Perception
Introduced| English |
|---|
| Perception/pəˈsepʃn/ |
| Bottom-up processing/ˈbɒtəm ʌp ˈprəʊsesɪŋ/ |
| Top-down processing/tɒp daʊn ˈprəʊsesɪŋ/ |
| Schemas/ˈskiːməz/ |
| perceptual sets/pəˈseptʃuːəl sets/ |
| cultural expectations/ˈkʌltʃərəl ekspɪkˈteɪʃnz/ |
| Attention/əˈtenʃn/ |
| Gestalt/ɡəʃˈtɑːlt/ |
| closure/ˈkləʊʒə/ |
| figure and ground/ˈfɪɡə ænd ɡraʊnd/ |
| proximity/prɒkˈsɪmɪti/ |
| similarity/ˌsɪmɪˈlærɪti/ |
| Binocular cues/bɪˈnɒkjʊlə kjuːz/ |
| retinal disparity/ˈretɪnl dɪˈspærɪti/ |
| convergence/kənˈvɜːdʒəns/ |
| Monocular cues/mɒˈnəʊkjʊlə kjuːz/ |
| texture gradient/ˈtekstʃə ˈɡreɪdɪənt/ |
| linear perspective/ˈlɪnɪə pəˈspektɪv/ |
| interposition/ˌɪntəpəˈzɪʃn/ |
| Perceptual constancies/pəˈseptʃuːəl ˈkɒnstənsiz/ |
| apparent movement/əˈpærənt ˈmuːvmənt/ |
Two people look at the same thing and see different things
- Sensation delivers the same raw data to both of them.
- What differs is what each brain does with it.
- Perception 知觉 is that second step — organising and interpreting sensation.
Bottom-up and top-down
- Bottom-up processing 自下而上加工 starts from the external sensory information itself.
- Top-down processing 自上而下加工 starts from what you already expect and know.
- Most perception uses both at once; questions ask which one a case relies on primarily.
Reading messy handwriting easily because you know the words relies mainly on...
Prior knowledge filling in unclear input is top-down processing.
The filters you bring with you
- Schemas 图式 and perceptual sets 知觉定势 are internal filters — frameworks that shape what you notice.
- Context, experience and cultural expectations 文化期待 are external filters.
- Attention 注意 is where sensation and perception meet, and it is affected by both kinds of filter.
An expectation that shapes what you notice before you notice it is a perceptual ____.
A perceptual set is an internal filter, alongside schemas.
Do not use sensation and perception as synonyms. Sensation is detection and transduction; perception is organisation and interpretation. A question about why two people disagree about what they saw is always a perception question.
Select all Gestalt principles the CED names.
Convergence is a binocular depth cue, not a Gestalt grouping principle.
Gestalt principles
- Gestalt 格式塔 psychology described how we group parts into wholes.
- The four the CED names are closure 闭合, figure and ground 图形与背景, proximity 邻近性 and similarity 相似性.
- Each one is the brain adding structure the sensory data did not contain.
Follow a stimulus from sensation to perception
Sensation is the signal; perception is what is made of it — and top-down expectation acts at the last step.
Perceptual constancy means an object looks different whenever its retinal image changes.
Constancy does the opposite — it keeps the object the same to you despite the changing image.
Match each cue to what it uses.
Disparity needs two eyes; interposition and texture gradient need only one.
Depth, constancy and movement
- Binocular cues 双眼线索 need two eyes: retinal disparity 视网膜像差 and convergence 辐辏.
- Monocular cues 单眼线索 work with one: relative clarity, relative size, texture gradient 纹理梯度, linear perspective 线条透视 and interposition 遮挡.
- Perceptual constancies 知觉恒常性 keep an object the same to you even as its retinal image changes; apparent movement 似动 is motion perceived where none occurs.
You read a handwritten note easily even though several letters are ambiguous. Bottom-up, the marks are unclear; top-down, your knowledge of the words fills them in. The same marks would be unreadable in a language you do not know.
Perception organises and interprets sensation, combining bottom-up and top-down processing. Schemas, perceptual sets, context and culture filter it. Gestalt principles group parts into wholes, binocular and monocular cues give depth, and constancies keep objects stable.