Electrophysiological indices of aesthetically stimulated processes in art-experienced individuals as compared to art-naïve individuals

HARTNACK, KATHARINE Electrophysiological indices of aesthetically stimulated processes in art-experienced individuals as compared to artnaïve individuals. Department on Neuroscience, June 2011. ADVISOR: Professor Stephen Romero Aesthetic judgment processes were investigated in art-experienced and artnaïve individuals. Previous electrophysiological data suggest that aesthetic judgment is a two-stage process (Hofel & Jacobson, 2007). The first stage of aesthetic judgment is impression formation which is not spontaneous, and is reflected by an early Event Related Potential (ERP) frontocentral deflection. The second stage reflected by a lateralized late ERP positivity, evaluative categorization is also not spontaneous. Participants in the current study were instructed to either simply view black and white geometric patterns or were instructed to contemplate the beauty of the patterns. Results suggest that aesthetically stimulated processes differ between art-expereinced individuals and art-naive individuals, and impression formation requires intention in art-naive individuals, but occurs spontaneously in art-experienced individuals. Effects of Art-Experience on Aesthetic Processing 11 Electrophysiological indices of aesthetically stimulated processes in art-experienced individuals as compared to art-naive individuals Neuroaesthetics, also known as the neuro-cognitive psychology of aesthetics, is an exciting new field of neuroscience investigating the neural processing of aesthetic experience (Cinzia and Vittorio, 2009). Aesthetic experience is what allows individuals to perceive, feel and sense an artwork by stimulating sensorimotor, emotion and cognitive processes. Although there are many mechanisms involved in aesthetic experience, most of the neuroaesthetic research done over the past ten years involves the psychophysical aspects of the visual processes in the brain. A variety of methodological techniques have been used including functional magnetic resonance (fMRI), magnetoencephalography (MEG) and electroencephalography (EEG). The neuro-cognitive psychology of aesthetics is an interesting topic for researchers because different aesthetic stimuli elicit different processes that can be studied independently (Leder, Belke, Oeberst, and Augustin, 2004). For example, emotional stimuli elicit affective processes and familiar stimuli elicit memory processes. One aspect of aesthetic experience that has been investigated in neuroaesthetics research is aesthetic judgment. An individual’s aesthetic judgment of a visual stimulus is influenced by many factors (Jacobsen, 2010) including the emotional state of the individual, the meaning or interestingness of the presented stimulus and the beauty and symmetry of the stimulus. Jacobsen and Hofel (2003, 2007) distinguished between descriptive and evaluative neuroaesthetic processes by comparing event-related potentials (ERPs) of Effects of Art-Experience on Aesthetic Processing 2 aesthetic judgment to ERPs of symmetric judgment. Descriptive judgments are cognitive processes that are nonevaluative, objective and do not depend on an individual’s personal experience (Jacobsen and Höfel, 2003). Evaluative judgments, in contrast, are cognitive processes based on an individual’s subjective experience. Jacobsen and Höfel (2003), investigated descriptive processes by asking participants to make judgments of symmetry and evaluative processes were investigated by asking participants to make judgments regarding beauty of a stimulus. The stimuli used to elicit aesthetic judgment processes were simple black and white geometric stimuli, some of which are shown in Figure 1. In Phase 1 of the Jacobsen and Höfel (2003) experiment, the participants became familiar with the 252 black and white geometric patterns while they judged each stimulus as either beautiful or not beautiful. The same geometric patterns were then presented to the participants during EEG recording. Figure 1. Examples of the black and white geometric patterns used as stimuli from Jacobsen and Höfel, (2003). Effects of Art-Experience on Aesthetic Processing 3 The Jacobsen and Höfel (2003) results yielded several definitive EEG signatures. A late positive potential with a right lateralization was elicited only by the beautiful judgment task. This finding concurs with a previous finding of right hemisphere involvement in aesthetic evaluative processes (Cacioppo, Crities, and Gardner, 1996). The finding that the evaluative task elicited ERPs that were not elicited by the descriptive task suggests that there are differences between descriptive and evaluative judgments processes. An early frontocentral negative deflection was also elicited during the beautiful judgment task and showed the most negative ERPs for the stimuli judged as not beautiful. The finding that not beautiful stimuli elicited different ERPs than beautiful stimuli suggests that negative and