Figure 1. The compatible (top) and incompatible (bottom) compound stimuli used in the study (Caparos, et al., 2013). Images not to scale. Procedure E-prime software version 1 (Schneider, Eschman, & Zuccolotto, 2002) was used to present the stimuli and collect behavioural responses. Participants viewed the visual stimuli in the following order: i) viewed instructions on identifying global shapes followed by a block of 24 global target practice trials; ii) viewed instructions on identifying local shapes followed by a block of 24 local target practice trials; iii) completed eight blocks of 72 trials each. The stimuli were presented in blocks to minimise the number of switches as previous research has suggested that individuals with eating disorders have weaknesses in set-shifting (Tchanturia et al., 2004). Prior to each block the participant was instructed to identify global or local shapes in the upcoming block (total four global blocks and four local blocks). Global and local blocks alternated, and the starting condition was counterbalanced across participants. Each began with a fixation cross (1000ms), followed by a blank screen (500ms). Next, a compound stimulus was presented and remained on the screen until the participant had made a response. Responses were collected via a computer keyboard, and participants were instructed to use their left index finger to press the key if the target shape was a square ‘A’ and to use their right index finger to press the key if the target shape was a cross. After ‘L’
Figure 1. The compatible (top) and incompatible (bottom) compound stimuli used in the study (Caparos, et al., 2013). Images not to scale. Procedure E-prime software version 1 (Schneider, Eschman, & Zuccolotto, 2002) was used to present the stimuli and collect behavioural responses. Participants viewed the visual stimuli in the following order: i) viewed instructions on identifying global shapes followed by a block of 24 global target practice trials; ii) viewed instructions on identifying local shapes followed by a block of 24 local target practice trials; iii) completed eight blocks of 72 trials each. The stimuli were presented in blocks to minimise the number of switches as previous research has suggested that individuals with eating disorders have weaknesses in set-shifting (Tchanturia et al., 2004). Prior to each block the participant was instructed to identify global or local shapes in the upcoming block (total four global blocks and four local blocks). Global and local blocks alternated, and the starting condition was counterbalanced across participants. Each began with a fixation cross (1000ms), followed by a blank screen (500ms). Next, a compound stimulus was presented and remained on the screen until the participant had made a response. Responses were collected via a computer keyboard, and participants were instructed to use their left index finger to press the ‘A’ key if the target shape was a square and to use their right index finger to press the ‘L’ key if the target shape was a cross. After
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