Silencing the Experience of Change. Sebastian Watzl (Harvard University)

Transcription

1 Silencing the Experience of Change Sebastian Watzl (Harvard University) 1

2 Our focus today: Visual experiences as of change.

3 Change of Color

4 Change of Size

5 Change of Shape

6 Change of Location (Movement)

7 A further fact? Experiences as of... Color Shape Size Location Change of Color Change of Shape Change of Size Change of Location...

8 Maybe not...

9 Your stream of experiences of color Your experience of change of color time fixes = = time

10 Cinematic Atomism Experiences as of changes in quality Q supervene on the temporal order and duration of experiences as of Q

11 Cinematic Atomism Attractions: No-further-fact-intuition Would allow reading-off the changes your experience presents to you from your stream of experience of the properties that are experienced as changing. Simplicity Explains something complex (experience as of change) in terms of something simple and uncontroversial (experience as of non-temporal properties). Obviousness If you first experience red, and the experience blue, isn t that just what it is to experience a sudden change from red to blue? What could be missing?

12 My Goal Show that a newly discovered visual illusion directly challenges cinematic atomism. Natural extensions of cinematic atomism attempting to capture the no-further fact idea do not succeed in overcoming that challenge. The experience of change is a further fact: experiencing a certain quality as changing (at a certain rate) is a separable and phenomenally manifest dimension of visual experience

13 The Illusion* Change of Color Stationary Rotation Phase *Suchow and Alvarez (2011): Motion silences awareness of visual change. Current Biology

14 The Illusion* Change of Color *Suchow and Alvarez (2011): Motion silences awareness of visual change. Current Biology

15 The Illusion* Change of Size *Suchow and Alvarez (2011): Motion silences awareness of visual change. Current Biology

16 The Illusion* Change of Shape *Suchow and Alvarez (2011): Motion silences awareness of visual change. Current Biology

17 The Illusion* *Suchow and Alvarez (2011): Motion silences awareness of visual change. Current Biology

18 Against Cinematic Atomism Focus on a particular dot #53

19 Against Cinematic Atomism Stream of Actual Colors Your stream of experiences of color Your experience of change of color Stationary Phase time time = Rotation Phase time time

20 Against Temporal Atomism Non-temporal sameness At each time t during the rotation phase (T R ) just like during the stationary phase (T S ), you experience the dots as having the hues (brightness, size, form) they have at (roughly) t, i.e. your experience of hue (brightness, size, form) is (roughly) veridical at each time during both phases. -> No difference in the (order and duration of) experiences of non-temporal quality Q. Change Difference You experience relatively slow changes of hue (brightness, size, form) during T R, while you experience relatively faster changes during T S. -> Difference in the experience of changes of Q.

21 Against Cinematic Atomism So, experiences of a change of Q do not supervene on the order and duration of experiences as of Q. So, Cinematic Atomism is false.

22 Cinematic Atomist Proposals?

23 Cinematic Atomist Proposals? 1. The Freezing Proposal Maybe motion does not silence the experience of change but freezes the experience of Q?

24 Cinematic Atomist Proposals? 1. The Freezing Proposal Stream of Actual Colors Your stream of experiences of color Your experience of change of color Stationary Phase time time Rotation Phase time time

25 Cinematic Atomist Proposals? 1. The Freezing Proposal An experimental test: The Flip Experiment Stream of Actual Colors Your stream of experiences of color Your stream of experiences of color Rotation Phase time time time Silencing Proposal Freezing Proposal

26 Cinematic Atomist Proposals? 1. The Freezing Proposal An experimental test: The Flip Experiment Stream of Actual Colors Your stream of experiences of color Your stream of experiences of color Rotation Phase time time time Flip color back to original color Silencing Proposal subjects do notice this flip! Freezing Proposal subjects do not notice this flip!

27 Cinematic Atomist Proposals? 1. The Freezing Proposal An experimental test: The Flip Experiment Stream of Actual Colors Your stream of experiences of color Your stream of experiences of color Rotation Phase time time time Flip color to close color Silencing Proposal subjects do not notice this flip! Freezing Proposal subjects do notice this flip!

