ORCID Profile
0000-0002-1784-3050
Current Organisation
Université Paris Descartes
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.CONCOG.2016.08.011
Abstract: Artificial Intelligence is at a turning point, with a substantial increase in projects aiming to implement sophisticated forms of human intelligence in machines. This research attempts to model specific forms of intelligence through brute-force search heuristics and also reproduce features of human perception and cognition, including emotions. Such goals have implications for artificial consciousness, with some arguing that it will be achievable once we overcome short-term engineering challenges. We believe, however, that phenomenal consciousness cannot be implemented in machines. This becomes clear when considering emotions and examining the dissociation between consciousness and attention in humans. While we may be able to program ethical behavior based on rules and machine learning, we will never be able to reproduce emotions or empathy by programming such control systems-these will be merely simulations. Arguments in favor of this claim include considerations about evolution, the neuropsychological aspects of emotions, and the dissociation between attention and consciousness found in humans. Ultimately, we are far from achieving artificial consciousness.
Publisher: BMJ
Date: 09-2004
Publisher: Elsevier BV
Date: 02-2015
DOI: 10.1016/J.VISRES.2014.12.014
Abstract: This study examines the encoding of multiple object locations into spatial memory by comparing localization accuracy for stimuli presented at different exposure durations. Participants in the longest duration condition viewed masked displays containing 1-10 discs for 1-10 s (durations typically used in simple span tasks), and then reported the locations of these discs on a blank screen. Compared to conditions that presented the same stimuli briefly for 50 or 200 ms (exposures more typical of simultaneous spatial arrays), localization accuracy did not improve significantly under longer viewing durations. Additionally, a clustering analysis found that responses were spread among different clusters of discs and not focused on in idual clusters, regardless of viewing duration. A second experiment tested this performance for displays containing two distinct clusters of discs to determine if clearly grouped subsets of objects would improve performance, but there was no substantial improvement for these two-cluster displays when compared to displays with one cluster. Overall, the results indicate that spatial information for a set of objects is extracted globally and quickly, with little benefit from extended encoding durations that should have favored some deliberative form of grouping. Such results cast doubt on the validity of Corsi blocks or equivalent common neuropsychological tests purportedly designed to evaluate specifically spatial short-term memory spans.
Publisher: Springer Science and Business Media LLC
Date: 06-11-2010
DOI: 10.3758/S13414-010-0030-5
Abstract: The fast and accurate enumeration of a small set of objects, called subitizing, is thought to involve a different mechanism from other numerosity judgments, such as those based on estimation. In this report, we examine the subitizing limit using a novel enumeration task that obtained the perceived locations of enumerated objects. Observers were shown brief masked displays (50, 200, and 350 ms) of 2-9 small black discs randomly placed on a gray screen and then asked to place a marker where each disc had been located. The number of these markers provided an estimate of the number of items processed. This "pointing" methodology enabled observers to accurately "enumerate" displays containing up to six items in contrast with the four-item limit typically found when using standard reporting methods (and replicated here in Experiment 2). These results suggest a different account of the limits found in most subitizing and enumeration studies.
Publisher: No Publisher Supplied
Date: 2011
DOI: 10.7282/T39P310B
Publisher: Springer Science and Business Media LLC
Date: 09-09-2014
DOI: 10.3758/S13423-014-0718-Y
Abstract: This paper aims to clarify the relationship between consciousness and attention through theoretical considerations about evolution. Specifically, we will argue that the empirical findings on attention and the basic considerations concerning the evolution of the different forms of attention demonstrate that consciousness and attention must be dissociated regardless of which definition of these terms one uses. To the best of our knowledge, no extant view on the relationship between consciousness and attention has this advantage. Because of this characteristic, this paper presents a principled and neutral way to settle debates concerning the relationship between consciousness and attention, without falling into disputes about the meaning of these terms. A decisive conclusion of this approach is that extreme views on the relationship between consciousness and attention must be rejected, including identity and full dissociation views. There is an overlap between the two within conscious attention, but developing a full understanding of this mechanism requires further empirical investigations.
