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Task Editor

The Task Editor is Cajal’s visual experiment builder where you design and configure psychology experiments without writing any code. Build everything from simple questionnaires to complex cognitive tasks using components as building blocks.

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What is the Task Editor?

The Task Editor provides a complete visual environment for creating experiments:

• Visual Design - See exactly what participants will see as you build
• Component-Based - Add pre-built psychology components (Stroop stimuli, Likert scales, instructions, etc.)
• No Coding Required - Configure everything through an intuitive interface
• Flexible - Create simple surveys or complex multi-block experiments

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Core Concepts

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Components: Building Blocks

Components are the fundamental building blocks of your experiment. Each component represents one screen or interaction that participants see:

• Instruction screens - Welcome messages, task explanations, debriefing
• Stimulus presentations - Images, words, sounds to display
• Response collection - Keyboard responses, button clicks, form inputs
• Feedback - Performance feedback, progress indicators
• Questionnaires - Likert scales, multiple choice, text inputs

Think of components as slides in a presentation - each one serves a specific purpose in your experiment sequence.

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Elements: Parts of Components

Each component contains one or more elements - the visual pieces that make up the screen:

• Text elements - Display instructions, questions, or stimuli
• Image elements - Show pictures, diagrams, or visual stimuli
• Button elements - Collect button-based responses
• Form fields - Text inputs, dropdowns, radio buttons, checkboxes, sliders
• Shapes - Backgrounds, dividers, visual markers
• Fixation crosses - Central focus points between trials

Elements can be positioned anywhere on the screen, styled independently, and configured with precise timing.

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Connecting Components Together

Components connect in sequence to create your experimental flow:

1. Linear sequences - One component after another (intro → task → debrief)
2. Loops - Repeat component sequences multiple times
3. Randomization - Shuffle the order of components
4. Conditional branching - Different paths based on participant responses

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Five Views

The Task Editor provides five specialized views for different aspects of experiment design:

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Getting Started

Here’s how to create your first component:

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Step 1: Add a Component

Click the “Add Component” button in the left sidebar or press A on your keyboard.

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Step 2: Select Component Type

Choose from the component library:

• Instruction - For welcome screens and task explanations
• Stimulus - For presenting images, words, or visual stimuli
• Response - For collecting keyboard or button responses
• Questionnaire - For surveys and forms
• Fixation - For inter-trial fixation crosses

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Step 3: Configure Properties

Use the right properties panel to customize:

• Component name - Give it a descriptive name
• Duration - How long it displays (or until response)
• Response settings - Valid keys, correct answers, feedback

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Step 4: Add Elements to Canvas

Switch to the Screens view to add visual elements:

1. Click ”+ Element” on the canvas
2. Select element type (text, image, button, etc.)
3. Position and style the element
4. Configure element properties

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Common Workflows

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Creating a Simple Questionnaire

Goal: Create a 5-question mood survey

1. Add an Instruction component for welcome message
2. Add 5 Questionnaire components (one per question)
3. For each questionnaire:
   • Add a text element for the question
   • Add a Likert scale element for the response
   • Configure scale (1-7, labels like “Not at all” to “Extremely”)
4. Add a final Instruction component for thank you message
5. Connect components in sequence (Timeline view)
6. Preview to test

Time to build: 5-10 minutes

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Building a Stroop Task

Goal: Create a classic Stroop experiment with 160 trials

1. Add an Instruction component explaining the task
2. Add a Fixation component (500ms duration)
3. Add a Stimulus component:
   • Add text element for word display
   • Configure color and word
   • Set duration to 2000ms
4. Add a Response component:
   • Set valid keys (e.g., F, J)
   • Configure correct response based on color
5. Add Feedback component for incorrect responses
6. Create a Loop frame around fixation-stimulus-response sequence
7. Use Variables view to define 160 trials (word, color, congruency, correct key)
8. Add intermissions every 40 trials for breaks
9. Preview with subset of trials

Time to build: 15-20 minutes

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Setting Up Instructions and Consent

Goal: Add proper consent form and task instructions

1. Add an Instruction component for consent:
   • Add text elements for consent form text
   • Add a button element labeled “I Consent”
   • Set button to advance to next component
2. Add an Instruction component for task overview:
   • Explain the task
   • Show example stimuli (using image elements)
   • Add “Continue” button
3. Add an Instruction component for detailed instructions:
   • Step-by-step what participants will do
   • Response key mappings
   • Example trial walkthrough
4. Add Practice Trial components (3-5 trials with feedback)
5. Add “Begin Experiment” transition screen
6. Connect all in sequence

Time to build: 10-15 minutes

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Keyboard Shortcuts

Speed up your workflow with keyboard shortcuts:

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Component Library

The Task Editor includes a comprehensive library of research-backed components:

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Setup Components

• Instructions - Welcome screens, explanations, debriefing
• Consent Form - IRB-approved consent collection
• Demographics - Age, gender, education questionnaires

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Stimulus Components

• Text Stimulus - Word or sentence display
• Image Stimulus - Picture presentation
• Audio Stimulus - Sound playback
• Video Stimulus - Video clips
• Sequential Stimulus - Rapid serial presentation (digit span, RSVP)
• Fixation Cross - Inter-trial fixation (+, •, ×)

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Response Components

• Keyboard Response - Single or multiple key press
• Button Response - On-screen clickable buttons
• Text Input - Open-ended text responses
• Multiple Choice - Radio buttons (single selection)
• Checkboxes - Multi-select options
• Dropdown - Select menu
• Likert Scale - 1-7 rating scales
• Slider - Continuous response slider
• Visual Analog Scale (VAS) - Line-based rating

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Specialized Components

• Matrix Response - Grid of questions × response options
• Semantic Differential - Bipolar adjective scales
• Pairwise Comparison - Compare stimulus pairs
• Ranking - Drag-to-rank items
• Hotspot Response - Click regions on images
• Grid Layout - Organize multiple elements in grid
• Split Screen - Two-panel layouts

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Best Practices

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Component Organization

• Use descriptive names - “Stroop_Word_Red_Congruent” not “Component_1”
• Group related components - Use Timeline folders for organization
• One purpose per component - Don’t combine stimulus and response in same component
• Consistent timing - Use same durations for similar component types

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Element Design

• Keep it simple - Fewer elements = clearer screens
• Use center alignment - Easier for participants to focus
• High contrast - Ensure text is readable (check color contrast ratios)
• Consistent fonts - Use same font family throughout
• Appropriate sizes - Text should be legible without strain

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Timing Configuration

• Standard fixation - 500ms for most cognitive tasks
• Stimulus duration - 2000-3000ms typical for reading tasks
• Response windows - Unlimited for accuracy, limited for speed
• Inter-trial intervals - 500-1000ms prevents fatigue
• Break frequency - Every 40-60 trials for long experiments

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Testing

• Preview early and often - Don’t wait until experiment is complete
• Test with colleagues - Get feedback on instructions and clarity
• Run full-length pilot - Test timing and fatigue
• Check on different devices - Desktop and tablet if applicable
• Verify data collection - Ensure all responses are captured

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Next Steps

Now that you understand the basics of the Task Editor, dive into each specialized view:

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Need Help?

• AI Assistant - Ask the AI to create or modify components using natural language
• Templates - Start from pre-built experiment templates
• Community - Browse experiments shared by other researchers

Build your first experiment today with the Task Editor’s intuitive, visual approach to psychology research.