Thursday, April 23, 2009

Honey Bees - Small Brains, Smart Minds

Honey Bees - Small Brains, Smart Minds
Visual Perception & Cognition Seminar

Shaowu Zhang Senior Fellow, Vision Sciences Group, Research School of Biological Sciences Australian National UniversityCanberra, Australia. Chief InvestigatorAustralian Research CouncilCentre of Excellence in Vision Science

University of Western Ontario, London, Ontario
7 April 2009

I attended this seminar a couple weeks ago and again did my best to take accurate notes. This topic was new to me so I tried to keep up. Any errors or omissions are mine and not the speaker's.

The bee's brain is small but bees, like humans, have trichromatic colour vision, motion sensitive vision, and spatial vision. We have discovered that bees are capable of abstracting features of patterns, have visual illusions, and top-down processing. They are able to use symbolic rules for navigating and even form concepts such as sameness and difference. This talk will review some of our recent findings on visual perception and cognition in honeybees.

Honey bees travel about 100 kms per day while foraging. This represents 40 trips x 2 to 3 kms per trip.

For the study they put radio frequency chips with .5 ml weight on the bees' thorax. They monitored traffic entering and exiting the hive. They captured and released these bees elsewhere in the city. For example, the middle of a lake, the other side of a mountain and they released them around the city.

They did return to the hive, an approximate 11 km trip.

Pattern Vision of Honey Bees

Orientation of visual objects bilateral - as an example they used a circle with 4 lines drawn, a circle with 3 lines and a dot, and a circle with half coloured in solid. The left drawn lines had 145 degrees orientation and the right drawn had 135 degrees orientation. They also altered the thicknesses of the lines drawn.

They discovered that bees can experience visual illusions the same as humans.

They created a white triangle by colouring in the corners of a circle in black - we see the white space as a triangle. The bees would see this triangle as well. They learn symmetry and asymmetry.

They worked with rewards and with no rewards using a circle with 4 symbols

Bees have cortical-like processing using directional motion cues.

When they used two circles, one with 5 random dots and one with 4 random dots they could not differentiate but when they used two circles with 7 dots and 6 dots in a structured pattern, the bees could differentiate between them.

The bees could be trained to distinguish the pattern differences very quickly (random vertical & horizontal stripes). They were shown the new pattern for 2 milliseconds duration - a very brief flash every 5 seconds.

Top down & bottom up (I think this referred to mental processing?)

Prior experience is involved in recognizing. The speaker used the example of a Beverly Doolittle painting of an Indian on a horse among the trees - the horse and trees are camouflaged. Bee's experience helps them in detecting and recognizing a camouflaged pattern. It took them 3 days to learn the 2 patterns.

They did pre-training with solid circles showing contour - then used the same design but camouflaged.

Smells or visual objects are retrieval cues. A green colour mark on a maze entrance was used. They learned to follow the colour mark throughout the maze to find the reward.

Yellow is a good colour to use and blue is not so good. Colour as signposts was used to indicate where to turn, i.e., green turn left, blue turn right.
Colour as an indicator to instruct bees to choose scents. The colour blue was used to indicate the lemon scent and the colour yellow was used for the mango scent.

Associative grouping & recall stimuli

Learning the concept of same and different

Categorization of natural visual objects - 4 types of visual patterns were used - a start shaped flower, a circular flower, etc., either a flower pattern or a solid circle. They had two differently scented feeders. They blew scent from the feeders into the hive.

Bees have circadian timed episodic-like memory. Bees can reverse their preference for a visual pattern with the time of day/with the task. There were two entrances to the hive.

Symbolic dancing and visual odometer - a 529 millisecond waggle = flight for 230 meters and a 411 millisecond waggle = 184 metre flight.

How Recruits Responded to the Dance:

Asiatic bees can communicate with European bees. The bees have a different dialect and a different distance dialect. (400meters, 500meters and 600meters).

The bees followed each other's dancing information - using both pure and mixed colonies. The vast majority of recruits found the pollen source at 500 meters.

Honeybees Can Count:

They can distinguish between two squares, one with 3 solid dots and one circle and a box with 2 solid dots and one circle (two versus 3 task).

They can count up to 4. They can use prior knowledge. The bee could not do more than 4.

They can form concepts and categorize visual stimuli.

Bees dropped 11 km away from the hive use sky information - polarization light, celestial cues and visual cues (such as a mountain). When released they don't fly back right away. When they see something familiar such as a landmark that they remember it helps them.

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