Perception Exam 1 Flashcards
The periphery of the eye is excellent at detecting a small flash of light in the dark, but less able to distinguish changes in the strength of an existing light. If we think about this in terms of thresholds, what can we conclude?
Psychophysics
_______ is the principle that describes the relationship between a stimulus and its resulting sensation, which says the magnitude of subjective sensation is proportional to the stimulus magnitude, raised to an exponent, which may differ between varying senses.
Steven’s Power law
Which of the following statements about the action potential is FALSE? [know the basics about action potentials]
True about action potentials: neurotransmitters trigger an electrical shift in the post-synaptic neuron, leading to the neuron “firing” an action potential
-how to tell how excited the neuron is during action potential: # of spikes per second
-they start near cell body of neuron, goes down axon, and ends at axon terminal
Absolute threshold is the minimum amount of stimulation necessary for a person to detect a stimulus _______% of the time.
50%
Which is NOT a key difference between Fechner’s and Stevens’s Laws?
- Logarithmic (fechner) vs Power (stevens) scale
- Both make broad assumptions about the “fit” of data to their metrics and about the scales they work on
- Both are only approximations of data and tuen out to not really be “laws”
- Main takeaways:
o Peoples internal perception can be modeled/predicted
o Sensation is proportional to other parameters
As an aside, there are few, if any, true LAWS in psychology
The method of _______ requires the random presentation of many stimuli, one at a time, ranging from rarely to almost always perceivable
Constant Stimuli
What differentiates the method of Limits from the method of Adjustments?
Method of Limits: researcher controls the magnitude
Method of Adjustments: participant controls it
When setting up a new monitor or video game, there is often a step in which you change the brightness of the screen until a logo is just barely visible. This is an example of
Method of adjustment
_______ is a psychophysical method in which the participant assigns values according to perceived magnitudes of the stimuli.
Magnitude Estimation
According to Signal Detection Theory, which of the following would result in an INCREASE in Hits?
Increasing the stimulus strength (decrease in miss)
If a stimulus is absent and the observer reports it as absent, this is called a
correct rejection
The criminal justice system in United States is designed to be biased such that it would rather let a guilty person go free than convict an innocent person. In terms of signal detection theory, the courts would rather have a _______ than a _______.
Miss, False alarm
Airport security is very tight. If a traveler even jokes about a bomb, they are detained and questioned to ensure that no real terrorist threat succeeds. In terms of signal detection theory, airport security is prioritizing _______, even if it results in this kind of error: _________.
False alarm, miss
how many cranial nerves are there?
12
The thalamus is deep in the brain, and not on the brain’s surface. Which technique would be a bad choice to look at the structure of the thalamus?
MEG
_______ makes it possible to measure localized patterns of activity in the brain by tracking changing levels of blood oxygenation
Functional Magnetic Resonance Imaging (fMRI)
A cranial nerve that sends information TO the brain from the body, is called _________ and is generally considered ________. [note: I am not asking about Cranial nerve #’s but types of cranial nerves]
Afferent, sensory
Byron is testing salty and sweet taste perception. He gives participants different cups of liquid and asks them to rate how salty and how sweet each liquid is. What two methods does this combine?
Scaling methods and magnetic estimation
When thinking about the physics of light, which of the following are true statements? [I will give you statements about the basic physics of light and you’ll need to identify which is not correct]
Absorbed: light is taken up and is not transmitted further
Scattered: light is dispersed in an irregular fashion
Reflected: light is redirected, generally back the way it came
Transmitted: light is passed through a surface (without being reflected or absorbed)
Refracted: light is altered as it passes through a medium/object but is being bent or modified
When you look at an opaque, solid red surface, what is happening to the light that hits it?
some is reflected and some is absorbed
Based on the physics of light, what is one contributing factor to why the sky appears red when the sun is low (sunset) vs. when the sun is high (noon)?
Sunset: reddish orange at dawn/dusk as the syn is not direct and therefore scatters more
Noon: blue light during the day as the sun is direct and not a lot of blue light is scattered
The transparent “window” on the outer part of the eye that allows light into the eyeball is called the _________________.
the cornea
what portion of the eye makes up 80% of its size?
Vitreous Chamber/Humor
Which part of the eye undergoes accommodation?
the lens
When considering the fovea, macula, and periphery, what is the pattern of sensitivity to light in low-light situations (from most sensitive to least sensitive)?
periphery, macula, fovea
which cells actually sense light?
rods and cones
People with _______ do not require an optical correction to see normally.
Emmetropia
Which is Not a mechanism for dark/light adaptation?
the 4 mechanisms:
1. pupil dilation
2. photopigment replenishment
3. duplex retina
4. neural circuitry beyond rods/cones
Suppose your pupils are dilated after visiting the eye doctor. What is the likely effect on the amount of photopigment in your photoreceptors, and why?
You have less photopigment than normal because your photoreceptors are trying to adapt to the increased amount of light striking the retina
In aging-related macular degeneration (AMD) there is a _______ loss of _______ vision.
severe, central
