Download presentation

Presentation is loading. Please wait.

Published byShakira Symmonds Modified over 2 years ago

2
Beauty in the Eye of the Beholder The Relativity of Visual Experience Andrew Duggins Westmead Hospital, University of Sydney andrew.duggins@sydney.edu.au

3
Is Experience Relative? Do the transformations of Einstein’s special relativity apply to subjective spacetime? Just as… – gravity is the curvature of objective spacetime by mass – attention is the curvature of subjective spacetime by information

4
Plan Subjective spacetime Special relativity – Time dilation – Limiting speed c Information theory – Efficient encoding General Relativity – Oddball effects – Artist’s perspective – Equivalence principle – Visual inattention – Sketch of a unifying theory

5
XII VI IX III IIX IV III XI

6
XII VI IX III

8
1 1 t x

9
1 1 t x

10
1 1 t x

11
1 1 t x

12
1 1 t x

13
1 1 t x

14
1 1 t x

15
1 1 t x

16
1 1 t x

17
1 1 t x t

18
1 1 t x t Speed of light, c = 1

19
1 1 t x t c ≠ 1

20
1 1 t x t

21
1 1 t x t x 1 1

22
t x 1 1 t x 1 1 t 2 – x 2 = 1

23
1 1 t x t 1

24
t x 1 1 t x 1 1 t 2 – x 2 = t 2 = 1 t2t2 – x 2 = 1 τ = 1 Proper time, τ = √ (t 2 – x 2 )

25
XII VI IX III IIX IV III XI

26
XII VI IX III IIX IV III XI

27
t x 1 1 t x 1 1 t x 1 1

28
speed, v 1 rapidity, φ Speed of light, c = 1 0.68 0.825 0.5 0.55 v = tanh φ

29
Vestibulo-ocular reflex

102
Vestibular nystagmus

283
Pulaski et al, Brain Research, 1981

284
c = 500 deg/sec v eye /500 = tanh (v head /500) Pulaski et al, Brain Research, 1981

285
Is Experience Relative? Do the transformations of Einstein’s special relativity apply to subjective spacetime? …..Perhaps!

286
00 01 10 11 To encode the sequence: 2 binary digits per trial

287
¼ ½ 1 2 1 0 -2 -3 -4 Probability (P) Information (I) = -log 2 (P) I 1 bit 2 bits 3 bits P½¼1/81/8P½¼1/81/8

289
0 10 110 111 To encode the sequence: 1.75 binary digits per trial 1.75 bits = = ‘Entropy’ 1.75 bits/trial = the most efficient possible code P = ½ P = ¼ P = 1 / 8

290
Choice Reaction Time Task

291
Choice Reaction Time Hick, 1952 – k items – Reaction time log 2 (k) Hyman, 1953 – Skewed distributions – Reaction time Entropy – ~ 129ms/bit Our Hypothesis Quicker reactions for more probable alternatives Minimum reaction time on average

293
‘Efficient Coding’ Hypothesis Survival depends on the minimum average reaction time Reaction time to stimulus x depends on the length of the ‘neural codeword’ Codeword length, and visual processing activity should vary with self-information, - log 2 P(x)

295
Strange et al (2005)

296
Comments Attention – Coextensive with visual attention network – ‘Oddball’ responses reflect efficient coding Repetition suppression – Updated probabilities increase with repetition – Self-information incrementally decays The Neural Codeword

297
Subjective Duration 1 Pariyadath, Eagleman (2007) 2 nd object: P = 1/2 P = 1/6 1 bit 2.58 bits Random 2 nd object perceived to last 60ms > Repeated = an extra 38ms/bit

298
Subjective Duration 2 Pariyadath, Eagleman (2007) Random/Sequential 2 nd object: ‐log 2 (1/3) = 1.58 bits Scrambled 2 nd object: ‐log 2 (1/9) = 3.17 bits Relative delay 75ms=an extra 47ms/bit

299
Coding Hypothesis Stimulus information expands: – Subjective duration – Reaction latency …to a similar extent

300
Am I a blue circle? Zombie celebrity heads

301
Conclusions Information prolongs experience Information delays reaction – Efficient coding – Minimum expected reaction time Experience first, react later: Information quantifies the difficulty inherent in the ‘Hard’ problem

302
Duration Dilation by Information Objective time 320ms 1 Bit 360ms Subjective time 2 Bits Subjective time 400ms 0 Bits 40ms / bit

304
Hypothesis Gravity is the curvature of objective spacetime by mass Attention is the curvature of subjective spacetime by information Time Space

310
r 2 =x2x2 + y 2

311
θ dr 2 + r 2 dθ 2 dσ 2 ≠ Length dilation at distance: dσ/dr = 1/√(1 + r 2 ) << 1

313
Equivalence Principle

315
Left Visual Inattention

316
Left Vestibular Stimulation

317
Left Angular Acceleration

318
Visual Inattention 0 π/6 π/3 π/2 2π/3 5π/6 π x = θ 1 metre

321
0π/6π/3π/22π/35π/6π x σ dσ/dx > 1

322
0π/6π/3π/22π/35π/6π x σ dσ/dx ≈ 1 Length contraction as x → 0

323
0π/6π/3π/22π/35π/6π x σ dτ/dt < 1 Basso et al, Neuroreport, 1996

324
0π/6π/3π/22π/35π/6π x s dτ/dt ≈ 1 Time dilation as x → 0

325
dτ 2 = (1 – 2MG/x) dt 2 – 1/(1 – 2MG/x) dx 2 -MG/x = ‘gravitational potential’ dτ 2 = (1 – 2IA/x) dt 2 – 1/(1 – 2IA/x) dx 2 -IA/x = ‘attentional potential’ I = ‘reduction in uncertainty’A = ‘attentional constant’

Similar presentations

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google