Intuitively, we often see absences. For example, if someone steals your laptop at a café, you may see its absence from your table. However, absence perception presents a paradox. On prevailing models of perception, we see only present objects and scenes (Marr, Gibson, Dretske). So, we cannot literally see something that is not present. This suggests that we never literally perceive absences; instead, we come to believe that something is absent cognitively on the basis of what we perceive. But this (...) cognitive explanation does not do justice to the phenomenology. Many experiences of absence possess immediate, perceptual qualities. One may further argue that the ability to detect certain absences confers strong adaptive advantage and therefore must be as primitive and fundamental to humans as seeing positive things. I argue that we can literally see absences; in addition to representing objects, perception represents absences of objects. I present a model of seeing absence based on visual expectations and a visual matching process. The phenomenon of seeing absence can thus serve as an adequacy-test for a theory of perceptual content. If experiences of absence are possible, then we have another reason (following Siegel) to reject the view that perceptual content is restricted to colors and shapes. Furthermore, if the proposed account is correct, then we have grounds for dissociating seeing absence from other imagery-based phenomena termed “perceptual presence-in-absence” (Noë, Macpherson). (shrink)

Large changes that occur in clear view of an observer can become difficult to notice if made during an eye movement, blink, or other such disturbance. This change blindness is consistent with the proposal that focused visual attention is necessary to see change, with a change becoming difficult to notice whenever conditions prevent attention from being automatically drawn to it. -/- It is shown here how the phenomenon of change blindness can provide new results on the nature of visual attention, (...) including estimates of its capacity and the extent to which it can bind visual properties into coherent descriptions. It is also shown how the resultant characterization of attention can in turn provide new insights into the role that it plays in the perception of scenes and events. (shrink)

This paper assesses five main empirical scientific arguments against the reliability of belief formation on the basis of introspecting phenomenal states. After defining ‘reliability’ and ‘introspection’, I discuss five arguments to the effect that phenomenal states are more elusive than we usually think: the argument on the basis of differences in introspective reports from differences in introspective measurements; the argument from differences in reports about whether or not dreams come in colours; the argument from the absence of a correlation between (...) visual imagery ability and the performance on certain cognitive tasks; the argument from our unawareness of our capacity of echolocation; the argument from inattentional blindness and change blindness. I argue that the experiments on which these arguments are based do not concern belief formation on the basis of introspection in the first place or fail to show that it is unreliable, even when limited to introspection of phenomenal states. (shrink)

According to rich views of consciousness (e.g., James, Searle), we have a constant, complex flow of experience (or 'phenomenology') in multiple modalities simultaneously. According to thin views (e.g., Dennett, Mack and Rock), conscious experience is limited to one or a few topics, regions, objects, or modalities at a time. Existing introspective and empirical arguments on this issue (including arguments from 'inattentional blindness') generally beg the question. Participants in the present experiment wore beepers during everyday activity. When a beep sounded, they (...) were to take note of the conscious experience, if any, they were having at the last undisturbed moment immediately prior to the beep. Some participants were asked to report any experience they could remember. Others were asked simply to report whether there was visual experience or not (and if so, what it was). Still others were asked about experience in the far right visual field, or tactile experience, or tactile experience in the left foot. A majority of participants in the full experience and the visual conditions reported visual experience in every single sample. Tactile and peripheral visual experience were reported less often. However, the proper interpretation of these results is uncertain. (shrink)

Philosophers have usually approached the concept of timing of experiences by addressing the question how the experiences of temporal phenomena can be explained. As a result, the issue of timing has been addressed in two different ways. The first, similar to the questions posed in sciences, concerns the relationship between the experienced time of events and the objective time of events. The second approach is more specific to philosophers’ debates, and concerns the phenomenology of experiences: how is the apparent temporal (...) structure of experiences constituted? In regard to both questions, this article shows why and how philosophers’ views differ from those held by most scientists. To conclude, I present a combination of views that is not only compatible with that of scientists, but also addresses the problems that engage philosophers. (shrink)

Experimenters generally infer whether participants have visual experiences based on metacognitive responses. We showed a well-studied blindsight participant, GY, several definitions of the term “qualia” and then questioned him about whether he felt or he experienced qualia in his normal and blind fields. We found, contrary to others who have used different methods for measuring qualia, that GY does not have qualia for stationary stimuli in his blind field. This novel method for directly assessing qualia embraces the idea that experiences (...) should be related by the experiencer, not the experimenter. (shrink)

Change blindness is the striking failure to see large changes that normally would be noticed easily. Over the past decade this phenomenon has greatly contributed to our understanding of attention, perception, and even consciousness. The surprising extent of change blindness explains its broad appeal, but its counterintuitive nature has also engendered confusions about the kinds of inferences that legitimately follow from it. Here we discuss the legitimate and the erroneous inferences that have been drawn, and offer a set of requirements (...) to help separate them. In doing so, we clarify the genuine contributions of change blindness research to our understanding of visual perception and awareness, and provide a glimpse of some ways in which change blindness might shape future research. (shrink)

