Bpod State Machine r2 is our newest system for precise measurement of small animal behavior. It measures the instant when discrete events happen (a snout enters a port, a tongue breaks a photogate, etc). The state machine can react to these events by rapidly changing aspects of the environment, providing an excellent low-latency link between behavioral events, stimuli and reinforcement. Bpod is most often used for the 2AFC (two alternative forced choice) behavioral paradigm, but has been adapted to power a diverse range of behavioral assays (conditioned place preference, go / no-go, self-stimulation, social value measurement, etc).
State machine r2 can interface with up to 4 behavior ports. Each behavior port contains one infrared photogate, one visible LED with software-adjustable intensity, and one solenoid valve for dispensing precisely measured liquid rewards through a drinking tube. The state machine has digital inputs and outputs for triggering and synchronization with linked electrophysiology and stimulation systems. Integration with Psychtoolbox 3 provides high quality audio stimuli with ~8ms latency on a properly configured computer, and with a firmware swap, our analog output module provides ~100 microsecond latency audio in applications where audio fidelity is not critical.
Please be advised that Bpod r2 is a flexible behavior platform, and is not guaranteed to do everything you have in mind out of the box. It has a learning curve, and will require some programming to develop a behavioral protocol. Documentation and information about getting started is available on the Bpod wiki. Individual support is available in the Bpod forums. A central focus of our company is to grow the current community of Bpod users, to optimize the system for ease of use, and to add to its capabilities.
State Machine r2 features several hardware improvements over r0.8:
- Modularity: Interfaces with 5 Bpod modules (up from 3)
- Integrated Power: Provides isolated power to 3 compatible modules
- Significantly faster CPU + more memory allows more complex state machine descriptions + mods
- Improved Valve Driver: drives larger inductive loads in parallel, and valves are now electrically isolated from other state machine control circuitry.
- Design optimized for manufacturing throughput, to improve availability