Sensation and Perception Flashcards
Exteroceptive Sensations
-Sensation from external stimuli (outside the body)
-Relies on our sensory organs to pick up that stimuli
Interoceptive Sensations
-Sensations from inside our body
-E.g. dancers have increased interoceptive accuracy (they ecould estimate heart rate more accurately than non-dancers)
Proprioception
-Sense of where our limbs are in space
-E.g. touching your nose with your eyes closed
Nociception
-Sense of pain due to body damage
-E.g. Throbbing pain from things like stubbing toe, dental problems
Equilibrioception
- Sense of balance
Synaesthesia
-A neurological condition in which one sense automatically triggers the experience of another sense
- E.g. hear colours, smell sounds, see time
- Genetic component
-More common in women
-Specific pairings tend to be stable in an individual
-Suggests brain is organized as ‘‘talking’’ circuits or regions
McGurk Effect: When you hear what you see
-A multisensory illusion
-A voice articulating a consonant (ba) paired with a face articulating another one (fa) leads you to ‘‘hear’’ what you ‘‘see’’
-A change in auditory perception from visual perception to reconcile these incongruent inputs
-Illustrates the dominance of visual input
-Illustrates integration of and cross-talk among senses
Early visual processing
-Sensation
-Eyes and the optic nerve
Late visual processing
-Perception
-The visual cortex or occipital lobe
Steps of early visual processing
- Lights waves enter the eye
- Porjected onto the retina
-The retina forms an inverted image (bends light) - Retina photoreceptors convert light to electrical activity
-Rods + Cones - The electrical signal is sent to bipolar cells
-Then sent to ganglion cells - The signal exits through the optic nerve
-To the brain for later visual processing
Ganglion cells
-Make up the optic nerve that exits to the brain
-Front of the retina
Photoreceptors
-Cells at the back of the retina
Blindspot
-‘‘exit location’‘(from retina to brain), there are no photoreceptors
-No vision!
Perceptual filling-in
The brain (later visual processes) will use surrounding visual information to make up for the missing information
Primary Visual Cortex
-Specialized regions that process specific visual attributes or features
-Edges, angles, color, light
-Processed seperately but at the same time in different regions
Visual Association Areas
-Interpret visual signal, assigns meaning
-What + where pathways
What (Ventral) Pathway
-Occipital to temporal lobes
-Shape, size, visual details
-What am I looking at.
Where (Dorsal) Pathway
-Occipital to parietal lobes
-Location, space, movement information
-Where something actually is in space
Bottom-up processing
-The influence of information of information from the external environment on perception
-Information from the sensory organs (eyes) to the visual cortex
-Looking at something and taking the information into the brain to help me perceive
-E.g. visual to head
Top-down processing
-The influence of knowledge (expectations, context and goals) on perception
-Information from higher processing brain regions (prefrontal cortex or higher visual processing areas) is sent back to the sensory organs
-Looking at something and also using prior knowledge to interact with how I’m perceiving
-E.g. head to visual
Constructivist Theory of Perception
-Top-down processes influence bottom-up processes
-We use what we know and expect to interpret sensory information
-Perception is influenced by stored knowledge + context
-This means what we perceive is not the ground truth!
-The world is an illusion!
The Ponzo Illusion
-To lines seem to be different lengths depending on their context
- E.g. train tracks
Terror Subterra
-To objects seem to be the same size depending on context
-E.g. 2 gorillas
The World is Lit from Above
- An object seems to indented a certain way because of our knowledge of light
-E.g. Hands in snow
The Letters in Context Effect
-The ability to read words in sentences even when the letters in the middle of some of the words are mixed up
-You ‘expect’ to see real words in a sentence
The Color in Context Effect
-The context a color apears changes how you see that color
-Depends on our expectation (from experience) of how objects look under contexts of illumination
