The goal of this study is to characterize observers’ abilities to discriminate between endogenous and exogenous changes. To do so, we developed a new experimental paradigm. On each trial, participants were shown a dot pattern on the screen. Next, the pattern disappeared and participants were to reproduce it. Changes were surreptuously introduced in the stimulus, either by presenting participants anew with the dot pattern they had themselves produced on the previous trial or by presenting participants with a slightly different dot (...) pattern . We analyzed awareness of the changes and behavioral adaptation to them in a dynamical manner. We observe signal attenuation in the presence of endogenous change, dissociation between self-attribution reports and behavioral effect of agency. We discuss the source of this sensitive attenuation as well as the relation between a minimal or core self and an extended, narrative or autobiographical self. (shrink)

It is generally accepted that there is something special about reasoning by using mental images. The question of how it is special, however, has never been satisfactorily spelled out, despite more than thirty years of research in the post-behaviorist tradition. This article considers some of the general motivation for the assumption that entertaining mental images involves inspecting a picture-like object. It sets out a distinction between phenomena attributable to the nature of mind to what is called the cognitive architecture, and (...) ones that are attributable to tacit knowledge used to simulate what would happen in a visual situation. With this distinction in mind, the paper then considers in detail the widely held assumption that in some important sense images are spatially displayed or are depictive, and that examining images uses the same mechanisms that are deployed in visual perception. I argue that the assumption of the spatial or depictive nature of images is only explanatory if taken literally, as a claim about how images are physically instantiated in the brain, and that the literal view fails for a number of empirical reasons – for example, because of the cognitive penetrability of the phenomena cited in its favor. Similarly, while it is arguably the case that imagery and vision involve some of the same mechanisms, this tells us very little about the nature of mental imagery and does not support claims about the pictorial nature of mental images. Finally, I consider whether recent neuroscience evidence clarifies the debate over the nature of mental images. I claim that when such questions as whether images are depictive or spatial are formulated more clearly, the evidence does not provide support for the picture-theory over a symbol-structure theory of mental imagery. Even if all the empirical claims were true, they do not warrant the conclusion that many people have drawn from them: that mental images are depictive or are displayed in some (possibly cortical) space. Such a conclusion is incompatible with what is known about how images function in thought. We are then left with the provisional counterintuitive conclusion that the available evidence does not support rejection of what I call the “null hypothesis”; namely, that reasoning with mental images involves the same form of representation and the same processes as that of reasoning in general, except that the content or subject matter of thoughts experienced as images includes information about how things would look. (shrink)

We investigated whether a pre-change representation is inhibited or weakened under correct change detection. Two arrays of six objects were rapidly presented for change detection in three experiments. After detection, the perceptual identification of degraded stimuli was tested in Experiments 1 and 2. The weakening of a pre-change representation was not observed under correct detection. The repetition priming effect was observed for a pre-change object and the magnitude was equivalent to the effect for a post-change object. Under change blindness, repetition (...) priming for a pre-change representation was observed when detection did not require report of location in Experiment 1 and was not observed when location was required to be reported in Experiment 2. The results of Experiment 3 showed that a pre-change representation was recognized at a higher rate under correct detection than under change blindness, reflecting a stronger rather than a weaker pre-change representation in the former context. (shrink)

