Sensation and Perception 2.1: Sensation vs. Perception Flashcards
Sensation -Synonym -Definition -CNS or PNS -
- Transduction
- Conversion of physical, electromagnetic, auditory, or other information from our internal and external environment to electrical signals in the nervous system.
- Occurs in the PNS and forward the raw, unfiltered, unprocessed signal to the CNS
Perception
- Definition
- How different from Sensation
- Processing of the information to make sense of its significance.
- It is the analyze of the raw signal paired with biases (external and Internal). This means that perception is apart of psychology.
Sensory Receptors
-What are they?
-Neurons that respond to stimuli and trigger electrical signals.
Psychophysics Definition
- The study of the relationship between the physical nature of stimuli and the sensations and perceptions they evoke.
Ganglia
-What are they
-A collection of neuron cell bodies found outside the CNS.
Projection Areas
-What are they
-Receive Electrochemical energy and analyze the sensory input
Sensory Receptors
- Sight
- Hearing and rotational/linear acceleration
- Pain
- Respond to Change in temperatures
- Respond to change in blood osomolarity (water homeostasis)
- Smell
- Taste
- Photoreceptors: Respond to electromagnetic waves in the visible spectrum
- Hair Cells: Respond to movement of fluid in the inner ear structures
- Nocireceptors: Respond to painful or noxious stimuli (Somatosensation)
- Thermoreceptors
- Osmoreceptors
- Olfactory Receptors: Respond to volatile compounds
- Taste Receptors: Respond to dissolved compounds
Threshold
- Definition
- A name for thresholds
- The minimum amount of a stimulus that renders a difference in perception.
- Limina
Absolute Threshold
- Definition
- Simply put
- What is the AT
- Minimum of stimulus energy that is needed to activate a sensory system. It is therefore a threshold in sensation, not in perception.
- How bright, loud, or intense a stimulus has to be before it is sensed
- If a sound is made an wiggles the hair cells but doesn’t trigger transduction, than the sound was not above the AT.
Threshold of Conscious Perception (Subliminal Threshold)
- Definition
- What is it
- Whats the difference between TCP and AT
- Perception of a stimulus below a given threshold
- Conscious Perception
- A stimulus below the AT will not be transduced and will not reach the CNS, A stimulus below TCP arrives at CNS, but does not reach higher brain regions that control attention and consciousness.
Difference Threshold (Just noticeable difference)
- Definition
- Weber’s Law Definition
- What does it mean
- Minimum difference in magnitude between two stimuli before one can perceive his difference.
- There is a constant ratio between the change in stimulus magnitude needed to produce a JND and the magnitude of the original stimulus.
- For higher magnitude stimuli, the actual difference must be larger to produce a JND.
Signal Detection Theory
- What is it
- Example
- Response Bias
- The idea that perception of stimuli can be affect by nonsensory factors: Internal (psychological) and external (environmental)
- You may not hear someone else’s name in a loud room, but you will hear yours
- Refers to tendency of subjects to systematically respond to stimulus in a particular way due to nonsensory factors.
Response Bias Study
- Catch Trials
- Noise Trials
- 4 possible outcomes
- What outcome determines a response bias
-A trial in which the signal is presented
-A trial in which the signal is not presented
-Hits: Signal given and subject correctly perceives it
Misses: Signal given and subject does not perceive it
False Alarms: Signal not given but Subject says he perceived it
Correct Negatives: Signal not given and Subject says he didn’t perceive it
-A significant amount of misses and false alarms
Adaption
- What is is
- How does it work
- Examples
-One way that the mind and body try to focus on only the most relevant stimuli, which are usually changes in the environment around us.
-Has a physiological (sensory) and a psychological (perceptual) component
-Pupils dilate in the dark and constrict in the light (physiological)
We get used to the cold water
