Hawkmoths, like Manduca sexta, hover and track moving flowers during natural foraging in low light environments. Neural recordings from the visual part of the moth’s brain have suggested that as light levels drop, the moth changes its sensitivity to light by integrating light for a longer period of time. Such a strategy raises the possibility […]
In an earlier research project with Dr. Jean-Michel Mongeau (now professor at PSU) we looked at the how cockroaches use their antennae as to feel surface in front of them and navigate in low light. Our approach in that project was to find the simplest control law the cockroaches could be using to maneuver by […]
Once a behaving organism has acquired, processed, and transmitted sensory information it must still alter patterns of motor activation in a manner that enables control. A central challenge in understanding motor control, particularly during complex rhythmic behaviors like flight, is decoding the specific features of body dynamics that are control by patterns of neural feedback […]
Locomotion is an inherently closed-loop process. What that means is that when we move it changes how we perceive the world — turning to your left is like the world around you rotating to the right. As a result, what we see (or sense) is the difference between how an object in our world is […]
Temperature is one of the most important variables affecting an animal’s physiology. Animal’s thermoregulate in a variety of ways from behaviorally seeking out warmer or cooler parts of their habitat to having extensive heat exchange strategies in their circulatory systems. Large moths like Manduca sexta typically spend the first moments before flight performing a behavior […]
The established perspective of flight control in insects holds that their remarkable maneuverability arises from neural modulation of relatively small steering muscles acting in concert with the regular, clock-like activation of larger power muscles. Yet the power output of these main muscles is very sensitive to subtle timing changes in neural activation. To test if […]
How big were ancient whales?Body size is perhaps the most obvious functionally important feature of an organism, yet it is complexly determined by many genes and environmental factors. Understanding body size trends through time and correlations with evolutionary transitions and ecology can give insight into characteristics of the process of evolution itself. Body size has […]
In the previous project we altered the commands the cockroach’s brain was sending to its muscle in real-time while the animal was running or maintaining its posture. We found that the same muscle could have three different function even when activated by the same commands. These differences seemed to arise for the mechanical context in […]
What is the potential of a particular muscle to control locomotion and how does mechanics affect the control consequences of neural feedback to a muscle?Electrophysiological recordings of nerves and muscles during perturbations do not address how particular motor activation patterns control locomotion since many muscles can change in parallel and each can act in unexpected […]
Even geckos encounter perturbations and environments that can challenge their ability to stick. The hairs of a gecko’s foot are composed of dry, hard keratin. Classic physics predicts dry, hard solids to have frictional forces that decrease at the onset of sliding (kinetic friction is less than static friction). We discovered that gecko adhesives actually […]