Understanding Sensation and Perception Processes

Supertasters

Individuals with heightened taste sensitivity due to more taste buds.

Empiricism

Philosophy stating knowledge arises from sensory experiences.

Proximal Stimulus

Physical energy interacting directly with sensory receptors.

Psychophysics

Study of relationship between stimuli and sensory perceptions.

Absolute Threshold

Minimum stimulus level detectable by sensory systems.

Difference Threshold

Smallest detectable change in a stimulus.

Weber's Law

Sensitivity to changes depends on proportional, not absolute, differences.

Signal Detection Theory

Framework for understanding stimulus detection and decision-making.

Vision

Sense providing information about shapes, colors, and distances.

Amplitude

Determines perceived brightness of light; higher means brighter.

Wavelength

Distance between wave crests; determines perceived color.

Visible Spectrum

Wavelength range visible to humans: 750-360 nanometers.

Photoreceptors

Cells in the retina that detect light.

Iris

Muscle controlling light entry by adjusting pupil size.

Cornea

Initial structure bending light for focus; fixed shape.

Lens

Adjustable structure fine-tuning light focus.

Rods

Photoreceptors for night vision; sensitive to low light.

Cones

Photoreceptors for day vision; responsible for color perception.

Fovea

Retinal area with highest concentration of cones.

Blind Spot

Area lacking photoreceptors where optic nerve exits eye.

Photopigments

Chemicals converting light into neural signals in photoreceptors.

Rhodopsin

Rod photopigment that breaks down in light, enabling low-light vision.

Contrast Effects

Visual sensitivity to brightness differences enhancing object identification.

Edge Enhancement

Visual system exaggerates edges for better visibility.

Visual Pathway

Pathway from optic nerve to visual cortex via thalamus.

Spatial Contrast

Sensitivity to brightness differences across visual field.

Mach Bands Illusion

Uniform gray strips show lighter and darker edges.

Lateral Inhibition

Neural process inhibiting adjacent neuron activity.

Feature Detectors

Neurons responding to specific visual elements.

Gestalt Psychology

Focuses on organized wholes in perception.

Mondegreens

Misperceptions of phrases in songs or speeches.

Hue

Color attribute distinguishing blue, green, red.

Brightness

Lightness or darkness of colors and shades.

Saturation

Purity of color compared to achromatic colors.

Perceptual Parsing

Organizing visual input into distinct objects.

Local Information

Features like T-junctions indicating depth.

Global Information

Principles like similarity guiding element grouping.

Good Continuation

Preference for smooth, continuous contours.

Figure and Ground

Distinguishing objects from their background.

Reversible Figures

Demonstrate perceptual flexibility in interpretation.

Feature Nets

Hierarchical detectors for recognizing visual patterns.

Bottom-up Processing

Data-driven activation from features to complex units.

Top-down Processing

Expectations influence perception of sensory input.

Geons

Building blocks for 3D object recognition.

Visual Agnosia

Impaired meaning despite intact structural description.

Subjective Contours

Perception fills in missing information to complete shapes.

Interpretation in Perception

Guided by experience and logical principles.

Perceptual Errors

Mistakes arising from interpretation of sensory data.

Object Recognition Challenges

Diverse appearances and partial views complicate recognition.

Interpretive Nature of Perception

Perception actively organizes incomplete sensory information.

Acoustic Input Ambiguity

Need for interpretation due to misheard sounds.

Complexity of Perception

Involves intricate organization and interpretation processes.

Figure-Ground Separation

Distinguishing objects from their backgrounds for perception.

Necker Cube

Demonstrates perception of orientation depends on interpretation.

Logical Inferences

Interpretations shaped by experience, generally accurate.

Visual System Rules

Prefers interpretations that explain all stimulus information.

Impossible Figures

Highlight limits of perceptual logic in interpretation.

Bottom-Up Processing

Data-driven flow from features to higher representations.

Top-Down Processing

Knowledge and expectations influence perceptual interpretation.

Top-Down Priming

Prior experience influences perception of ambiguous stimuli.

Motion Perception

Understanding object actions and navigating environments.

Retinal Motion

Not sufficient alone for accurate motion perception.

Apparent Movement

Perception of motion from stationary stimuli in succession.

Eye Movements

Compensate for retinal shifts to maintain perception.

Induced Motion

Perception of motion in stationary objects by surroundings.

Correspondence Problem

Determining element correspondence in changing visual scenes.

Perceptual Selection

Attending to relevant sensory information amidst input.

Mental Spotlight

Attention allows focused analysis of individual stimuli.

Illusory Conjunctions

Miscombined features due to divided attention.

Data-Driven Priming

Recent exposure enhances subsequent perception of stimuli.

Inattentional Blindness

Failure to perceive prominent stimuli when distracted.

Cocktail Party Effect

Focusing on one conversation amidst background noise.

Dichotic Listening

Minimal processing of unattended auditory information.

Attention's Role

Crucial for binding features into coherent objects.

Active Perception

Perception is interpretive, constructed by the brain.