Cognition, Perception, and Knowledge: Understanding the Intertwined Processes

Cognition, Perception, and Knowledge

• Cognition: The processes a system uses to acquire, store, represent, use, and respond to signals/information from the body and environment (e.g., body signals, environmental stimuli).

• Cognition: The mental operations that support people’s acquisition and use of knowledge.

• Conscious Cognition: Thought processes we are aware of, such as reasoning, decision-making, and problem-solving.

• Non-conscious Cognition: Mental processes that occur automatically, without conscious awareness, such as perception, memory retrieval, and habitual actions.

• All aspects of cognition are... INTERTWINED

• Top-down Processing: Processes (i.e., knowledge-based; e.g., thought and motivations) influence what we detect, attend to, and perceive!

  • Bottom-up Processing: Processes (i.e., stimulus/data-based; e.g., sensations) influence what we perceive, attend to, and think about.

  • Applicable to real-world problems, as understanding how people process information allows for improvements in various fields.

    • Improving safety (traffic systems are designed based on how people perceive visual signals and react to inform).

    • Knowledge: traditionally has been understood as things consciously known, meaning information and concepts acquired through experience, learning, and reasoning.

• Nurture (Experience-Based Knowledge):

  • Knowledge is shaped by life experiences, learning, and cultural/environmental factors. For example, learning a new language.

• Nature (Innate Processing Abilities):

  • Some cognitive abilities are hardwired into the brain and do not require conscious learning.

  • Example: Depth perception, facial recognition.

• Perception is subjective, meaning that it is a construct of the brain rather than a direct representation of reality.

• Perception is shaped by:

  • Past experience: What we have learned influences what we notice and expect.

  • Habits: Repeated exposure to certain stimuli shapes automatic responses.

  • Evolutionary predispositions: Some cognitive biases and tendencies are hardwired for survival, such as fear of heights or rapid detection of movement.

• Knowledge is also subjective because:

  • It is based on perception, which is already filtered and interpreted by the brain.

• Understanding how perception is shaped allows us to influence behavior, learning, and decision-making.

• Examples:

  • Marketing and UX design: Using color contrast and perceptual cues to draw attention to specific elements.

• Since all knowledge is based on perception, and perception is subjective, our understanding of reality is inherently limited and shaped by our cognitive processes.

Luminance Contrast Effects

Brightness differences create visual illusions where edges appear exaggerated.

Color Contrast Effects: A gray region looks tinted when surrounded by a strong color.

Visual Adaptation Effects: After looking at a stimulus for a while, the opposite effect appears.

Transduction: The process of converting environmental energy into electrochemical signals in the brain.

Perception is influenced by context (spatial, temporal, and past experience). e.g., luminance contrast, motion aftereffects, ambiguous figures

Absolute Threshold → Determines whether you can detect a stimulus at all.

Difference Threshold (JND) → Measures how much a stimulus must change before you notice a difference.

Threshold refers to the point of transition from one state to the other.

• Weber’s Law and Weber Fractions

• Weber Law: The amount of difference needed between 2 stimuli to detect the Just Noticeable Difference is a CONSTANT PROPORTION of the intensity of the starting stimulus.

• Weber Fractions: The constant fraction that scales up in a fixed, proportional amount when changing a stimulus.