The Hand�s Brain: Its Role in Architectural Imagery

Abstract

This research concerns the relationship between hand movements, as they occur in the act of freehand drawing, and creativity. Since ancient times it was observed that hand movements were linked with intelligence. This issue has gained importance particularly in the field of architectural imagery because automated drawing techniques with computer aided design (CAD) have replaced the hand drawings. This has risen concerns about the impairment of creative ideas that may ensue. The working hypothesis of this research is that the complex, meaningful freehand movements are connected to a larger activity of the cortical neurons compared to the simple, rather meaningless movements of the CAD drawing. The research was aimed to provide electroencephalographic evidence supporting this hypothesis, with the preliminary assumption that creativity could be linked to recruitment of a larger neuronal population. In 10 subjects, we recorded the electroencephalogram (EEG) using the technique of movement related potentials (MRPs), and analysed the epoch spanning from 1000 ms before to 1000 ms after movements while freehand drawing or using the mouse for CAD drawing. A digitising tablet was used for freehand drawing. Latency, amplitude and area under signal of the recordings under the two conditions were assessed. The most relevant premotion components of the MRPs were the N-150 and P-40 (occurring 150 and 40 ms before movement), followed by the post-motion components N+30 and P+120 (30 and 120 ms after movement). Freehand drawing was linked to larger cortical activity, which suggests that a larger number of specialised cortical neurons were activated than with CAD drawing. The amount of neuronal activity could be a reflection of the cognitive process occurring in preparation for the skilled movements of the hand, and the results reported lead to the conclusion that freehand drawing is preceded by a strong cognitive activity bringing new ideas.