Papers by Nicolas Dupuis-Roy
Fair-division problems are ubiquitous. They range from the day-to-day chore assignments to the Is... more Fair-division problems are ubiquitous. They range from the day-to-day chore assignments to the Israeli-Palestinian conflict and include the division of an inheritance to the heirs . Many intuitive and self-implementable algorithms guaranteeing "fairness" have been devised in the past 50 years . So far, very few empirical studies have put them to the test Schneider & Krämer, 2004). In fact, it is not even known to what extent the solutions derived from these algorithms are satisfactory to human players. Here, we present an experiment that investigated the satisfaction of two pairs of players who divided 10 indivisible goods between themselves. A genetic algorithm was used to search for the best division candidates. Results show that some of the best divisions found by the genetic algorithm were rated as more mutually satisfactory than the ones derived from six typical fair-division algorithms. Analyses on temporal fluctuation and non-additivity of preferences could partially explain this result. Ideas for the future implementation of a more flexible and unconstrained approach are discussed.
Journal of Insect Behavior, 2001
In three experiments, bumble bees were trained to discriminate between a reinforcing pattern (S+)... more In three experiments, bumble bees were trained to discriminate between a reinforcing pattern (S+) and a nonreinforcing one (S−) which differed only in the configuration of four artificial petals. They were subsequently tested for recognition of the S+ rotated by 90° (S + 90). Experiment 1 used petals of four colors, and the other experiments used four symbols. The symbols either remained unchanged when the whole pattern was rotated (e.g., “+” in Experiment 2) or changed appearance (e.g., “<” in Experiment 3). The bees failed to recognize the S + 90 in the first two experiments, but in Experiment 3, the choice proportion for S + 90 in the presence of a New pattern was significantly higher than chance. Bumble bees can recognize a rotated pattern, possibly by using mental rotation, provided that a cue as to the extent of the pattern transformation is given.
In three experiments, bumble bees were trained to discriminate between a reinforcing pattern (S+)... more In three experiments, bumble bees were trained to discriminate between a reinforcing pattern (S+) and a nonreinforcing one (S−) which differed only in the configuration of four artificial petals. They were subsequently tested for recognition of the S+ rotated by 90 • (S + 90). Experiment 1 used petals of four colors, and the other experiments used four symbols. The symbols either remained unchanged when the whole pattern was rotated (e.g., "+" in Experiment 2) or changed appearance (e.g., "<" in Experiment 3). The bees failed to recognize the S + 90 in the first two experiments, but in Experiment 3, the choice proportion for S + 90 in the presence of a New pattern was significantly higher than chance. Bumble bees can recognize a rotated pattern, possibly by using mental rotation, provided that a cue as to the extent of the pattern transformation is given.
The use of spatial frequencies for visual word recognition in each cerebral hemisphere
Journal of Vision, 2010
Abstract A matter of important debate remains regarding whether the range of spatial frequencies ... more Abstract A matter of important debate remains regarding whether the range of spatial frequencies (SFs) preferred by the left cerebral hemisphere is higher than that preferred by the right hemisphere. In visual word recognition, relatively low SFs allow access to coarse ...
A Matlab Toolbox for Classification Image Experiments
Examining the top-down component of perceptual learning
Journal of Vision, 2005
Perceptual learning (PL) has been observed in tasks as dissimilar as pop-out detection (Ahissar &... more Perceptual learning (PL) has been observed in tasks as dissimilar as pop-out detection (Ahissar &amp; Hochstein, 2004), illusory contours shape discrimination (Rubin, Nakayama &amp; Shapley, 2002), face identification (Gold, Bennett &amp; Sekuler, 1999) and visual position ...
The time course of face-gender discrimination: Disentangling the use of color and luminance cues
Journal of Vision, 2010
In a recent study using spatial Bubbles (Dupuis-Roy, et al., 2009), we identified the eyes, the e... more In a recent study using spatial Bubbles (Dupuis-Roy, et al., 2009), we identified the eyes, the eyebrows and the mouth as the most potent features for face-gender discrimination (see also Brown &amp; Perrett, 1993; Russell, 2003, 2005; Yamaguchi, Hirukawa, &amp; Kanazawa, 1995). ...
Vision Research, 2007
Perceptual learning is characterized by an improvement in a perceptual task following practice. S... more Perceptual learning is characterized by an improvement in a perceptual task following practice. Several studies have demonstrated that top-down processes, such as attention and task-related expectations, can be necessary components of perceptual learning [Ahissar ]. Here, we report an experiment that isolated top-down processes in perceptual learning, using a variant of the Gosselin and Schyns (1992) no-signal procedure. Results indicate that top-down processes can be sufficient to produce substantial, possibly long-lasting and rotation-invariant perceptual learning.
Journal of Vision, 2010
Perceptual learning is characterized by an improvement in a perceptual task following practice. S... more Perceptual learning is characterized by an improvement in a perceptual task following practice. Several studies have demonstrated that top-down processes, such as attention and task-related expectations, can be necessary components of perceptual learning [Ahissar ]. Here, we report an experiment that isolated top-down processes in perceptual learning, using a variant of the Gosselin and Schyns (1992) no-signal procedure. Results indicate that top-down processes can be sufficient to produce substantial, possibly long-lasting and rotation-invariant perceptual learning.
Journal of Vision, 2009
Which face cues do we use for gender discrimination? Few studies have tried to answer this questi... more Which face cues do we use for gender discrimination? Few studies have tried to answer this question and the few that have tried typically used only a small set of grayscale stimuli, often distorted and presented a large number of times. Here, we reassessed the importance of facial cues for gender discrimination in a more realistic setting. We applied BubblesVa technique that minimizes bias toward specific facial features and does not necessitate the distortion of stimuliVto a set of 300 color photographs of Caucasian faces, each presented only once to 30 participants. Results show that the region of the eyes and the eyebrowsVprobably in the light-dark channelVis the most important facial cue for accurate gender discrimination; and that the mouth region is driving fast correct responses (but not fast incorrect responses)Vthe gender discrimination information in the mouth region is concentrated in the red-green color channel. Together, these results suggest that, when color is informative in the mouth region, humans use it and respond rapidly; and, when it's not informative, they have to rely on the more robust but more sluggish luminance information in the eye-eyebrow region.
Isolating the top-down component of perceptual learning
Journal of Vision, 2010
Perceptual learning (ie an improvement in performance in a perceptual task following practice) is... more Perceptual learning (ie an improvement in performance in a perceptual task following practice) is known to be driven by low-level, bottom-up processes (eg Crist, Li &amp; Gilbert, 2001; Gold, Bennett &amp; Sekuler, 1999, Karni &amp; Sagi, 1991). It has even been shown to ...
Neuroscience
Sixteen healthy subjects took part in this event-related potentials (ERPs) study aimed at investi... more Sixteen healthy subjects took part in this event-related potentials (ERPs) study aimed at investigating the neural response of the taste-visual cross-modal pairing. An interference effect was observed at the behavioral level: the mismatched condition was performed more slowly than the matched condition. ERP analyses revealed a more negative component between 400 and 600 ms in the mismatched condition than in the matched condition. Dipole source analysis of the difference wave (mismatched minus matched) indicated that two generators localized in prefrontal cortex (PFC) and posterior cingulate cortex (PCC) contributed to this cross-modal interference effect. These results provided the electrophysiological evidence of interference during the extraction of taste information from memory and conflict control during the incongruent taste-visual information processing.▶The taste-visual Pairings task was done for the first time. ▶Mismatched condition elicited a more negative component than did matched one. ▶PFC and PCC contributed to the cross-modal interference.
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Papers by Nicolas Dupuis-Roy