The importance of feature distribution and correlation for simulating 3 to 4-month-old infants' visual categorization processes

Mareschal, French, and Quinn (2000) and Mareschal, Quinn, and French (2002) have proposed a connectionist model of visual categorization in 3- to 4-month-old infants that simulates and predicts previously unexplained behavioural effects such as the asymmetric categorization effect (French, Mareschal, Mermillod, & Quinn, 2004). In the current paper, we show that the model's ability to simulate the asymmetry depends on the correlational structure of the stimuli. These results are important given that adults (Anderson & Fincham, 1996) as well as infants (Younger & Cohen, 1986) are able to rely on correlation information to perform visual categorization. At a behavioural level, the current paper suggests that pure bottom-up processes, based on the correlational structure of the categories, could explain the disappearance of the asymmetry in older 10-month-old infants (Furrer & Younger, 2005). Moreover, our results also raise new challenges for visual categorization models that attempt to simulate the shift from asymmetric categorization in 3- to 4-month-old to symmetric categorization in 10-month-old infants (Shultz & Cohen, 2004; Westermann & Mareschal, 2004, 2012).     

Reference frames and haptic perception of orientation: Body and head tilt effects on the oblique effect

The aim of this study was to examine the effect of body and head tilts on the haptic oblique effect. This effect reflects the more accurate processing of vertical and horizontal orientations, relative to oblique orientations. Body or head tilts lead to a mismatch between egocentric and gravitational axes and indicate whether the haptic oblique effect is defined in an egocentric or a gravitational reference frame. The ability to reproduce principal (vertical and horizontal) and oblique orientations was studied in upright and tilted postures. Moreover, by controlling the deviation of the haptic subjective vertical provoked by postural tilt, the possible role of a subjective gravitational reference frame was tested. Results showed that the haptic reproduction of orientations was strongly affected by both the position of the body (Experiment 1) and the position of the head (Experiment 2). In particular, the classical haptic oblique effect observed in the upright posture disappeared in tilted conditions, mainly because of a decrease in the accuracy of the vertical and horizontal settings. The subjective vertical appeared to be the orientation reproduced the most accurately. These results suggest that the haptic oblique effect is not purely gravitationally or egocentrically defined but, rather, depends on a subjective gravitational reference frame that is tilted in a direction opposite to that of the head in tilted postures (Experiment 3).     

Two conceptions of subjective experience

Do philosophers and ordinary people conceive of subjective experience in the same way? In this article, we argue that they do not and that the philosophical concept of phenomenal consciousness does not coincide with the folk conception. We first offer experimental support for the hypothesis that philosophers and ordinary people conceive of subjective experience in markedly different ways. We then explore experimentally the folk conception, proposing that for the folk, subjective experience is closely linked to valence. We conclude by considering the implications of our findings for a central issue in the philosophy of mind, the hard problem of consciousness.     

If Folk Intuitions Vary,Then What?

We have recently presented evidence for cross‐cultural variation in semantic intuitions and explored the implications of such variation for philosophical arguments that appeal to some theory of reference as a premise. Devitt (2011) and Ichikawa and colleagues (forthcoming) offer critical discussions of the experiment and the conclusions that can be drawn from it. In this response, we reiterate and clarify what we are really arguing for, and we show that most of Devitt’s and Ichikawa and colleagues’ criticisms fail to address our concerns.     

Adults and 5‐year‐old children draw rectangles and triangles around a prototype but not in the golden ratio

This study uses a production task to probe the representations of two geometrical shape categories (rectangles and triangles) in adults and children before the onset of geometry instruction. We specifically assessed whether drawings of these shapes would average around a prototype and whether the prototypical side‐length ratio of the shapes would be situated in the range of the ‘golden ratio’, as it has been reported in the perception domain. We asked 78 adults and 68 five‐year‐old children to draw one rectangle and one triangle. In both populations, the prototypical rectangle was horizontally oriented with a ratio between sides superior to the ‘golden’ value of 1.62. For the triangle, both children and adults tended to produce horizontal acute isosceles triangles with a ratio inferior to the golden value. These findings suggest that adults’ and children's shape categories of triangles and rectangles are organized around a prototypical shape, but the characteristics of this prototype may differ to a certain extent with the ones observed in previous perceptual tasks. Implications of this perception/production dissociation for length concept development, as well as the potential origins of these prototypes are discussed.     

The perception and representation of orientations: A study in the haptic modality

This research examines the haptic perception of orientations in the frontal plane in order to identify the nature of their representation. Blindfolded participants inserted the tip of the index finger into a thimble mounted on the extremity of a haptic interface and manually explored the orientation of a "virtual rod". After a short delay, participants had to reproduce the scanned orientation with the same hand without the guidance of the virtual rod. The analysis of the systematic errors showed that the recalled orientations were markedly biased toward the nearest diagonal in each quadrant with the exception of the orientations nearest to the vertical, which were biased toward the vertical. The variable error was greater for the oblique orientations than for the horizontal or vertical orientation. These results are interpreted with the Category-Adjustment model, which posits that orientations are categorically represented. We show that it is necessary to assume the existence of vertical and horizontal categories in addition to the previously postulated oblique categories to predict the error patterns observed in the present and former studies. The similarity of the error patterns in the visual and haptic modalities suggests that a common mechanism is at play in perceiving and reproducing orientations in both sensory modalities.     

Concept empiricism: a methodological critique

Thanks to Barsalou's, Damasio's, Glenberg's, Prinz' and others' work, neo-empiricism is gaining a deserved recognition in the psychology and philosophy of concepts. I argue, however, that neo-empiricists have underestimated the difficulty of providing evidence against the amodal approach to concepts and higher cognition. I highlight three key problems: the difficulty of sorting out amodal predictions from neo-empiricist predictions, the difficulty of finding experimental tasks that are not best solved by imagery and the difficulty of generalizing findings concerning a given cognitive process in a given context to other cognitive processes or other contexts. Finally, solutions to these three problems are considered.     

The intuitive is a red herring

In this article, we discuss critically some of the key themes in Max Deutsch’s excellent book, The Myth of the Intuitive. We focus in particular on the shortcomings of his historical analysis – a missed opportunity by our lights, on the claim that philosophers present arguments in support of the judgments elicited by thought experiments, and on the claim that experimental philosophy is only relevant for the methodology of philosophy if thought experiments elicit intuitions.