# Proceeding in Cognitive Science Autumn 2010 Xuan Zhao Zhejiang University

## Presentation on theme: "Proceeding in Cognitive Science Autumn 2010 Xuan Zhao Zhejiang University"— Presentation transcript:

Proceeding in Cognitive Science Autumn 2010 Xuan Zhao Zhejiang University E-mail: zhaoxuanzju@gmail.com

WHAT WHY HOW Bayesian Inference

Flip a coin. Event: A, B A: One head at least B: Both heads or tails Question: P(B|A)? P(h|D)=P(h)*P(D|h)/P(D) P(h|D) = P(hD) / P(D) P(hD)=P(h)*P(D|h)

He didn’t say “hi” when passing by. Compare P(h1|D) and P(h2|D) to reach the most likely assumption. P(h2|D)=P(h2)*P(D|h2)/P(D) P(h1|D)=P(h1)*P(D|h1)/P(D) P(Bi|A) ∝ P(Bi) * P(A|Bi) D Didn’t say “hi” h1 Didn’t see me h2 Didn’t like me P(hi|D) ∝ P(hi) * P(D|hi)

priori probability

WHAT WHY HOW Bayesian Inference

Complexity Ambiguity Duplicity Insufficiency

One object? Two objects?

What is perceived are essentially those objects and events that under normal conditions would be most likely to produce the received sensory stimulation.

WHAT WHY HOW Bayesian Inference

P(h|D) ∝ P(h) * P(D|h)

‘‘Calling some skill or behavior innate tends to stop analysis of how it develops’’ (Fischer & Stewart, 1999, p. 150). WRONG!

Ina Innate assumptions validated by comparative research (Hershberger, 1970) Single light source. Light source above.

Natural Image Parsing N: non-terminal nods (models)

Evidence from behavioral research Evidence from neural science ERP and fMRI (Murray, et al, 2002): Dorsal regions provide input to lateral occipital complex (LOC), where signatures of illusory contour completion first appear, then followed by activity in V1/V2. MEG and fMRI (Bar et al, 2006): Low spatial frequency specific activity appeared in left orbitofrontal cortex 50 ms earlier than in fusiform gyrus of temporal cortex.

Bayesian Ideal Observer And more…

Vision as Bayesian inference: analysis by synthesis? Alan Yuille and Daniel Kersten, 2006 References 平凡而又神奇的贝叶斯方法 刘未鹏, 2008 Innateness (and Bayesian) Visual Perception Brian Scholl, 2005

Proceeding in Cognitive Science Autumn 2010 Xuan Zhao Zhejiang University E-mail: zhaoxuanzju@gmail.com

Similar presentations