The Posterior Sustained Negativity Revisited—An SPN Reanalysis of Jacobsen and Höfel (2003)

Functional MRI was used to investigate the neural correlates of aesthetic judgments of beauty of geometrical shapes. Participants performed evaluative aesthetic judgments (beautiful or not?) and descriptive symmetry judgments (symmetric or not?) on the same stimulus material. Symmetry was employed because aesthetic judgments are known to be often guided by criteria of symmetry. Novel, abstract graphic patterns were presented to minimize influences of attitudes or memory-related processes and to test effects of stimulus symmetry and complexity. Behavioral results confirmed the influence of stimulus symmetry and complexity on aesthetic judgments. Direct contrasts showed specific activations for aesthetic judgments in the frontomedian cortex (BA 9/10), bilateral prefrontal BA 45/47, and posterior cingulate, left temporal pole, and the temporoparietal junction. In contrast, symmetry judgments elicited specific activations in parietal and premotor areas subserving spatial processing. Interestingly, beautiful judgments enhanced BOLD signals not only in the frontomedian cortex, but also in the left intraparietal sulcus of the symmetry network. Moreover, stimulus complexity caused differential effects for each of the two judgment types. Findings indicate aesthetic judgments of beauty to rely on a network partially overlapping with that underlying evaluative judgments on social and moral cues and substantiate the significance of symmetry and complexity for our judgment of beauty.

Descriptive symmetry and evaluative aesthetic judgment processes were compared using identical stimuli in both judgment tasks. Electrophysiological activity was recorded while participants judged novel formal graphic patterns in a trial-by-trial cuing setting using binary responses (symmetric, not symmetric; beautiful, not beautiful). Judgment analyses of a Phase 1 test and main experiment performance resulted in individual models, as well as group models, of the participants' judgment systems. Symmetry showed a strong positive correlation with beautiful judgments and was the most important cue. Descriptive judgments were performed faster than evaluative judgments. The ERPs revealed a phasic, early frontal negativity for the not-beautiful judgments. A sustained posterior negativity was observed in the symmetric condition. All conditions showed late positive potentials (LPPs). Evaluative judgment LPPs revealed a more pronounced right lateralization. It is argued that the present aesthetic judgments engage a two-stage process consisting of early, anterior frontomedian impression formation after 300 msec and right-hemisphere evaluative categorization around 600 msec after onset of the graphic patterns.