FUNCTIONAL NEAR INFRARED SPECTROSCOPY IN ANIMAL COGNITION: POTENTIALS AND LIMITS

Finding non-invasive animal based indicators of animal emotion and cognition processes is an important goal in disciplines ranging from comparative neuroanatomy to animal welfare science. The functional near infrared spectroscopy (fNIRS) is a non-invasive brain imaging technique that measures changes of oxyhemoglobin concentration [O2Hb] and deoxyhemoglobin concentration [HHb]. Such changes are related to the neurovascular coupling and allow scientists to infer information about the underlying neuronal activity occurring in a specific brain area. Differently from fMRI, fNIRS can be applied in unsedated animals after short training periods. So fNIRS shows great potential in the multiple scenarios of animal cognition and animal emotion studies. Nevertheless, the current limits of this technology must be taken seriously into account. At the moment, the assessable cerebral structures are mostly limited to the cortex, while subcortical structures well known to play a crucial role in emotions cannot be reached. Another limit is that scientific information about modern functional neuroanatomy in animals is scarce or lacking; a certain degree of knowledge on brain functions, neuroendocrine milieu and cognitive processes of a given species is mandatory to develop and define the emotional processes. We will present preliminary results of a pilot study to a three-year long project. The project adopts a multidisciplinary approach to the study of the functional organization of the central nervous system (CNS) of freely-moving sheep by the non-invasive application of fNIRS. Our aim is to record the hemodynamic response of selected areas of the brain involved in the performance of various tasks by applying especially adapted fNIRS instruments to the head of the sheep. A series of behavioural motor and associative tasks were planned to analyse basic executive functions and potential brain capacities. Combining the exploration of the neural substrates underlying cognitive functions with existing behavioural and physiological measures will strengthen knowledge of how animals perceive different environmental situations.