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.
Top-Down Processing
Process by which the brain uses prior knowledge to assist in interpreting perceptual information.
When you see a B or 13, you’re using prior knowledge.
Stroop Effect
Phenomena where it’s easier to read the names of colors if their colors match the word, but much more challenging when the colors don’t match the word.
- reaction time is significantly impaired when the colors and their names dont match
- relates to top-down processing because you’re prior knowledge affects your ability to read the words
Kinesthesia
awareness of the position and movement of the parts of the body by means of sensory organs (proprioceptors) in the muscles and joints
Vestibular Sense
Awareness of body balance, rotation and gravity due to fluid in the inner ear
-sense organs are the semi-circular canals
Semicircular canals
Sense organs in the inner ear that detect twisting of the head
-Movement of the fluid in the canals causes the movement of hair cells
–hair cells transmit information aobut speed and direction of body rotation via the vestibular nerve
Otolith Organs
Vestibular sacs located between cochlea and semicircular canals that detect gravitation and movement
- Utricle is sensitive to horizontal movement
- Saccule sensitive to vertical acceleration (accel. of elevator)
Somatic Sensation
senses arising from skin, skeletal muscles, etc.
-receptors collectively called somatic receptors and different types respond to touch, pressure, temperature and pain
–skin contains large quantities of such somatic receptors
Sensory Receptors of the Skin
1) Meissner’s Corpuscles
2) Merckel’s Corpuscles
3) Thermoreceptors and Nociceptors
4) Pacinian Corpuscles
5) Ruffini Corpuscles
Meissner’s Corpuscles
- Detection of superficial pressure / touch, movement and virbrations
- located in dermis, close to skin’s surface
- are rapidly adapting (fire as soon as stim changes)
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Merckel’s Corpuscles
- detect touch and pressure
- located close to the surface
- slowly adapting
Pacinian Corpuscles
- Detects vibrations and deep pressure
- Deep in the dermis
- Rapidly adapting
Ruffini Corpuscles (bulbous corpuscles)
- Detect skin stretching, sustained pressure and perception of heat
- Located between Pacinian and more superficial receptors
- Slowly adapting
Thermoreceptors and Nociceptors
- Reach into the epidermis as free nerve endings
- Detect pain and temperature changes
- Slowly adapting (contnue discharging during stim.)
Thermoreceptors
- Highly specialized free nerve endings extending into the epidermis
- Afferent w/ little to no myelination
- Temperature sensors contain ion channels belonging to transient recepter potential class of proteins
- different ion channels open at different temperatures
- some able to respond to spices like capsaicin (hot) and menthol (cold)
Transient Receptor Potential Proteins (TRPs)
- Ion channel proteins in cell membranes involved in various types of sensory reception (thermo, chemo, mechano, photo)
- In thermoreceptors, different isoforms of these proteins will respond to different temperatures
- mechanism of action due to influx of nonspecific cation current (Na+ or K+)
- cation influx causes cell membrane depolarization leading to the generation of an action potential
- TRPs open for different temperature thresholds
Nociceptors
- Free axon terminals of neurons that detect pain due to surrounding cellular damage from intense mechanical deformation, temperature, chemical and noxious stimuli
- typically unmyelinated or lightly myelinated
- afferent neuron
What is Gestalt Psychology?
Gestalt psychology or gestaltism is a school of psychology that emerged in Austria and Germany in the early twentieth century based on work by Max Wertheimer, Wolfgang Köhler, and Kurt Koffka. As used in Gestalt psychology, the German word gestalt is interpreted as “pattern” or “configuration.
- provided foundation for the modern study of perception
What is similarity in gestalt psychology?
The gestalt principle of similarity says that elements that are similar are perceived to be more related than elements that are dissimilar. Similarity helps us organize objects by their relatedness to other objects within a group and can be affected by the attributes of color, size, shape and orientation
Which principle of gestalt psychology is depicted by the image?
The principle of similarity
Explain the Gestalt principle of proximity.
The Gestalt law of proximity states that “objects or shapes that are close to one another appear to form groups”. Even if the shapes, sizes, and objects are radically different, they will appear as a group if they are close. Refers to the way smaller elements are “assembled” in a composition.
Explain the Gestalt principle of continuity.
The principle of continuity states that elements that are arranged on a line or curve are perceived to be more related than elements not on the line or curve.
Explain the Gestalt principle of closure.
The law of closure states the brain tends to perceive forms and figures in their complete appearance, despite the absence of one or more of their parts, either hidden or totally absent
Explain the Gestalt principle of connectedness.
The law of unified connectedness states that 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.
Which principle of Gestalt psychology is depicted by the image below
The Principle of Proximity
Which principle of Gestalt psychology is depicted by the image below?
The Principle of Continuity
- The straight line appears as one despite the different colors and the same with the curved line.
Which principle of Gestalt psychology is depicted by the images below?
The principle of Closure.
Which principle of Gestalt psychology is depicted by the image below?
The principle of Connectedness
Explain figure and ground as it pertains to Gestalt psychology.
Figure–ground organization is a type of perceptual grouping that is a vital necessity for recognizing objects through vision. In Gestalt psychology it is known as identifying a figure from the background. For example, words on a printed paper are seen as the “figure,” and the white sheet as the “background”
Which principle of Gestalt psychology is depicted by the image below?
Figure and Ground
Explain the Gestalt principle of Common Region.
The principle of common region is highly related to proximity. It states that when objects are located within the same closed region, we perceive them as being grouped together.
What Gestalt Principle is depicted by the image below?
The Principle of Common Region
