"Properties of food representation and recognition"
Food is essential for our survival. It is therefore not surprising that the ability to discriminate what is edible from what is not, or the high-fat from low-fat food are fast occurring processes. The first question I will try to answer in my presentation is whether there are other properties that can be discriminated equally early in visual food recognition, such as its level of processing. For instance, mice and non-human primates have been observed to prefer food that underwent some kind of processing, especially thermic, and cooked food has been argued to have made us human. Second, I will discuss on whether humans, likewise non-human primates, evaluate food quality based on brightness of red and green shades of color, with red signaling higher energy or greater protein content in fruits and leafs. Third, I will report a study in which we explored higher-level cognitive representation of food, by hypothesising that recognition of natural and processed food might mirror, to some extent, the differences between living and non-living things. In the second part of my talk I will present several studies in which we examined how the recognition of food and non food, and natural and processed food items eventually declines in normally ageing individuals and how such ability breaks down in brain-damaged individuals. An attempt to identify the atrophic areas that correlated with reduced accuracy has also been carried out in dementia patients. The main results are beginning to shape the domain specificity of food. First, our brain is able to detect as early as 120 milliseconds whether a food is natural or processed, everything else being equal. Second, humans too seem to use colour as a strategy in food quality evaluation. Third, food seems to be resilient to brain damage, especially if it is processed. Centenarians, however, are more accurate in recognizing natural food items which they report to have consumed more often in their long life. Lastly, there is also evidence that sensory properties are better associated with natural foods and functional properties with transformed food, although these parings do not hold in some circumstances.