Attention, Fixation, and Change Blindness (original) (raw)

Attention, Seeing, and Change Blindness

Here are two crowds of balls (from Dretske 2010): View crowd A first and then view crowd B, each for a second or two. If you are like most people, you will fail to notice any difference in the crowds. But there is a difference: crowd A has one more ball. This is an example of change blindness. Do you see the ball that is the difference in the two crowds? You fail to see that there is a difference in the two crowds, but do you see the extra ball? The question is significant for three reasons. First, reflection upon it enables us to understand better the character or texture of visual experience. Secondly (and relatedly), how we answer the question is tied up with how we handle the further vexing question of the nature of attention and its relationship to consciousness. Finally , what we say about this case (and others like it) is relevant to how we think about the vehicles of consciousness awareness – the conscious states in our heads that are directed at things outside us. My discussion is divided into eight parts. I begin with a discussion of seeing and visual consciousness. In Section 2, I relate this discussion to the crowd of balls example and the issue of change blindness. I argue that the view Fred Dretske takes of this case (and others like it) is mistaken. Section 3 takes up the topic of levels of representation involved in visual awareness. I distinguish here two different general hypotheses with respect to change blindness – the comparison failure hypothesis and the representational failure hypothesis – and I adjudicate between them. The next three sections are concerned with various aspects of attention and the relationship of attention to seeing. Section 7 turns to the nature of the vehicles of conscious awareness. The final section addresses the general question of whether we see all the things in the field of view that are large enough to see. It is suggested that on

Change Blindness: Implications for the Nature of Visual Attention

Vision and Attention, 2001

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. 1 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?

Attention: Change Blindness and Inattentional Blindness

In Encyclopedia of Consciousness, Vol 1. W. Banks (ed). New York: Elsevier. pp. 47-59. , 2009

As observers, we generally have a strong impression of seeing everything in front of us at any moment. But compelling as it is, this impression is false – there are severe limits to what we can consciously experience in everyday life. Much of the evidence for this claim has come from two phenomena: change blindness (CB) and inattentional blindness (IB). CB refers to the failure of an observer to visually experience changes that are easily seen once noticed. This can happen even if the changes are large, constantly repeat, and the observer has been informed that they will occur. A related phenomenon is IB – the failure to visually experience an object or event when attention is directed elsewhere. For example, observers may fail to notice an unexpected object that enters their visual field, even if this object is large, appears for several seconds, and has important consequences for the selection of action. Both phenomena involve a striking failure to report an object or event that is easily seen once noticed. As such, both are highly counterintuitive, not only in the subjective sense that observers have difficulty believing they could fail so badly at seeing but also in the objective sense that these findings challenge many existing ideas about how we see. But as counterintuitive as these phenomena are, progress has been made in understanding them. Indeed, doing so has allowed us to better understand the limitations of human perception in everyday life and to gain new insights into how our visual systems create the picture of the world that we experience each moment our eyes are open.

Change blindness and inattentional blindness

Wiley Interdisciplinary …, 2011

Change blindness is the failure to notice an obvious change. Inattentional blindness is the failure to notice the existence of an unexpected item. In each case, we fail to notice something that is clearly visible once we know to look for it. Despite similarities, each type of blindness has a unique background and distinct theoretical implications. Here, we discuss the central paradigms used to explore each phenomenon in a historical context. We also outline the central findings from each field and discuss their implications for visual perception and attention. In addition, we examine the impact of task and observer effects on both types of blindness as well as common pitfalls and confusions people make while studying these topics.

To see or not to see: The need for attention to perceive changes in scenes

Psychological Science, 1997

When looking at a scene, observers feel that they see its entire structure in great detail and can immediately notice any changes in it. However, when brief blank fields are placed between alternating displays of an original and a modified scene, a striking failure of perception is induced: identification of changes becomes extremely difficult, even when changes are large and made repeatedly. Identification is much faster when a verbal cue is provided, showing that poor visibility is not the cause of this difficulty. Identification is also faster for objects mentioned in brief verbal descriptions of the scene. These results support the idea that observers never form a complete, detailed representation of their surroundings. In addition, results also indicate that attention is required to perceive change, and that in the absence of localized motion signals it is guided on the basis of high-level interest.

Change blindness: past, present, and future

Trends in Cognitive Sciences, 2005

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.