Task 6

Question 1

What is the Blocked design?

Answer 1

• stimuli from a given condition are presented consecutively together
• allows for the comparison of different conditions (which are presented in different blocks, that result in different levels of recollection)

Question 2

What are principles of the Blocked design?

Answer 2

• cognitive engagement in a task is maintained, by presenting stimuli sequentially within a condition
• alternattion of two conditions: AB block

Question 3

What are advantages of the Blocked design?

Answer 3

• in fMRI has more power to detect small effects than event-related designs
• allows for high experimental control
• can yield higher signal to noise ratios, due to the longer duration of each condition

Question 4

What are disadvantages of the Blocked design?

Answer 4

• cannot be used if things need to occur infrequently/ unexpectedly
• cannot be used if one doesn´t know how to group things together

Question 5

What is the event-related design?

Answer 5

stimuli from 2+ conditions are resented randomly, or interleaved

Question 6

what are the advantages of the event-related design?

Answer 6

• ability to detect transient variations in hemodynamic responses
• less sensitivity to head motion artefacts
• can be used to assess pratcie effects
• allows for randomisation of conditions
• time between stimulus representations can be varied (= good for attention levels, since it reduces the predictability)

Question 7

What are the disadvantages of the event-related design?

Answer 7

• time-consuming
• challanging to present a large number of trial types within a single experiment

Question 8

What is the behaviourally driven design?

Answer 8

• alternative to the paradigm used in conventional designs
• observing subjects spontaneous activity/ resting state as variations of the BOLD response
• the design is intrinsically dependent on each subject’s performance, and the inter-subject variability, number of events per condition and consequently the statistical power of the study is largely unknown beforehand

Question 9

What strategies are there?

Answer 9

• subtraction method
• factorial design
• parametric design
• conjunction analysis

Question 10

What is the subtraction method?

Answer 10

• images “active” condition - images “control” condition
• based on pure insertion assumption and absence of interaction (-> assumption is often violated)

Question 11

What are activation maps?

Answer 11

• based on processing steps
• activation maps evolve around a single subject
• first level analysis: brain areas that meat a statistical threshold

Question 12

How are activation maps computed?

Question 13

How are activation maps interpreted?

Question 14

What is the study by Wagner (1998)?

Answer 14

• hypothesis:
  > experiment 1 (block design)
  >
• fMRI design:
• control conditions:

Question 15

What is the first experiment in the study by Trojano at al (2018)? AND ROEFS

Answer 15

• hypothesis:
• fMRI design:
• control conditions:

Question 16

What is the factorial design?

Answer 16

• when cognitive conditions are processed in a factorial manner then it can be tested for interactions
• relies upon neuropsychological evidence for precise definition of the task components (= should be intermingled in one and separated in another moment

Question 17

What is the parametric design?

Answer 17

• the cognitive task is performed at different difficulty levels, without modifying its intrinisc nature
• increase in the BOLD effect, when cognitive demand is increased (= implies an association)
• technique allows for an analysis separating these areas from other brain regions (= otherwise baseline activity is included in the analysis)

Question 18

What is the conjunction analysis?

Answer 18

• variation of the factorial design: at least two or more conditions of the fMRI paradigm share the cognitive component of interest
• not based on detecting differences, but commonalities between conditions (common patterns of BOLD in each condition)