Ided written consent according to the Declaration of Helsinki (BMJ 1991; 302: 1194) and received financial compensation for their participation ( 40). For the temperature task, data from 23 participants (mean age ?22.7, s.d. ?4.6) were analyzed. For the trust game results, the first seven participants were excluded due to changes in the design of the trust game (final n ?16, mean age ?23.6, s.d. ?5.0). All participants were right handed, and met the standard fMRI safety criteria, as approved by the Yale University Human Investigation Committee. Procedure Participants were informed that they would perform RG7800 chemical information several unrelated tasks in the scanner. Study 2 used a within-subject design (Figure 1), having participants primed with both cold and warm packs, both followed by a trust game. Temperature manipulation. An experimenter placed a cold (158C) or warm (408C) pack on the participants’ left palm for 20 s, alternating with a neutral (room temperature) pack for 20 s, with a transition intervals (no pack) of 10 s. The order of the temperature conditions (cold, warm) was randomized across participants. An entire temperature run comprised an initial 6 s of resting followed by five blocks of a temperature-interval-neutral sequence, altogether lasting for 5 min and 6 s. A given scanning run included conditions that were either cold and neutral, or warm and neutral. Both were intended to influence brain activity during both the current and the next scanning run (trust game).SCAN (2011)Y Kang et al. .Fig. 1 Study 2 and the trust game timeline.Trust game. After each temperature task, participants played a trust game that was modified to be compatible with the demands of the scanning environment. The decision phase consisted of a 6 s consideration phase in which participants decided how much to invest among four options ( 0, 0.40, 0.65, 1.00) and a 2-s choice phase when the participants pressed the button of their choice (Figure 1). After a 6-s interval, a trustee’s response was presented on the screen, followed by a fixation. There were 15 trials of the trust game, which lasted a total of 7 min and 26 s. Immediately following the first trust game, a 3-back working memory task was introduced as a distracter task in order to attenuate any carry-over effects from the first series. Upon completion of the scanning, participants were probed for suspicions concerning the experimental hypotheses, thanked for their participation, and paid. fMRI data acquisition and analysis. Imaging data were collected using a 3.0-T Siemens Trio scanner at the Yale Magnetic Resonance Research Center. Three structural images (plane localizer; T1-weighted MPRAGE, and T1 flash axial) and five functional runs were acquired (gradient-echo EPI sequence; TR ?2000 ms; TE ?25 ms; FOV ?240 cm, flip angle ?808, matrix size ?64 ?64, slice thickness ?4 mm with no gap). The functional series lasted for 306, 446, 426, 306 and 446 s for the temperature task-1, trust game-1, working memory distracter task, temperature task-2 and trust game-2, respectively. Thirty-two contiguous oblique-axial slices parallel to the anterior commissure osterior commissure (AC C) line were obtained. Stimuli were presented using a laptop running PsyScope (Cohen et al., 1993). Participants viewed stimuli projected onto a screen through a mirror mounted on thehead coil. Responses were made using a fiber-optic response buttons, using the fingers of the right hand. The data were AG-221 biological activity analyzed using FMRIB Software Library 4.Ided written consent according to the Declaration of Helsinki (BMJ 1991; 302: 1194) and received financial compensation for their participation ( 40). For the temperature task, data from 23 participants (mean age ?22.7, s.d. ?4.6) were analyzed. For the trust game results, the first seven participants were excluded due to changes in the design of the trust game (final n ?16, mean age ?23.6, s.d. ?5.0). All participants were right handed, and met the standard fMRI safety criteria, as approved by the Yale University Human Investigation Committee. Procedure Participants were informed that they would perform several unrelated tasks in the scanner. Study 2 used a within-subject design (Figure 1), having participants primed with both cold and warm packs, both followed by a trust game. Temperature manipulation. An experimenter placed a cold (158C) or warm (408C) pack on the participants’ left palm for 20 s, alternating with a neutral (room temperature) pack for 20 s, with a transition intervals (no pack) of 10 s. The order of the temperature conditions (cold, warm) was randomized across participants. An entire temperature run comprised an initial 6 s of resting followed by five blocks of a temperature-interval-neutral sequence, altogether lasting for 5 min and 6 s. A given scanning run included conditions that were either cold and neutral, or warm and neutral. Both were intended to influence brain activity during both the current and the next scanning run (trust game).SCAN (2011)Y Kang et al. .Fig. 1 Study 2 and the trust game timeline.Trust game. After each temperature task, participants played a trust game that was modified to be compatible with the demands of the scanning environment. The decision phase consisted of a 6 s consideration phase in which participants decided how much to invest among four options ( 0, 0.40, 0.65, 1.00) and a 2-s choice phase when the participants pressed the button of their choice (Figure 1). After a 6-s interval, a trustee’s response was presented on the screen, followed by a fixation. There were 15 trials of the trust game, which lasted a total of 7 min and 26 s. Immediately following the first trust game, a 3-back working memory task was introduced as a distracter task in order to attenuate any carry-over effects from the first series. Upon completion of the scanning, participants were probed for suspicions concerning the experimental hypotheses, thanked for their participation, and paid. fMRI data acquisition and analysis. Imaging data were collected using a 3.0-T Siemens Trio scanner at the Yale Magnetic Resonance Research Center. Three structural images (plane localizer; T1-weighted MPRAGE, and T1 flash axial) and five functional runs were acquired (gradient-echo EPI sequence; TR ?2000 ms; TE ?25 ms; FOV ?240 cm, flip angle ?808, matrix size ?64 ?64, slice thickness ?4 mm with no gap). The functional series lasted for 306, 446, 426, 306 and 446 s for the temperature task-1, trust game-1, working memory distracter task, temperature task-2 and trust game-2, respectively. Thirty-two contiguous oblique-axial slices parallel to the anterior commissure osterior commissure (AC C) line were obtained. Stimuli were presented using a laptop running PsyScope (Cohen et al., 1993). Participants viewed stimuli projected onto a screen through a mirror mounted on thehead coil. Responses were made using a fiber-optic response buttons, using the fingers of the right hand. The data were analyzed using FMRIB Software Library 4.
