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Visually guided decision making in foraging honeybees.

Zhang S, Si A, Pahl M - Front Neurosci (2012)

Bottom Line: The trained animals learn how to solve a task, and do so with a high accuracy, but when they are presented with a new variation of the task, they apply the learnt rules from the earlier setup to the new situation, and solve the new task as well.Honeybees therefore not only feature a rich behavioral repertoire to choose from, but also make decisions most apt to the current situation.The experiments in this review give an insight into the environmental cues and cognitive resources that are probably highly significant for a forager bee that must continually make decisions regarding patches of resources to be exploited.

View Article: PubMed Central - PubMed

Affiliation: Centre of Excellence in Vision Science, Research School of Biology, The Australian National University Canberra, ACT, Australia.

ABSTRACT
Honeybees can easily be trained to perform different types of discrimination tasks under controlled laboratory conditions. This review describes a range of experiments carried out with free-flying forager honeybees under such conditions. The research done over the past 30 or so years suggests that cognitive abilities (learning and perception) in insects are more intricate and flexible than was originally imagined. It has become apparent that honeybees are capable of a variety of visually guided tasks, involving decision making under challenging situations: this includes simultaneously making use of different sensory modalities, such as vision and olfaction, and learning to use abstract concepts such as "sameness" and "difference." Many studies have shown that decision making in foraging honeybees is highly flexible. The trained animals learn how to solve a task, and do so with a high accuracy, but when they are presented with a new variation of the task, they apply the learnt rules from the earlier setup to the new situation, and solve the new task as well. Honeybees therefore not only feature a rich behavioral repertoire to choose from, but also make decisions most apt to the current situation. The experiments in this review give an insight into the environmental cues and cognitive resources that are probably highly significant for a forager bee that must continually make decisions regarding patches of resources to be exploited.

No MeSH data available.


Number-based decision making in a delayed match-to-sample task. The stimulus below each pair of bars is the sample, and that above each bar is the respective choice stimulus. The data present the pooled first choices of individual bees. (A) The configuration of dots on the sample and choice stimuli is randomized. (B) The blue dots are replaced with yellow stars, to see if bees can transfer their matching ability to different, unknown stimuli. (C) The sample and choice stimuli are composed of two different elements. (D–F) Bees trained to discriminate between two and three are tested on stimuli with (D) three and four elements, (E) four and five elements, (F) five and six elements, (G) four and six elements. n, Number of bees per condition. Error bars show standard error. ***Denotes statistically significant difference at p < 0.001, **Denotes p < 0.01, *denotes p < 0.05, and O denotes p > 0.05. Modified from Gross et al. (2009).
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Figure 15: Number-based decision making in a delayed match-to-sample task. The stimulus below each pair of bars is the sample, and that above each bar is the respective choice stimulus. The data present the pooled first choices of individual bees. (A) The configuration of dots on the sample and choice stimuli is randomized. (B) The blue dots are replaced with yellow stars, to see if bees can transfer their matching ability to different, unknown stimuli. (C) The sample and choice stimuli are composed of two different elements. (D–F) Bees trained to discriminate between two and three are tested on stimuli with (D) three and four elements, (E) four and five elements, (F) five and six elements, (G) four and six elements. n, Number of bees per condition. Error bars show standard error. ***Denotes statistically significant difference at p < 0.001, **Denotes p < 0.01, *denotes p < 0.05, and O denotes p > 0.05. Modified from Gross et al. (2009).

Mentions: Numerical abilities are an important marker in the cognitive abilities of an animal. So far, mainly vertebrate species like pigeons (Koehler, 1941) and monkeys (Brannon and Terrace, 2000) have been tested for the ability to make number-based decisions, and few convincing accounts for invertebrates exist so far (Chittka and Geiger, 1995; Franks et al., 2006; Dacke and Srinivasan, 2008). Gross et al. (2009) set out to shift the balance more in favor of the invertebrates. Honeybees, by virtue of their other impressive cognitive features, are prime candidates for investigations of this nature. Using the DMTS paradigm, the limits of the bees’ ability to match two visual stimuli solely on the basis of the shared number of present elements were tested. After the experimental animals had learned the basic DMTS task in a modified Y-maze, they were able to discriminate patterns containing two or three elements. To make sure that the experimental bees were indeed using the amount of objects on a stimulus to make a decision, a series of experiments was carried out. Firstly, to exclude direct visual matching of the stimuli, the positions of the objects in sample and matching stimuli was randomized. The bees could still match two and three in all configurations (Figure 15A). The next step was to present the bees with novel objects, which they had never seen before in training. The animals solved this task very well, demonstrating the ability to transfer the matching rule even to novel objects (Figure 15B). In the following experiment, the bees’ ability to generalize over different objects was tested by using blue dots in the sample stimulus, and yellow lemons in the matching stimulus (Figure 15C). Even in this configuration, the bees had no trouble matching the stimuli based on number. When the bees were tested on a novel numerosity, a four to four match, the performance dropped significantly. In the three vs four configuration shown in Figure 15D, the bees could still do the three to three match, but their decisions in the four to four match were randomly distributed in two out of three experiments. In the experiments on the discrimination of higher object numbers, such as four vs five (Figure 15E) and five vs six (Figure 15F), the decisions were randomly distributed. Interestingly, when the bees were tested in a four vs six discrimination task, they were able to do the four to four match, but not the six to six match (Figure 15G). Thus, the bees’ numerosity discrimination ability does not follow Weber’s law, indicating that the animals are using absolute number, and not relative amount of objects, to discriminate between the stimuli. A series of control experiments confirmed that the bees were not using lower order cues such as the color or configuration of elements, combined area, or edge lengths of elements, spatial frequency of the stimuli, or illusory contours formed by the elements.


