Chapter 4: Sensation & Perception Flashcards
Sensation
process of receiving stimulus energies from the external environment
Perception
process of organizing and interpreting sensory information
Bottom-up Processing
is initiated by sensory input, the influence of the outside world on perception
Top-Down Processing
is initiated by cognitive processing, the influence of the internal/mental world on perception
(expectations and prior understanding)
Sensory Receptors
specialized cells that selectively detect and transmit sensory information to the brain, these signals are sent through distinct neural pathways
3 Categories of Receptors
Photoreception - vision, detection of light
Mechanoreception - touch/hearing, detection of pressure, vibration, & movement
Chemoreception - smell/taste, detection of chemical stimuli
Absolute Threshold
minimum amount of stimulus an organism can detect 50% of the time
ex: a candle flame at 30 miles on a dark, clear night
Difference Threshold/JND
amount of stimulus change needed for detection, weber’s law states that it is not necessarily about amount of change but more about proportion of change
Signal Detection Theory
how we notice things, “did I detect something?”
4 outcomes =
- Hit -> a stimulus is present and is detected
- Miss -> a stimulus is present but not detected
- False Alarm -> false detection of stimulus
- Correct Rejection -> no stimulus present and no detection
Attention
focusing awareness on a narrowed aspect of the environment
Cocktail Party Phenomenon
Selectively paying attention within a loud setting (certain things in the environment grab attention more than others)
Stroop Effect
mixed sensory signals confuse perception
Sensory Adaptation
our brain cells become less sensitive to to constant stimuli that is detected by our senses
ex: our eyesight
adjusting to darkness
Retina
consists of rods and cones, converts light that enters our eye into signals sent to the brain
Rods
are sensitive to dim light, but not color. function well in low illumination, humans have about 120 million
Cones
are responsive to color, operate best under high illumination, humans have around 6 million. mostly located in the fovea which is densely populated with those vital to many visual tasks
Optic Chiasm
the optic nerve that fibers divide
Trichromatic Theory of Color
there are 3 main categories of receptors: green, blue, and red cones
Opponent Process Theory (Afterimages)
sensation remains after a stimulus is removed, cannot be explained by trichromatic theory
What is the outer ear consisted of?
pinna and external auditory canal
What is the middle ear consisted of?
ear drum and hammer, anvil, & stirrup
What is the inner ear consisted of?
oval window, cochlea (fluid that is in the cochlea orients balance), basilar membrane (hair cells/cilia), tectorial membrane
Pathway of Auditory Information
Cochlea -> Auditory Nerve -> brain stem -> temporal lobe
Localizing Sound
each ear receives slightly different stimuli from the sound source, intensity of sound depends on distance and the sound shadow
Sound Shadow
the listener’s head serves as a barrier that reduces sound intensity
Skin Senses
Touch, Temperature, and Pain
Pathway of Touch
receptors -> spinal cord -> thalamus -> somatosensory cortex (parietal lobe)
Thermoreceptors (Temperature)
help to detect warmth and cold
Pain
mixture of mechanical, chemical, and heat receptors. endorphins are responsible for turning pain receptors on and off
Papillae (Taste)
the receptors on our tongues, otherwise known as taste buds
5 Taste Qualities
sweet, sour, bitter, salty, umami
Olfactory bulb/nerve
the lining of the roof of the nasal cavity that contains receptors for smell
How is smell connected to memory and emotion?
the neural pathway for smell is directly connected to various brain regions, especially the limbic system, which is involved in memory and emotion.
Kinesthetic
involves movement, posture, & orientation
Vestibular
involves information about balance, movement, and acceleration
