PSY2043 Ch05 Lecture Notes

PSY2043 Introduction to Psychology

Ch05 Perception

Intended Learning Outcomes

• Describe the role, benefits, and costs of selective attention in perception.
  • benefits – selective attention pares down the amount of necessary information processing to the point where it is manageable by the brain
  • costs – ignoring large parts of the environment, we lose the ability to remember much about those parts of the environment
• Understand the principles of object separation, distance perception, and motion perception.
  • Object separation
    • Figure and ground 图形和背景
    • Grouping of objects 物体的分组
      • 邻近性（grouping by proximity）
      • 相似性（similarity）
      • 连续（good continuation）
      • 闭合（closure）
  • Distance perception
    • Binocular cues 双眼线索
      • Binocular disparity 双眼像差：双眼所得视像间的差异
        • 当物体离我们近时像差最大，距离越远像差越小
    • Monocular cues 单眼线索
      • 相对大小
      • 重叠
      • 相对高度
      • 透视
      • 阴影
  • Motion perception
    • Stroboscopic motion 频闪运动
    • Real motion
      • Selective adaptation (motion aftereffect)
• Explain how object features are bound together and the involvement of pre-attentive and attentive processes.
  • Feature integration theory 特征整合论
    • 在前注意阶段，基本的特征（primitive features），被知觉到
    • 在注意阶段，using attentions to “glue” features together
    • 特征整合论的问题：研究发现太多的 ”primitives“ （原始特征）并不现实
    • 替代理论 - 动态控制论（dynamic control theory）
      • system rearranges itself for different tasks
• Learn what the difference is between bottom-up and top-down processing.
  • Bottom-up processes – driven solely by the input
  • Top-down processes – driven by person’s knowledge, experience, attention and expectations
• Learn why abstraction is important.
  • Abstracted information takes less space and is therefore faster to work with than raw information.
• Explain how the perceptual system achieves and maintains constancy, and how this can cause illusions.
  • illusions – the perceptual system’s insistence on maintaining
    constancies.
• Briefly describe the neural underpinnings of attention, recognition, and localization.
  • Three separate brain systems
    • The first system is generally associated with arousal.
    • The second, or posterior system, selects objects on the basis of location, shape, or color.
    • The third, or anterior system is responsible for guiding this process, depending on the goals of the viewer.
  • The visual cortex operates according to the principle of division of labor. Localization is mediated by a region near the top of the cortex, and recognition by a region near the bottom of the cortex. Recognition processes are further subdivided into separate modules such as color, shape, and texture.
  • Recognition and localization are carried out by two different regions of the visual cortex.

What is the use of perception?

Processing and using incoming sensory information

Five functions of perception

• 1）注意
• 2）定位
• 3）辨识
• 4）抽象
• 5）恒常性

Attention 注意

Selective attention 选择性注意

• 调整身体的感觉感受器以关照那些感兴趣的物体
• Eye movements 眼球运动
  • 视觉扫描采取一种注视的形式，被眼跳动区隔开
  • 注视（eye fixations）：一种眼睛保持短暂静止的状态
  • 眼跳动（saccades）：眼睛从某处快速跳动到另一处的状态
• Weapon focus 武器聚焦
• Ditected attention without eye movements 不涉及眼动的直接注意

Auditory attention 听觉的注意

• 选择性注意

Attention, perception, and memory 注意，知觉与记忆

• 我们对未曾注意的信息将无法察觉，即使有意识，所能记得的也不多

Costs and benefits of selectively attending to stimuli

Localization 定位

Separation of objects 物体的分离

• Figure and ground 图形和背景
• Grouping of objects 物体的分组
  • 邻近性（grouping by proximity）
  • 相似性（similarity）
  • 连续（good continuation）
  • 闭合（closure）

Perceiving distance 深度知觉

• Binocular cues 双眼线索
  • Binocular disparity 双眼像差：双眼所得视像间的差异
    • 当物体离我们近时像差最大，距离越远像差越小
• Monocular cues 单眼线索
  • 相对大小
  • 重叠
  • 相对高度
  • 透视
  • 阴影

