Perceptual awareness and categorical representation of faces: evidence from masked priming

How internal categories influence how we perceive the world is a fundamental question in cognitive sciences. Yet, the relation between perceptual awareness and perceptual categorization has remained largely uncovered so far. Here, we addressed this question by focusing on face perception during subliminal and conscious perception. We used morphed continua between two face identities and we assessed, through a masked priming paradigm, the perceptual processing of these morphed faces under subliminal and supraliminal conditions. We found that priming from subliminal faces followed linearly the information present in the primes, while priming from visible faces revealed a non-linear profile, indicating a categorical processing of face identities. Our results thus point to a special relation between perceptual awareness and categorical processing of faces, and support the dissociation between two modes of information processing: a subliminal mode involving analog treatment of stimuli information, and a supraliminal mode relying on discrete representation.     

Similarity on the rebound: inhibition of similarity assessment leads to an ironic postsuppressional rebound

A widely held but rarely tested assumption among cognitive scientists is that different cognitive tasks may rely upon a single basic cognitive process. Using an established methodology to examine the suppression and subsequent rebound of mental operations, the present research indicates that suppressing use of similarity in one domain results in the subsequent rebound of similarity assessment in a different domain, suggesting that both domains rely on the same underlying cognitive process. In two studies, we demonstrate that leading people to suppress natural similarity assessment in one task produces increased reliance on similarity in subsequent, different, and apparently unrelated tasks. In Experiment 1, participants led to suppress similarity in a concentration task subsequently made more errors in a false-memory paradigm than did control participants. In Experiment 2, participants suppressing similarity in a categorization task made more false-memory errors and perceived more similarity between word pairs than participants who did not suppress. The findings suggest that the cognitive process of similarity assessment may be a domain-general process, such that it is widespread across a number of different mental tasks.     

The relationship between psychological contract breach and organizational commitment: Exchange imbalance as a moderator of the mediating role of violation

This study tested the mediating role of violation in the relationship between breach and both affective and continuance commitment and the extent to which this mediating role is moderated by exchange imbalance amongst a sample of 103 sales personnel. Results suggest that violation mediated the relationship between breach and commitment. Also, results suggest that perceived exchange imbalance moderates this mediating pathway: Low exchange imbalance increases the mediating role of violation in the case of affective commitment. On the other hand, exchange imbalance failed to moderate the mediating influence of violation in the case of continuance commitment. Results are discussed in view of the importance of a) including both measures of violation and breach in future studies and b) the role of social exchange in explaining psychological contract violation.     

Stimulus range and discontinuity effects on information-integration category learning and generalization

Two studies are reported that support the hypothesis that categories that require a multiple-unit, as opposed to a single-unit, representation lead to worse initial acquisition but better generalization. On the basis of the constraints imposed by the procedural-based learning system thought to mediate information-integration categorization, we argue that the need to train multiple units during initial category acquisition slows the procedural-based category learning process and adversely affects learning performance. However, we speculate that better generalization occurs because of the increased likelihood that a novel stimulus will activate at least one of the multiple units needed to represent the category. Relations to other findings in the literature and the implications of this work for training and clinical assessment are discussed.     

Subjective discriminability of invisibility: A framework for distinguishing perceptual and attentional failures of awareness

Conscious visual perception can fail in many circumstances. However, little is known about the causes and processes leading to failures of visual awareness. In this study, we introduce a new signal detection measure termed subjective discriminability of invisibility (SDI) that allows one to distinguish between subjective blindness due to reduction of sensory signals or to lack of attentional access to sensory signals. The SDI is computed based upon subjective confidence in reporting the absence of a target (i.e., miss and correct rejection trials). Using this new measure, we found that target misses were subjectively indistinguishable from physical absence when contrast reduction, backward masking and flash suppression were used, whereas confidence was appropriately modulated when dual task, attentional blink and spatial uncertainty methods were employed. These results show that failure of visual perception can be identified as either a result of perceptual or attentional blindness depending on the circumstances under which visual awareness was impaired.     

Towards defining a unified concept for the acceptability of Intelligent Transport Systems (ITS): A conceptual analysis based on the case of Intelligent Speed Adaptation (ISA)

A key success factor in the future implementation of new in-vehicle technologies is in understanding how users will experience and respond to these devices. Although it is recognized that acceptance, acceptability and/or support is important, consistency in the definition of acceptability, and how it can be measured, is absent. In this paper we conceptualize acceptance as the attitudes towards a new device after its introduction and acceptability as the attitudes to it before its introduction. It is our goal to describe and conceptualize the most common and relevant socio-psychological factors that can influence acceptance and acceptability of Intelligent Speed Adaptation (ISA). By analysing the different theories and methods used in ISA trials we arrived at the 14 most potential indicators that could influence the definition of acceptability and acceptance. A test survey was conducted to determine if these indicators are relevant and if they affect acceptability. The use of a factor analysis helped to single out those questions that were deemed relevant in doing our conceptual acceptability analysis, and to allocate correlations between the different items. We conclude that we have found a concept with some main possible indicators that directly influence the acceptability of ISA.     

Neural enhancement and pre-emptive perception: the genesis of attention and the attentional maintenance of the cortical salience map

One of the stable hypotheses in systems neuroscience is the relationship between attention and the enhancement of visual responses when an animal attends to the stimulus in its receptive field (Goldberg and Wurtz, 1972 Journal of Neurophysiology 35 560-574). This was first discovered in the superior colliculus of the monkey: neurons in the superficial layers of the superior colliculus responded more intensely to the onset of a stimulus during blocks of trials in which the monkey had to make a saccade to it than they did during blocks of trials in which the monkey had to continue fixating a central point and not respond to the stimulus. This enhancement has been found in many brain regions, including prefrontal cortex (Boch and Goldberg, 1987 Investigative Ophthalmology 28 Supplement, 124), V4 (Moran and Desimone, 1985 Science 229 782-784), and lateral intraparietal area (Colby et al, 1996 Journal of Neurophysiology 76 2841-2852; Colby and Goldberg, 1999 Annual Review of Neuroscience 22 319-349), and even V1 (Lamme et al, 2000 Vision Research 40 1507-1521). In these studies the assumption has been that the monkey attended to the stimulus because the stimulus evoked an enhanced response. In the experiments described here we show that for abruptly appearing stimuli, attention is not related to the initial response evoked by the stimulus, but by the activity present on the salience map in the parietal cortex when the stimulus appears. Attention to the stimulus may subsequently, by a top down signal, sustain the map, but stimuli can as easily be suppressed by top down features as they can be enhanced.     

INCOMMENSURABILITY,RELATIVISM, SCEPTICISM: REFLECTIONS ON ACQUIRING A CONCEPT

Some opponents of the incommensurability thesis, such as Davidson and Rorty, have argued that the very idea of incommensurability is incoherent and that the existence of alternative and incommensurable conceptual schemes is a conceptual impossibility. If true, this refutes Kuhnian relativism and Kantian scepticism in one fell swoop. For Kuhnian relativism depends on the possibility of alternative, humanly accessible conceptual schemes that are incommensurable with one another, and the Kantian notion of a realm of unknowable things‐in‐themselves gives rise to the possibility of humanly inaccessible schemes that are incommensurable with even our best current or future science. In what follows we argue that the possibility of incommensurability of either the Kuhnian or the Kantian variety is inescapable and that this conclusion is forced upon us by a simple consideration of what is involved in acquiring a concept. It turns out that the threats from relativism and scepticism are real, and that anyone, including Davidson himself, who has ever defended an account of concept acquisition is committed to one or the other of these two possibilities. 1