This glossary defines key terms used throughout the LabMaestro documentation. Terms are organized alphabetically for quick reference.
A
Arc Region — A region component that defines a curved, arc-shaped area on the stimulus display. Its geometry is specified by inner radius, outer radius, and angle rather than width and height.
B
Bit Depth — The number of bits used per colour channel to represent pixel values on a display. Higher bit depths allow finer gradations of colour and luminance. VPixx devices support beyond-8-bit colour precision.
Block — See Epoch.
C
Cartesian Coordinates — A coordinate system that positions elements along X (horizontal) and Y (vertical) axes. One of three coordinate systems available in LabMaestro, alongside Polar and Clock.
Clock Coordinates — A coordinate system similar to Polar, but with the 0-degree origin at the top of the display and angles increasing clockwise.
CLUT (Colour Lookup Table) — A mapping that translates pixel index values to specific RGB colour outputs. Used in advanced rendering modes such as M16 for high bit-depth colour precision.
Coherence — In drifting dot patterns, the proportion of dots moving in a consistent direction. Higher coherence means more dots share the same motion direction.
Combine Mode — A property of pattern components that determines how multiple patterns within the same region are composited. Options are Add (sum the patterns) and Multiply (modulate one pattern by another).
Command — One of the three main component types in LabMaestro. Commands provide extended functionality beyond visual stimulus display, such as waiting for input, playing sounds, setting variables, and controlling experiment flow.
Component — A building block used to construct experiments in LabMaestro. Components are placed on timelines within epochs and come in three types: Regions, Patterns, and Commands.
Component Library — The UI panel in LabMaestro that lists all available components. Components can be dragged from the library onto timelines or the visual preview to add them to an experiment.
Condition List — A table of independent variable values defined within a Method component. Each row represents one experimental condition (trial), and columns represent independent variables. Values from the list are passed to timelines on a trial-by-trial basis.
Constant Stimuli — A method type in which a predefined set of conditions is presented, typically in randomized order, across a specified number of repetitions.
Custom Variable — A user-defined variable within a timeline that is not tied to a specific component. Custom variables can be initialized, read, and updated using expressions and the Set Variables command.
D
DATAPixx3 — A VPixx Technologies video I/O hub and data acquisition system. It connects to the computer via USB and serves as a central hub for connecting other VPixx peripherals, including the TRACKPixx3.
Degrees of Visual Angle — A unit of measurement based on the angle subtended at the observer's eye. Commonly used in vision science to specify stimulus sizes independently of viewing distance and display resolution.
Device — In LabMaestro, any VPixx hardware connected to the computer via USB. This includes VIEWPixx displays, PROPixx projectors, and DATAPixx3 hubs.
Device Settings — A configuration menu for VPixx devices, accessed by double-clicking a device in the Environment panel. Allows configuration of device-specific features and settings.
Display — In LabMaestro, a monitor or projector connected to the computer via a video cable. Displays appear in the Environment panel and can be added to a project for stimulus presentation.
Drift Frequency — A parameter that continuously shifts the phase of a spatial waveform over time, creating the appearance of motion (e.g., a drifting grating).
E
Environment — The section of the LabMaestro Project panel that lists all connected displays and VPixx devices. Hardware must be added from the Environment to a project before it can be used in experiments.
Epoch — A structural container within a timeline that groups and organizes a set of components. Epochs divide timelines into discrete segments, each represented by a thumbnail preview showing the visual stimulus for that segment. Timelines consist of one or more epochs.
Exit Condition — A boolean expression evaluated at the end of each epoch iteration. When the expression evaluates to true, the epoch ends and the timeline advances. Commonly used to end loops after a set number of trials.
Experiment Design — The top-level organizational framework within the Project panel that defines the structure of an experiment, including Methods, Timelines, Epochs, and Components.
Expression — A formula assigned to a value field in LabMaestro, prefixed with the = sign. Expressions are evaluated at runtime and can include mathematical operations, functions, variable references, and conditional logic.
Expression Editor — A graphical tool for building complex expressions node by node. Accessed via the fx icon in expression-compatible fields.
F
Flicker Waveform — A temporal modulation applied to a region or pattern, causing its appearance to oscillate over time. Configurable waveform shapes include sinusoidal, square, triangle, and ramp.
Frame — A single rendered image displayed on the screen. The global variable FrameCount tracks the number of frames presented since experiment launch.
G
Gabor Patch — A common psychophysical stimulus consisting of a sinusoidal grating multiplied by a Gaussian envelope. Created in LabMaestro by combining a Grating pattern and a Gaussian pattern in Multiply combine mode within the same region.
Gamma Calibration — The process of measuring and correcting a display's luminance response so that pixel values map linearly to perceived brightness. Essential for accurate stimulus presentation in vision research.
Gaussian Pattern — A pattern component that produces a smooth, bell-shaped luminance distribution. Often used as an envelope (via Multiply combine mode) to create stimuli such as Gabor patches.
Geometry — A shared region property that defines the physical size (width and height) of a region. Can be specified in pixels, centimetres, or degrees of visual angle.
Grating Pattern — A pattern component that produces alternating light and dark bars (a sinusoidal, square, triangle, or ramp waveform). One of the most commonly used stimuli in vision research.
H
High Bit Depth Rendering — Techniques for rendering stimuli with more than 8 bits per colour channel, enabling finer luminance and colour gradations. Supported by VPixx hardware through modes such as M16.
High Refresh Rate Rendering — Modes that increase the display's temporal resolution beyond standard rates (e.g., 1440 Hz on PROPixx), enabling precise control over rapid temporal events.
L
LabMaestro — A visual experiment builder by VPixx Technologies for designing, running, and managing psychophysics and neuroscience experiments with VPixx hardware.
