A delivery system for olfactory stimuli

This paper describes the design of anew method for controlling and administ ering olfactory stimuli-namely, the hood system. The hood system involves a stream of vaporized odor tab (at known concentrations) mixed with odorless air and pumped (at a constant flow rate) into an oxygen therapy hood. It i s designed to be used with odorants in solution, such as essential oils, as the olfactory stimulus. The use of oxygen therapy hoods allows for the pre cise control of a constant concentration of odorized air over time, while a llowing subjects to breathe normally. The hood system provides a natural ad ministration of olfactory stimuli and the exact determination of the stimul us concentration. The use of this system will allow experimental conditions to be completely defined and results and replication studies to be accurat ely interpreted. The hood system is portable, cost effective, and construct ed from readily available components. It is proposed that the hood system c ould be adopted to suit a wide range of olfactory research, particularly th at in which the effects of chronic exposure to olfactory stimuli on cogniti on are examined.