Galvanic skin response or GSR allows the researcher to tap into unconscious behaviour. With GSR, it is possible to access and measure involuntary unconscious behavior. This makes GSR highly suitable for exploring emotional arousal that is not censored through language, culture and rational thought. Source: IMotions. (2017). GSR Pocket Guide. iMotions.
Research undertaken by Fisher et. al. suggests that searching the Internet for explanatory knowledge creates an illusion whereby people mistake access to information for their own personal understanding of the information. Source: Fisher, M., Goddu, M.K. & Keil, F.C., 2015. Searching for explanations: How the Internet inflates estimates of internal knowledge. Journal of Experimental Psychology: General, 144(3), pp.674–687
Emotions such as heightened arousal can make pupils dilate. Belladonna (or deadly nightshade) was once used by women to dilate their pupils, thus making them seemingly more attractive. Source: Wade, N. J. & Swanston, M. T. (2013), Visual Perception. An Introduction. 3rd edition, London, Taylor and Francis Group.