Frank Bremmer: Self-motion processing in primates

Philipps-University Marburg,  Department of Neurophysics

Title: Self-motion processing in primates

Abstract:

The perception and control of self-motion is a central task in everyday life. The visual system
derives information about heading, traveled distance, and body movement from optic flow,
yet these signals must be integrated with eye movements, non-visual sensory information,
and prior knowledge to generate stable representations of self-motion. In this talk, I will
present a series of studies combining psychophysics, electrophysiology, brain stimulation,
neuroimaging, and computational modeling in humans and macaque monkeys to investigate
the neural mechanisms underlying visual self-motion processing.

I will first discuss evidence that neuronal representations of heading are dynamically shaped
by eye movements and active behavior, demonstrating that self-motion signals are not static
sensory representations but depend on behavioral context. I will then show that
preattentive processing of optic flow is remarkably similar in humans and non-human
primates, suggesting evolutionary conserved mechanisms for the rapid extraction of self-
motion information. Complementary studies using transcranial magnetic stimulation
establish a causal role of human area hMST in heading perception, while fMRI and EEG
experiments reveal how predictive mechanisms, multisensory interactions, and reference-
frame transformations contribute to path integration and navigation. Recent computational
work further demonstrates how internal priors and reference-frame transformations
account for seemingly contradictory biases in heading perception, providing a unified
explanation of longstanding findings in the field.

Together, these studies provide an integrated view of self-motion processing across species
and methods, illustrating how sensory signals, prediction, and action are combined to
support robust navigation in complex environments. Finally, if time allows, I will briefly
discuss how these insights may contribute to translational approaches for assessing deficits
of postural control in neuropsychiatric disorders, including Parkinson's disease.

 

Guests are welcome!

 

Organized by

Michael Brecht / Lisa Rosenblum