This essay defends the claim that endogenous attention is necessary for the justification of perceptual beliefs. I criticize the so-called phenomenal approach, according to which perceptual experiences provide justification in virtue of being phenomenally conscious. I specifically target Siegel and Silins’ (2014 ; 2019) version of the phenomenal approach. As against their view, I claim that perceptual justification cannot be understood without reference to the cognitive mechanisms which underlie the mobilization of reasons in support of propositional attitudes – attention being (...) instrumental to those very mechanisms. Relying on the distinction between propositional and doxastic justification, I first criticize the alleged cases of justification in the absence of attention before elaborating a two-stage argument in favor of the necessity of attention for perceptual justification. In the first stage, I contend that the functional role of endogenous attention makes it a necessary condition for doxastic justification. In the second stage, by relying on Turri’s (2010) analysis, I establish that propositional justification itself necessitates attention. (shrink)

The Emergic Cognitive Model (ECM) is a unified computational model of visual filling-in based on the Emergic Network architecture. The Emergic Network was designed to help realize systems undergoing continuous change. In this thesis, eight different filling-in phenomena are demonstrated under a regime of continuous eye movement (and under static eye conditions as well). -/- ECM indirectly demonstrates the power of unification inherent with Emergic Networks when cognition is decomposed according to finer-grained functions supporting change. These can interact to raise (...) additional emergent behaviours via cognitive re-use, hence the Emergic prefix throughout. Nevertheless, the model is robust and parameter free. Differential re-use occurs in the nature of model interaction with a particular testing paradigm. -/- ECM has a novel decomposition due to the requirements of handling motion and of supporting unified modelling via finer functional grains. The breadth of phenomenal behaviour covered is largely to lend credence to our novel decomposition. -/- The Emergic Network architecture is a hybrid between classical connectionism and classical computationalism that facilitates the construction of unified cognitive models. It helps cutting up of functionalism into finer-grains distributed over space (by harnessing massive recurrence) and over time (by harnessing continuous change), yet simplifies by using standard computer code to focus on the interaction of information flows. Thus while the structure of the network looks neurocentric, the dynamics are best understood in flowcentric terms. Surprisingly, dynamic system analysis (as usually understood) is not involved. An Emergic Network is engineered much like straightforward software or hardware systems that deal with continuously varying inputs. Ultimately, this thesis addresses the problem of reduction and induction over complex systems, and the Emergic Network architecture is merely a tool to assist in this epistemic endeavour. -/- ECM is strictly a sensory model and apart from perception, yet it is informed by phenomenology. It addresses the attribution problem of how much of a phenomenon is best explained at a sensory level of analysis, rather than at a perceptual one. As the causal information flows are stable under eye movement, we hypothesize that they are the locus of consciousness, howsoever it is ultimately realized. (shrink)

Often when there is no attention to an object, there is no conscious perception of it either, leading some to conclude that conscious perception is an attentional phenomenon. There is a well-known perceptual phenomenon—visuo-spatial crowding, in which objects are too closely packed for attention to single out one of them. This article argues that there is a variant of crowding—what I call ‘‘identity-crowding’’—in which one can consciously see a thing despite failure of attention to it. This conclusion, together with new (...) evidence that attention to an object occurs in unconscious perception, suggests there may be a double dissociation between conscious perception of an object and attention to that object, constraining the extent to which consciousness can be constitutively attentional. The argument appeals to a comparison between the minimal resolution (or ‘‘grain’’) of object-attention and object-seeing. (shrink)

We present a computational model of multiple-object tracking that makes trial-level predictions about the allocation of visual attention and the effect of this allocation on observers' ability to track multiple objects simultaneously. This model follows the intuition that increased attention to a location increases the spatial resolution of its internal representation. Using a combination of empirical and computational experiments, we demonstrate the existence of a tight coupling between cognitive and perceptual resources in this task: Low-level tracking of objects generates bottom-up (...) predictions of error likelihood, and high-level attention allocation selectively reduces error probabilities in attended locations while increasing it at non-attended locations. Whereas earlier models of multiple-object tracking have predicted the big picture relationship between stimulus complexity and response accuracy, our approach makes accurate predictions of both the macro-scale effect of target number and velocity on tracking difficulty and micro-scale variations in difficulty across individual trials and targets arising from the idiosyncratic within-trial interactions of targets and distractors. (shrink)

