How expectations influence perception during human communication

• Applicant: Dr. Helen Blank
• Subject Area: Human Cognitive and Systems Neuroscience ; Cognitive, Systems and Behavioural Neurobiology
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 434144931

Our ability to successfully communicate with other people is an essential skill in everyday life. Therefore, unravelling how the human brain is able to derive meaning from acoustic speech signals and to recognize our communication partner based on seeing a face represents an important scientific endeavour. Speech recognition depends on both the clarity of the acoustic input and on what we expect to hear. For example, in noisy listening conditions, listeners of the identical speech input can differ in their perception of what was said. Similarly for face recognition, brain responses to faces depend on expectations and do not simply reflect the presented facial features. These findings for speech and face recognition are compatible with the more general view that perception is an active process in which incoming sensory information is interpreted with respect to expectations. The neural mechanisms supporting such integration of sensory signals and expectations, however, remain to be identified. Conflicting theoretical and computational models have been suggested for how, when, and where expectations and new sensory information are combined (e.g., computations of prediction errors or sharpened signals). The overall aim of this research program is understand how the human brain combines cross-modal expectations and sensory information to communicate and how individuals differ in their use of expectations. To this end, the three proposed projects will use model-based, multivariate analysis of fMRI and EEG data to measure how expectations are represented and learned during speech and face recognition. Differences in weighting expectations and sensory input will also be investigated by testing individuals with an increased need for using expectations due to decreased clarity of sensory input during communication (i.e., hearing impaired cochlear implant users).

• DFG Programme: Independent Junior Research Groups