Protocol

Mouse port-based visual contrast 2AFC task

Freely moving mice initiate each trial at a central port, view a lateralized visual contrast stimulus, and report the perceived stimulus side by choosing a left or right response port. This variant preserves the port-based action sequence and reward/history effects separately from head-fixed wheel tasks.

Task structure

Stimulus, choice, feedback, and training as declared in the protocol record.

Stimulus

evidence_schedule
A visual stimulus of variable contrast is presented on the left or right; signed contrast encodes both stimulus strength and side.
evidence_type
static
modalities
visual
notes
—
units
percent contrast
variables
signed contrast, stimulus side

Choice

action_mapping
After central-port trial initiation and stimulus presentation, choosing the left or right port reports the stimulus side.
alternatives
left port, right port
choice_type
2afc
notes
—
response_modalities
nose-poke

Feedback

feedback_type
mixed
notes
Busse et al. modeled choice as a function of contrast, overall bias, and recent success/failure history; the protocol record keeps those analysis variables distinct from the visual stimulus variables.
penalty
Error or timeout penalty for incorrect choices and task-rule violations.
reward
Water reward for correct left or right port choices.

Training

notes
—
stages
port shaping, side response training, contrast detection

Trial timing

  1. trial_initiation
    self-paced

    Mouse initiates a trial by entering or holding the central port.

  2. visual_stimulus
    protocol-specific

    Lateralized visual contrast stimulus is presented.

  3. report
    response-limited

    Mouse exits the central port and selects a side response port.

  4. feedback
    outcome-dependent

Expected analyses

  • psychometric curve by signed contrast
  • contrast threshold by session and subject
  • port bias estimates
  • logistic choice model with stimulus, bias, and recent-history predictors

Interpretive claims

  • visual contrast detection
    Confidence: high · ref.busse-2011-detection-visual-contrast

    Reward imbalance and recent trial outcomes can influence choices, so contrast sensitivity should not be interpreted from raw accuracy alone.

Open questions

  • Locate or request reusable trial-level data from Busse et al. or close replications.
  • Decide whether later port-based history-bias studies should share this protocol or get source-specific variants.