In grapheme-color synesthesia, a number or letter can evoke two different and possibly conflicting color sensations at the same time. In this study, we investigate the relationship between synesthesia and executive control functions. First, no general skill differences were obtained between synesthetes and non-synesthetes in classic executive control paradigms. Furthermore, classic executive control effects did not interact with synesthetic behavioral effects. Third, we found support for our hypothesis that inhibition of a synesthetic color takes effort and time. Finally, individual differences (...) analyses showed no relationship between the two skills; performance on a ‘normal’ Stroop task does not predict performance on a synesthetic Stroop task. Across four studies, the current results consistently show no clear relationship between executive control functions and synesthetic behavioral effects. This raises the question of which mechanisms are at play in synesthetic ‘management’ during the presence of two conflicting sensations. (shrink)

Angry faces have been shown to be detected more efficiently in a crowd of distractors compared to happy faces, known as the anger superiority effect (ASE). The present study investigated whether the ASE could be modified by top-down manipulation of working memory (WM), in central and peripheral visual fields. In central vision, participants held a colour in WM for a final memory test while simultaneously performing a visual search task that required them to determine whether a face showed a different (...) expression from other coloured faces. The colour held in WM matched either the colour of the target face (target-matching), the colour of a distractor face (distractor-matching), or neither (non-matching). Results showed that the ASE was observed when the probability of target-matching trials was low. However, when the top-down WM effect was strengthened by raising the probability of target-matching trials, the ASE in the target-matching condition was completely eliminated. Intriguingly, when the visual search task was substituted by a peripheral crowding task, similar results to central vision were found in the target-matching condition. Taken together, our findings indicate that the ASE is subject to the top-down WM effect, regardless of the visual field. (shrink)

The common view of the transition between subitizing and numerosity estimation regimes is that there is a hard bound on the subitizing range, and beyond this range, people estimate. However, this view does not adequately address the behavioral signatures of enumeration under conditions of attentional load or in the immediate post-subitizing range. The possibility that there might exist a numerosity range where both processes of subitizing and estimation operate in conjunction has so far been ignored. Here, we investigate this new (...) proposal, that people strategically combine the processes of subitizing and estimation to maximize accuracy and precision, given time or attentional constraints. We present a process-level account of how subitizing and estimation can be combined through strategic deployment of attention to maximize the precision of perceived numerosity given time constraints. We then describe a computational model of this account and apply it in two experimental simulations to demonstrate how it can explain key findings in prior enumeration research. While recent modeling work has argued that the behavioral signatures of enumeration can best be explained through a single numerosity system with a single form of representation, we argue that our model demonstrates how the traditional two-systems view of numerical representation accounts for behavioral data through coordination with a unified attentional mechanism, rather than a unified representation. (shrink)

Despite the remarkable advances in behavioral and brain sciences over the last decades, the mind/body (brain) problem is still an open debate and one of the most intriguing questions for both cognitive neuroscience and philosophy of mind. Traditional approaches have conceived this problem in terms of a contrast between physicalist monism and Cartesian dualism. However, since the late sixties, the landscape of philosophical views on the problem has become more varied and complex. The Multiple Realization Thesis (MRT) claims that mental (...) properties can be (or are) realized, and mental processes can be (or are) implemented by neural correlates of different kinds. Thus, MRT challenges the psychoneural type-identity theory and the corresponding reductionism. Many philosophers have acknowledged the a priori plausibility of MRT. However, the existence of empirical evidence in favor of intraspecific, human multiple realizations of mental processes and properties is still controversial. Here we illustrate some cases that provide empirical evidence in support of MRT. Recently, it has been proposed that foveal agnosic vision, like peripheral vision, can be restored by increasing object parts’ spacing (Strappini et al., 2017a; Crutch and Warrington, 2007). Agnosic fovea and normal periphery are both limited by crowding, that impairs object recognition, and provides the signature of visual integration. Here we define a psychological property of restored object identification and we cross-reference the data of visually-impaired patients with different etiologies. In particular, we compare the data of two stroke patients, two patients with posterior cortical atrophy (PCA), six cases of strabismic amblyopia, and one case with restored sight. We also compare these patients with unimpaired subjects tested in the periphery. We show that integration (i.e. restored recognition) seems to describe quite accurately the visual performance in all these cases. While the patients have different etiologies and different neural correlates, the unimpaired subjects have no neural damage. Thus similarity in the psychological property given the differences in the neural substrate can be interpreted in relation to MRT and provide evidence in its support. Finally, we will frame our contribution within the current debate concerning MRT providing new and compelling empirical evidence. (shrink)

