MONAT - Measurement of Naturalness
Humans are surprisingly good at distinguishing between synthetic and natural materials. A quick squeeze of a handbag, for example, will usually provide the final clue as to whether it's leather or not. Join the researchers to take part in experiments to help in determining how these visual and tactile processes work.
Natural materials are generally perceived as being highly desirable. For example, silk, cashmere and walnut all have a long history of being associated with quality, craftsmanship and exclusivity. Many natural materials have an inner beauty that is hard to emulate in synthetic products, so although artificial materials are often cheaper, more durable and less scarce than their natural counterparts, they tend to be regarded by consumers as inferior to 'the real thing'.
As consumer demand for natural materials grows, so does the pressure on the Earth's limited natural resources. Already many hardwood forest habitats have been destroyed and trade in items such as ivory and fur has brought many animals close to extinction. Never has there been a greater need for improved materials that generate a perception of naturalness.
So what are the elusive material properties and attributes which determine whether people will perceive them as natural? After all, many of the plastics and synthetic fibres we encounter in everyday life have remarkable properties too, but something is subtly different, some critical cues pertaining to naturalness are often lost - but which? And how do we make decisions based on these cues?
The MONAT project team is exploring these questions and believe the answers lie in our ability to distinguish slight differences in the appearance and feel of different materials. The processes involved in deciding whether the look and feel of a material label it as 'natural' are complex and not well understood. The physical properties of a material or object, e.g. the roughness of the surface, its colour and texture, is generally assessed first by looking at it, and then reinforced or changed by touching it. Interactions between the material and the sensory transducers in our skin and eyes generate sensory impulses, which then pass along nerve fibres to the brain. The strength of these signals depends on factors such as the sensitivity of human sensors, the physical properties of the material and the environmental conditions. Surface structure at the nano-scale, for example, will not be sensed by our fingertips but may affect the visual appearance. Once they reach the brain, the nerve impulses are combined and interpreted to generate a percept; in our case, whether or not the material is natural. But this perception also depends on factors such as memory, expectation and emotional state, and these factors can be just as important as the raw information transmitted by the nerve cells in our eyes and skin. Thus, although we have the feeling that we are in direct contact with our environment, and make decisions based solely on this information, this feeling is an illusion. Everything we perceive is determined indirectly, through transformation of physical stimuli into electrical signals and the transformation of these signals into conscious experience.
By studying the complete sensory chain, from the properties of the material right through to what happens in the brain, the MONAT project is unravelling some of the secrets of the perceptual process.
A key feature of the project is the development and application of innovative, leading-edge techniques and knowledge from the fields of metrology, psychophysics, neuropsychology and mathematics to support the development of software models that bridge the gap between measurement of the physical attributes of an object and the human perception of whether that object is natural. Models that can then be used to predict human reactions to new materials and objects. This will revolutionise our understanding of how the human perceptual system functions, for the first time providing a complete link from the physical (objective) properties of a material right through to the perceptual (subjective) impression of whether it is natural.
Where necessary, the MONAT project team is developing new capabilities for properties that it are currently not possible to measure (e.g. visual texture and multi-angular appearance of materials) and adapting leading-edge methods for use in novel ways (such as the use of functional neuroimaging techniques to establish dynamic neural pathways and interactions between these). The project is also using cutting-edge MEMS technology to develop a new measurement tool for touch, based on a bio-mimetic approach.