Visually guided decision making in foraging honeybees.

Zhang S, Si A, Pahl M - Front Neurosci (2012)

Number-based decision making in a delayed match-to-sample task. The stimulus below each pair of bars is the sample, and that above each bar is the respective choice stimulus. The data present the pooled first choices of individual bees. (A) The configuration of dots on the sample and choice stimuli is randomized. (B) The blue dots are replaced with yellow stars, to see if bees can transfer their matching ability to different, unknown stimuli. (C) The sample and choice stimuli are composed of two different elements. (D–F) Bees trained to discriminate between two and three are tested on stimuli with (D) three and four elements, (E) four and five elements, (F) five and six elements, (G) four and six elements. n, Number of bees per condition. Error bars show standard error. ***Denotes statistically significant difference at p < 0.001, **Denotes p < 0.01, *denotes p < 0.05, and O denotes p > 0.05. Modified from Gross et al. (2009).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376410&req=5

Figure 15: Number-based decision making in a delayed match-to-sample task. The stimulus below each pair of bars is the sample, and that above each bar is the respective choice stimulus. The data present the pooled first choices of individual bees. (A) The configuration of dots on the sample and choice stimuli is randomized. (B) The blue dots are replaced with yellow stars, to see if bees can transfer their matching ability to different, unknown stimuli. (C) The sample and choice stimuli are composed of two different elements. (D–F) Bees trained to discriminate between two and three are tested on stimuli with (D) three and four elements, (E) four and five elements, (F) five and six elements, (G) four and six elements. n, Number of bees per condition. Error bars show standard error. ***Denotes statistically significant difference at p < 0.001, **Denotes p < 0.01, *denotes p < 0.05, and O denotes p > 0.05. Modified from Gross et al. (2009).
Mentions: Numerical abilities are an important marker in the cognitive abilities of an animal. So far, mainly vertebrate species like pigeons (Koehler, 1941) and monkeys (Brannon and Terrace, 2000) have been tested for the ability to make number-based decisions, and few convincing accounts for invertebrates exist so far (Chittka and Geiger, 1995; Franks et al., 2006; Dacke and Srinivasan, 2008). Gross et al. (2009) set out to shift the balance more in favor of the invertebrates. Honeybees, by virtue of their other impressive cognitive features, are prime candidates for investigations of this nature. Using the DMTS paradigm, the limits of the bees’ ability to match two visual stimuli solely on the basis of the shared number of present elements were tested. After the experimental animals had learned the basic DMTS task in a modified Y-maze, they were able to discriminate patterns containing two or three elements. To make sure that the experimental bees were indeed using the amount of objects on a stimulus to make a decision, a series of experiments was carried out. Firstly, to exclude direct visual matching of the stimuli, the positions of the objects in sample and matching stimuli was randomized. The bees could still match two and three in all configurations (Figure 15A). The next step was to present the bees with novel objects, which they had never seen before in training. The animals solved this task very well, demonstrating the ability to transfer the matching rule even to novel objects (Figure 15B). In the following experiment, the bees’ ability to generalize over different objects was tested by using blue dots in the sample stimulus, and yellow lemons in the matching stimulus (Figure 15C). Even in this configuration, the bees had no trouble matching the stimuli based on number. When the bees were tested on a novel numerosity, a four to four match, the performance dropped significantly. In the three vs four configuration shown in Figure 15D, the bees could still do the three to three match, but their decisions in the four to four match were randomly distributed in two out of three experiments. In the experiments on the discrimination of higher object numbers, such as four vs five (Figure 15E) and five vs six (Figure 15F), the decisions were randomly distributed. Interestingly, when the bees were tested in a four vs six discrimination task, they were able to do the four to four match, but not the six to six match (Figure 15G). Thus, the bees’ numerosity discrimination ability does not follow Weber’s law, indicating that the animals are using absolute number, and not relative amount of objects, to discriminate between the stimuli. A series of control experiments confirmed that the bees were not using lower order cues such as the color or configuration of elements, combined area, or edge lengths of elements, spatial frequency of the stimuli, or illusory contours formed by the elements.

Bottom Line: The trained animals learn how to solve a task, and do so with a high accuracy, but when they are presented with a new variation of the task, they apply the learnt rules from the earlier setup to the new situation, and solve the new task as well.Honeybees therefore not only feature a rich behavioral repertoire to choose from, but also make decisions most apt to the current situation.The experiments in this review give an insight into the environmental cues and cognitive resources that are probably highly significant for a forager bee that must continually make decisions regarding patches of resources to be exploited.

View Article: PubMed Central - PubMed

Affiliation: Centre of Excellence in Vision Science, Research School of Biology, The Australian National University Canberra, ACT, Australia.

ABSTRACT
Honeybees can easily be trained to perform different types of discrimination tasks under controlled laboratory conditions. This review describes a range of experiments carried out with free-flying forager honeybees under such conditions. The research done over the past 30 or so years suggests that cognitive abilities (learning and perception) in insects are more intricate and flexible than was originally imagined. It has become apparent that honeybees are capable of a variety of visually guided tasks, involving decision making under challenging situations: this includes simultaneously making use of different sensory modalities, such as vision and olfaction, and learning to use abstract concepts such as "sameness" and "difference." Many studies have shown that decision making in foraging honeybees is highly flexible. The trained animals learn how to solve a task, and do so with a high accuracy, but when they are presented with a new variation of the task, they apply the learnt rules from the earlier setup to the new situation, and solve the new task as well. Honeybees therefore not only feature a rich behavioral repertoire to choose from, but also make decisions most apt to the current situation. The experiments in this review give an insight into the environmental cues and cognitive resources that are probably highly significant for a forager bee that must continually make decisions regarding patches of resources to be exploited.

No MeSH data available.