Perceiving motion 运动知觉

• Stroboscopic motion 动景运动

Recognition 辨识

Global-to-local processing

• Global processing (what the scene is)
• Local processing (using knowledge about scene to identify object)

The binding problem: pre-attentive & attentive processes 整合的问题：前注意与注意过程

• Feature integration theory 特征整合论
  • 在前注意阶段，基本的特征（primitive features），被知觉到
  • 在注意阶段，using attentions to “glue” features together
  • 特征整合论的问题：研究发现太多的 ”primitives“ （原始特征）并不现实
  • 替代理论 - 动态控制论（dynamic control theory）
    • system rearranges itself for different tasks

Determining waht an object is 决定物体为何

• Shape形状 扮演了重要的角色
• Visual processing 视觉处理过程
  • 早期阶段，使用 retina视网膜 上的信息，来描述物体
  • 后期阶段，与视觉记忆中的物体形状比对，并选出最佳配对
  • Simple cells
  • Complex cells
  • Hypercomplex cells
• Relations among features

Later stages of recognition: network models 辨识的后期阶段：网络模式

• Simple networks简单网络
  • Connectionist models 连接者模式：字母是以某些特征来描述的，而符合知识的特征被包含于一连结的网络中
    • 兴奋型连结（excitatory connections)
  • 为了弥补 Connectionist models 的不足，引入 augmented network（扩大的网络）
    • 抑制性连结（inhibitory connections）
• Network with feedback反馈网络

Recognising natural objects & top-down processing

• Features of natural objects
• The importance of context
  • Bottom-up processes – driven solely by the input
  • Top-down processes – driven by person’s knowledge, experience, attention and expectations
  • 背景合适时，加强知觉；背景不合适时，损害知觉

Special processing of socially relevant stimuli: face recognition

• Development of special face recognition processes
  • Three sources of evidence
    • 面部辨识困难症 Prosopagnosia 大脑某部分损伤引起的脸盲
    • 面孔倒置效应 Inversion effect 很难辨认倒置的人脸

Failure of recognition

Abstraction 抽象

Exact to abstract

The advantages of abstraction: required storage and processing speed

• 节省储存空间，加快处理速度

Perceptual Constancies 知觉恒常性

• 即使物体因为其他原因 “感觉” 起来不一样了，我们仍能感知出事物的 实质 reality

• Color and brightness constancy 颜色和明度恒常性

• Shape constancy 形状恒常性

• Size constancy 大小恒常性

  • Dependence on depth cues 深度线索的依恃关系
    • size-distance invariance principle 大小-距离不变原则
      • 物体被知觉到的大小会依物体在视网膜上成像的大小和被知觉到的距离而增加

• Constancies in all sensory modalities

  • 所有感觉都存在恒常性，视觉最突出

• Illusions 错觉

  • 恒常性与错觉

Divisions of Labor in the Brain 脑部中的分工

• 注意的神经基础
  • 三种注意系统
    • One keeps us alert
    • Posterior system 前部系统:
    • Anterior system 后部系统: controls when and how these features will be used for selection
    • Anterior guides posterior, anterior systems is called CEO.
• The visual cortex 视皮层
• Recognition vs Localization systems 辨识与定位系统

Perceptual Development 知觉的发展

Discrimination by infants 婴儿的识别能力

• 研究婴儿的方法
  • 视觉偏好法
  • 习惯法：测量婴儿是否能分辨两种物理刺激
• 形状的知觉
• 深度的知觉
  • The Visual Cliff 实验
  • 3个月开始出现，6个月完全建立
• 知觉的恒常性

Controlled stimulation 在控制刺激环境下养育

• 缺乏刺激
  • 在黑暗中养育的黑猩猩会缺失知觉能力，并且视神经衰退
  • 天生的视觉能力发展有 Critical Period
• 限制刺激
  • 在只有水平或垂直线条的房间中养育的小猫，会对另外一个方向刺激毫无反应，视皮层细胞退化
  • 某些类别的刺激对天生知觉能力的维持及发展甚为重要
• 主动知觉
  • 小猫旋转木马实验
  • 学习在知觉与运动反应的协调中扮演一个主要的角色