.lm File — The native project file format for LabMaestro. An .lm file contains all elements of an experiment, including the design hierarchy, components, resources, and data.
M
M16 Mode — A high bit-depth video mode that uses 16 bits per colour channel by encoding additional precision across multiple pixel components. Allows luminance precision beyond what standard 8-bit displays provide.
Method — A structural element at the second level of the experiment design hierarchy. Methods define how independent variables behave across trials, controlling the number of conditions, repetitions, and randomization. Variables defined in a method are passed to its child timelines.
O
Oval Region — A region component that defines an elliptical area on the stimulus display. Setting equal width and height creates a circle.
P
Pack&Go — A VPixx platform for deploying LabMaestro experiments to run remotely in a web browser, enabling online data collection.
Pattern — One of the three main component types. Patterns define the visual content that fills a region, such as gratings, noise, Gaussian blobs, checkerboards, pictures, or movies.
Pixel Density (PPI) — The number of pixels per inch on a display. Used together with viewing distance to convert between pixel units and degrees of visual angle.
Polar Coordinates — A coordinate system that specifies position by distance from a centre point (eccentricity) and angle (meridian). The 0-degree origin is to the right, with angles increasing counterclockwise.
Polygon Region — A region component that defines a regular polygon shape. The number of sides is configurable via the Sides geometry property.
Project — The highest-level structural element in LabMaestro. A project includes all elements of the experiment: design, components, resources, and data. Saved as .lm files.
Project Panel — The main UI panel that displays the full hierarchy of a LabMaestro project, from Environment and Experiment Design down to individual components.
PROPixx — A VPixx Technologies research-grade projector supporting high refresh rates (up to 1440 Hz), 3D rendering, and specialized video modes for psychophysics research.
Properties Panel — The UI panel that displays and allows editing of the configurable properties for a selected component, device, or display.
R
Rectangle Region — A region component that defines a four-sided, right-angled area on the stimulus display. Equal width and height produces a square.
Region — One of the three main component types. Regions define the area and shape of visual stimuli on the display. Available shapes include rectangles, ovals, arcs, polygons, text, and shape masks.
Resource — A digital media file (image, audio, video) packaged within a LabMaestro project file (.lm). Resources are used by components such as Picture Patterns, Movie Patterns, and audio commands.
RESPONSEPixx — A VPixx Technologies button box used for collecting participant responses with precise timing.
RIFT (Rapid Invisible Frequency Tagging) — A technique that flickers visual stimuli at frequencies above perceptual threshold, producing steady-state neural responses detectable by EEG or MEG. Supported by PROPixx's high refresh rate capabilities.
S
Set Variables — A command component used to update the values of custom variables during an experiment. Allows expressions that reference other variables and properties.
Shape Mask Region — A region component whose shape is defined by a custom image resource rather than a geometric primitive. Includes filter options for controlling visibility based on colour channel thresholds.
Shared Component Library — A feature that allows users to import, export, and share reusable components across projects and with other users.
Spatial Frequency — The rate of luminance variation across space in a pattern, typically measured in cycles per degree of visual angle. Controls the fineness or coarseness of gratings and similar patterns.
Spatial Waveform — A parameter group that defines the one-dimensional waveform mapped across a pattern's spatial extent. Options include sine, square, triangle, and ramp shapes, with configurable amplitude, offset, phase, symmetry, and drift.
Staircase — A psychophysical method that adaptively adjusts stimulus parameters based on participant responses, used to efficiently estimate perceptual thresholds.
T
Text Region — A region component that displays text strings on the stimulus display. Supports configurable font, size, style, and alignment properties.
Timeline — The third and deepest level of the Experiment Design hierarchy. Timelines dictate the presentation, appearance, and timing of components during the experiment. They are composed of one or more epochs.
Timeline Preview — A visual window in the LabMaestro interface that renders a preview of how a timeline's stimuli will appear during an experiment run. Supports drag-and-drop placement and resizing of regions.
TRACKPixx3 — A VPixx Technologies high-speed binocular eye tracker. Connected via the DATAPixx3, it provides gaze position data and supports calibration routines and gaze-contingent experiment control within LabMaestro.
Trial — A single presentation of one experimental condition. In LabMaestro, a trial corresponds to one iteration through the epochs of a timeline, driven by values from a Method's condition list.
U
Uniform Pattern — A pattern component that fills a region with a single solid colour. Can be combined with the Flicker Waveform to create a flickering field.
V
Value — The data assigned to a component property or variable. LabMaestro supports five value types: Integer, Floating, Boolean, Text, and Colour.
Viewing Distance — The distance between the participant's eyes and the centre of the display, measured in centimetres. Used with pixel density to convert between pixels and degrees of visual angle. Default is 57.3 cm (where 1 cm on screen ≈ 1 degree).
VIEWPixx — A family of VPixx Technologies research-grade LCD monitors designed for psychophysics and neuroscience, supporting high temporal precision and specialized video modes.
VOCAL (VPixx Online Classroom) — Video tutorials and training materials provided by VPixx Technologies for learning LabMaestro and VPixx hardware.
VPixx Technologies — The manufacturer of research-grade display, data acquisition, eye tracking, and response hardware used in psychophysics and neuroscience laboratories. Developer of LabMaestro.
W
Wait for Input — A command component that pauses experiment execution until a specified input event (such as a keypress or button press) is detected. Records the event details in a LastEvent property.
X
X-Rite — A manufacturer of colour measurement instruments. VPixx-edition X-Rite colorimeters (i1Display Pro) and spectrophotometers (i1 Pro) are supported in LabMaestro for display calibration.
For more detailed information on any term, refer to the relevant documentation page in the navigation above, or consult the Expression Reference and Component Reference.