Class 7- Sensation/Perception, Attention, Cognition, & Language Flashcards
Compare and contrast sensation and perception.
Sensation is the detection and encoding of physical energy from the environment.
Perception is the selection, organization, and interpretation of our sensations.
A stimulus is any detectable change in the environment.
Define the difference between the absolute threshold and a difference threshold in sensory processing.
Absolute threshold: lowest level of a stimulus we can detect 50% of the time.
Difference threshold: minimum difference between two stimuli that we can detect 50% of the time (known as Just Noticeable Difference (JND))
Weber’s law states that the size of the JND is a constant proportion of the original stimulus value.
Describe the Signal Detection Theory.
The Signal Detection Theory proposes a method for quantifying a person’s ability to detect a given stimulus (signal) among other, nonimportant stimuli (noise).
Responses include:
Hit, Miss (false negative), False alarm (false positive), correct rejection
What is a Receiver Operating Characteristic Curve?
A receiver operating characteristic (ROC) curve is a graphical plot that demonstrates the hit rate vs. the false alarm rate.
Graphically demonstrates a receiver’s (person’s) accuracy.
When you encode sensory stimuli, 4 properties need to be communicated to the CNS. What are they?
For encoding stimuli, the following properties need to be communicated:
- Modality: type of stimulus (determined by receptor activated)
- Location: receptive field
- Intensity: strength encoded by firing rate
- Duration
Tonic receptors generate APs as long as stimuli present.
Phasic receptors fire only when stimulus begins (communicate changes)
Define sensory adaptation.
Sensory adaptation is a decrease in the frequency of AP when the intensity of the stimulus remains constant.
Explain feature detection theory.
How does parallel processing relate?
Feature Detection Theory explains that certain parts of the brain are activated for specific visual stimuli.
Certain feature detection neurons respond only to specific features, like shape, angle, or motion.
Parallel processing occurs so that many aspects of a visual stimulus (shape, color, motion, depth) are processed simultaneously.
________ allows us to sense the position of our limbs in space and detect bodily movements.
What type of mechanoreceptors are involved in this?
Kinesthesis (proprioception)
Proprioceptors are mechanoreceptors that detect mechanical disturbances.
- Muscle spindle detects muscle stretch.
- Golgi tendon organs detect tension in the tendons
- Joint capsule receptors detect pressure, tension, and movement in the joints
These 3 receptor types work together to monitor musculoskeletal activity.
What are the differences between the bottom-up and top-down processing theories of perception?
Bottom-up processing: starts with info from sensory receptors and builds up to final product in brain; start with details
Top-down processing: starts with larger concept and works down to ideas; start with idea of final representation
What is perceptual organization?
What is gestalt psychology? Give some examples.
Perceptual organization helps us to understand sensory information. We must perceive objects as being separate from their environments and having constant form, detect motion and perceive distance.
Gestalt psychology demonstrates how our minds influence what we perceive in predictable ways. (Emergence, Figure/ Ground, Multistability, Laws of Grouping)
Define depth perception.
Depth perception is the ability to see objects in 3D. It allows us to judge distance.
Compare and contrast binocular and monocular depth cues. What are examples of each?
Binocular Cues are depth cues that depend on information received from both eyes.
- Retinal disparity: brain compares the images projected on the two retinas to perceive distance; greater difference, the shorter the distance
- Convergence: extent to which eyes turn inward to look at an object; closer objects have greater angle of convergence
Monocular cues depend on either eye alone.
- Relative size: if assumed same size, smaller image appears more distant
- Interposition: blocks view of another, perceive it as closer
- Relative clarity: perceive hazy objects as being more distant
- Texture gradient: change for distinct to indistinct texture indicates increasing distance
- Relative height: higher in visual field as farther away
- Relative motion: near objects move faster than objects far away
- Linear perception: parallel lines appear to converge as distance increases
- Light and shadow: dimmer of two objects will seem farther away
What is motion perception?
Motion perception states that our brains assume that objects that are decreasing in size are moving farther away.
The pi phenomenon describes the illusion of movement that is created due to adjacent blinking lights.
What is perceptual constancy?
Perceptual constancy is perceiving an object as unchanging even as the illumination, angle, and distance of the object change.
Examples include:
- Shape constancy: familiar objects are perceived as having constant form
- Size constancy: perceive opbjects as having constant size even as distance changes
- Lightness constancy: constant brightness despite changes in illumination
Define attention.
What are some models of attention?
Attention is the active consciousness that allows us to focus awareness on some stimuli vs others.
The resource model views attention as a limited resource that can be spread too thin.
The spotlight model views attention as a focal point that can shift.
The spotlight model says that some attention passes through a filter into working memory and other info is filtered out and decays.
The attenuation model says information that is not attended to doesn’t decay, it just gets “turned down”. Example for support is the cocktail party effect.
Describe Baddeley’s Model of Working Memory.
Baddeley’s Model of Working Memory includes an explanation of how our three short-term sensory stores interact with the central executive, which controls the flow of info from/to the sensory stores.
Includes the Central Executive, the phonological loop, the visuospatial sketchpad, the episodic buffer, the semantic verbal memory, semantic visual memory, and episodic memory.
What are the stages of Lawrence Kohlberg’s Theory of Moral Development? What are their milestones and around what age do they occur?
