Sensation and Perception Introduction

Sensation and Perception Introduction

• Sensation and perception work together, but play different roles in interpreting the world.
• This chapter describes theories, and explains their role in psychology.

Sensation

• It's the process where senses gather info, and send it to the brain.
• A large amount of information is sensed simultaneously.

Absolute Threshold

• It's the point where something becomes noticeable to our senses (softest sound, slightest touch).
• It's when a stimulus goes from unnoticeable to detectable.

Difference Threshold

• Weber's Law states that a constant percentage of change, not a fixed amount, is needed for a difference to be perceived.

Signal Detection Theory

• It describes how we focus on specific stimuli, and ignore others in situations like a noisy room.
• We try to select what to focus on and eliminate distractions

Sensory Adaptation

• It describes stimuli that become less noticeable over time when unchanged.
• Example: the ticking of a clock.

Perception

• Perception is our interpretation of sensory information, which differentiates us from others and explains individual differences.
• The way we perceive our environment differs between individuals.

Gestalt Principles of Grouping

• Gestalt psychology believes the whole is more than the sum of its parts.
• It helps us interpret incoming sensory information by arranging it into distinct groups.

Types of Gestalt Principles of Grouping

• Similarity: Grouping similar objects together. (e.g. like circles).
• Proximity: Grouping objects near each other together. (e.g. closely arranged dots).
• Continuity: Grouping continuous patterns together. (e.g. smooth curves)
• Closure: Completing incomplete figures/shapes. (e.g. drawing a circle around a partial circle).

Maintaining Perceptual Constancy

• Perceptual constancy is our ability to perceive objects consistently, despite changes in context.
• Examples: our perception of an object size when it moves from far to close, not changing how big it should appear to be.

Types of Perceptual Constancy

• Size Consistency: Perceiving objects as having a consistent Size, regardless of distance.
• Shape Consistency: Perceiving objects as having a consistent shape, regardless of its orientation.
• Brightness Consistency: Perceiving objects as having a consistent brightness regardless of lighting conditions.

Perceiving Distance

• Distance perception is the process of judging the space between two points.
• It's done using monocular and binocular cues.

Monocular Cues

• Size: Larger images signal closer objects.
• Texture: Smoother textures appear further away.
• Overlap: Overlapping objects appear closer.
• Shading/Shadows: Closer objects cast longer shadows, overlapping those farther away.
• Height: Objects higher in the visual field appear further away (compared to objects closer to the bottom of the field).
• Clarity: Clearer images imply closeness.

Binocular Cues

• Binocular cues require both eyes to perceive distance.
• Convergence: Eyes turn inward more for closer objects.
• Retinal Disparity: Slight difference in the images received by each eye (different angles/view).

The Five Senses

• Sight, smell, taste, touch, and hearing are the traditional five senses.
• Aristotle is credited with defining them.

Sight

• Occurs when light is processed by the eye and interpreted by the brain
• Light passes through the cornea (transparent part of the eye).
• The pupil (the opening) adjusts to regulate light entering the eye

Hearing

• Auditory processing involves steps in which the ear and auditory nervous system work together.

Taste

• The gustatory system perceives flavor.
• Receptors in the mouth (mostly the tongue) detect it through chemical reactions.

Smell

• Smell is part of the chemosensory system (chemical senses).
• Olfactory sensory neurons in the nose detect it directly and signal to the brain.

Touch

• Tactile sense involves receptors on the skin that process pressure, temperature, vibration, and pain.

Beyond the Five Senses

• Equilibrioception: sense of balance, spatial orientation. Prevents from falling.
• Thermoception: perception of temperature and temperature differences.
• Nociception: detection of painful stimuli, sending alerts to the body.
• Kinesthesia: awareness of muscle and joint movement.
• Synesthesia: one stimulation evokes another sensation. (e.g. colors with numbers)

Explore the fundamental concepts of sensation and perception in psychology. This quiz covers various theories, absolute and difference thresholds, signal detection theory, and sensory adaptation. Test your knowledge on how our senses work together to interpret the world around us.