This paper inquires into the nature of intertheoretic relations between psychology and neuroscience. This relationship has been characterized by some as one in which psychological explanations eventually will fall away as otiose, overthrown completely by neurobiological ones. Against this view it will be argued that it squares poorly with scientific practices and empirical developments in the cognitive neurosciences. We analyse a case from research on visual perception, which suggests a much more subtle and complex interplay between psychology and neuroscience than (...) a complete take-over of the former by the latter. In the case of vision, cross-theory influences between psychology and neuroscience go back and forth, resulting in refinement in both disciplines.We interpret this case study as showing that:(1) Mutual co-evolution of psychological and neurobiological theories, exemplifying persisting top-down influences from psychology, is a more empirically adequate way to describe psychoneural theory relations than a view on co-evolution, favoured by reductionists, which regards the cross-theory contributions from psychology as merely heuristically useful with no enduring influence on neurobiological theorizing;(2) In research on vision, discovering (or hypothesizing) the neural basis of functions vindicates psychological approaches, it does not eliminate them;(3) Current work on vision shows that many perceptual phenomena must be understood in terms of dynamical interactions between an observer and his/her environment. Therefore, we argue that internalist characterizations of the visual system must be supplemented with externalist accounts that address these reciprocal observer-environment interactions involved in vision. Such processes seem quite different from (internal) cellular and molecular ones, and as such seem to lie outside the scope of neuroscientific inquiry. We conclude that psychoneural reduction or elimination is implausible as a meta-theoretical prediction of theory choice in empirical work. Instead, this case study of vision shows that both psychology and neuroscience contribute to, and complement one another in the study of visual perception. 1. Psychoneural reductionism1.1Introduction1.2New Wave Reductionism1.3NWR and psychology: three characteristics of psychoneural reductionism1.4NWR and the problem of mutual feedback1.4.1The ‘Mere Heuristics’ claim1.4.2The disappearance of psychology as an irrelevant historical accident1.5Summary: three claims of NWR on psychoneural reduction2. Vision: a case study2.1Introduction2.1.1Three opposing claims2.1.2Psychology and neuroscience of vision: the orthodoxy2.2Testing claim 1: vanishing heuristics or persisting influences?2.2.1From what and where to perception and action2.2.2Real co-evolution: more than vanishing heuristics2.2.3First moral2.3Testing claim 2: replacement or vindication?2.3.1Perception and action revisited: mapping approaches on systems2.3.2Vindicating psychological approaches2.3.3Second moral2.4Testing claim 3: equipotent image or explanatory loss?2.4.1Perception and action extended: including the environment2.4.2Distinguishing levels, widening explanations2.4.3Third moral3. Conclusion: three morals. (shrink)

People often fail to detect large changes to scenes, provided that the changes occur during a visual disruption. This phenomenon, known as ''change blindness,'' occurs both in the laboratory and in real-world situations in which changes occur unexpectedly. The pervasiveness of the inability to detect changes is consistent with the theoretical notion that we internally represent relatively little information from our visual world from one glance at a scene to the next. However, evidence for change blindness does not necessarily imply (...) the absence of such a representation-people could also miss changes if they fail to compare an existing representation of the pre-change scene to the post-change scene. In three experiments, we show that people often do have a representation of some aspects of the pre-change scene even when they fail to report the change. And, in fact, they appear to ''discover'' this memory and can explicitly report details of a changed object in response to probing questions. The results of these real-world change detection studies are discussed in the context of broader claims about change blindness. (shrink)

We are prone to gross error, even in favorable circumstances of extended reflection, about our own ongoing conscious experience, our current phenomenology. Even in this apparently privileged domain, our self-knowledge is faulty and untrustworthy. We are not simply fallible at the margins but broadly inept. Examples highlighted in this essay include: emotional experience (for example, is it entirely bodily; does joy have a common, distinctive phenomenological core?), peripheral vision (how broad and stable is the region of visual clarity?), and the (...) phenomenology of thought (does it have a distinctive phenomenology, beyond just imagery and feelings?). Cartesian skeptical scenarios undermine knowledge of ongoing conscious experience as well as knowledge of the outside world. Infallible judgments about ongoing mental states are simply banal cases of self-fulfillment. Philosophical foundationalism supposing that we infer an external world from secure knowledge of our own consciousness is almost exactly backward. (shrink)

