FR1approach
The FED4 Approach task is a behavioral paradigm designed to assess approach behavior in mice using the FED4 operant feeder system. This task requires the mouse to perform a specific sequence of actions in order to earn food pellets, thereby coupling operant responding with spatial approach.
This task may be beneficial for assays where behavior benefits from being more constrained, such as when aligning brain recording data with behavioral events.
Trial initiation:
The trial begins when the mouse performs a nose poke in the left port.
Approach requirement: After the left poke, the mouse has a 2-second window to approach the center port, which is monitored with a VL53L4CD ToF sensor.
Outcome contingencies:
- Approach within 2 seconds → a pellet is dispensed into the food well.
- No approach within 2 seconds → no pellet is delivered, and the trial ends.
Each event is logged in the FED4 system under the Event column. Relevant event codes: Left → initiation poke. Approach → center port entry within 2s. No_approach → failure to enter center within 2s. PelletDrop → pellet dispensed (only occurs after a valid Approach). PelletTaken → pellet retrieved by the mouse.
Cumulative counts of Approach and No_approach events can be plotted over time to quantify success rates and engagement.
Retrieval Time distributions provide additional measures of latency and motivation.
Accuracy (Left pokes / Total pokes) plot shows that they explore more during the dark phase.
