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The approximate number system (ANS) is a primitive system used to estimate quantities. It can process quantities in visual and auditory modalities. The aim of the present study was to examine whether ANS can process quantities presented haptically. Moreover, to assess age-related changes, two groups of children (5- and 7-year-olds) were compared. In a newly designed haptic task, children compared two arrays of dots by touching them simultaneously using both hands, without seeing them, and for limited duration to prevent counting. Using Panamath, a frequently used visual ANS task, we verified that our population exhibited the typical pattern of approximation with visual arrays: Older children outperformed younger children, and an increased ratio between the two quantities to be compared led to more accurate responses. Performance in the haptic task revealed that children, in both age-groups, were able to haptically compare two quantities above chance level, with improved performance in older compared with younger children. Moreover, our results revealed a ratio effect, a well-known signature of the ANS. These findings suggest that haptic numerical discrimination in children is dictated by the ANS, and that ANS acuity measured with a haptic task improves with age, as commonly observed with the visual task., (© The Author(s) 2015.)

Recent data show that psychosocial factors affect visual perception. We tested this hypothesis by investigating the relationship between affective closeness and the perception of apertures between two people. People feel discomfort when they are near someone they are not affectively close to. Therefore, we predict that they will be less likely to perceive that they can pass between two people not affectively close to them. Participants had to imagine passing through the aperture between two life-size classmate pictures. We found that the closer participants felt to their classmates, the more they felt able to pass between them. This provides the first evidence of a relationship between affective closeness and the perception of aperture between two people, suggesting that psychosocial factors constrain space perception.

People undeniably pay attention to faces, and facial resemblance may act as a kinship cue. However, previous studies have shown that the ability to detect kinship through facial resemblance is limited, and it has been suggested that this may be due to several types of perceptual factors. To further understand the processes that underpin kinship judgment, it is important to investigate which perceptual factors predict the probability of parent-child pairs being detected as related. To this end, we performed two experiments. In the first, we evaluated the ability of human observers to match newborns with one of their parents. In the second, we explored three perceptual factors that may have influenced kinship detection (gender discrimination, facial attractiveness, and perceptual similarity). Results showed that the participants were able to match newborns with one of their parents, even though the task was perceived as difficult. Moreover, our study goes further than previous findings, showing that the perceptual factors investigated may significantly contribute to kinship detection.

Factors affecting manual discrimination of spatial orientations and orientation preferences in 5-month-old infants have been investigated by using a familiarisation/reaction to novelty procedure. In the first experiment we explored whether the 'vertical preference' observed by Gentaz and Streri (2004 Journal of Cognitive Neuroscience 16 1-7) and Kerzerho et al (2005 Neuro Report 16 1833-1837) is an intrinsic preference or whether it is due to familiarisation. In the second experiment we examined whether the magnitude of angular deviation to the vertical influences the direction of preference. Results showed that when both gravitational vertical and body axes were aligned, the intrinsic 'vertical preference' exists when the angular difference between the two orientations was 10 degrees. When the angular deviation from the vertical was greater than 10 degrees, the novel orientation was preferred. This modification of orientation preference in the manual discrimination of orientation by 5-month-old infants is discussed in relation to the magnitude of the angular deviation to the gravitational vertical and the spatial reference cues available in each condition.

The haptic perception of vertical, horizontal, and diagonal orientations was studied in children (aged 7 and 9 years) and in adults. The purpose was to test the hypothesis that the haptic oblique effect results from the different scanning movements at work when one hand explores an oblique standard and the other hand sets the response rod. In experiment 1, blindfolded subjects reproduced the orientation of a standard rod presented in either the frontal, the horizontal, or the sagittal plane, and this task was achieved either ipsilaterally (the same hand explored the standard and set the response rod) or contralaterally (one hand explored the standard and the other hand set the response rod). Since, in the sagittal plane, scanning movements are analogous when the left and right hands explore oblique orientations, no oblique effect should be observed in this condition if the hypothesis is valid. Moreover, a development effect should be observed, since young children generally rely more on movement coding than do older children and adults. Results did not support these predictions: the same oblique effect appeared in the frontal and the sagittal planes both in the ipsilateral and in the contralateral condition, and the effect of age was not in the direction predicted by the hypothesis. The results were consistent with the hypothesis in the horizontal plane only. Experiments 2 and 3 provided further tests of this hypothesis but both failed to support it. Taken together, the results of these three experiments did not support the assumption and it is suggested that the haptic oblique effect may be linked to the gravitational cues provided by the arm-hand system when it acts in the three spatial planes.