This paper argues that a theory of situated vision, suited for the dual purposes of object recognition and the control of action, will have to provide something more than a system that constructs a conceptual representation from visual stimuli: it will also need to provide a special kind of direct (preconceptual, unmediated) connection between elements of a visual representation and certain elements in the world. Like natural language demonstratives (such as `this' or `that') this direct connection allows entities to be (...) referred to without being categorized or conceptualized. Several reasons are given for why we need such a preconcep- tual mechanism which individuates and keeps track of several individual objects in the world. One is that early vision must pick out and compute the relation among several individual objects while ignoring their properties. Another is that incrementally computing and updating representations of a dynamic scene requires keeping track of token individuals despite changes in their properties or locations. It is then noted that a mechanism meeting these requirements has already been proposed in order to account for a number of disparate empiri- cal phenomena, including subitizing, search-subset selection and multiple object tracking (Pylyshyn et al., Canadian Journal of Experimental Psychology 48(2) (1994) 260). This mechanism, called a visual index or FINST, is brie. (shrink)

In his paper, in this journal, Sterelney claims that cases of extended mind are limiting cases of environmental scaffolding and that a niche construction model is a more helpful, general framework for understanding human action. He further claims that extended mind cases fit into a corner of a 3D space of environmental scaffolds of cognitive competence. He identifies three dimensions which determine where a resource fits into this space and suggests that extended mind models seem plausible when a resource is (...) highly reliable, individualised/entrenched and a single-user resource. Sterelney also claims that the most important cognition-enhancing resources are provided collectively by one generation to the next. In this paper, I argue that Sterelney is both right and wrong and this because he focuses primarily on external, physical resources and construes scaffolding as exclusively unidirectional and diachronic. Using examples of unfamiliar tool use, visual processing and human emotional ontogenesis, I argue, respectively, that extended mind cases include those which fail to meet Sterelney’s dimensional criteria; that the most important cognition—enhancing resources are those which actually build brains; that these are provided on a one-to-one basis in emotional ontogenesis; and, this depends on bidirectional and synchronic cognitive scaffolding. (shrink)

The topic of this paper is the complex interaction between attention, fixation, and one species of change blindness. The two main interpretations of the target phenomenon are the ‘blindness’ interpretation and the ‘inaccessibility’ interpretation. These correspond to the sparse view (Dennett 1991; Tye, 2007) and the rich view (Dretske 2007; Block, 2007a, 2007b) of visual consciousness respectively. Here I focus on the debate between Fred Dretske and Michael Tye. Section 1 describes the target phenomenon and the dialectics it entails. Section (...) 2 explains how attention and fixation weigh in these debates, and argues that Dretske’s hyper-rich view fails precisely because he overlooks certain effects of attention and fixation. Section 3 explains why Tye’s view is also unsatisfying, mainly because he misconceives the degree of access. Section 4 then puts forward the positive model covariance, which has it that the degree of cognitive access tracks the degree of phenomenology, and contrasts it with Block’s view on the Sperling iconic memory paradigm. The paper ends with a discussion of levels of seeing, which involve crowding, indexing, and other visual phenomena. Change ‘blindness’ is a set of phenomena that was discovered about two decades ago, yet an entirely satisfying understanding is still lacking. To move forward, a more detailed understanding of attention and fixation is called for. (shrink)

6. Seeing With the Mind’s Eye 1: The Puzzle of Mental Imagery .................................................6-1 6.1 What is the puzzle about mental imagery?..............................................................................6-1 6.2 Content, form and substance of representations ......................................................................6-6 6.3 What is responsible for the pattern of results obtained in imagery studies?.................................6-8..

I recently discovered that work I was doing in the laboratory and in theoretical writings was implicitly taking a position on a set of questions that philosophers had been worrying about for much of the past 30 or more years. My clandestine involvement in philosophical issues began when a computer science colleague and I were trying to build a model of geometrical reasoning that would draw a diagram and notice things in the diagram as it drew it (Pylyshyn, Elcock, Marmor, (...) & Sander, 1978). One problem we found we had to face was that if the system discovered a right angle it had no way to tell whether this was the intersection of certain lines it had drawn earlier while constructing a certain figure, and if so which particular lines they were. Moreover, the model had no way of telling whether this particular right angle was identical to some bit of drawing it had earlier encountered and represented as, say, the base of a particular triangle. There was, in other words, no way to determined the identity of an element (I use the term “element” when referring to a graphical unit such as used in experiments. Otherwise when speaking informally I use the term “thing” on the grounds that nobody would mistake that term for a technical theoretical construct. Eventually I end up calling them “Visual Objects” to conform to usage in psychology) at two different times if it was represented differently at those times. This led to some speculation about the need for what we called a “finger” that could be placed at a particular element of interest and that could be used to identify it as particular token thing (the way you might identify a particular feature on paper by labeling it). In general we needed something like a finger that would stay attached to a particular element and could be used to maintain a correspondence between the individual element that was just noticed now and one that had been represented in some fashion at an earlier time. The idea of such fingers (which.... (shrink)

