PSYCHOLOGY 445 FINAL EXAM VERSION A AND
B NEWEST 2025 ACTUAL EXAM QUESTIONS
AND CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) |ALREADY GRADED A+
A neuron performs only transmissive activity, while astrocytes perform only integrative activity.
True or false? - RIGHT ANSWER -False (neurons do BOTH, astrocytes play a role in TRANSMISSIVE
activity)
An experiment manipulates __________________ and measures ____________________. -
RIGHT ANSWER -independent variables; dependent variables
An MR image (2D) slice is:
A) a visual description of the temporal evolution of brain activity
B) a photograph of the scanned object
C) a visual description of how spin properties vary over space
Approximately how many seconds does the canonical Hemodynamic Response Function (HRF)
take to peak after the neural activity that caused it? - RIGHT ANSWER -5 sec (after neural activity
occurs, this is peak HRF)
Blocked designs are better for: -
A.) estimation of the time course of activity
B.) detection of activity AND better signal to noise ratio than event-related designs
BOLD fMRI measures changes in total amount of deoxygenated hemoglobin in each voxel. True
or false? - RIGHT ANSWER -True
,Collinear regressors (choose all that apply) - RIGHT ANSWER -
a) Create linearity in coregressors
b) Are only linear if included in the design matrix together
c) Do not allow unequivocal separation of variance associated with them
d) Need not be avoided, because they can always be fixed using orthogonalization
e) Reduce validity of multiple regression analyses
f) Are highly correlated with one another
Collinear regressors are good or bad? - RIGHT ANSWER -BAD! These are at least 2 regressors that
are correlated with each other
-we want all regressors to be independent
Comparing fMRI signal in the basal ganglia during reward processing between drug-addicts and
non-addicts is an example of:
A.) Between-subject manipulation
B.) Within-subject manipulation
Contrast, spatial resolution and temporal resolution all contribute to functional resolution. True
or false? - RIGHT ANSWER -True
Contrasts between conditions generally use weights that sum up to ____. - RIGHT ANSWER -0
Define "design matrix" (in the context of fMRI analyses). - RIGHT ANSWER -"Design matrix" is a
matrix that specifies how the model factors of an fMRI experiment change over time.
-consists of all regressors of interest as well as nuisance regressors
, -y axis always = time
Deoxygenated hemoglobin: - RIGHT ANSWER
-a. Distorts the local magnetic field within the tissue
b. Becomes more prevalent during the initial dip of the hemodynamic response.
c. Is paramagnetic
Design matrix setup - RIGHT ANSWER -Goal is to find out each of the beta values: to what degree
each of the regressors contributes to the output (anything unexplained goes into the error term)
-# of columns=# of regressors
-# of rows (in 1st level stats)=# of brain volumes
Event-related designs can be interactive and change depending on subjects' responses. Hence,
event-related designs are thought to be ________. - RIGHT ANSWER -flexible
Everything that fMRI researchers do to ensure data quality can be viewed as efforts to (choose
all that apply) - RIGHT ANSWER -
A) optimize estimation of the parameter weights (Bi)
B) minimize the number of regressors
C) maximize the number of regressors
D) minimize values in the error vector (E)
Experimental contrast images are generated by linearly combining ________. - RIGHT ANSWER
-beta images
B NEWEST 2025 ACTUAL EXAM QUESTIONS
AND CORRECT DETAILED ANSWERS (VERIFIED
ANSWERS) |ALREADY GRADED A+
A neuron performs only transmissive activity, while astrocytes perform only integrative activity.
True or false? - RIGHT ANSWER -False (neurons do BOTH, astrocytes play a role in TRANSMISSIVE
activity)
An experiment manipulates __________________ and measures ____________________. -
RIGHT ANSWER -independent variables; dependent variables
An MR image (2D) slice is:
A) a visual description of the temporal evolution of brain activity
B) a photograph of the scanned object
C) a visual description of how spin properties vary over space
Approximately how many seconds does the canonical Hemodynamic Response Function (HRF)
take to peak after the neural activity that caused it? - RIGHT ANSWER -5 sec (after neural activity
occurs, this is peak HRF)
Blocked designs are better for: -
A.) estimation of the time course of activity
B.) detection of activity AND better signal to noise ratio than event-related designs
BOLD fMRI measures changes in total amount of deoxygenated hemoglobin in each voxel. True
or false? - RIGHT ANSWER -True
,Collinear regressors (choose all that apply) - RIGHT ANSWER -
a) Create linearity in coregressors
b) Are only linear if included in the design matrix together
c) Do not allow unequivocal separation of variance associated with them
d) Need not be avoided, because they can always be fixed using orthogonalization
e) Reduce validity of multiple regression analyses
f) Are highly correlated with one another
Collinear regressors are good or bad? - RIGHT ANSWER -BAD! These are at least 2 regressors that
are correlated with each other
-we want all regressors to be independent
Comparing fMRI signal in the basal ganglia during reward processing between drug-addicts and
non-addicts is an example of:
A.) Between-subject manipulation
B.) Within-subject manipulation
Contrast, spatial resolution and temporal resolution all contribute to functional resolution. True
or false? - RIGHT ANSWER -True
Contrasts between conditions generally use weights that sum up to ____. - RIGHT ANSWER -0
Define "design matrix" (in the context of fMRI analyses). - RIGHT ANSWER -"Design matrix" is a
matrix that specifies how the model factors of an fMRI experiment change over time.
-consists of all regressors of interest as well as nuisance regressors
, -y axis always = time
Deoxygenated hemoglobin: - RIGHT ANSWER
-a. Distorts the local magnetic field within the tissue
b. Becomes more prevalent during the initial dip of the hemodynamic response.
c. Is paramagnetic
Design matrix setup - RIGHT ANSWER -Goal is to find out each of the beta values: to what degree
each of the regressors contributes to the output (anything unexplained goes into the error term)
-# of columns=# of regressors
-# of rows (in 1st level stats)=# of brain volumes
Event-related designs can be interactive and change depending on subjects' responses. Hence,
event-related designs are thought to be ________. - RIGHT ANSWER -flexible
Everything that fMRI researchers do to ensure data quality can be viewed as efforts to (choose
all that apply) - RIGHT ANSWER -
A) optimize estimation of the parameter weights (Bi)
B) minimize the number of regressors
C) maximize the number of regressors
D) minimize values in the error vector (E)
Experimental contrast images are generated by linearly combining ________. - RIGHT ANSWER
-beta images
