Limits...
Number-based visual generalisation in the honeybee.

Gross HJ, Pahl M, Si A, Zhu H, Tautz J, Zhang S - PLoS ONE (2009)

Bottom Line: Using a y-maze, we found that bees can not only differentiate between patterns containing two and three elements, but can also use this prior knowledge to differentiate three from four, without any additional training.Control experiments confirmed that the bees were not using cues such as the colour of the exact configuration of the visual elements, the combined area or edge length of the elements, or illusory contours formed by the elements.To our knowledge, this is the first report of number-based visual generalisation by an invertebrate.

View Article: PubMed Central - PubMed

Affiliation: Biocentre, University of Würzburg, Würzburg, Germany.

ABSTRACT
Although the numerical abilities of many vertebrate species have been investigated in the scientific literature, there are few convincing accounts of invertebrate numerical competence. Honeybees, Apis mellifera, by virtue of their other impressive cognitive feats, are a prime candidate for investigations of this nature. We therefore used the well-established delayed match-to-sample paradigm, to test the limits of honeybees' ability to match two visual patterns solely on the basis of the shared number of elements in the two patterns. Using a y-maze, we found that bees can not only differentiate between patterns containing two and three elements, but can also use this prior knowledge to differentiate three from four, without any additional training. However, bees trained on the two versus three task could not distinguish between higher numbers, such as four versus five, four versus six, or five versus six. Control experiments confirmed that the bees were not using cues such as the colour of the exact configuration of the visual elements, the combined area or edge length of the elements, or illusory contours formed by the elements. To our knowledge, this is the first report of number-based visual generalisation by an invertebrate.

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(a) Learning curve for bees trained on a basic delayed match-to-sample (DMTS) task. Each ‘block’ represents two twenty-minute sessions of training (one for each sample S1 and S2). Bees were considered to be trained in this task when their performance reached a stable plateau (approximately 70% correct choices). n denotes number of bees per condition. Error bars show standard error. *** denotes statistically significant difference at p<0.001, * denotes p<0.05. (b) The incorrect second choices of bees in each of the training blocks, following a positive first choice.
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pone-0004263-g002: (a) Learning curve for bees trained on a basic delayed match-to-sample (DMTS) task. Each ‘block’ represents two twenty-minute sessions of training (one for each sample S1 and S2). Bees were considered to be trained in this task when their performance reached a stable plateau (approximately 70% correct choices). n denotes number of bees per condition. Error bars show standard error. *** denotes statistically significant difference at p<0.001, * denotes p<0.05. (b) The incorrect second choices of bees in each of the training blocks, following a positive first choice.

Mentions: Over a period of three days, a group of approximately 20 bees were able to learn the basic DMTS paradigm, where they had to match one of two choice patterns to a previously encountered sample pattern (See the experimental apparatus in Fig. 1). In particular, bees could choose a pattern of two or three blue dots that exactly matched the sample pattern in every way, in order to obtain a sugar reward. The ANOVA tests revealed that the data collected across all blocks and across all bees were homogeneous (p>0.05). The exact p values for each block are summarised in Supporting Table S1. Fig. 2a shows the learning curve of the experimental bees in the six training blocks; performance is seen to plateau at approximately 70% correct choices after the 4th block. Fig. 2b shows the percentage of incorrect second choices following a positive first choice. The percentage of incorrect second choices of the 1st block was 50.0%; this declined to a low 24% by the last block.


Number-based visual generalisation in the honeybee.

Gross HJ, Pahl M, Si A, Zhu H, Tautz J, Zhang S - PLoS ONE (2009)

(a) Learning curve for bees trained on a basic delayed match-to-sample (DMTS) task. Each ‘block’ represents two twenty-minute sessions of training (one for each sample S1 and S2). Bees were considered to be trained in this task when their performance reached a stable plateau (approximately 70% correct choices). n denotes number of bees per condition. Error bars show standard error. *** denotes statistically significant difference at p<0.001, * denotes p<0.05. (b) The incorrect second choices of bees in each of the training blocks, following a positive first choice.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2629729&req=5

pone-0004263-g002: (a) Learning curve for bees trained on a basic delayed match-to-sample (DMTS) task. Each ‘block’ represents two twenty-minute sessions of training (one for each sample S1 and S2). Bees were considered to be trained in this task when their performance reached a stable plateau (approximately 70% correct choices). n denotes number of bees per condition. Error bars show standard error. *** denotes statistically significant difference at p<0.001, * denotes p<0.05. (b) The incorrect second choices of bees in each of the training blocks, following a positive first choice.
Mentions: Over a period of three days, a group of approximately 20 bees were able to learn the basic DMTS paradigm, where they had to match one of two choice patterns to a previously encountered sample pattern (See the experimental apparatus in Fig. 1). In particular, bees could choose a pattern of two or three blue dots that exactly matched the sample pattern in every way, in order to obtain a sugar reward. The ANOVA tests revealed that the data collected across all blocks and across all bees were homogeneous (p>0.05). The exact p values for each block are summarised in Supporting Table S1. Fig. 2a shows the learning curve of the experimental bees in the six training blocks; performance is seen to plateau at approximately 70% correct choices after the 4th block. Fig. 2b shows the percentage of incorrect second choices following a positive first choice. The percentage of incorrect second choices of the 1st block was 50.0%; this declined to a low 24% by the last block.

Bottom Line: Using a y-maze, we found that bees can not only differentiate between patterns containing two and three elements, but can also use this prior knowledge to differentiate three from four, without any additional training.Control experiments confirmed that the bees were not using cues such as the colour of the exact configuration of the visual elements, the combined area or edge length of the elements, or illusory contours formed by the elements.To our knowledge, this is the first report of number-based visual generalisation by an invertebrate.

View Article: PubMed Central - PubMed

Affiliation: Biocentre, University of Würzburg, Würzburg, Germany.

ABSTRACT
Although the numerical abilities of many vertebrate species have been investigated in the scientific literature, there are few convincing accounts of invertebrate numerical competence. Honeybees, Apis mellifera, by virtue of their other impressive cognitive feats, are a prime candidate for investigations of this nature. We therefore used the well-established delayed match-to-sample paradigm, to test the limits of honeybees' ability to match two visual patterns solely on the basis of the shared number of elements in the two patterns. Using a y-maze, we found that bees can not only differentiate between patterns containing two and three elements, but can also use this prior knowledge to differentiate three from four, without any additional training. However, bees trained on the two versus three task could not distinguish between higher numbers, such as four versus five, four versus six, or five versus six. Control experiments confirmed that the bees were not using cues such as the colour of the exact configuration of the visual elements, the combined area or edge length of the elements, or illusory contours formed by the elements. To our knowledge, this is the first report of number-based visual generalisation by an invertebrate.

Show MeSH