Chapter 1 Flashcards
Sensation
Detection of physical energy by our senses
Perception
Brain’s interpretation of the signals
Transduction
Physical energy is converted to electrochemical signals so the brain can process
7 Steps of Perceptual Process
- Stimulus
- Light is reflected and focused
- Receptor processes
- Neural processing
- Perception
- Recognition
- Action
5 Senses
- vision
- auditory
- olfaction
- gustation
- somatosensory
Receptor Processes
- Specialized cells respond to environmental stimuli
- Each sensory system’s receptors can only respond to a specific type of energy
Receptors for Light
photoreceptors (rods and cones)
Receptors of Sound
Hair cells in the inner ear
Receptors of Taste
- Taste bud
- Taste hair
- Gustatory cell
- Supporting cell
- Sensory nerve fiber
Receptors of Smell
- olfactory receptors
- olfactory bulb
Receptors of Touch
- Meissner Corpuscle = Heavy pressure
- Pacinian Corpuscle = Vibration
- Merkel Disks = Light Touch
- Ruffini Endings = Skin Stretch
Neural Processing
- Changes occur as signals are transmitted from receptors to neurons to receiving areas in the brain
- signals can be prevented OR amplified
Frontal Lobe Controls
- motor control
- concentration, planning, problem solving
- speech
- smell
Parietal Lobe Controls
- touch
- pressure
- taste
- body awareness
Occipital Lobe Controls
Vision
Cerebellum Controls
coordination
Temporal Lobe Controls
- Hearing
- Facial Recognition
Behavior Responses
- signals are turned into conscious experiences (perception)
- placing object into a category (recognition)
- involving motor activities such as walking, moving eyes/head (action)
Visual form Agnosia
Inability or difficulty recognizing objects (caused by brain injury)
- able to see object but unable to identify it
Prosopagnosia
Inability or difficulty recognizing a face “face blindness”
- unable to recognize their face or family members
Patient “WJ”
- had a stroke
- Prosopagnosia
- became a farmer
- found it easier to identify sheep instead of human faces
Patient “Mr. W”
- unable to recognize faces
- thought he looked funny
- no difficulty identifying his own cows and dogs by general colors, form, etc
Patient “MX”
- farmer
- had lesions in the occipital lobes
- had prosopagnosia, eventually disappeared
- unable to recognize his cows
Top-Down Processing
Influenced by experiences, beliefs, and expectations, “knowledge-based” processing, most common form
- Vision experiment
Bottom-Up Processing
Whole is constructed form parts, the most basic sensation and perception, “entry level”, data based processing
- Ex: chefs blind taste test
Measuring Perception (3)
- Thresholds
- Absolute Threshold
- Different Threshold
Threshold
- measure limits of the sensory systems
- measure of minimums
Absolute Threshold
Lowest level of a stimulus needed for nervous system to detect a change (50% of the time)
Difference Threshold
- Sometimes called “just noticeable difference”
- smallest change of intensity of a stimulus that we can detect
Weber’s Law
To perceive a difference, 2 stimuli must differ by a constant minimum percentage (not a constant amount)
- true for most senses, but every sense is different
- keys vs penny
Human Sensory System
- Not as sensitive to changes in weight as old scale
- Difference threshold for weight = 2%
- Ex: 2% of 200 is 4 (4 is needed to detect a difference)
Magnitude Estimation
- humans are good at estimating line length but not too good at electric shock or brightness
Response Expansion
Perceived magnitude increases more than the increase in actual intensity (electric shock)
Response Compression
Increase in perceived magnitude is smaller than increase in actual intensity (Brightness)
Reaction Time
The time between stimulus presentation and reaction
- reaction time is slower when not paying attention
Phenomenological Report
- Describing what you see
- We perceive objects and backgrounds based on our experiences
SUBJECTIVE
