.1 (FSL, Analysis Group, FMRIB, Oxford, UK). The first three volumes (6 s) were discarded to allow for T1 equilibration. Preprocessing was done using the first-level FEAT default settings, including motion correction (MCFLIRT; Jenkinson et al., 2002), brain extraction (BET; Smith, 2002), and spatial smoothing (5 mm FWHM). A high-pass filter of 100 s was used for temporal filtering. The mean functional image and the MPRAGE for each participant was then spatially normalized into standard stereotaxic space (MNI152 T1 2 mm: Montreal Neurological AZD0156 web Institute, MNI), using 12-parameter affine transformation followed by nonlinear warping. Results are CV205-502 hydrochloride chemical information reported as significant for P < 0.05 corrected for multiple comparisons using a Z threshold of 2.4 and minimum cluster-size constraints. All coordinates are reported in MNI space. Only clusters of at least 5 voxels in gray matter are reported. Results Temperature effects on neural activity The key fMRI analyses for the temperature conditions were two group-level contrasts. First, brain areas that were more active during experience of cold and warm temperatures compared to neutral were identified. Within each run, neural responses to cold or warm temperature were contrasted with neutral temperature from that run. Both cold and warm evoked greater activation in right primary somatosensory cortex relative to neutral (Table 1, Figure 2). More importantly, cold (but not warm) temperature evoked greater activation than neutral in bilateral insula and bilateral central and parietal opercular cortexPhysical temperature effects on trust behavior Table 1 Brain regions that were sensitive to warm and cold temperatures: increased activity in response to warmth or coldness compared to neutral temperature (Z threshold ?2.4, P < 0.05)Region of activation Warm > Neutral R Primary somatosensory Cold > Neutral Local maxima R Insula/Central operculum R Primary somatosensory L Insula/Central operculum Voxels 1828 3572 567 48 40 ?8 ?8 ?0 ?2 14 62 14 4.28 4.03 3.64 X 52 Y ?6 Z 54 Zmax 4.SCAN (2011)Fig. 3 Contrast between brain activations during warm and cold experiences.whereas warmth elicited greater activation in PCC and inferior medial frontal area (Figure 3). Temperature effects on neural process during the trust game The decision and outcome phases were modeled as different events in a general linear model. All 16 participants who completed the trust game later reported that they made the trust-related decisions during the decision phase of the game. The decision phase after each temperature condition was contrasted with the baseline intervals within each run using the FEAT higher level analysis. Activation foci within the bilateral occipital poles (OC), anterior cingulate cortex (ACC), left thalamus and left dorsolateral prefrontal cortex (DLPFC) were identified during trust decision after both cold and warm pack manipulations (Table 3; Figure 4). In accord with our a priori hypotheses about the insula, the left-anterior insula was significantly more active during the trust game for sessions preceded by a cold-temperature scan. Greater left-anterior insula activation during trust decision (relative to baseline) was identified only after exposure to cold temperature, and not warm, as revealed in whole-brain corrected comparisons. Next, we directly contrasted the decision phases of trust game after the cold and warm manipulations. Decision phases after cold and warm temperatures were combined then contrasted. Results..1 (FSL, Analysis Group, FMRIB, Oxford, UK). The first three volumes (6 s) were discarded to allow for T1 equilibration. Preprocessing was done using the first-level FEAT default settings, including motion correction (MCFLIRT; Jenkinson et al., 2002), brain extraction (BET; Smith, 2002), and spatial smoothing (5 mm FWHM). A high-pass filter of 100 s was used for temporal filtering. The mean functional image and the MPRAGE for each participant was then spatially normalized into standard stereotaxic space (MNI152 T1 2 mm: Montreal Neurological Institute, MNI), using 12-parameter affine transformation followed by nonlinear warping. Results are reported as significant for P < 0.05 corrected for multiple comparisons using a Z threshold of 2.4 and minimum cluster-size constraints. All coordinates are reported in MNI space. Only clusters of at least 5 voxels in gray matter are reported. Results Temperature effects on neural activity The key fMRI analyses for the temperature conditions were two group-level contrasts. First, brain areas that were more active during experience of cold and warm temperatures compared to neutral were identified. Within each run, neural responses to cold or warm temperature were contrasted with neutral temperature from that run. Both cold and warm evoked greater activation in right primary somatosensory cortex relative to neutral (Table 1, Figure 2). More importantly, cold (but not warm) temperature evoked greater activation than neutral in bilateral insula and bilateral central and parietal opercular cortexPhysical temperature effects on trust behavior Table 1 Brain regions that were sensitive to warm and cold temperatures: increased activity in response to warmth or coldness compared to neutral temperature (Z threshold ?2.4, P < 0.05)Region of activation Warm > Neutral R Primary somatosensory Cold > Neutral Local maxima R Insula/Central operculum R Primary somatosensory L Insula/Central operculum Voxels 1828 3572 567 48 40 ?8 ?8 ?0 ?2 14 62 14 4.28 4.03 3.64 X 52 Y ?6 Z 54 Zmax 4.SCAN (2011)Fig. 3 Contrast between brain activations during warm and cold experiences.whereas warmth elicited greater activation in PCC and inferior medial frontal area (Figure 3). Temperature effects on neural process during the trust game The decision and outcome phases were modeled as different events in a general linear model. All 16 participants who completed the trust game later reported that they made the trust-related decisions during the decision phase of the game. The decision phase after each temperature condition was contrasted with the baseline intervals within each run using the FEAT higher level analysis. Activation foci within the bilateral occipital poles (OC), anterior cingulate cortex (ACC), left thalamus and left dorsolateral prefrontal cortex (DLPFC) were identified during trust decision after both cold and warm pack manipulations (Table 3; Figure 4). In accord with our a priori hypotheses about the insula, the left-anterior insula was significantly more active during the trust game for sessions preceded by a cold-temperature scan. Greater left-anterior insula activation during trust decision (relative to baseline) was identified only after exposure to cold temperature, and not warm, as revealed in whole-brain corrected comparisons. Next, we directly contrasted the decision phases of trust game after the cold and warm manipulations. Decision phases after cold and warm temperatures were combined then contrasted. Results.
