Neuroengineering Glossary & Jargon

Neural Signals & Interfaces

Action Potential (AP): The rapid electrical signal ("spike") generated by a neuron when it fires. It is the fundamental unit of information transmission in the nervous system.
Local Field Potential (LFP): The transient electrical signal generated by the summed synchronized synaptic activity of a local group of neurons, typically recorded with extracellular microelectrodes.
Electroencephalography (EEG): A non-invasive method referencing the electrical activity of the brain, recorded from electrodes placed on the scalp. It primarily measures post-synaptic potentials of pyramidal neurons.
Electrocorticography (ECoG): An invasive technique where electrodes are placed directly on the exposed surface of the brain (the cortex) to record electrical activity.
Brain-Computer Interface (BCI): Also known as a Brain-Machine Interface (BMI). A direct communication pathway between an enhanced or wired brain and an external device (like a robotic arm or cursor control).

Microelectrode Array (MEA): A device containing multiple microelectrodes through which neural signals are either obtained or delivered. The Utah Array is a classic example.
Foreign Body Response (FBR): The immune system's reaction to an implanted neuro-device. Typically involves microglial activation and the formation of a glial scar, which can insulate electrodes and degrade signal quality over time.
Neuromorphic Engineering: The use of very-large-scale integration (VLSI) systems containing electronic analog circuits to mimic neuro-biological architectures present in the nervous system.
PEDOT:PSS: A conductive polymer commonly used as a coating for neural electrodes to lower impedance and improve charge injection capacity while being mechanically softer than rigid metals.

Deep Brain Stimulation (DBS): A surgical treatment involving the implantation of a medical device (a brain pacemaker) that sends electrical impulses to specific targets in the brain (e.g., subthalamic nucleus) for the treatment of movement and affective disorders.
Transcranial Magnetic Stimulation (TMS): A non-invasive form of brain stimulation in which a changing magnetic field is used to cause electric current flowing in a small region of the brain via electromagnetic induction.
Closed-Loop Stimulation: A system where neural activity is continuously recorded and analyzed in real-time, and stimulation is delivered dynamically only when specific biomarker states are detected.