In the not-too-distant past, vision was often said to involve three levels of processing: a low level concerned with descriptions of the geometric and photometric properties of the image, a high level concerned with abstract knowledge of the physical and semantic properties of the world, and a middle level concerned with anything not handled by the other two. The negative definition of mid-level vision contained in this description reflected a rather large gap in our understanding of visual processing: How could (...) the here-and-now descriptions of the low levels combine with the enduring knowledge of the high levels to produce our perception of the surrounding world? A number of experimental and theoretical efforts have been made over the past few decades to solve this "mid-level crisis". One of the more recent of these is based on the phenomenon of change blindness—the difficulty in seeing a large change in a scene when the transients accompanying that change no longer convey information about its location (Rensink, O'Regan, & Clark, 1997; Rensink, 2000a). Phenomenologically, this effect is quite striking: the change typically is not seen for several seconds, after which it suddenly snaps into awareness. During the time the change remains "invisible", there is an apparent disconnection of the low-level descriptions (which respond to the change) from subjective visual experience (which does not). As such, this effect would seem to have the potential to help us understand how mid-level mechanisms might knit low- and high-level processes into a coherent representation of our surroundings. -/- It is argued here that this potential can indeed be realized, and that change blindness can teach us much about the nature of mid-level vision.3 A number of studies are first reviewed showing that the perception of a scene does not involve a steady buildup of detailed representation: rather, it is a dynamic process, with focused attention playing one of the main roles, viz., forming coherent object representations whenever needed. It is then argued that change blindness can also shed considerable light on the nature of focused attention itself, such as its speed, capacity, selectivity, and ability to bind together visual properties into coherent structures. (shrink)

The present empirical study investigates limitations of human visual working memory. The experiments of the present work involve the experimental paradigm of change detection using simple geometrical objects in the form of rectangles of different colour, length, and orientation. It can be shown, that a limited performance in the temporary storage of visual information has multiple sources. Limitations of VWM can be attributed to a limited capacity or a limited duration, but also to limitations in retrieval, which so far has (...) found only little attention. Key findings of the present study show, that a capacity limitation cannot be described by a simple and generally valid size of the store. It is in fact generally acknowledged that the capacity limitation of VWM is object-based, which means that the capacity can roughly be determined by the number of visual objects. However, it could be shown that the complexity of the objects has an influence on memory performance: Experimental evidence shows, e.g., that memory performance decreases, when an object is characterized not only by one feature, but by a number of features. The results are explained by increased storage demands for the binding of the features. Other key findings of the present study relate to the process of retrieval of information from VWM. For example, an asymmetric performance pattern could be observed: In a change detection task a memory performance was observed that corresponds to a capacity of 3 - 4 objects. In contrast a drastic decrease of performance corresponding to a capacity of only 1 object was observed, when the task was to find a matching item among changed distractors. These results lead to the idea of a change signal, by which the empirical data can be explained. The change signal is elicited by a local mismatch between the information stored in VSTM and perceptual online information. The retrieval process is efficient, when the change signal can be used in the memory task. However, retrieval is extremely limited, when in the presence of multiple changes a less efficient strategy has to be applied. In the course of the present study, moreover, it became evident that there are various links between VWM processes and visual attention. Visual attention is probably crucial for feature binding in VWM. In retrieval the change signal probably involves mechanisms of visual attention. The present study could, therefore, contribute to a clarification of the relation between VWM and visual attention. (shrink)