In a series of three experiments, we explored the nature of implicit representations in change blindness . Using 3 × 3 letter arrays, we asked subjects to locate changes in paired arrays separated by 80 ms ISIs, in which one, two or three letters of a row in the second array changed. In one testing version, a tone followed the second array, signaling a row for partial report . In the other version, no PR was required. After Ss reported whether (...) a change had been detected and the PR had been completed , they were asked to identify a degraded letter trigram that was either novel, or from a previously shown row . Our findings indicate that when CB occurs, both the pre-change and post-change stimulus information primes despite its unavailability to consciousness. Surprisingly, findings also indicate that when change detection occurs only the post-change information primes. (shrink)

It’s often held that undetectable inversion of mental qualities is, if not possible, at least conceivable. It’s thought to be conceivable that the mental quality your visual states exhibit when you see something red in standard conditions is literally of the same type as the mental quality my visual states exhibit when I see something green in such circumstances. It’s thought, moreover, to be conceivable that such inversion of mental qualities could be wholly undetectable by any third-person means. And since (...) first- person access is limited to a single individual, and so could not reveal a disparity in mental quality between us, third-person undetectability means undetectability tout court. (shrink)

A modest proposal concerning laws, counterfactuals, and explanations - - Why be Humean? -- Suggestions from physics for deep metaphysics -- On the passing of time -- Causation, counterfactuals, and the third factor -- The whole ball of wax -- Epilogue : a remark on the method of metaphysics.

This paper is concerned with a quality space model as an account of the intelligibility of explanation. I argue that descriptions of causal or functional roles (Chalmers Levine, 2001) are not the only basis for intelligible explanations. If we accept that phenomenal concepts refer directly, not via descriptions of causal or functional roles, then it is difficult to find role fillers for the described causal roles. This constitutes a vagueness constraint on the intelligibility of explanation. Thus, I propose to use (...) quality space models to develop a systematic way of studying different modalities of perception and feelings, e.g., visual and auditory perception, pain, and emotion, that can reveal some structural relations among these modalities. It might turn out that topological explanation can be more intelligible than causal explanation in this case. I discuss two accounts of a quality space for color vision (Clark, 2000; Rosenthal, 2010) and propose how to construct a quality space for pain. Daniel Kostic is Associated Researcher at Berlin School of Mind and Brain. (shrink)

Drawing on work in psychophysics, psychometrics, and sensory neurophysiology, Clark analyzes the character and defends the integrity of psychophysical explanations of qualitative facts, arguing that the structure of such explanations is sound and potentially successful.

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)

Many philosophers doubt that one can provide any successful explanation of sensory qualities - of how things look, feel, or seem to a perceiving subject. To provide such an explanation, one would need to explain qualitative facts in non-qualitative terms. Attempts to construct such explanations have seemed, in principle, doomed. Austen Clark examines the strategy used in psychophysics, psychometrics, and sensory neurophysiology to explain qualitative facts. He argues that this strategy could succeed: its structure is sound, and it can answer (...) the various philosophical objections lodged against it. On this basis Professor Clark presents an analysis of senosry qualities that offers the possibility of explaining at least some qualia, and he sketches how this scheme might eventually reduce to neurophysiology. If he is correct, we are not doomed to an eternity of mere acquaintance with our qualia. (shrink)

Ordinary perceiving relies heavily on our sensing the spatial properties of objects, e.g., their shapes, sizes, and locations. Such spatial perception is central in everyday life. We safely cross a street by seeing and hearing the locations of oncoming vehicles. And we often identify objects by seeing and feeling their distinctive shapes. -/- To understand how we perceive spatial properties, we must explain the nature of the mental states figuring in spatial perception. The experience one has when seeing a cube, (...) e.g., differs from the experiences one has when seeing other shapes, e.g., spheres and pyramids. We must explain how such experiences differ to fully understand how we perceive differences in the spatial properties of objects. This presents a challenge often overlooked in philosophy and cognitive science. Whereas we can differentiate physical objects by their spatial properties, we cannot differentiate the experiences involved in perception in respect of their own spatial properties. Experiences are mental states, not physical objects, so they do not themselves have spatial properties; a visual experience of a 50 ft. tall cube, e.g., isn’t itself 50 ft. tall or cubical. So we must differentiate our perceptual experiences of those objects some other way, in terms of their own properties. -/- I argue the experiences figuring in spatial perception have mental properties distinct from, but analogous to, the spatial properties we perceive. The experience one has when seeing a square, e.g., has a property that resembles and differs from other such mental properties in ways parallel to the ways physical squares resemble and differ from other shapes. Just as squares are more similar to rectangles than triangles, the mental property of an experience of a square is more similar to that of an experience of a rectangle than that of an experience of a triangle. -/- I show how this theory helps solve several problems in philosophy and cognitive science; explaining change blindness, accounting for our ability to perceive combinations of distinct properties, e.g., color and shape, and determining whether the properties of experiences pertaining to the same spatial properties in different sensory modalities are themselves the same. (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)

Evidence from many different paradigms (e.g. change blindness, inattentional blindness, transsaccadic integration) indicate that observers are often very poor at reporting changes to their visual environment. Such evidence has been used to suggest that the spatio-temporal coherence needed to represent change can only occur in the presence of focused attention. In four experiments we use modified change blindness tasks to demonstrate (a) that sensitivity to change does occur in the absence of awareness, and (b) this sensitivity does not rely on (...) the redeploy- ment of attention. We discuss these results in relation to theories of scene percep- tion, and propose a reinterpretatio n of the role of attention in representing change. (shrink)

Change blindness—our inability to detect changes in a stimulus—occurs even when the change takes place gradually, without disruption (Simons et al., 2000). Such gradual changes are more difficult to detect than changes that involve a disruption. In this experiment, we extend previous findings to the domain of facial expressions of emotions occurring in the context of a realistic scene. Even with changes occurring in central, highly relevant stimuli such as faces, gradual changes still produced high levels of change blindness: Detection (...) rates were three times lower for gradual changes than for displays involving disruption, with only 15% of the observers perceiving the gradual change within a single trial. However, despite this high rate of change blindness, changes on faces were significantly better detected than color changes occurring on non facial objects in the same scene. (shrink)