Why Do Irrelevant Alternatives Matter? An fMRI-TMS Study of Context-Dependent Preferences.

Both humans and animals are known to exhibit a violation of rationality known as "decoy effect": introducing an irrelevant option (a decoy) can influence choices among other (relevant) options. Exactly how and why decoys trigger this effect is not known. It may be an example of fast heuristic decision-making, which is adaptive in natural environments, but may lead to biased choices in certain markets or experiments. We used fMRI and transcranial magnetic stimulation to investigate the neural underpinning of the decoy effect of both sexes. The left ventral striatum was more active when the chosen option dominated the decoy. This is consistent with the hypothesis that the presence of a decoy option influences the valuation of other options, making valuation context-dependent even when choices appear fully rational. Consistent with the idea that control is recruited to prevent heuristics from producing biased choices, the right inferior frontal gyrus, often implicated in inhibiting prepotent responses, connected more strongly with the striatum when subjects successfully overrode the decoy effect and made unbiased choices. This is further supported by our transcranial magnetic stimulation experiment: subjects whose right inferior frontal gyrus was temporarily disrupted made biased choices more often than a control group. Our results suggest that the neural basis of the decoy effect could be the context-dependent activation of the valuation area. But the differential connectivity from the frontal area may indicate how deliberate control monitors and corrects errors and biases in decision-making.SIGNIFICANCE STATEMENT Standard theories of rational decision-making assume context-independent valuations of available options. Motivated by the importance of this basic assumption, we used fMRI to study how the human brain assigns values to available options. We found activity in the valuation area to be consistent with the hypothesis that values depend on irrelevant aspects of the environment, even for subjects whose choices appear fully rational. Such context-dependent valuations may lead to biased decision-making. We further found differential connectivity from the frontal area to the valuation area depending on whether biases were successfully overcome. This suggests a mechanism for making rational choices despite the potential bias. Further support was obtained by a transcranial magnetic stimulation experiment, where subjects whose frontal control was temporarily disrupted made biased choices more often than a control group.

The Power Law of Learning in Transumbilical Single-Port Laparoscopic Subtotal Hysterectomy.

STUDY OBJECTIVE: To analyze the surgical outcomes and learning curve of transumbilical single-port laparoscopic subtotal hysterectomy, which requires sutures of the cervical stump. DESIGN: A prospective observational study (Canadian Task Force classification II-2). SETTING: A university-affiliated center. PATIENTS: From the first (July 2012) and consecutive patients of benign uterine disease scheduled for subtotal hysterectomy until October 2013. INTERVENTIONS: All single-port laparoscopies were performed using straight instruments by 1 gynecologist. An ancillary port was added whenever technical difficulties could endanger surgical quality. MEASUREMENT AND MAIN RESULTS: Seventy-five patients were recruited for intention-to-treat analysis with a mean (±SD) age of 44.7 ± 3.8 years and a body mass index of 24.2 ± 3.7 kg/m2. No major complication was noted. The mean uterine weight was 432.5 ± 344.0 g with 24 (32%) uteri ≧500 g. The patients' sequential order, or gradually increasing experience, was the determining factor in progressively decreasing operative time. Furthermore, most cases that required an additional ancillary port (67%) were clustered in the first 20 cases, whereas 4 were scattered after the 47th patient because of severe pelvic adhesion. The mean operative time decreased in the power law function of the patients' sequential order with a plateau achieved at the 20th patient. CONCLUSION: The patients' sequential order was identified as an independent factor of achieving purely single-port access, and the trend of decreasing operative time delineated the existence of a learning curve. Approximately 20 patients were needed for an experienced multiport laparoscopist to reach technical competency in the current series.

Natural orifice transluminal endoscopic surgery-assisted versus laparoscopic ovarian cystectomy (NAOC vs. LOC): a case-matched study.

