

Stroop Inference: timed test in which the subject must read a list of words or identify colors presented with varying instructions and different degrees of distraction. (MeSH) (For example), a test (where the subject is) presented a word that is itself the name of a color. (For example) present the word ‘blue’ in the (ink) color ‘green’ (and the subject is asked to) name the color of the ink. (Results in) a much slower reaction time then (if presented with) the word ‘justice’ presented in blue letters. Unmasks the clash between the strong, involuntary and automatic impulse to read the word and the unusual, deliberate, and effortful task demand to state the color of the print. (Eagleman, 132) Also referred to as ‘stroop test.’

System of Units (SI Units): a base or derived unit of weight or measure that belongs to the decimal International System of Units (Systeme International d'Unites, SI) derived from and extending the metric system. (NCIt) A system of physical units in which the fundamental quantities are length, time, mass, electric current, temperature, luminous intensity, and amount of substance, and the corresponding units are the meter, second, kilogram, ampere, kelvin, candela, and mole. The system has been given official status and recommended for universal use by the General Conference on Weights and Measures. (MeSH)

Units of Electricity: (measure) energy made available by the flow of electric charge through a conductor. (NCIt)

Ampere (Amp): a unit of electric current, one of the seven base units of the International System of Units. It is that constant current which, if maintained in two straight parallel conductors of infinite length and zero diameter separated by one meter in a vacuum, would produce between these conductors a force equal to 2x10E7 newton per meter of length. This is dependent upon the definitions of the meter, kilogram, and second. One ampere represents 6.24 x 10E18 unit electric charge carriers, such as electrons, passing a specified fixed point in one second. (NCIt)

Ohm: a unit of electrical resistance equal to the resistance between two points on a conductor when a potential difference of one volt between them produces a current of one ampere. (NCIt)

Volt: a unit of electric potential and electromotive force, equal to the difference of electric potential between two points on a conducting wire carrying a constant current of one Ampere when the power dissipated between the points is one watt. This is equivalent to the potential difference across a resistance of one ohm when one Ampere of current flows through it. (NCIt)

Millivolt (mV): one-thousandth of a volt. (Oxford) Editor’s note - commonly used to highlight electrical potential differences and changes in electrical potential differences between the inner and outer membranes of a neuron.

Units of Length: units used to measure distance. (Oxford)

Centimeter: a hundredth of a meter, equal to 0.3937 inch. (Oxford) A measure of length in the metric system. There are 100 centimeters in a meter and 2 1/2 centimeters in an inch. (NCIt)

Meter: a unit of linear measure in the metric system, one of the seven base units of the International System of Units. A meter is defined as the length of the path traveled by light in a vacuum during a (specific) time interval. Equal to 1.093 61 yards.

Millimeter (mm): one-thousandths of a meter. (Oxford) A measure of length in the metric system. A millimeter is one thousandth of a meter. There are 25 millimeters in an inch. (NCIt)

Micrometer (μ): one-millionth of a meter. (Oxford) A unit of length in metric system equal to 10E-6 meter. (NCIt) Also referred to as a ‘micron.’

Nanometer (nm): one-billionth of a meter. (Oxford) A measure of length in the metric system. A nanometer is one billionth of a meter. An average human hair is about 60,000 nanometers thick. Nanometers are used to measure wavelengths of light and distances between atoms in molecules. (NCIt)

Units of Time: units used to measure duration. (Oxford) An indication of the type of unit of measure being used to express a time. (NCIt)

Millisecond (msec or ms): a unit of time, which is equal to one thousandth of a second. (NCIt)

Microsecond (μs): a unit of time equal to one millionth of a second. (NCIt)

Nanosecond (ns): one-billionth of a second. (Oxford)

Second: a unit of time, one of the seven base units of the International System of Units. (NCIt)

Time: the continuum of experience in which events pass from the future through the present to the past. (NCIt) The dimension of the physical universe which, at a given place, orders the sequence of events. (MeSH)

Collection Time: the hour, minute, and/or second at which the sample or data was collected. (NCIt)

Elapsed Time: the interval between two reference points in time. (NCIt) Also referred to as a ‘time period.’

End Time: the time when an event has ceased. (NCIt)

Repetition Time: the amount of time in milliseconds between successive pulse sequences applied to the same (sample). (NCIt)

Test Time: the point in time when an assessment was performed. (NCIt)

Timespan: the period of time between two dates or events or between the beginning and end of something. (NCIt)

Timezone: a geographic region throughout which the same standard time is used. (NCIt)

Transcranial Magnetic Stimulation (TMS): technique using a magnetic wand (‘transcranial magnetic stimulator’) to send a electrical signal into the brain. The magnet temporarily stuns and fatigues the targeted population of neurons. (Blakeslee, 56, 205) Briefly stuns the neurons in the area - in effect creating a temporary brain "lesion." (RamachandranTTB, 61) A technique for probing brain function using powerful electromagnets held directly over the head. (Blakeslee, 215)