Reorganizing the Perceptional World

Transcription

1 Reorganizing the Perceptional World

2 How do we recognize WHAT objects are? Info is analyzed by the brain Brain finds a match from memory (recognition) Placed into a perceptual category

3 Can your brain recognize the pattern of information & place it into a perceptual category?

4 Perceptual Categories

5 Right ½ room close eyes

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8 Left ½ room close eyes

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12 How does this perceptual categorization occur? Bottom-up Processing First recognize basic FEATURES of stimuli (feature detectors in brain) Light/Dark? Color/Motion? Top-down Processing Recognition depends on EXPECTATIONS & EXPERIENCE & MOTIVATION. Schemas lead to perceptual sets.

13 Bottom-Up Processing Relies on specific, detailed info elements from sensory receptors that are integrated and assembled into a whole Data driven

14 Bottom-Up Processing analyze stimuli into basic features before higher centers of the brain recombine them to create a full perceptual experience color, motion, spatial orientation, and patterns of light and darkness are some features visual systems analyze In face recognition, not all features are equally weighted; we tend to rely on large-scale features, such as hair and head shape, to recognize people

15 2011 by The Royal Society Little A C et al. Phil. Trans. R. Soc. B 2011;366:

16 2011 by The Royal Society Little A C et al. Phil. Trans. R. Soc. B 2011;366:

17 Bottom-Up Processing Hidden Bird Biological Motion

18 Top-Down Processing Guided by knowledge, expectations, and other psychological factors. Schema: mental representations about the world can bias our perception leading to a perceptual set a readiness or predisposition to perceive a stimulus in a certain way Motives can alter perceptions; we perceive more easily what we are motivated to perceive

19 The phaonmneal pweor of the hmuan mnid: Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it dseno't mtaetr in waht oerdr the ltteres in a wrod are, the olny iproamtnt tihng is taht the frsit and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it whotuit a pboerlm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. If you read the words which perceptual method is at work?

20 Top Down Relies on prior experience with an object. Faster, but because of the quick judgments often made it may be inaccurate. Bottom Up Achieves recognition of an object by breaking it down into its component (sensory) parts. LEMON EXAMPLE: When perceiving the taste sensations of a lemon, which of the following explains top down perceptual processing, and which explains bottom up perceptual processing? The first time you eat a lemon you recognize it is sour. The next time you eat a lemon you may salivate or wince before ever tasting it.

21 Parallel Distributed Processing Model (PDP) recognition occurs as a result of simultaneous (parallel) operation of connected neural network units that are activated by stimulus features Enlightened by past experience Blotted letters

22 Culture, Experience & Perception A study conducted in Kenya showed that the villagers could not interpret it in that way. As far as they were concerned the picture showed either a very big man or a very small rhino.

23 Use Bottom-Up Processing to explain how you recognize this stimulus:

24 Use Top-Down Processing to explain how you recognize this stimulus:

25 Use the PDP model to explain how you recognize this stimulus: