Limits...
Ontogeny of numerical abilities in fish.

Bisazza A, Piffer L, Serena G, Agrillo C - PLoS ONE (2010)

Bottom Line: Forty-day old guppies from both treatments were able to discriminate 4 vs. 8 fish while at 20 days this was only observed in fish grown in groups.Control experiments showed that these capacities were maintained after guppies were prevented from using non numerical perceptual variables that co-vary with numerosity.Overall, our results suggest the ability of guppies to discriminate small numbers is innate and is displayed immediately at birth while discrimination of large numbers emerges later as a result of both maturation and social experience.

View Article: PubMed Central - PubMed

Affiliation: Department of General Psychology, University of Padova, Padova, Italy.

ABSTRACT

Background: It has been hypothesised that human adults, infants, and non-human primates share two non-verbal systems for enumerating objects, one for representing precisely small quantities (up to 3-4 items) and one for representing approximately larger quantities. Recent studies exploiting fish's spontaneous tendency to join the larger group showed that their ability in numerical discrimination closely resembles that of primates but little is known as to whether these capacities are innate or acquired.

Methodology/principal findings: We used the spontaneous tendency to join the larger shoal to study the limits of the quantity discrimination of newborn and juvenile guppies. One-day old fish chose the larger shoal when the choice was between numbers in the small quantity range, 2 vs. 3 fish, but not when they had to choose between large numbers, 4 vs. 8 or 4 vs. 12, although the numerical ratio was larger in the latter case. To investigate the relative role of maturation and experience in large number discrimination, fish were raised in pairs (with no numerical experience) or in large social groups and tested at three ages. Forty-day old guppies from both treatments were able to discriminate 4 vs. 8 fish while at 20 days this was only observed in fish grown in groups. Control experiments showed that these capacities were maintained after guppies were prevented from using non numerical perceptual variables that co-vary with numerosity.

Conclusions/significance: Overall, our results suggest the ability of guppies to discriminate small numbers is innate and is displayed immediately at birth while discrimination of large numbers emerges later as a result of both maturation and social experience. This developmental dissociation suggests that fish like primates might have separate systems for small and large number representation.

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Related in: MedlinePlus

Experimental apparatus used in experiment 4a.Subjects could only see one stimulus fish at a time from any position of its compartment. To reduce the access to non-numerical cues, one third of the sample were tested matching the overall space occupied (a), one third matching the density (b) and one third matching the surface from which a fish was visible (c). The apparatus for Exp. 4b was similar but enlarged in size in order to adapt to the larger size of juvenile fish.
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pone-0015516-g005: Experimental apparatus used in experiment 4a.Subjects could only see one stimulus fish at a time from any position of its compartment. To reduce the access to non-numerical cues, one third of the sample were tested matching the overall space occupied (a), one third matching the density (b) and one third matching the surface from which a fish was visible (c). The apparatus for Exp. 4b was similar but enlarged in size in order to adapt to the larger size of juvenile fish.

Mentions: A total of 48 one-day-old fish were used as subjects. Fish were reared in pairs before the test and used only once. The experimental apparatus was similar to that used in a previous study [39] with a closely related species, the eastern mosquitofish, and was composed of a tank subdivided into three adjacent sectors (Fig. 5). The central one, the ‘subject sector’, was an hourglass-shaped sector of 18.5×15.5 cm consisting of a corridor interconnecting two identical choice areas (5×15.5 cm). At the two ends there were two sectors, ‘stimulus sectors’, facing the subject sector. Each stimulus sector (7.5×15.5 cm) was subdivided into 5 identical compartments (6×2.6 cm) by translucent walls that prevented stimuli from seeing each other. Only the three central compartments were used. To avoid the subject seeing more than one stimulus at a time, in each choice area 12 vertical green screens (1.6×6 cm) were placed, set in a grid of 6×2. In this way the subject could only see one stimulus at a time from any position in its sector.


