Psych/Soc 1 Flashcards
Types of sensory receptors
- Electromagnetic receptor
- Thermoreceptor
- Mechanoreceptor
- Chemoreceptor
- Nociceptor
- Baroreceptor
Electromagnetic receptor
Sense EM waves (such as light).
Ex: photoreceptors in the eye
Thermoreceptor
Sense temperature (cold or hot) Ex: found in the skin
Mechanoreceptor
Sense a mechanical disturbance, such as stretching or compression.
Ex: Pacinian corpuscles, Ruffini endings/corpuscles, and Meissner’s corpuscles in skin; auditory and vestibular hair cells
Chemoreceptor
Detect chemicals and their levels.
- Taste buds and olfactory nerves
- Also sense changes inside the body such as fluid osmolarity, pH levels, CO2 levels, etc.
Nociceptor
Sense pain.
-Found in the skin and throughout most body tissues
Baroreceptor
Sense pressure.
-Found in the aortic arch and sense arterial pressure
Sensory Pathways
- Sensory information sent from the PNS (detected) to the CNS.
- In the CNS, interpretation of the stimulus occurs
- Most senses are contralateral (exception is hearing which is both ipsilateral and contralateral).
- 2 types of pathways (conscious and subconscious)
In the CNS, interpretation of stimulus occurs based on…
1) which neurons sent the impulse/where they synapse (information about sensory modality)
2) Frequency of the action potentials (codes for signal intensity)
3) Duration of continuous firing (codes for stimulus exposure)
Conscious perception
PNS -> spinal cord -> thalamus -> cerebral cortex
- Sensory information enters consciousness
- Olfactory information doesn’t go through the thalamus.
Subconscious perception
PNS -> spinal cord -> cerebellum
-Sensory information doesn’t enter consciousness
Psychophysics
Looks at the relationship between physical stimuli and the resultant sensation and perceptions
Absolute threshold
The level of a stimulus at which it will be detected 50% of the time
Difference threshold
How different two stimuli need to be for an individual to be able to recognize that they aren’t the same (at least 50% of the time0
-Aka Just Noticeable Difference (JND)
Weber’s Law
The size of the JND is a constant proportion of the original stimulus value.
-The value of the proportion varies across sensory modalities, stimuli, and tasks.
Signal detection theory
Attempts to assess/quantify when an individual will detect the presence of a stimuli against all other background “noise”
HIT
Signal present, subject responds “yes”
Type 1 error
False positive.
-Signal absent, subject responds “yes”
Type II error
False negative
Signal present, subject responds “no”
Correct rejection
Signal absent, subject responds “no”
Sensory adaptation
Change in the responsiveness of one’s sensory system to a constant stimulus.
- Not the same as habituation, which is a type of “learning” and involves changes in the physiological, emotional, or behavioral response to a stimulus.
- Receptors may be fast-adapting, slow-adapting, or non-adapting (nociceptors)
Perception
The process of becoming aware of, organizing, and interpreting sensory information.
- Dependent not only on the sensory information but also the individual’s memory, past experiences, expectations, and attention.
- Perception occurs through both bottom-up and top-down processing.
Bottom-up processing
Using the sensory information to compile a cohesive understanding of the whole.
-“data-driven”
Top-down processing
Applying one’s own knowledge, experiences, and expectations in interpreting and understanding the sensory information
- Applying higher level information to lower level (more basic) information.
- Often occurs when the sensory information is vague or incomplete.
Parallel processing
The ability of the brain to simultaneously process different streams of sensory information
Gestalt Principles
Different rules that describe how people tend to organize, group, and perceive sensory stimuli (usually visual)
-“the whole exceeds the sum of its parts” -> what we perceive is based not only on the sensory input but also on the innate tendency of our brain to organize the stimuli in a certain way.
Figure/ground
We tend to pick out and focus on one figure/object, perceiving it as separate from the background of an image.
Law of Proximity
Elements that are close together tend to be perceived as a unified group.
-Items that are close to each other tend to be grouped together, whereas items further apart are less likely to be grouped together
Law of closure
If there is a break in the object, we perceive the object as continuing in a smooth pattern
Law of similarity
Elements that are similar to each other tend to be perceived as a unified group.
-Similarity can refer to any number of features, including color, orientation, size, or indeed motion
Law of connectedness
Elements that are connected to each other using colors, lines, frames, or other shapes are perceived as a single unit when compared with other elements that are not linked in the same manner.
Law of Continuity
There is a tendency to perceive a line continuing its established direction. If a figure is split into two parts, then the figure is seen as the whole instead of 2 separate smaller figures.
Cornea
Clear tissue in front of the eye that acts like a lens to focus and refract light
Iris
Changes the size of the pupil to control how much light gets into the eye.
-Colored part of the eye
Lens
Region through which light enters the eye.