ERP modulation during observation of abstract paintings by Franz Kline

Abstract

The aim of this study was to test the involvement of sensorimotor cortical circuits during the beholding of the static consequences of hand gestures devoid of any meaning.In order to verify this hypothesis we performed an EEG experiment presenting to participants images of abstract works of art with marked traces of brushstrokes. The EEG data were analyzed by using Event Related Potentials (ERPs). We aimed to demonstrate a direct involvement of sensorimotor cortical circuits during the beholding of these selected works of abstract art. The stimuli consisted of three different abstract black and white paintings by Franz Kline. Results verified our experimental hypothesis showing the activation of premotor and motor cortical areas during stimuli observation. In addition, abstract works of art observation elicited the activation of reward-related orbitofrontal areas, and cognitive categorization-related prefrontal areas. The cortical sensorimotor activation is a fundamental neurophysiological demonstration of the direct involvement of the cortical motor system in perception of static meaningless images belonging to abstract art. These results support the role of embodied simulation of artist's gestures in the perception of works of art.

Figure 1. Stimuli used in the study.

(A) Painting stimuli: from up to bottom: 1953 Suspended; 1954 Painting number 2 and 1952 Painting Number 7 (B) Modified stimuli created removing the dynamic components of the three original paintings.

Figure 2. Clusters of electrodes selected for the analysis of ERP component.

Six different clusters, of three electrodes each, have been selected: 2 frontal (red), 2 central (blue), and 2 parietal (yellow).

Figure 3. Grande-average ERP waveform (19 participants).

The different colors indicate the 2 different Conditions: Paintings (blue line) and Modified stimuli (red line).

Figure 4. ERP waveforms recorded over frontal (F3 and F4), central (C3 and C4) and parietal (P3 and P4) sites.

The different colors indicate the 2 different Conditions: Paintings (blue line) and Modified stimuli (red line). Paintings evidently have a greater effect especially on the signal recorded on left frontal and central sites.

Figure 5. T-test applied on the two conditions (Paintings vs Modified stimuli).

It was conducted on bins of 40(from −200 to 1000 ms). In the upper part of the figure the t values topomaps are shown. The lower part of the figure shows the modulation, in the two experimental Conditions (blue line = Paintings; red line = Modified stimuli), of grand averaged signal recorded from C3. 240 ms after stimulus presentation the two conditions significantly differ on the fronto-central electrodes.

Figure 6. Modulation of the negative ERP component during observation of Paintings and Modified stimuli.

Bars represent significant RegionXCondition interaction resulted from the ANOVA performed on the mean amplitude (µV). Paintings (dark gray) and Modified stimuli (light gray). In the frontal and central electrodes the two conditions are significantly different (*).

Figure 7. sLORETA inverse solution applied on the difference wave ‘Paintings – Modified Stimuli’.

The neural generators resulted in the following cortical areas: sensorimotor (dashed lines), left prefrontal (continuous lines) and orbitofrontal (dotted lines), are evidenced.

Figure 8. Results of the T-test conducted on the scores of the questionnaire.

Scores given to the “Amount of movement” and to the “Aesthetic appraisal” resulted significantly higher for the Paintings than for the Modified stimuli (p_s<0,01).