Hand preference on unimanual and bimanual tasks in strepsirrhines: The case of the ring‐tailed lemur (Lemur catta)

Abstract

Assessing manual lateralization in non-human primates could be an optimal way to understand the adaptive value of this asymmetry in humans. Though many studies have investigated hand preferences in Old and New World monkeys and apes, fewer studies have considered manual lateralization in strepsirrhines, especially in experimental tasks. This study investigated hand preferences for a unimanual and a bimanual task of 17 captive ring-tailed lemurs (Lemur catta), housed at Parco Natura Viva (VR), Italy. The effect of age on handedness has been also investigated. The lemurs were tested on a unimanual task, in which subjects were restricted to using one hand to retrieve the food inside an apparatus, and on a bimanual task, in which lemurs had to use one hand to keep the apparatus door open while reaching with the other hand to retrieve the food inside it. At the population-level, our results revealed an asymmetrical hand use distribution, in particular a bias toward a right hand preference for food reaching in both the unimanual and the bimanual tasks. Furthermore, at the individual-level, the bimanual task seems to elicit a greater hand preference than the unimanual task. Results of this study underline the importance of experimental tasks in determining hand preference in strepsirrhines. Furthermore, as bimanual tasks elicited a stronger degree of lateralization, they appear to be more suited to investigate manual laterality. Finally, findings from this study highlight the presence of a right hand preference in ring-tailed lemurs, shedding new light on the evolution of human right handedness. Am. J. Primatol. 78:851-860, 2016. © 2016 Wiley Periodicals, Inc.

Hand preferences and differences in extractive foraging in seven capuchin monkey species

“…In the last decades, studies evaluating hand preference in non‐human primates have increased greatly, both in captive and wild populations, and various authors suggested that a right hand bias at the population level does occur in non‐human primates (Hopkins et al, ; Humle & Matsuzawa, ; Llorente et al, ; Lonsdorf & Hopkins, ; Molesti, Vauclair, & Meguerditchian, ; Neufuss, Humle, Cremaschi, & Kivell, ; Poindexter, Reinhardt, Nijman, & Nekaris, in press; Regaiolli, Spiezio, & Hopkins, , 2018; Spinozzi, Castorina, & Truppa, ; Tabiowo & Forrester, ), but this right hand bias is not as strong and stable across different tasks as in humans (Cashmore, Uomini, & Chapelain, ; Marchant & McGrew, ). Other studies, however, with the same and different species report that lateralization in hand preference occurs only at an individual level (Brand et al, ; Leca, Gunst, & Huffman, ; Lilak & Phillips, ; Marchant & McGrew, ; Meunier & Vauclair, ; Papademetriou, Sheu, & Michel, ; Westergaard & Suomi, ).…”

“…The tube task consists of a tube of PVC, with variable dimensions depending on the studied species, that requires coordinated bimanual actions, that is, the primate holds the tube with one hand and uses a finger of the opposite hand, to retrieve a food reward from inside the tube. The tube task is considered a reliable and appropriate task for investigating manual asymmetries that allows consistent comparisons to be made among non‐human primates (Hopkins et al, ; Maille, Belboc'h, Rossard, Bec, & Blois‐Heulin, ; Regaiolli et al, ). Moreover, in non‐human primates the tube task has been shown to elicit hand preference that is associated with neuroanatomical asymmetry within the primary motor cortex in chimpanzees and capuchin monkeys (Hopkins & Cantalupo, ; Phillips & Sherwood, ).…”

年龄、性别与行为任务对野生川金丝猴手偏好的影响

“…In humans, strong lateralization in handedness was found early and was considered the most obvious example of cerebral lateralization and an exclusive characteristic (Perelle & Ehrman, 2005). Over the past 20 years, however, numerous systematic investigations of handedness in non-human primates (NHP) have been published (Regaiolli et al, 2016). Interestingly, these studies have not shown a similar strong hand preference in NHP as observed in humans, with contradictory findings reported thus far (Regaiolli et al, 2018).…”

Slow lorises (Nycticebusspp.) display evidence of handedness in the wild and in captivity

“…The roots of motor asymmetries can be traced back to early vertebrates (Vallortigara, Rogers, & Bisazza, 1999). To uncover the root of this asymmetry, researchers investigated handedness and laterality in invertebrates and vertebrates including non-human primates (MacNeilage, Neufuss et al, 2015;Regaiolli, Spiezio, & Hopkins, 2016a;Regaiolli, Spiezio, & Vallortigara 2016b;Wiper, 2017). Hopkins (2013) suggested that the lack of universal handedness in primates compared to humans was related to a qualitative difference in the way behavioural and brain asymmetries are expressed.…”

“…Studies on strepsirrhines have covered lemur species (e.g. Nelson, O'Karma, Ruperti, & Novak, 2009;Regaiolli et al, 2016a;Schnoell et al, 2014), galagos (e.g. Dodson, Stafford, Forsythe, Seltzer, & Ward, 1992;Sanford, Guin, & Ward, 1984) and pottos (Karberger, 1980), using both spontaneous and experimental conditions in both unimanual and bimanual tasks though primarily were tested in captive settings (e.g.…”