Sasha Danilovich, PhD student, supervised by Dr Yossi Yovel, head of the laboratory of sensual perception and cognition, Department of Zoology

The way in which sensory information received by one sense is translated into a neuro- representation that is accessible to another sense, and the way in which information coming from several sensual systems is assessed, are fundamental issues in neuroscience. Bats present ideal model animals for studying these issues, because their behaviour is based on two sensory systems that provide high-resolution spatial information on the bats’ distant environment: vision and biological sonar (echolocation). The Egyptian fruit bat (Rousettus aegyptiacus), found in Israel, also employs these two systems in order to construct a sensual representation of the world.
In our lab we conduct various studies to engage with the issues described above. For example, we examine how sight availability (controlled by changing the light level) affects the bats’ gathering of information via echolocation. We found that when the light level is high, the pace and intensity of echolocation is low. This presents the first evidence that information gathered by one sense affects information gathering from another sense. In another study we trained bats to discern between several objects using only one sense (vision or sonar), and then tested them in the other sense to determine whether they could still discern between objects. The ability to transfer information between different senses implies that, using only one sense, the bats are capable of constructing a neuro-representation accessible to other senses. In this study we also used the fact that echolocation is an active sense (in other words, a sense that requires the animal to actively produce sound in order to gather information), in order to understand how the information is acquired. Recording the calls that the bats produce while performing the task has enabled us to evaluate the information gathered by the bats prior to choosing one of the objects and constructing its decision-making model.

Sasha Danilovich