Lecture Notes: Top-Down vs Bottom-Up Processing

Introduction

Understanding the difference between top-down and bottom-up processing is crucial in cognitive psychology.

Bottom-Up Processing

• Definition: Begins with the stimulus; perception is influenced by the stimulus.
  • Example: Looking at a banana without any prior knowledge or preconceived notions.
  • Key Characteristics:
    • Data-driven.
    • Starts with no preconceived idea.
    • Perception directs cognitive awareness.
  • Illustration: Observing a plane's cockpit without being a pilot, leading to confusion due to unfamiliar stimuli.

Top-Down Processing

• Definition: Uses background knowledge to influence perception.
  • Example: Observing a bunch of circles and lines, but perceiving a cube due to prior knowledge of cubes.
  • Key Characteristics:
    • Theory-driven.
    • Uses learning, expectations, and background information.
    • Influences perception based on what's already known.
  • Illustration: Interpreting an incomplete image as a cube by using mental concepts.

Contrast Between Top-Down and Bottom-Up

• Bottom-Up: Stimulus-driven, no prior knowledge.
• Top-Down: Expectation-driven, uses prior knowledge.
  • Examples:
    • Bottom-Up: A new, complex scene like a plane cockpit.
    • Top-Down: "Where's Waldo?", where the goal directs perception to find Waldo among distractions.

Conclusion

• Top-Down: Perception and behavior are influenced by expectations.
• Bottom-Up: Perception is driven by the direct stimulus.

Understanding these processes helps in discerning how different types of information and stimuli affect perception and cognitive understanding.