Visual Occlusion Goggles Module

Getting Started

1. Connect your Visual Occlusion Goggles — USB (sVOG) or XBee dongle (wVOG)
2. Enable the module — From the Modules menu
3. Wait for the device tab — Indicates successful detection
4. Configure and record — Set experiment type, then start recording

User Interface

Each connected device gets its own tab with controls and real-time feedback.

When you start a recording session, the device enters experiment mode, the chart clears, and the trial counter resets. Each trial captures timing data for all lens state changes with timestamps synchronized to system time.

Data Output

File Location and Naming

{session_dir}/VOG/{prefix}_VOG_{port}.csv

Example: 20251208_143022_VOG_ttyACM0.csv

CSV Columns

Common Columns (sVOG and wVOG)

Additional wVOG Columns

Interpreting TSOT (Visual Demand)

TSOT measures how much time participants needed to see to complete a task:

• Lower TSOT = less visual demand (easier/more familiar task)
• Higher TSOT = more visual demand (harder/unfamiliar task)
• Approximate glances = TSOT / open_duration (typically 1500 ms)

Example values in Cycle mode (1.5s open/close periods):

Timing Details

Measurement Accuracy

TSOT and TSCT are measured by the device firmware (not your computer) with ±1-2 ms accuracy for both sVOG and wVOG.

PDLC Lens Transitions

"Functionally opaque" blocks enough light to prevent useful vision — this is what matters for participant behavior.

Host Timestamps

The record_time_unix column shows when your computer logged the data, not when the trial ended (typically 20-50 ms delay). This delay does not affect TSOT/TSCT accuracy. Use host timestamps only for synchronizing with other modules (video, audio, DRT, eye tracking).

DRT Integration (wVOG only)

When wVOG and wDRT share the same XBee network, the DRT CSV includes a lens column showing VOG state at each stimulus for combined visual occlusion + reaction time studies.

Experiment Types

Cycle (Standard Visual Occlusion)

Lenses alternate between clear and opaque at fixed intervals (typically 1.5s each). Button starts/stops the trial. TSOT measures visual demand. Compliant with ISO 16673 and NHTSA Visual-Manual Distraction Test.

Best for: Measuring visual demand of in-vehicle interfaces, touchscreens, or any task requiring visual attention.

Peek (Self-Paced Visual Confirmation)

Lenses remain opaque. Participant presses button to "peek" — lenses clear briefly, then return to opaque. A lockout period prevents consecutive peeks.

Data collected: Number of peeks, cumulative peek time (TSOT), peek timing patterns.

Best for: Evaluating voice-controlled systems or auditory interfaces to measure how much visual verification users need.

eBlindfold (Visual Search Time)

Trial begins with lenses clear. Participant searches for a target, then presses the button when found. Lenses go opaque and trial ends. TSOT equals search time.

Best for: Measuring visual search performance, comparing display layouts, evaluating element discoverability.

Direct (Manual Control)

Lenses mirror button state directly. No automatic timing or trial structure.

Best for: Integration with eye trackers, simulators, or custom experiment software.

Device Types

Choosing a Device

• sVOG: Fixed workstation setups, simulators, simple plug-and-play
• wVOG: Mobile participants, in-vehicle studies, DRT integration, independent L/R lens control

Configuration

Click "Configure Unit" on any device tab to access settings.

Standard values (1500 ms each) implement the ISO 16673 / NHTSA visual occlusion protocol. The dialog adapts to show available options for your device type.

Troubleshooting