Figure 1.
This figure illustrates the block design for the N-back task, in which the type of masked distracter stimuli (NEUTRAL (N); FOOD (F); AVERSIVE (A)) and the level of difficulty (1-BACK, 2-BACK) are alternated in a fixed order with each 30 s block. A total of 12 blocks are presented in the study, with 20 trials (involving presentation of 20 distracter stimuli and 20 letter targets) in each block.
Figure 2.
Schematic diagram of the backward masking procedure.
This figure illustrates the order and timing of presentation of distracters and targets, using the example of a food stimulus (presented for 23 ms so as to not be consciously perceived), immediately followed by a target letter (in this example, ‘D’) on a mosaic background for 1077 ms, followed by a blank fixation circle on a white background for 400 ms.
Table 1.
Accuracy and response times in the go/no-go and n-back tasks.