28 Cinematic Atomist Proposals? 1. The Freezing Proposal time from Suchow and Alvarez (2011): Motion silences awareness of visual change. Current Biology

29 Cinematic Atomist Proposals? 1. The Freezing Proposal On the basis of The Flip Experiment, the freezing proposal should be rejected.

30 Cinematic Atomist Proposals? 2. Indeterminacy Proposals Doesn t the Silent Updating Interpretation make unwarranted assumptions concerning how determinate our visual experience is? Maybe during the rotation phase our experience is just less determinate. So, no need to believe in silent updating.

31 Cinematic Atomist Proposals? 2. Indeterminacy Proposals a. Radical Hue Indeterminacy During T S you do not experience # 53 as having any specific hue at all (i.e. indeterminate between all hues on the color wheel) Problems: how would something with experienced as having a completely indeterminate hue look like? would have to be correct for all dots: But then all dots would look to be the same hue! But they don t!

32 Cinematic Atomist Proposals? 2. Indeterminacy Proposals b. Mild Hue Indeterminacy During T R you experience # 53 as having a more indeterminate hue h (e.g. h could be indeterminate between red and orange) than during T S. Problem: Is the experienced h constant througout the rotation phase?

33 Cinematic Atomist Proposals? 2. Indeterminacy Proposals Dilemma: Assume that # 53 is experienced as having a constant h, e.g. (generic, indeterminate) red. Incompatible with the results of The Flip Experiment red red red red red red red red

34 Cinematic Atomist Proposals? 2. Indeterminacy Proposals Dilemma: Assume that # is experienced as having a non-constant h Stationary Phase Rotation Phase red yellow green blue red At what rate does h appear to change (one cycle from red to... to red again) during T R?

35 Cinematic Atomist Proposals? 2. Indeterminacy Proposals Dilemma: Assume that # is experienced as having a non-constant h Stationary Phase Rotation Phase red yellow green blue red Subjects indicate that: the apparent rate of change (one cycle) during T R << the apparent rate of change (one cycle) during T S. So, apparent rate of change of h during T R apparent rate of change of the determinates of h during T S.

36 Cinematic Atomist Proposals? 2. Indeterminacy Proposals Dilemma: Assume that # is experienced as having a non-constant h Stationary Phase Rotation Phase red yellow green blue red But then the apparent rate of change in color is not fixed by the temporal order and duration of the experiences of color.

37 Cinematic Atomist Proposals? 2. Indeterminacy Proposals Dilemma: Assume that # is experienced as having a non-constant h Stationary Phase Rotation Phase red yellow green blue red But then the apparent rate of change in color is not fixed by the temporal order and duration of the experiences of color.

38 Cinematic Atomist Proposals? 2. Indeterminacy Proposals c. Sortal Indeterminacy During T S you do not experience each dot indivually, but only the dots collectively. Problem: Might be true, but doesn t explain the difference in temporal phenomenology (measured by the silencing factor) during the two phases: During T S the dots appear to change fast. During T R the dots appear to change slower.

39 Cinematic Atomist Proposals? 2. Indeterminacy Proposals None of the indeterminacy proposals can by themselves account for all the phenomenal and experimental data.

40 Cinematic Atomist Proposals? 3. The Seeing-that Proposal The Standstill case can be seen as a form of change blindness: a change is happening in front of your eyes, but you fail to see it. Fred Dretske* has recently proposed that other forms of change blindness are cognitive, and not perceptual failures: not failure of seeing a change (since temporal atomism is true you can t specifically be blind to changes). But failure to see that there is a difference between how something is at one time and how it is at a different time. Can this idea be applied here? *Dretske, F. I. (2004). Change blindness. Philosophical Studies, 120, 1-18

41 Cinematic Atomist Proposals? 3. The Seeing-that Proposal No, the seeing-that proposal cannot be applied here (Dretske, I believe, would agree!): Can t explain appearance of slowing down. Changes are not concealed, but phenomenally manifest (phenomenally present during T S, and phenomenally absent/slowed down during T R ). Would mistakently say that during T R you do experience fast changes, while you report/believe that there are slow changes. This is phenomenally inadequate.

42 1 st Conclusion: Cinematic Atomism fails because it can t account for your experiences during The Illusion.

