Studying sixth sense in fish help equip robots with multiple sensors

Washington, August 29 : A team of scientists is exploring the fundamental basis for the unique sixth sense of fish to "touch" objects in their surroundings without direct physical contact, or to "see" in the dark, which could better equip robots to orient themselves in their environments with multiple sensors.

The research work is being led by Professor Leo van Hermmen and his team in the physics department of the Technische Universitaet Muenchen (TUM) in Germany.

Even in murky waters hardly penetrated by light, pike and pickerel can feel out their prey before making contact.

The blind Mexican cave fish can perceive structures in its surroundings and can effortlessly avoid obstacles.

“It’s not just that it describes a different quality of reality, but also that in place of just two eyes or ears this sense is fed by many discrete lateral-line organs, each of which in turn is composed of several neuromasts. The integration behind it is a tour de force,” he added.

The neuronal processing and integration of diverse sense impressions into a unified mapping of reality is a major focus for van Hemmen’s group.

“My dream is to endow robots with multiple sensory modalities. Instead of always building in more cameras, we should also along the way give them additional sensors for sound and touch,” said van Hemmen.

Catfish on the hunt follow invisible tracks that lead directly to their prey.

The organ that makes this possible is the lateral-line system, which registers changes in currents and even smaller disturbances, providing backup support for the sense of sight particularly in dark or muddy waters.

“The lateral-line sense fascinated me from the start because it’s fundamentally different from other senses such as vision or hearing, not just at first glance but also the second,” van Hemmen said.

Infrared light, electromagnetic waves, and ultrasound are just a few examples of the external influences that we humans can grasp only with the help of technological measuring devices - whereas some other animals use special sense organs, their own biological equipment, for the purpose.