Ontogeny of numerical abilities in fish.

Bisazza A, Piffer L, Serena G, Agrillo C - PLoS ONE (2010)

Experimental apparatus used in experiment 4a.Subjects could only see one stimulus fish at a time from any position of its compartment. To reduce the access to non-numerical cues, one third of the sample were tested matching the overall space occupied (a), one third matching the density (b) and one third matching the surface from which a fish was visible (c). The apparatus for Exp. 4b was similar but enlarged in size in order to adapt to the larger size of juvenile fish.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2991364&req=5

pone-0015516-g005: Experimental apparatus used in experiment 4a.Subjects could only see one stimulus fish at a time from any position of its compartment. To reduce the access to non-numerical cues, one third of the sample were tested matching the overall space occupied (a), one third matching the density (b) and one third matching the surface from which a fish was visible (c). The apparatus for Exp. 4b was similar but enlarged in size in order to adapt to the larger size of juvenile fish.
Mentions: A total of 48 one-day-old fish were used as subjects. Fish were reared in pairs before the test and used only once. The experimental apparatus was similar to that used in a previous study [39] with a closely related species, the eastern mosquitofish, and was composed of a tank subdivided into three adjacent sectors (Fig. 5). The central one, the ‘subject sector’, was an hourglass-shaped sector of 18.5×15.5 cm consisting of a corridor interconnecting two identical choice areas (5×15.5 cm). At the two ends there were two sectors, ‘stimulus sectors’, facing the subject sector. Each stimulus sector (7.5×15.5 cm) was subdivided into 5 identical compartments (6×2.6 cm) by translucent walls that prevented stimuli from seeing each other. Only the three central compartments were used. To avoid the subject seeing more than one stimulus at a time, in each choice area 12 vertical green screens (1.6×6 cm) were placed, set in a grid of 6×2. In this way the subject could only see one stimulus at a time from any position in its sector.

Bottom Line: Forty-day old guppies from both treatments were able to discriminate 4 vs. 8 fish while at 20 days this was only observed in fish grown in groups.Control experiments showed that these capacities were maintained after guppies were prevented from using non numerical perceptual variables that co-vary with numerosity.Overall, our results suggest the ability of guppies to discriminate small numbers is innate and is displayed immediately at birth while discrimination of large numbers emerges later as a result of both maturation and social experience.

View Article: PubMed Central - PubMed

Affiliation: Department of General Psychology, University of Padova, Padova, Italy.

ABSTRACT

Background: It has been hypothesised that human adults, infants, and non-human primates share two non-verbal systems for enumerating objects, one for representing precisely small quantities (up to 3-4 items) and one for representing approximately larger quantities. Recent studies exploiting fish's spontaneous tendency to join the larger group showed that their ability in numerical discrimination closely resembles that of primates but little is known as to whether these capacities are innate or acquired.

Methodology/principal findings: We used the spontaneous tendency to join the larger shoal to study the limits of the quantity discrimination of newborn and juvenile guppies. One-day old fish chose the larger shoal when the choice was between numbers in the small quantity range, 2 vs. 3 fish, but not when they had to choose between large numbers, 4 vs. 8 or 4 vs. 12, although the numerical ratio was larger in the latter case. To investigate the relative role of maturation and experience in large number discrimination, fish were raised in pairs (with no numerical experience) or in large social groups and tested at three ages. Forty-day old guppies from both treatments were able to discriminate 4 vs. 8 fish while at 20 days this was only observed in fish grown in groups. Control experiments showed that these capacities were maintained after guppies were prevented from using non numerical perceptual variables that co-vary with numerosity.

Conclusions/significance: Overall, our results suggest the ability of guppies to discriminate small numbers is innate and is displayed immediately at birth while discrimination of large numbers emerges later as a result of both maturation and social experience. This developmental dissociation suggests that fish like primates might have separate systems for small and large number representation.

Show MeSH
Related in: MedlinePlus