Lateral biases in aesthetic preferences: pictorial dimensions and neural mechanisms.

Observers often prefer one orientation of a stimulus over its mirror image; these lateral biases are assumed to reflect aspects of the observer's neural organisation. However, the precise dimensions of pictorial organisation that influence these preferences, as well as the underlying neural mechanisms, are not clear. The present experiments addressed these issues by employing a stimulus set allowing for a factorial combination of three dimensions of pictorial organisation: Weight, Interest, and Directionality. Experiments 1 and 2 found that subjects exhibited robust and consistent preferences for stimuli with left-to-right directionality, especially for stimuli with left-biased interest; right-biased interest eliminated the preference for left-to-right directionality. The dimension of weight had little effect. Inter-task correlations from Experiment 3 suggested that this preference for left-to-right directionality (i) reflects a stable, underlying directional bias in perceptuo-motor processing, and (ii) is not related to individual differences in hemispheric activation.