Chapter 4: Research Methods - Histology, Imaging, and Stimulation

Vocabulary flashcards covering histology, physiological recordings, brain scans/imaging, and brain stimulation techniques.

Empiricism

The principle that all knowledge comes from our senses of the natural world and begins with observation.

Hypothesis

A testable prediction derived from empirical observation about how something in nature works.

Independent Variable

The experimental factor that is directly manipulated by the researcher.

Dependent Variable

The variable being measured in an experiment to evaluate the effects of the independent variable.

General Process Approach

An approach in animal research based on the concept that fundamental principles of genetics, physiology, learning, and neuroscience are similar across species.

Transgenic Mice

Mice that have had a foreign gene inserted into their genome for research purposes.

Knockout Mice

Mice engineered to have a specific gene inactivated to study its biological function.

Electrocardiogram (ECG)

A physiological recording technique that measures heart rate and heart rate variability (HRV) as an indicator of physiological arousal.

Heart Rate Variability (HRV)

The variation in time intervals between consecutive heartbeats, used as a measure of stress and concentration.

Electrodermal Activity (EDA)

A physiological measurement, also known as galvanic skin response or skin conductance level, that assesses skin perspiration to quantify arousal and stress.

Electromyography (EMG)

A technique that measures electrical activity produced by muscle movement, commonly applied to facial muscles to quantify microexpressions.

Computerized Axial Tomography (CT Scan)

A structural brain imaging technique that uses a computer to combine a series of X-rays taken at different angles, creating a 3D image based on tissue density absorption differences.

Electroencephalography (EEG)

A real-time neuroimaging method that records continuous electrical activity from cortical neurons using electrodes placed on the scalp.

Event-Related Potentials (ERP)

EEG wave recordings that are time-locked to specific occurrences, such as a presentation of a stimulus or a motor movement.

Magnetic Resonance Imaging (MRI)

A noninvasive imaging method that uses powerful magnetic fields to align hydrogen protons in body tissue, detecting radio waves emitted as the protons realign to form detailed structural images.

Functional MRI (fMRI)

A neuroimaging method that evaluates brain function and active regions during specific tasks or emotions by measuring changes in blood oxygen levels.

BOLD-Contrast Imaging

Blood-Oxygen-Level-Dependent imaging in fMRI, which detects functional brain activity based on changes in the ratio of oxygen-rich to oxygen-poor hemoglobin.

Voxel

A three-dimensional block of neural tissue, typically $1\,\text{mm}^3$ to $5\,\text{mm}^3$, used to map detailed functional changes in fMRI scans.

Diffusion Tensor Imaging (DTI)

A specialized MRI technique that measures the directional movement of water molecules to image nerve fiber pathways and detect white matter tract abnormalities.

Tractography

The process used in DTI to visualize and map white matter pathways by tracking the diffusion of water molecules along myelinated axons.

Positron Emission Tomography (PET Scan)

An imaging technique that assesses neuronal metabolic activity and blood flow by injecting a radioactively labeled molecule (such as water or glucose) and detecting annihilation photons produced in active brain regions.

Magnetoencephalography (MEG)

A high spatial resolution, real-time brain imaging technique that records magnetic fields generated by neuronal electrical activity on the scalp.

Transcranial Magnetic Stimulation (TMS)

A brain stimulation technique that uses electromagnetic fields to noninvasively excite or inhibit specific cortical regions.

Transcranial Direct Current Stimulation (tDCS)

A noninvasive brain stimulation procedure that delivers low-frequency electrical current across the scalp to modulate cognitive functions and treat depression.

Deep Brain Stimulation (DBS)

A surgical treatment involving stereotaxic placement of electrodes into deep brain structures, connected to an implanted pulse generator to regulate neural activity.

Biofeedback

A therapeutic technique where monitoring devices deliver real-time visual or auditory feedback on autonomic processes, enabling individuals to gain conscious control over physiological functions.