Covert spatial attention in search for the location of a color-afterimage patch speeds up its decay from awareness: Introducing a method useful for the study of neural … (original) (raw)
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Vision Research, 2010
Previous research has reported that attention to color afterimages speeds up their decay. However, the inducing stimuli in these studies have been overlapping, thereby implying that they involved overlapping receptive fields of the responsible neurons. As a result it is difficult to interpret the effect of focusing attention on a phenomenally projected target-afterimage. Here, we present a method free from these shortcomings. In searching for a target-afterimage patch among spatially separate alternatives the target fades from awareness before its competitors. This offers a good means to study neural correlates of visual awareness unconfounded with attention and enabling a temporally extended pure phenomenal experience free from simultaneous inflow of sensory transients.
Scholarpedia, 2008
For the past three decades there has been a substantial amount of scientific evidence supporting the view that attention is necessary and sufficient for perceptual representations to become conscious (i.e., for there to be something that it is like to experience a representational perceptual state). This view, however, has been recently questioned on the basis of some alleged counterevidence. In this paper we survey some of the most important recent findings. In doing so, we have two primary goals. The first is descriptive: we provide a literature review for those seeking an understanding of the present debate. The second is editorial: we suggest that the evidence alleging dissociations between consciousness and attention is not decisive. Thus, this is an opinionated overview of the debate. By presenting our assessment, we hope to bring out both sides in the debate and to underscore that the issues here remain matters of intense controversy and ongoing investigation.
Recent evidence that attention is necessary, but not sufficient, for conscious perception
Annals of the New York Academy of Sciences, 2020
Early descriptions of attention in the psychological literature highlighted its interdependence with conscious awareness. As the study of attention developed, consciousness and attention began to be considered separable phenomena, experimentally and theoretically. In recent years, an energetic debate has developed concerning the extent to which the two phenomena are related. One school of thought considers the two to be doubly dissociable, whereas the other considers them to be necessarily linked. In this review, we highlight experimental findings from the last 5 years that contribute to the leading consensus view: attention is necessary, but not sufficient, for conscious perception. We review studies that show attention operating in conjunction with unconscious information, and other evidence linking attention necessarily to conscious perception. By drawing upon evidence that attention comprises many cognitive and neural processes, we argue that by studying how different forms of attention are related to conscious perception, it is possible to gain new insights about the neural states or processes that are necessary for conscious perception to occur.
Opposing effects of attention and consciousness on afterimages
Proceedings of the …, 2010
The brain's ability to handle sensory information is influenced by both selective attention and consciousness. There is no consensus on the exact relationship between these two processes and whether they are distinct. So far, no experiment has simultaneously manipulated both. We carried out a full factorial 2 × 2 study of the simultaneous influences of attention and consciousness (as assayed by visibility) on perception, correcting for possible concurrent changes in attention and consciousness. We investigated the duration of afterimages for all four combinations of high versus low attention and visible versus invisible. We show that selective attention and visual consciousness have opposite effects: paying attention to the grating decreases the duration of its afterimage, whereas consciously seeing the grating increases the afterimage duration. These findings provide clear evidence for distinctive influences of selective attention and consciousness on visual perception. awareness | continuous flash suppression | Troxler fading | dual-task | visibility S ince the latter part of the past century, interest in the influences of selective attention and consciousness on perception has steadily increased. This discussion has raised the question of the relationship between attention and consciousness. By attention, we refer to selective perceptual attention and not vigilance or arousal; by consciousness, we refer to the content of consciousness (sometimes also referred to as awareness), and not to states of consciousness (e.g., wakefulness, dreamless sleep, or coma). Though some claim that both processes are inextricably connected (1-4), others suggest a certain level of independence . Psychophysical studies show that observers can pay attention to an invisible stimulus , and that a stimulus can be clearly seen in the (near) absence of attention (4, 17). Though these data could be explained by arguing that these two processes covary and therefore any increase (respectively decrease) in one is associated with a similar but smaller increase (respectively decrease) in the other, this argument fails if attention and consciousness were to have opposing perceptual effects on the same stimulus. Finding such opponency would considerably strengthen the hypothesis that these processes are distinct (5).
Introduction to research topic: attention and consciousness in different senses
Frontiers in Psychology, 2013
The question of the origin of consciousness has engaged scientists and philosophers for centuries. Early scholars relied on introspection, leading some to conclude that attention is necessary for consciousness, and in some cases equating attention and consciousness. Such a tight relationship between attention and consciousness has also been proposed by many modern theo-Cohen et al., 2012). The relationship between attention and consciousness has come under increasing scrutiny with the development of neuroscientific methods. In modern neuroscience, the effects of attention are often objectively defined and measured as reduced reaction time and improved performance. Similarly, conscious awareness of an object is established by a subjective report in combination with objective forced-choice performance . With these measures in place, a variety of methods has been used to manipulate attention (e.g., cueing, divided attention, etc.) and consciousness [e.g., masking, crowding, and binocular rivalry (Kim and Blake, 2005)]. These empirical studies have culminated in recent proposals that attention and consciousness are supported by different neuronal processes and they are not necessarily correlated all the time (Iwasakivan Boxtel et al., 2010).
Attention and consciousness: Two distinct brain processes
Trends in Cognitive Sciences, 2007
The close relationship between attention and consciousness has led many scholars to conflate these processes. This article summarizes psychophysical evidence, arguing that top-down attention and consciousness are distinct phenomena that need not occur together and that can be manipulated using distinct paradigms. Subjects can become conscious of an isolated object or the gist of a scene despite the near absence of top-down attention; conversely, subjects can attend to perceptually invisible objects. Furthermore, top-down attention and consciousness can have opposing effects. Such dissociations are easier to understand when the different functions of these two processes are considered. Untangling their tight relationship is necessary for the scientific elucidation of consciousness and its material substrate.
Attentional Routes to Conscious Perception
Frontiers in Psychology, 2012
The relationships between spatial attention and conscious perception are currently the object of intense debate. Recent evidence of double dissociations between attention and consciousness cast doubt on the time-honored concept of attention as a gateway to consciousness. Here we review evidence from behavioral, neurophysiologic, neuropsychological, and neuroimaging experiments, showing that distinct sorts of spatial attention can have different effects on visual conscious perception. While endogenous, or topdown attention, has weak influence on subsequent conscious perception of near-threshold stimuli, exogenous, or bottom-up forms of spatial attention appear instead to be a necessary, although not sufficient, step in the development of reportable visual experiences. Fronto-parietal networks important for spatial attention, with peculiar inter-hemispheric differences, constitute plausible neural substrates for the interactions between exogenous spatial attention and conscious perception.