The aim of this research consists in investigating the effects of odours on appraisal processes and consequent emotional responses. The temporal sequence of novelty detection and intrinsic pleasantness evaluations is the main interest of this experiment. The main hypothesis is that a stimulus is detected as perceptually novel before being evaluated as pleasant or unpleasant. In order to tackle this issue, we have adopted a multicomponential approach consisting in measuring motor (facial EMG), physiological (ECG, respiratory frequency and EDA) and brain reactions (EEG) to odours. Participants were engaged in a delayed matching to sample recognition task in which several pairs of unpleasant or pleasant odours (composed by a sample and a target odours) were presented. Within a pair, the sample and the target could be either identical or different. The effect of novelty was tested by comparing identical and different target odours. The effect of pleasantness was examined through the comparison between unpleasant and pleasant sample odours. Preliminary results suggest earlier differentiations on behavioural and brain indices in response to novelty detection as compared to pleasantness evaluation, suggesting the existence of a sequence of appraisal process in the emotional reaction