Action potential

The stereotyped jump in membrane potential seen in brain cells. Famously quantified by Hodgkin and Huxley in a series of Nobel-prize winning experiments.

Bayes' rule
The conditional probability of A given B (posterior probability) is equal to the conditional probability of B given A times the probability of A (the prior probability) divided by the probability of B (normalizing constant).

Bayesian network
A network used to compute the probabilities associated with particular variables, e.g. the probability of a coin sitting on my desk if I just did my laundry.

The stuff of thought.

Cognitive neuroscience
A sub-field of neuroscience that focuses on cognition.

Cognitive science
Definitions tend to vary wildly, but more or less the field takes a more abstract approach to studying cognition than cognitive neuroscience. Affiliated with the cognitive revolution that followed in the wake of Chomsky's rebuke of Skinner's "Verbal Behavior". Early on, the field consisted primarily of computer scientists, philosophers and linguists, e.g. Marvin Minsky, Steven Pinker, and Jerry Fodor.

Computational neuroscience
The use of computational tools, e.g. computer simulations or neuromorphic technology, to study the brain.

Synonymous with what most people call the brain. Part of the central nervous system responsible sensory, motor, and associative functions.

Defense Advanced Research Projects Agency. Government overlords responsible for the creation of the Internet (praise be!).

Systems of Neuromorphic Adaptive Plastic Scalable Electronics. Basically, DARPA wants to build chips that act like biological neural networks since brains excel at certain things computers stink at, e.g. object recognition, speech recognition, and navigation.

Dorsal stream
Processing stream in visual cortex that carries where or object position information.

The use of fine-tipped electrodes and tools such as voltage and current clamps to study the electrical properties of excitable membranes. Can be used to measure the spikes of a single cell.

Functional magnetic resonance imaging. Method of measuring the rush of oxygenated blood to a brain area, perhaps correlated with spiking activity or synaptic input. Though what its a measure of is still unclear, it is currently the best non-invasive method of studying the human central nervous system.

Inferotemporal cortex (IT)
Area of cortex in the inferior temporal lobe that supposedly underlies object recognition. The final stop in the ventral stream.

A mathematical representation of a system. More popular examples include climate and traffic models, which are used mainly for predictions. In general, models (ideally) act as rigorous, falsifiable, clearly-stated theories in the sciences.

The outer layer of highly convoluted (i.e. folded) grey matter in the brain.

Neural network (biological)
A collection of neurons that constitute some form of processing unit. For instance, a collection of cells that codes the direction of an eye movement.

Neural network (computational)
A group of computational units loosely modeled after neurons used to perform a task, e.g. cancel echo in a speech signal or detect an object.

Neologism, coined at the Department of Cognitive and Neural Systems, Boston University, describing the interesting combination of a "nerd" who has devoted his academic career to the study of "neurons".

Simulating brain-like behavior with very large scale integration (VLSI) circuits.

They are the core cells of the brain responsible of processing and transmitting information by electrochemical signaling.

The scientific study of the brain.

Object recognition
To detect the presence of an object across substantial variation, e.g. in position, illumination, and angle.

Prefrontal cortex (PFC)
The most anterior part of cortex implicated in categorization, i.e. whether something belongs in the category "dog" or "tree", short term memory, and decision making.

See "Action potential".

Area of the brain that sits underneath the cortex.

The connection that is the locus of communication between neurons.

A brain region believed to relay sensory inputs to the cerebral cortex, and mediate communication between different cortical regions.

Different areas of the visual cortex that constitute a loose hierarchy, i.e. information flows from V1 to V4.

Ventral stream
Processing stream in visual cortex that carries what or object identity information.

Visual cortex
Area of cortex comprised of the occipital lobe and parts of the parietal and temporal lobes.