Table 2.

IB metrics assessed through laboratory investigations.

	IB metric	Description	Indicator	Reference study
Act of buying	Impulse buying behaviour	Expression of impulsive buying behaviour during the act of purchase	Real unplanned purchase	Vohs and Faber, 2007; De Vries and Fennis, 2019
			Experimental product category chosen	Bossuyt et al., 2017
	Physiological and behavioural response	Individual reactions encompassing individual's central or peripheral nervous system activity, instinctive non-verbal actions or behavioural exteriorisation	Neural cortical and sub-cortical activations	Hubert et al., 2013, 2018
			Decision time	Huang and Kuo, 2012
			Information ocular search patterns	Huang and Kuo, 2012
			Pupil dilation	Serfas et al., 2014
			Ocular fixations count	Khachatryan et al., 2018
			Facial expressions	Weinberg and Gottwald, 1982
			Electrodermal activations	Bossuyt et al., 2017