Mindfulness can be understood as the mental ability to focus on the direct and immediate perception or monitoring of the present moment with a state of open and nonjudgmental awareness. Descriptions of mindfulness and methods for cultivating it originated in eastern spiritual traditions. These suggest that mindfulness can be developed through meditation practice to increase positive qualities such as awareness, insight, wisdom, and compassion. In this article we focus on the relationships between mindfulness, with associated meditation practices, and the cognitive (...) neuroscience of attention and awareness. Mindful awareness is related to distributed attention, phenomenal consciousness, and momentary self-awareness, as characterized by recent findings in cognitive psychology and neuroscience as well as in influential consciousness models. Finally, we outline an integrated neurocognitive model of mindfulness, attention, and awareness, with a key role of prefrontal cortex. (shrink)

Rensink, O’Regan, and Clark (1997) drew attention to the phenomenon of change blindness, in which even large changes can be difficult to notice if made during the appearance of motion transients elsewhere in the image. This article provides a sketch of the events that inspired that article as well as its subsequent impact on psychological science and on society at large.

In three experiments, we investigated the priming effects induced by an image change on a successive animate/inanimate decision task. We studied both perceptual and conceptual priming effects, under correct change detection and change blindness . Under correct change detection, we found larger positive priming effects on congruent trials for probes representing animate entities than for probes representing artifactual objects. Under CB, we found performance impairment relative to a “no-change” baseline condition. This inhibition effect induced by CB was modulated by the (...) semantic congruency between the changed item and the probe in the case of probe images, but not for probe words. We discuss our results in the context of the literature on the negative priming effect. (shrink)

To make behavioral choices that are in line with our goals and our moral beliefs, we need to gather and consider information about our current situation. Most information present in our environment is not relevant to the choices we need or would want to make and thus could interfere with our ability to behave in ways that reflect our underlying values. Certain sources of information could even lead us to make choices we later regret, and thus it would be beneficial (...) to be able to ignore that information. Our ability to exert successful self-governance depends on our ability to attend to sources of information that we deem important to our decision-making processes. We generally assume that, at any moment, we have the ability to choose what we pay attention to. However, recent research indicates that what we pay attention to is influenced by our prior experiences, including reward history and past successes and failures, even when we are not aware of this history. Even momentary distractions can cause us to miss or discount information that should have a greater influence on our decisions given our values. Such biases in attention thus raise questions about the degree to which the choices that we make may be poorly informed and not truly reflect our ability to otherwise exert self-governance. (shrink)

Several recent findings support the notion that changes in the environment can be implicitly represented by the visual system. S. R. Mitroff, D. J. Simons, and S. L. Franconeri (2002) challenged this view and proposed alternative interpretations based on explicit strategies. Across 4 experiments, the current study finds no empirical support for such alternative proposals. Experiment 1 shows that subjects do not rely on unchanged items when locating an unaware change. Experiments 2 and 3 show that unaware changes affect performance (...) even when they occur at an unpredictable location. Experiment 4 shows that the unaware congruency effect does not depend simply on the pattern of the final display. The authors point to converging evidence from other methodologies and highlight several weaknesses in Mitroff et al.’s theoretical arguments. It is concluded here that implicit representation of change provides the most parsimonious explanation for both past and present findings. (shrink)

Recent developments in vision science have resulted in several major changes in our understanding of human visual perception. For example, attention no longer appears necessary for "visual intelligence"--a large amount of sophisticated processing can be done without it. Scene perception no longer appears to involve static, general-purpose descriptions, but instead may involve dynamic representations whose content depends on the individual and the task. And vision itself no longer appears to be limited to the production of a conscious "picture"--it may also (...) guide processes outside the conscious awareness of the observer. (shrink)

An overview is presented of the ways that change blindness has been applied to the study of various issues in perception and cognition. Topics include mechanisms of change perception, allocation of attention, nonconscious perception, and cognitive beliefs. Recent work using change blindness to investigate these topics is surveyed, along with a brief discussion of some of the ways that these approaches may further develop over the next few years.

Rensink [Rensink, R. A. . Visual sensing without seeing. Psychological Science, 15, 27–32] has presented evidence suggesting visual changes may be sensed without an accompanying visual experience. Here, we report two experiments in which we monitored observers’ eye-movements whilst they searched for a difference between two simultaneously presented images and pressed separate response keys when a difference was seen or sensed. We first assessed whether sensing performance was random by collecting ratings of confidence in the validity of sensing and assessing (...) gaze location during sensing. Sensing was not random: fixation position and confidence ratings were different when a difference was present compared to catch trials. Furthermore, the uniformity of objects in the images and the type of difference appear to affect seeing and sensing differently, suggesting that these processes are dissociated. The possibility is discussed of a sensing mechanism that increases vigilance toward unconsciously registered differences, particularly changes to scene layout. (shrink)

According to reductive intentionalism, the phenomenal character of a conscious experience is constituted by the experience's intentional (or representational) content. The goal of this article is to show that a phenomenon in visual perception called change blindness poses a problem for this doctrine. It is argued, in particular, that phenomenal character is not sensitive, as it should be if reductive intentionalism is correct, to fine-grained variations in content. The standard anti-intentionalist strategy is to adduce putative cases in which phenomenal character (...) varies despite sameness of content. This paper explores an alternative anti-intentionalist tack, arguing, by way of a specific example involving change blindness, that content can vary despite sameness of phenomenal character. (shrink)

This volume presents mathematical game theory as an interface between logic and philosophy.