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SUMMARY:Going with the flow:  Visually guided flight and navigation in hon
 eybees - Professor Mandyam V. Srinivasan\, Queensland Brain Institute
DTSTART:20081127T130000Z
DTEND:20081127T140000Z
UID:TALK15115@talks.cam.ac.uk
CONTACT:John Mollon
DESCRIPTION:Insects\, in general\, and honeybees\, in particular\, perform
  remarkably well at seeing and perceiving the world and navigating effecti
 vely in it\, despite possessing a brain that weighs less than a milligram 
 and carries fewer than 0.01% as many neurons as ours does. Although most i
 nsects lack stereo vision\, they use a number of ingenious strategies for 
 perceiving their world in three dimensions and navigating successfully in 
 it. \n\nA number of investigations are revealing that flying insects perce
 ive the world in three dimensions and navigate safely in it by using cues 
 derived from image motion\, rather than complex stereo mechanisms. For exa
 mple\, distances to objects are gauged in terms of the apparent speeds of 
 motion of the objects' images. Objects are distinguished from backgrounds 
 by sensing the apparent relative motion at the boundary. Narrow gaps are n
 egotiated safely by balancing the apparent speeds of the images in the two
  eyes. The speed of flight is regulated by holding constant the average im
 age velocity as seen by both eyes. This ensures that flight speed is autom
 atically lowered in cluttered environments\, and that thrust is appropriat
 ely adjusted to compensate for headwinds and tail winds. Visual cues are a
 lso used to compensate for crosswinds. Bees landing on a horizontal surfac
 e hold constant the image velocity of the surface as they approach it\, th
 us automatically ensuring that flight speed is close to zero at touchdown.
  Bees approaching a vertical surface hold the rate of expansion of the ima
 ge of the surface constant during the approach\, again ensuring smooth doc
 king. Mid-air collisions with other flying insects are avoided by turning 
 away from areas in the visual field that experience high image velocity\, 
 rather than by using looming cues or stereo information. Foraging bees gau
 ge distance flown by integrating optic flow: they possess a visually-drive
 n "odometer" that is robust to variations in wind\, body weight\, energy e
 xpenditure\, and the properties of the visual environment. Bees appear to 
 use two different odometers: a “community” odometer to signal the dist
 ance of a newly-discovered source of food to their nest mates\, and a “p
 ersonal” odometer to return repeatedly to a familiar food source. \n\nSo
 me of the insect-based strategies described above are being used to design
 \, implement and test biologically-inspired algorithms for the guidance of
  autonomous terrestrial and aerial vehicles. \n\n
LOCATION:Lecture Theatre\, Department of Experimental Psychology\, Downing
  Site
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