Scented Envelopment and ERP Basis Waves
Yasuhiko Saito*, Takuji Yamamoto*, S Kanamura**
*Psychiatric Research Institute of Tokyo
**Takasago International Corporation
It has been reported that a brief presentation of odorous stimulus has some effects on Event-related brain potentials (ERPs). In this present study, effects of continuous presentation of odorous stimulus (scented environment) were studies with special references to ERP basis waves which associated to cognitive function. Contingent negative variation (CNV) was recorded before and after continuous presentation of 0.2g lemon oil. ERP basis waves were extracted by Multivariate analysis of single trial CNVs, and it is shown that the ERP basis waves of CNV contained a number of positive components after S1 and S2 of the conventional CNV paradigm. These positive components corresponded from the view point of their latency and topographic characteristics to the late positive complex. In the scented environment by the lemon oil, Sl +350p basis wave, which is a positive basis wave developed 350msec after S1, and S2 +350p, a positive basis wave 350msec after S2, decreased their amplitude significantly and S2 +650p, the second positive basis wave after S2, was also decreased in its amplitude. On the contrary to this, there noted increased amplitude of S1 +500p and S2 +500p in the scented environment. According to the report after the experiment, the odor of lemon oil induced tranquil and hedonic feeling among the subjects and they felt rather relaxed in the scented environment. The effects on the ERP basis waves are thought to be explained along this line of affective changes in the subjects.