Exam 1 Flashcards
What is the definition of sensation?
initial steps in converting physical stimulation to electrochemical signals
What is the definition of perception?
later steps in which representations are formed to guide other behavior
What is the difference between distal and proximal stimulus?
distal is physical objects/events in the environment. proximal is physical phenomenon evoked by distal stimulus on sensory receptors.
What is the difference between transduction and transmission?
transduction occurs when environmental energy changes to nerve impulses. transmission occurs when signals from the receptors travel to the brain
What is an action potential?
rapid increase in positive charge in a nerve fiber that travels down the fiber
Which part of the neuron sends out the action potential?
axon (nerve fiber)
A synapse is a specialized junction between two neurons. What is the difference between an electrical synapse and a chemical synapse?
Electrical is within a neuron
Chemical is between neurons
What do excitatory and inhibitory transmitters do and how do they affect action potentials?
Excitatory transmitters cause depolarization making the neuron more positive and increasing likelihood of action potential.
Inhibitory transmitters cause hyperpolarization making the neuron more negative and decreasing likelihood of action potential.
What is convergence in terms of simple neural circuits?
output of circuit increases as length of stimulus increases
What are the two surface features and four lobes of the brain?
Two surface features: sulci and gyri
Four lobes: frontal, parietal, temporal, occipital
Where is the Sylvian fissure?
separates frontal and parietal from temporal
Dorsal Orientation
Above
Ventral Orientation
Below
Lateral Orientation
Side
Medial Orientation
Middle
Anterior Orientation
Front
Posterior Orientation
Tail
What is the logic behind double dissociation and how does it help us understand the independence of two processes?
If damage to brain are A impairs function X but not Y, and damage to brain area B impairs Y but not X, these brain areas are functionally independent
What is the manipulation and measurement of cognitive neuroscience?
Manipulation - cognitive processes
Measurement - brain activities
What is the manipulation and measurement of brain perturbation?
Manipulation - brain functions
Measurement - task performance
EEG - measurements, advantages, and disadvantages
Arrays of electrodes on the scalp to measure electrical activity of neurons
High temporal resolution
Low spatial resolution
ERP - measurements, advantages, disadvantages
Time-locked average of EEGs
Good temporal resolution
Poor spatial resolution, source localization problematic (inverse problem)
fMRI - measurements, advantages, and disadvantages
Measures changes in the amount of oxygenated blood
High spatial resolution
Low temporal resolution
TMS (transcranial magnetic stimulation)
electromagnetic coil to temporarily disrupt local cortical functions
Differences between qualitative and quantitative methods
Qualitative: describing, recognizing
Quantitative: detecting/discriminating, perceiving magnitude
General procedure for method of adjustment
Stimulus intensity is adjusted continuously until observer detects it, repeated trials averages for threshold
General procedure for method of constant stimuli
Five to nine stimuli of different intensities are presented in random order, multiple trials are presented for each intensity, threshold is the intensity that results in detection in 50% of trials
General procedure for staircase method
A sequence of stimuli is presented, the intensity of which is stepped up or down depending on participants’ response, threshold can be estimated by averaging the intensity at reversals in the staircase
What is a psychometric function?
relationship between perception and stimulus property
According to Fechner’s law, how does stimulus intensity relate to perceived intensity?
Perceived stimulus intensity is a logarithmic function of the physical stimulus intensity, JND grows larger as stimulus intensity increases
Steven’s power law describes the relationship between physical intensity and perceived magnitude as a power function. What are the two response profiles?
Response compression (n<1), perceived magnitude (S) increases more slowly than intensity (I)
Response expansion (n>1), perceived magnitude (S) increases more quickly than intensity (I)
It can be difficult to measure absolute threshold because different individuals can have different response criteria. What are the two types of response criteria?
Liberal responder - responds yes if there is the slightest possibility of experiencing the stimulus
Conservative responder - responds yes only if they are sure that the stimulus was present
What is signal detection theory?
A theory about statistical decision making. It can be applied to decision making problems in which evidence being used to make a decision is a noisy (imperfect) indicator)
What are the procedures for a signal detection experiment?
A tone is presented to participant multiple times where they will produce one of four outcomes:
“Yes” when stimulus is present is a hit
“No” when stimulus is present is a miss
“Yes” when no stimulus is a false alarm
“No” when no stimulus is a correct rejection
How to calculate outcome rates of signal detection experiement
Hit Rate = # hits / # hits + # misses
FA Rate = # FA / # FA + # CR
Two underlying constructs of SDT: sensitivity and criterion
criterion - cutoff value determined by the person trying to detect the signal; measure as Hit + FA
sensitivity - measure as Hit - FA
What are some physical properties of light?
it is an electromagnetic wave, also a particle (light particle is a photon)
What are the anatomical structures of the eye in the order of light entering it?
Pupil, cornea, lens, retina