Publisher: Springer Science and Business Media LLC
Date: 23-02-2018
DOI: 10.3758/S13414-018-1492-0
Abstract: The double-drift stimulus produces a strong shift in apparent motion direction that generates large errors of perceived position. In this study, we tested the effect of attentional load on the perceptual estimates of motion direction and position for double-drift stimuli. In each trial, four objects appeared, one in each quadrant of a large screen, and they moved upward or downward on an angled trajectory. The target object whose direction or position was to be judged was either cued with a small arrow prior to object motion (low attentional load condition) or cued after the objects stopped moving and disappeared (high attentional load condition). In Experiment 1, these objects appeared 10° from the central fixation, and participants reported the perceived direction of the target's trajectory after the stimulus disappeared by adjusting the direction of an arrow at the center of the response screen. In Experiment 2, the four double-drift objects could appear between 6 ° and 14° from the central fixation, and participants reported the location of the target object after its disappearance by moving the position of a small circle on the response screen. The errors in direction and position judgments showed little effect of the attentional manipulation-similar errors were seen in both experiments whether or not the participant knew which double-drift object would be tested. This suggests that orienting endogenous attention (i.e., by only attending to one object in the precued trials) does not interact with the strength of the motion or position shifts for the double-drift stimulus.
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 07-2015
DOI: 10.1167/15.9.1
Abstract: Various studies have identified systematic errors, such as spatial compression, when observers report the locations of objects displayed around the time of saccades. Localization errors also occur when holding spatial representations in visual working memory. Such errors, however, have not been examined in the context of eye blinks. In this study, we examined the effects of blinks and saccades when observers reproduced the locations of a set of briefly presented, randomly placed discs. Performance was compared with a fixation-only condition in which observers simply held these representations in working memory for the same duration this allowed us to elucidate the relationship between the perceptual phenomena related to blinks, saccades, and visual working memory. Our results indicate that the same amount of spatial compression is experienced prior to a blink as is experienced in the control fixation-only condition, suggesting that blinks do not increase compression above that occurring from holding a spatial representation in visual memory. Saccades, however, tend to increase these compression effects and produce translational shifts both toward and away from saccade targets (depending on the time of the saccade onset in relation to the stimulus offset). A higher numerosity recall capacity was also observed when stimuli were presented prior to a blink in comparison with the other conditions. These findings reflect key differences underlying blinks and saccades in terms of spatial compression and translational shifts. Such results suggest that separate mechanisms maintain perceptual stability across these visual events.
Publisher: BMJ
Date: 06-2003
DOI: 10.1136/TC.12.2.184
Abstract: About 81% of cigarette manufacturers' marketing expenditures in the USA is spent to promote cigarette sales in stores. Relatively little is known about how these expenditures help the manufacturers achieve their marketing goals in stores. A better understanding of how tobacco companies influence the retail environment would help researchers and tobacco control activists to monitor industry presence in stores. To describe the types of tobacco company incentive programmes offered to retailers, how these programmes impact the store environments, and possible visual indicators of retailer participation in incentive programmes. In-depth qualitative interviews with a convenience s le of 29 tobacco retailers were conducted in 2001. USA. The types and requirements of retailer incentive programmes provided by tobacco companies, and how participation in a programme alters their stores. The retailers provided insights into how tobacco companies convey promotional allowances and special offers to them and how these incentives shape the retail environment. Retailers noted that tobacco companies exert substantial control over their stores by requiring placement of products in the most visible locations, and of specific amounts and types of advertising in prime locations in the store. Retailers also described how tobacco companies reduce prices by offering them volume based discounts, "buy two, get one free" specials, and "buying down" the price of existing product. Tobacco companies are concentrating their marketing dollars at the point-of-sale to the extent that the store is their primary communication channel with customers. As a result, all shoppers regardless of age or smoking status are exposed to pro-smoking messages. Given the financial resources spent by tobacco companies in stores, this venue warrants closer scrutiny by researchers and tobacco control advocates.
