Editor's view: Is the brain's perception of ideas an underappreciated human sense?

Humans have developed sensory organs for their 'major' senses and specific neuronal receptors for a number of additional senses. Although information from sensors is integrated and processed in the brain, the brain itself has not been proposed as a sensory organ associated with a particular sense - at least not in Western culture or scientific literature. Perception of ideas has many elements of a separate sense, with the brain being a primary sensory organ. I support this notion based on 17 years of experience in the application of the Child Health and Nutrition Research Initiative (CHNRI) method for setting research priorities, which resulted in more than 150 publications involving thousands of experts who prioritised more than 20 000 research ideas. This body of work allows for the generalisation of the following key concepts: defining an idea in the context of the brain's sensory perception; defining the point of origin, sensory qualities, and common types of ideas; considering responses of the body to the brain's sensory exposure to ideas; and defining the key criteria that the brain uses to discriminate between and prioritise ideas. The human brain is continuously being exposed to ideas, which can be self-generated, triggered by information from other sensors, or introduced from the external world. From the brain's sensory perspective, ideas are competing possibilities of purposeful activities that, if followed, would be expected to result in an alternative version of the future. Pursuing ideas tends to drive most of human activity. It requires prioritising between short-, mid-, and long-term investment of energy and time. The brain's sensory role is to continuously assess many competing ideas and prioritise between them based on motivational/emotional ('attractiveness'), operational/rational ('feasibility') and outcome-related perspective ('impact'). Exposure to new ideas may instigate physiological and psychological responses, ranging from enthusiasm and excitement to feeling a threat or fear. Ideas can be used to mobilise large groups of people whose brains respond with excessive enthusiasm that can sometimes be fanatical. The judgment on the attractiveness, feasibility, and potential impact of ideas is affected by education, experience, and cognitive abilities. This sense may be sharpened through an increased level of expert knowledge and experience. Misinformation and disinformation are dangerous because they affect the brain's perception of ideas. Impairment of this inherent sense may perhaps contribute to some mental health issues. The proposed view of the brain as the sensor of ideas could lead to many qualitative or quantitative experiments to further explore the properties of this sense in both individuals and populations, establishing 'the science of ideas'.