Yiran Lang

Hemodynamic Responses of Rat Brain Measured by Near-infrared Spectroscopy During Various Whisker Stimulations

NIRS (Near-infrared spectroscopy) is a relatively, new, non-invasive, and non-ionizing method of measuring hemodynamic responses in thick biological tissues such as the cerebral cortex. In this study, we measured the hemodynamic responses of the rat barrel cortex to whisker stimulation by using a frequency-domain NIRS system. We designed multiple optical probes comprising multi-mode optical fibers and manipulating arms, both of which can be easily applied to small animals. Various electrical stimulations were applied to rat whiskers at different voltage levels and stimulation frequencies. Our results show that the hemodynamic responses are highly dependent on the stimulation voltage level, and not so much on stimulation frequency. This paper suggests that NIRS technology is highly suitable for the study of small animal brains.

Development of a Neuron Based Internet Game Driven by a Brain-Computer Interface System

Have you ever imagined that you could play an internet game against an animal like a rat? How would you feel if you lose? In the present study, we have developed an internet game driven by and linked to a brain-computer interface (BCI) system. The BCI system translated real-time neuronal activities from prefrontal cortex (PFC), or hippocampaus (CA1) of a rat into external device control commands and used them to drive a neuron based internet game series called RaviDuel.

Encoding-based brain-computer interface controlled by non-motor area of rat brain

As the needs of disabled patients are increasingly recognized in society, researchers have begun to use single neuron activity to construct brain-computer interfaces (BCI), designed to facilitate the daily lives of individuals with physical disabilities. BCI systems typically allow users to control computer programs or external devices via signals produced in the motor or pre-motor areas of the brain, rather than producing actual motor movements. However, impairments in these brain areas can hinder the application of BCI. The current paper demonstrates the feasibility of a one-dimensional (1D) machine controlled by rat prefrontal cortex (PFC) neurons using an encoding method. In this novel system, rats are able to quench thirst by varying neuronal firing rate in the PFC to manipulate a water dish that can rotate in 1D. The results revealed that control commands generated by an appropriate firing frequency in rat PFC exhibited performance improvements with practice, indicated by increasing water-drinking duration and frequency. These results demonstrated that it is possible for rats to understand an encoding-based BCI system and control a 1D machine using PFC activity to obtain reward.