Sensory Perception Flashcards
What is a sensory receptor?
cellular receptors that respond to external stimulus ie) hair cells in ear (mechanoreceptor) move and creates AP.
What are the sensory receptor types?
1) chemoreceptors - detects chemicals (nose, gustatory cells) 2) nociceptors - pain 3) proprioceptors - sense position 4) thermoreceptors - temperature 5) baroreceptors - pressure (in blood vessels) 6) osmoreceptors - osmolarity of fluid (hypothalmus) -helps brain monitor osmolarity of blood 7) electromagnetic sensors - photo receptors
What are the two groups of cutaneous receptors?
1) Free nerve endings (nociceptors and thermoreceptors) 2) Encapsulated receptors - more specialized (all other types of cutaneous receptors)
Tonic receptors
Slowly adapting receptors that respond for the duration of the stimulus
Phasic receptor
receptor that rapidly adapts to a constant stimulus and turns off, then fires once again when stimulus ceases (very sensitive to changes)
Types of nociceptors
1) Thermal - hot and cold 2) Mechanoreceptor - laceration in skin, strong pressure or mechanical deformation 3) Chemoreceptors - located on tongue (spices) 4) Silent nociceptors - some dont respond to stimulus unless there is an injury
What is the pathway for nociception?
- nociceptors are afferent neurons carrying pain info to the spinal cord
- info synapses at dorsal horn
- strong enough stimulus travels to the thalamus for integration (reflex arc may cause motor response to stim)
What is vestibular sense?
Provides sense of balance and spacial orientation for the purpose of coordinating movement with balance. Organs for which are located in inner ear.
Semicircular canals
detect rotation
Vestibular sacs
saccule - detects gravitation; they are filled with crystals that contact hairs generating impulse
utricle - detects horizontal motion
What is proprioception
Ability to sense stimuli arising within the body regarding position, motion and equilibrium. - When blindfolded you still know your arms are above your head
Kinesthesia
Awareness of the position and movement of the parts of the body by means of sensory organs in muscles and joints
Label the following parts of the Cochlea and explain how they contribute to vestibular sense.
- Utricle is sensitive to horizontal movement
- Saccule sensitive to vertical acceleration (accel. of elevator)
- Semicircular canals detect rotational movement
Weber’s Law (Weber-Fechner Law)
Change in stimuls that is just noticeable is a constant ratio of the original stimulus.
K = (change in stim.) / (original stim)
If you can tell the difference between a 2 kg weight and a 2.2 kg weight, can you tell the difference between a 10 and 11 kg weight?
K = (2.2 - 2) / (2) = 0.1
K = (11 - 10) / (10) = 0.1
Yes - the fraction must be greater than or equal to the original value in order to determine if the difference is noticeable.
Define Psychophysics
The studying of relationships between physical stimuli and our responses to them.
Absolute threshold
Minimum amount of stim. an organism can detect.
- Varies for different people and different organisms
- For this reason, psychophysicists use signal detection theory
Signal Detection Theory
states that the detection of a stimulus depends on both the intensity of the stimulus and the physical/psychological state of the individual. Basically, we notice things based on how strong they are and on how much we’re paying attention
Difference Threshold
The smalles amount by which two sensory stimuli can differ in order for an individual to perceive them as different (related to Weber’s Law)
Bottom-Up Processing (Data-Driven Processing)
Process by which the brain pieces together perceptual stimuli in what is perceived, based solely on data available through the senses.