Overview

Sensation and perception describe how we detect and interpret sensory information from the environment. Sensation refers to the raw data received by sensory organs, while perception is how our brain organizes and makes sense of that input. These processes work together to help us navigate and understand the world.

Key Themes and Concepts

• Receptor Processes: Specialized cells in the eyes and ears detect light and sound through transduction — converting physical energy into neural signals.
• Vision: Rods and cones in the retina respond to light; the optic nerve carries signals to the brain's occipital lobe for processing.
• Audition: Sound waves are translated into vibrations by the ear, eventually reaching the cochlea where hair cells trigger neural impulses.
• Other Senses: Includes taste (gustation), smell (olfaction), touch (somesthesis), and balance (vestibular system).
• Sensory Mechanisms: Thresholds (absolute and difference), sensory adaptation (decreased response to constant stimulation), and signal detection theory explain how stimuli are perceived.
• Perceptual Development: Influenced by both nature and nurture; infants develop depth perception, facial recognition, and pattern preferences early in life.
• Perceptual Processes: Top-down (driven by experience and expectations) and bottom-up (stimulus-driven) processing shape perception. Gestalt principles explain how we group stimuli into patterns.
• Attention: Selective attention determines which stimuli we focus on; inattentional blindness and change blindness illustrate limitations in perception.

Quick Tip

Transduction is the key process where sensory input is converted into electrical signals the brain can interpret — without it, perception wouldn’t happen. Our senses are constantly adapting to prevent overload, which is why you stop noticing a strong smell over time. Vision and hearing dominate our sensory world, but lesser-known systems like vestibular balance and signal detection theory play critical roles in how we interpret reality.