MODULE 4_SENSATION AND PERCEPTION

MODULE 4: SENSATION AND PERCEPTION

• Instructor: Dr. Rachelle S. Garcia/Blas/Laza

Page 1: Introduction

• Overview of the relationship between sensation and perception.

Page 2: Key Concepts

• Sensation vs. Perception: Differentiates sensation as the initial detection of stimuli and perception as the organization and interpretation of sensory input.

• Types of Sensation: Haptic (touch), echoic (hearing), iconic (sight), olfactory (smell), gustatory (taste).

Page 3: Definitions

• Sensation: Awareness from stimulation of sense organs; it involves receiving information via sensory organs.

• Perception: Organizing and interpreting incoming information for understanding and reaction.

Page 4: Interaction of Sensation and Perception

• Sensation and perception work together for complete sensory experience.

• Combination of current environmental learning and prior knowledge aids comprehension.

Page 5: Transduction

• Transduction: Conversion of stimuli by receptor cells into electrical impulses sent to the brain.

• Absolute Threshold: Minimum stimulation needed for detection of stimulus.

• Psychophysics: Studies the relationship between physical stimuli and sensory experiences.

Page 6: Sensitivity and Response Bias

• Sensitivity: The true ability to detect a stimulus.

• Response Bias: Likelihood to respond affirmatively regardless of sensitivity.

• Difference Threshold / Just Noticeable Difference (JND): Smallest change in a stimulus that can be detected, governed by Weber's Law (constant proportion).

Page 7: Vision - Sense of Sight

• Anatomy of the Human Eye: Light follows a pathway from cornea -> pupil (iris) -> lens -> retina -> optic nerve to the visual cortex.

• Images are processed upside down on the retina before transmission to the brain.

Page 8: Primary Visual Cortex

• Primary Visual Cortex: Located in the occipital lobe, responsible for awareness of visual stimuli.

Page 9: Depth Perception

• Convergence: Eyes turn inward to focus on nearby objects; a binocular cue for depth.

• Linear Perspective: Parallel lines appear to converge in the distance, indicating depth.

Page 10: Sense of Hearing

• Sound waves travel through the ear: pinna -> external auditory canal -> eardrum -> ossicles -> cochlea.

• Hair Cells: Convert vibrations into neural signals, sent via the auditory nerve to the brain.

Page 11: Auditory Processing

• Processing of sound signals in the auditory cortex allows perception of pitch, loudness, and timbre.

Page 12: Sound Characteristics

• Frequency: Determines pitch.

• Amplitude: Relates to loudness measured in decibels (dB).

• Thresholds: 0 dB absolute threshold; sounds above 80 dB can cause hearing loss.

Page 13: Levels of Noise

• Various decibel levels and associated sounds, indicating potential discomfort or danger:

  • 140 dB: Painful (e.g., fireworks)

  • 120 dB: Uncomfortable (e.g., jet planes)

  • 80 dB: Loud (e.g., alarm clocks) and can cause hearing loss with prolonged exposure.

Page 14: Gustation - Sense of Taste

• Six taste sensations: sweet, salty, sour, bitter, piquancy (spicy), umami (savory).

• Taste buds trigger nerve impulses sent to sensory cortex during chewing.

Page 15: Olfaction - Sense of Smell

• Smell enhances the experience of taste; airborne molecules stimulate olfactory receptors.

• Olfactory bulb houses 10-20 million receptor cells, capable of detecting many odors.

Page 16: Age and Smell

• Significant decline in sense of smell occurs between ages 60-70, affecting taste and perception.

Page 17: Sense of Touch

• Skin as the largest organ, with nerve endings sensitive to pressure, pain, and temperature.

Page 18: Tactile Mechanoreceptors

• Two primary receptors:

  • Meissner's Corpuscles: Detect light touch and texture.

  • Pacinian Corpuscles: Sense deep pressure and vibration.

Page 19: Proprioception

• Proprioception: Awareness of body position and movement.

• Vestibular System: Monitors head position and movement, maintaining balance via fluid-filled canals and sacs.

Page 20: Summary of Sensation and Perception

• Comparison of senses:

  • Vision: Light waves

  • Hearing/Auditory: Sound waves

  • Smell/Olfactory: Odor molecules

  • Taste/Gustation: Food flavors

  • Touch: Pressure change

  • Proprioception: Body movement awareness.