Publisher: Informa UK Limited
Date: 2008
Publisher: American Psychological Association (APA)
Date: 12-06-2023
DOI: 10.1037/CNS0000363
Publisher: Frontiers Media SA
Date: 2013
Publisher: No Publisher Supplied
Date: 2008
DOI: 10.7282/T34X5853
Publisher: Springer Science and Business Media LLC
Date: 04-10-2011
DOI: 10.3758/S13414-011-0204-9
Abstract: It has been proposed that the mechanism that supports the ability to keep track of multiple moving objects also supports subitizing--the ability to quickly and accurately enumerate a small set of objects. To test this hypothesis, we investigated the effects on subitizing when human observers were required to perform a multiple object tracking task and an enumeration task simultaneously. In three experiments, participants (Exp. 1, N = 24 Exp. 2, N = 11 Exp. 3, N = 37) enumerated sets of zero to nine squares that were flashed while they tracked zero, two, or four moving discs. The results indicated that the number of items participants could subitize decreased by one for each item they tracked. No such pattern was seen when the enumeration task was paired with an equally difficult, but nonvisual, working memory task. These results suggest that a shared visual mechanism supports multiple object tracking and subitizing.
Publisher: The Royal Society
Date: 25-02-2019
Publisher: Informa UK Limited
Date: 11-2008
Publisher: SAGE Publications
Date: 10-11-2020
Abstract: In the visual quartet, alternating diagonal pairs of dots produce apparent motion horizontally or vertically, depending on proximity. Here, we studied a tactile quartet where vibrating tactors were attached to the thumbs and index fingers of both hands. Apparent motion was felt either within hands (from index finger to thumb) or between hands. Participants adjusted the distance between their hands to find the point where motion changed directions. Surprisingly, switchovers occurred when between-hand distances were as much as twice that of within-hand distances—a general bias that was also found for tactile judgments of static distances. This expansion of within-hand felt distances was again seen when lights were placed on the hands rather than vibrating tactors. Importantly, switchover points were similar when the hands were placed at different depths, indicating that representations governing tactile motion were in perceptual three-dimensional space, not retinal two-dimensional space. This was true whether the quartets were visual stimuli on the hands or were purely visual on a monitor, suggesting that proximity is generally determined in three-dimensional coordinates for motion perception. Finally, the similarity of visual and tactile results suggests a common computation for apparent motion, albeit with different built-in distance biases for separate modalities.
Publisher: Walter de Gruyter GmbH
Date: 02-2017
DOI: 10.1515/REVNEURO-2016-0067
Abstract: Here, we provide a review of behavioural, cognitive, and neural studies of the thalamus, including its role in attention, consciousness, sleep, and motor processes. We further discuss neuropsychological and brain disorders associated with thalamus function, including Parkinson’s disease, Alzheimer’s disease, Korsakoff’s syndrome, and sleep disorders. Importantly, we highlight how thalamus-related processes and disorders can be explained by the role of the thalamus as a relay station.
Publisher: SAGE Publications
Date: 02-2003
Abstract: The present study examined smoking culture and lifestyle Web sites listed on Yahoo!, a popular Internet search catalog, to determine whether the sites were easily accessible to youth, featured age or health warnings, and mentioned specific tobacco brands. A content analysis of photographs on these sites assessed the demographics of in iduals depicted and the amount of smoking and nudity in the photographs. The s le included 30 Web sites, all of which were accessible to youth and did not require age verification services to enter them. Cigarette brand names were mentioned in writing on 35% of the sites, and brand images were present on 24% of the sites. Nearly all of the photographs (95%) depicted smoking, 92% featured women, and 7% contained partial or full nudity. These results underscore the need for greater research and monitoring of smoking-related Internet content by health educators and tobacco control advocates.
Location: United States of America
No related grants have been discovered for Harry Haladjian.