perceptual organization
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Perceptual organization. How do we form meaningful perceptions from sensory information?. Gestalt psychology. Branch of cognitive psychology Organization of many sensations into perceptions of wholes Gestalt = whole or form Based on experience and expectations - PowerPoint PPT PresentationTRANSCRIPT
Perceptual organization
• How do we form meaningful perceptions from sensory information?
Gestalt psychology
• Branch of cognitive psychology• Organization of many sensations into
perceptions of wholes– Gestalt = whole or form
• Based on experience and expectations• Perceived whole is not always the same
as its parts!
Form perception
• Simplification into easily interpretable wholes
• Figure-ground
Form perception
• Grouping principles– Proximity– Similarity– Continuity– Connectedness– Closure
Depth perception
• Distance is perceived with vision and hearing
• Visual depth perception– Binocular cues– Monocular cues
Binocular depth cues
• Retinal disparity– Strongest visual depth cue
Monocular depth cues
• Light and shadow• Relative size and
position• Relative
height/vertical position
• Linear perspective
Auditory location cues
• Intensity and pitch• Arrival times at each ear• Clarity
Perceptual constancy
• Cognitive functions that maintain the features of an object, despite changing illumination, color, size, or shape– Based on comparisons between the figure
and ground
Color and lightness constancy
• Consistent color and light intensity, despite changes in illumination
Shape and size constancy
• Familiar objects are perceived as unchanging despite changes in retinal images.
Perceptual interpretation
• Making sense of the perceptions produced by the cortex– Genetics– Experience
• Critical periods• Plasticity and adaptation
Perceptual set
• Psychological predisposition to perceive stimuli in a particular way– Shaped by learned assumptions and beliefs– Affects how we interpret sensory stimuli
• Examples
Other sensory modalities
Hearing
• Stimulus - sound waves– Frequency– Amplitude
The ear
Auditory stimuli
• Bending of hair cells in the cochlea transduces vibrations into neural signals
• Auditory nerve• Primary
auditory cortex• Auditory
association cortex
Touch
• Stimulus - pressure, pain, warmth, cold– Receptors– Other sensations
• Stimuli organized in primary somatosensory cortex
• Perceptions created in somatosensory association cortex
Pain
• Critical alert system• Subjective
– Physiology– Prior experiences– Attention– Context– Culture
Pain
• Gate-control theory
• Pain control/management
Taste
• Stimulus - chemical molecules that impart the sensations of sweet, sour, salty, bitter and umami
• Tastebuds contain taste and touch receptors
Sweet Sour Salty Bitter Umami
Taste perception
• Flavor – Based on taste, olfactory, and touch stimuli
• Begins in brainstem• Completed in the limbic system
Taste preferences
• Genetic predisposition
• Biological predisposition
• Learned responses
Smell
• Stimulus - chemical molecules • Receptors in olfactory epithelium
– Axons project directly to the olfactory bulb of the brain
– Perception begins in the olfactory bulb, completed in the limbic system
Kinesthesis & vestibular sense
• Kinesthesis - sense of body position and movement
• Vestibular sense - sense of head postion and movement
• Stimulus - gravity and movement• Receptors found in muscles (body) and
inner ear (head)
Kinesthesis & vestibular sense
• Sensory signals about position and movement are organized in the medulla and cerebellum
• Perception occurs throughout the brain– Brain stem– Temporal cortex