Enactive perception

• Applicant: Professor Dr. Eckart Zimmermann
• Subject Area: Biological Psychology and Cognitive Neuroscience
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 449495537

The central aim of this grant proposal is to explain how the brain distinguishes self- from externally generated motion. Sensorimotor contingencies consist in stimuli which necessarily reoccur during certain actions. A prime example is the motion on the retina during saccadic eye movements. How does the brain distinguish self- from externally generated motion? The first four experiments of the grant proposal shall investigate the hypothesis that the sensorimotor system habituates to sensorimotor contingencies. Such a habituation occurs under the combined condition that a copy of the motor command (efference copy) and the self-produced stimulus arrive in an extra-retinal storage. To investigate this hypothesis, experiments shall test if the reduction of sensitivity during saccades is selective for exactly that motion speed which reoccurs during a certain saccade vector. Another research question asks if new contingencies can be learned. The hypothesis predicts that this is the case. Furthermore, the hypothesis shall be tested for head movements. We experience the motion produced by head movements but classify it correctly as self-generated. Similarly in this case an extra-retinal storage could support acknowledgement of self-produced motion. The idea of an extra-retinal storage is more parsimonious than current theories which include forward models. A further example which can be explained by a more simple hypothesis than the forward model is sensory attenuation of the consequences of actions. If we touch ourselves we perceive the touch as less intensive as when someone else touches us. The corresponding experiments of the grant proposal follow the hypothesis that an attention boost is induced at the touching finger, leading to an attenuation in all other sensory channels. To investigate this hypothesis, tactile attention at the touching finger and sensory attenuation for self-produced sounds shall be investigated in the same experiment. 
In conclusion, the idea of enactive perception shall be investigated in this grant proposal, in particular sensorimotor contingencies and the sensory consequences of actions. These shall explain how the brain distinguishes between self- and externally generated stimulation. These results would provide evidence for a more parsimonious theory.

• DFG Programme: Research Grants