Individual-level consistency of different laterality measures in the goldbelly topminnow.

Abstract

In humans, hemispheric language dominance is, to some degree, associated with handedness. Significant associations have been reported between several other lateralized functions. Much less is known about the organization of cerebral asymmetries in nonhuman species and, in particular, whether the presence of reversed asymmetry of one function is associated with a reversal of other lateralized functions or, instead, if cognitive functions lateralize independently. In this study, we compare four measures of sensory and motor laterality in the same individuals in a sample of goldbelly topminnows. A significant association was found between two measures of eye preference and two measures of motor laterality, but sensory and motor asymmetries were uncorrelated. We found interesting that individuals preferring to examine a predator with the right eye tended to use the left eye to look at a shoal mate and the reverse was true for fish that monitored predators with the left eye. This complementarity of functions could be adaptively advantageous for a small social fish, because it allows an individual to monitor the movements of its shoal mates with one eye as the other eye remains free to scan the surroundings for the presence of predators.

Detecting behavioural lateralisation in Poecilia reticulata is strongly dependent on experimental design

“…Previous investigation in Girardinus falcatus has identified a negative association in visual laterality between two methods (quasicircular mirror maze assay and detour assay with predator valence: r = − 0.440) and motor laterality between two methods (spontaneous turns in the dark and rotational preference: r = − 0.341). However, no relationship was identified between these types of lateralisation (r = − 0.068-0.167) (Dadda et al 2012). The social 'visual' quasi-circular mirror maze assay, which was found to produce lateralisation indexes uncorrelated with those from either 'motor' assay in our study, demonstrated a greatly reduced level of variation between individuals and no apparent asymmetry in monocular eye-use.…”

Laterality enhances numerical skills in the guppy, Poecilia reticulata

“…There are two lines of reasoning that allow us to discount this possibility. Firstly, previous studies have shown strong associations between various tests of laterality in this and other species (Dadda et al, 2012 ). Thus the outcome would likely to have been the same even if we had examined laterality using an alternative assay (Bisazza et al, 1997 ).…”

“…Seventy subjects were observed in this test. We employed the same apparatus described elsewhere (Dadda et al, 2012 ; Figure 1A ). Briefly, the fish was placed in a clear cylinder in the center of an octagonal tank with mirrored walls.…”

Lateralization correlates with individual differences in inhibitory control in zebrafish

“…However, hemispheric use is task dependent [24], and we measured social lateralization [14,16]. This is expected to correlate with inhibitory control lateralization, but it does not necessarily predict the hemisphere involved [15]. Patterns of neural activity, which can be measured in larvae, are necessary to answer this question.…”

“…Therefore, we measured it using a social task. Because lateralization of different cognitive functions is correlated in individuals [15,16], our social lateralization measure provided a proxy for overall individual differences in lateralization, including those of inhibitory control functions. Zebrafish were observed for 20 min in an octagonal apparatus with mirror walls (electronic supplementary material, figure S1).…”