43 Extending Cinematic Atomism? 1 s

44 Extending Cinematic Atomism? 1. Non-cinematic atomism s In The Illusion the experience of motion silences the experience of chance. Non-Cinematic atomism about the experience of change can explain that, and captures what was essential to the atomistic idea! Non-cinematic atomism Experiences as of temporal properties supervene on the temporal order and duration of experiences as of non-temporal properties.

45 Extending Cinematic Atomism? 1. Non-cinematic atomism Total stream of experiences s Your experience of change of color Your experience of change of location Stationary Phase time Rotation Phase time

46 Extending Cinematic Atomism? 1. Non-cinematic atomism Non-cinematic atomism is unmotivated: 1. Must give no-further-fact intuition, simplicity and obviousness. s Can t in any obvious way read-off the experience of temporal properties from the experience of nontemporal properties. Given the temporal order and duration of your experience as of non-temporal properties, it remains an empirical question which temporal properties/changes you experience. In this sense, the experience of change is a clear further fact!

47 Extending Cinematic Atomism? 1. Non-cinematic atomism 2. Must give up cinematic motivation. s [E]xperience presents temporal phenomena in virtue of its own temporal layout [ ] [where there is a] direct link between the temporal properties of perception, and its temporal content [ ] * Experience would not present temporal phenomenal in virtue of its own temporal layout. The temporal contents of experience do not even crucially depend on the temporal properties of the experience itself. *Lee, G. (2007). Consciousness in a space-time world. Philosophical Perspectives, 21 (1),

48 Extending Cinematic Atomism? 1. Non-cinematic atomism 3. Must give up naive realist motivation. the world induces experience s temporal structure (at least in the good case). * s Object-time (here: the rate at which the dots are represented as changing) and act-time (here: the rate at which your experience is changing) can come apart: Your experience of hue in both phases changes in the same way, while the changes that your experience presents to you in both phases differ. *Philips, I. (2009). Experience and time. Ph.D. Thesis (University College London)

49 Extending Cinematic Atomism? 1. Non-cinematic atomism s Non-cinematic atomism does not vindicate the non-further fact idea and as such is unmotivated.

50 Extending Cinematic Atomism? 2. Holistic Unificationism (Dainton?*) Total stream of experiences s fixes Experiences of change (in location, color, size, shape,..) time + Diachronic unity relation *Dainton, B. (2008). Sensing change. Philosophical Issues, 18(1),

51 Extending Cinematic Atomism? 2. Holistic Unificationism (Dainton?*) s The silencing results imply the (empirical) possibility of a fragmentation of time consciousness: You do experience (fast) changes of location You do not experience (fast) changes of color/size/ shape) *Dainton, B. (2008). Sensing change. Philosophical Issues, 18(1),

52 Extending Cinematic Atomism? 2. Holistic Unificationism (Dainton?*) So, experiences as of change do not supervene on: s Total stream of experiences time + Diachronic unity relation *Dainton, B. (2008). Sensing change. Philosophical Issues, 18(1),

53 Extending Cinematic Atomism? 3. Holistic Retentionism (Husserl?*) By the same argument, experiences as of change do not supervene on: total streams of experience + retentions of earlier total experiences s Total stream of experiences time + Retention of earlier total experience * discussed in: Dainton, B. Temporal consciousness, The Stanford Encyclopedia of Philosophy

54 2 nd Conclusion: Natural extensions of cinematic atomism attempting to capture the no further fact intuition fail as well: Non-cinematic atomism Holistic Unificationism Holistic Retentionism

55 So, after all, the experience of change is...

56 A further fact!! Experiences as of... Color Shape Size Location Change of Color Change of Shape Change of Size Change of Location... Change is a separable and phenomenally manifest dimension of visual experience

57 One Further Implication: Change Blindness Since the silencing illusion depends on the absence of focal attention, my result suggests that outside attention the experience of change is selectively impoverished. Change-blindness, thus, generally may just be what the term suggest: a selective blindness to change. It provides no support to the view that our visual experience of nontemporal properties is poor (or absent) outside the focus of attention (as suggested by Tye (2010)*). *Tye, M. (2010). Attention, seeing, and change blindness. Philosophical Issues, 20 (1),

58 The END Thanks especially to: Jordan Suchow for the beautiful experiments, very insightful comments, and general help. Thanks also to: George Alvarez, Susanna Siegel, Enrico Grube, and Sean Kelly for very helpful comments and discussion.