The naïve view of temporal experience (Phillips, in: Lloyd D, Arstila V (eds) Subjective time: the philosophy, psychology, and neuroscience of temporality, forthcoming-a) comprises two claims. First, that we are perceptually aware of temporal properties, such as succession and change. Second, that for any temporal property apparently presented in experience, our experience itself possesses that temporal property. In his paper ‘Silencing the experience of change’ (forthcoming), Watzl argues that this second naïve inheritance thesis faces a novel counter-example in the form (...) of the striking motion silencing effects recently demonstrated by Suchow and Alvarez (Curr Biol 21(2):140–143, 2011). Here I clarify the form which any counter-example to naïve inheritance must take. I then explain how, on a plausible, rival ‘crowding’ interpretation of Suchow and Alvarez’s data, motion silencing poses no more of a threat to naïve inheritance than standard cases of change blindness. (shrink)

In this study, we examined the word superiority effect in Arabic and English, two languages with significantly different morphological and writing systems. Thirty-two Arabic–English bilingual speakers performed a post-cued letter-in-string identification task in words, pseudo-words, and non-words. The results established the presence of the word superiority effect in Arabic and a robust effect of context in both languages. However, they revealed that, compared to the non-word context, word and pseudo-word contexts facilitated letter identification more in Arabic than in English. In (...) addition, the difference between word and pseudo-word contexts was smaller in Arabic compared to English. Finally, there was a consistent first-letter advantage in English regardless of the context, while this was more consistent only in the word and pseudo-word contexts in Arabic. We discuss these results in light of previous findings and argue that the differences between the patterns reported for Arabic and English are due to the qualitative difference between word morphophonological representations in the two languages. (shrink)

One of the most important topics in current work on consciousness is what relationship it has to attention. Recently, one of the focuses of this debate has been on the phenomenon of identity crowding. Ned Block has claimed that identity crowding involves conscious perception of an object that we are unable to pay attention to. In this article, we draw upon a range of empirical findings to argue against Block's interpretation of the data. We also argue that current empirical evidence (...) strongly supports an interpretation of the data that emphasises cognitive inference over conscious perception. (shrink)

Thought: A Journal of Philosophy, EarlyView.

In order to assess the unique reading processes in Arabic, given its unique orthographic nature of natural inherent variations of inter letter spacing, the current study examined the extent and influence of connectedness disparity during single word recognition using the optimal viewing position paradigm. The initial word viewing position was systematically manipulated by shifting words horizontally relative to an imposed initial viewing position. Variations in recognition and processing time were measured as a function of initial viewing position. Fully connected/unconnected Arabic (...) words were used. It was found that OVP effects occurred during the processing of isolated Arabic words. In Arabic, the OVP may be in the center of the word. No OVP was found in three-letter words; for four- and five-letter words, the OVP effect appeared as a U-shaped curve with a minimum towards the second and third letters. Thus, the OVP effects generalize across structurally different alphabetic scripts. (shrink)

In cases of identity crowding, a subject consciously sees items in a figure, even though they are presented too closely together for her to shift attention to each item. Block uses such cases to challenge the view that attention is necessary for consciousness. I argue that in identity crowding cases, subjects really do attend to the items. Specifically, they attend to the figure as a global object that contains the individual items as parts. To support this view, I provide evidence (...) that attention can be directed to a global object or a local object. My response helps to defend the view that attention is necessary for conscious perception. (shrink)