Spatial receptive field shift by preceding cross-modal stimulation in the cat superior colliculus

Area of Science:

• Neuroscience
• Sensory processing
• Multisensory integration

Background:

• Cross-modal spatial interactions are known, but neural mechanisms remain unclear.
• Psychophysical phenomena like ventriloquism demonstrate spatial entrainment between senses.
• Dynamic recalibration of spatial perception by different sensory inputs is not well understood.

Purpose of the Study:

• To investigate the neural basis of cross-modal spatial recalibration in individual neurons.
• To determine if cross-modal spatial calibration occurs dynamically.
• To explore the role of the superior colliculus (SC) in integrating spatial information across senses.

Main Methods:

• Used sequential cross-modal stimulation in cat superior colliculus (SC) multisensory neurons.
• Measured shifts in auditory and visual receptive fields (RFs) following preceding stimuli.
• Varied temporal and spatial gaps, stimulus salience, and stimulus modality.

Main Results:

• Preceding stimuli dynamically shifted the spatial receptive fields of SC neurons.
• Cross-modal calibration occurred in both auditory and visual RFs, with auditory RFs showing a slightly larger shift.
• RF shifts were dependent on temporal/spatial gaps and stimulus salience; narrower gaps and higher salience induced larger shifts.
• Simultaneous visual and auditory stimuli also induced significant RF shifts.

Conclusions:

• Demonstrates a neural mechanism for dynamic cross-modal spatial calibration in the SC.
• Highlights the role of SC multisensory neurons in integrating and recalibrating spatial information.
• Provides insights into how the brain achieves inter-sensory spatial alignment.