Predicting Product Preferences on Retailers' Web Shops through Measurement of Gaze and Pupil Size Dynamics.

Previous studies used gaze behavior to predict product preference in value-based decision-making, based on gaze angle variables such as dwell time, fixation duration and the first fixated product. While the application for online retail seems obvious, research with realistic web shop stimuli has been lacking so far. Here, we studied the decision process for 60 Dutch web shops of a variety of retailers, by measuring eye movements and pupil size during the viewing of web shop images. The outcomes of an ordinal linear regression model showed that a combination of gaze angle variables accurately predicted product choice, with the total dwell time being the most predictive gaze dynamic. Although pupillometric analysis showed a positive relationship between pupil dilation and product preference, adding pupil size to the model only slightly improved the prediction accuracy. The current study holds the potential to substantially improve retargeting mechanisms in online marketing based on consumers' gaze information. Also, gaze-based product preference proves to be a valuable metric in pre-testing product introductions for market research and prevent product launches from failure.

Acute administration of haloperidol does not influence 123I-FP-CIT binding to the dopamine transporter.

UNLABELLED: A recent (123)I-FP-CIT ((123)-I-N-ω-fluoropropyl-2ß-carbomethoxy-3ß-(4-iodophenyl)nortropane) SPECT study on rats suggested that a single 1 mg/kg dose of the antipsychotic haloperidol induces enough dopamine release to compete with (123)I-FP-CIT for binding to the dopamine transporter. Taking into account the far-reaching consequences of this proposition, we were interested in testing whether we could reproduce this finding using storage phosphor imaging. METHODS: Twenty rats were pretreated with saline or haloperidol (1 mg/kg of body weight) and then injected with (123)I-FP-CIT. Two hours after (123)I-FP-CIT injection, the rats were sacrificed and binding in the striatum, nucleus accumbens, and cerebellum (nonspecific binding) was measured. RESULTS: In contrast to the earlier SPECT finding, acute administration of haloperidol did not induce a significant change in (123)I-FP-CIT binding ratios in the striatum and nucleus accumbens. CONCLUSION: Changes in synaptic dopamine due to acute haloperidol administration were not detectable with (123)I-FP-CIT.