positive aesthetic evaluative processes are distinct and occur at different locations in the brain. From these results, Jacobsen and Höfel (2003) concluded that descriptive and evaluative processes are elicited individually and the aesthetic judgment process elicits an early, frontocentral negativity and a late positivity. Jacobsen and Hӧfel labeled the early frontocentral negativity impression formation and the lateral late positivity evaluative categorization. Impression formation and evaluative categorization are the two stages of aesthetic judgment processing. Höfel and Jacobsen (2007) expanded their previous conclusion by determining the automaticity of evaluative and descriptive processes. In this followup study, participants were randomly assigned to one of two conditions: Viewing or Contemplation. Participants assigned to the Viewing condition were instructed to view the patterns, (i.e., a nonevaluative task), and participants assigned to the Effects of Art-Experience on Aesthetic Processing 4 Contemplation condition, were told to contemplate the beauty of the patterns, (i.e., an evaluative task). Neither group in the study was asked to judge the patterns as beautiful or not-beautiful. The same black and white geometric pattern stimuli from the Hӧfel and Jacobsen (2003) study were used in the Hӧfel and Jacobsen (2007) experiment, but 40 of the patterns had an additional small black or white imbedded probe circle. The only overt response required was in response to the participant detecting this probe in the circle to ensure the participants were engaged with the stimuli in the specific tasks. Hӧfel and Jacobsen (2007) found a similar result to their previous study. A posterior sustained negativity was elicited in both groups, indicating descriptive processes of symmetry analysis occur automatically. The early frontal negativity reflecting impression formation in the previous study was not elicited in either group, suggesting that the process of making an aesthetic judgment must be explicitly instructed and is not automatic. Hӧfel and Jacobsen (2007) did find a lateralized late positivity similar to their previous study, but only for the participants assigned to the Contemplation condition, which implies impression formation and evaluative categorization are two separate processes, both which require intention and do not occur automatically. Specifically, impression formation requires an explicit instruction to judge aesthetic stimuli as beautiful or not beautiful and evaluative categorization requires instruction to aesthetically evaluate the stimuli. Evaluation processes occur when an individual is only thinking about aesthetic value (i.e. judgment condition in Hӧfel and Jacobsen, 2007), but judgment processes occur only when an individual makes on overt decision about the aesthetic value (i.e., Hӧfel and Effects of Art-Experience on Aesthetic Processing 5 Jacobsen 2003). These results suggest that aesthetic appreciation of beauty is influenced by intention. Aesthetic processes are influenced by other factors besides intention, including art-related experience (Jacobsen, 2009). Individuals who have art-training and previous structured art-related knowledge utilize different cognitive systems, resulting in differences perceptual analysis and appreciation of visual stimuli (Jacobsen, 2009). Art-knowledge also influences how individuals engage with aesthetic stimuli (Chatterjee, 2011) and an individual’s aesthetic appraisal (Hekkert and Van Wieringen, 1996). For example, Nodine, Locher and Krupinski (1993) investigated the effect of art-training on perception and judging of aesthetic stimuli. Seven untrained individuals and seven art-trained individuals with previous graduate level art-training who were working professionally in an art field were presented with 12 pieces of modern art shown in pairs. One piece of art per pair had a more formal geometric structure and was considered more balanced than the second piece of art in the pair. The participants’ eye movements were recorded during the presentation of the stimuli and the participants were instructed to judge the pairs of artworks and choose which one they preferred. Results suggested differences in eye movements and art preferences for art-trained individuals as compared to art-naïve individuals. Specifically, differences in the eye movements suggested that art-training influences attention to the design and details of an aesthetic stimulus such that art-trained participants paid more attention to the global design of the piece of art and the untrained participants focused on the local details. Art-trained individuals analyze the Effects of Art-Experience on Aesthetic Processing 6 relationships between the features of the stimuli and not necessarily the elements individually. Art-trained individuals also preferred different pieces of art as compared to the untrained individuals. Nodine et al. (1993) also found that aesthetic judgments are made based on an individual’s perception of the lines, shapes, colors and t