BACKGROUND: Natural orifice transluminal endoscopic surgery (NOTES) has shown its prospection as a minimally invasive endoscopic surgery. This study aimed to examine the safety and efficacy of combined NOTES and vaginal approach, natural orifice transluminal endoscopic surgery-assisted ovarian cystectomy (NAOC), in the conservative management of benign ovarian tumors. METHODS: Records were reviewed for the 34 consecutive NAOC procedures between May 2011 and March 2014. Age, body mass index, parity, size of the mass, and bilaterality of the mass were used to select comparable patient who had undergone laparoscopic ovarian cystectomy (LOC). RESULTS: A total of 277 patients were recruited in this study (243 LOCs and 34 NAOCs, respectively). There was no incidence of switching to abdominal laparotomy. Length of operation and length of postoperative stay were significantly greater in the LOC group than in the NAOC group, but total hospital charges were similar in both groups. There was no difference in febrile morbidity between the two groups but more estimated blood loss (EBL) in NAOC group, although EBL was <50 mL in the two groups. Linear correlations of mass size with operating time and EBL existed in LOC group, but not in NAOC group. CONCLUSION: NAOC can be safely performed for benign and large ovarian tumors. Besides, NAOC offers a superior operative efficiency compared with LOC.

Hysterectomy via transvaginal natural orifice transluminal endoscopic surgery for nonprolapsed uteri.

BACKGROUND: Natural orifice transluminal endoscopic surgery has shown its prospection as a minimally invasive endoscopic surgery. This study aimed to examine the safety and feasibility of transvaginal natural orifice transluminal endoscopic hysterectomy (tVNOTEH) for nonprolapsed uteri in the management of benign gynecological diseases. METHODS: Records were reviewed for the 147 consecutive tVNOTEH procedures between April 2011 and October 2013. Age, body mass index, number of vaginal delivery, and specimen weight were used to select comparable patient who had undergone laparoscopically assisted vaginal hysterectomy (LAVH). RESULTS: A total of 512 patients were recruited in this study (147 tVNOTEHs and 365 LAVHs, respectively). These patients were stratified into six subgroups according to the uterine weight and type of hysterectomy. There was no incidence of switching to abdominal laparatomy. Length of operation, estimated blood loss (EBL), requirement of blood transfusion, and length of postoperative stay were significantly greater in the LAVH group than in the tVNOTEH group but total hospital charges were higher in the tVNOTEH group (p < 0.001). There was no difference in overall incidence of operative complications between the two groups but more complications in LAVH for uterine weight more than 500 g (4.3 vs. 0 %, p < 0.001); this likely reflects higher hospital charges in this subgroup. Significant linear correlations of uterine weight with operating time and EBL existed in both groups. CONCLUSION: tVNOTEH can be safely performed for large and nonprolapsed uterus. Besides, as uterine weight increased, the operative efficiency of tVNOTEH increases compared with LAVH.

Temperature-regulated metabolites of Serratiamarcescens inhibited reproduction of pinewood nematode Bursaphelenchus xylophilus.

The pinewood nematode Bursaphelenchus xylophilus is an invasive and destructive pathogen in forestry. Serratia marcescens AHPC29 was previously found to have nematicidal activity on B. xylophilus. The effect of AHPC29 growth temperature on B. xylophilus inhibition is unknown. Here we show that AHPC29 cultured at 15°C or 25°C, but not 37°C, inhibited B. xylophilus reproduction. Metabolomic analysis found 31 up-regulated metabolites as potential effective substances in this temperature-related difference, with five of them were tested to be effective in inhibiting B. xylophilus reproduction. Among the five metabolites, salsolinol was further verified in bacterial cultures with effective inhibition concentrations. This study found the inhibition of S. marcescens AHPC29 on B. xylophilus reproduction was temperature regulated and the differently expressed metabolites salsolinol played roles in this temperature-regulated effect, which implies the capability of S. marcescens and its metabolites as promising new agents for the management of B. xylophilus.

Choices behind the veil of ignorance in Formosan macaques.

An ongoing debate regarding the evolution of morality is whether other species show precursory moral behavior. The veil of ignorance (VOI) paradigm is often used to elicit human moral judgment but has never been tested in other primates. We study the division of resources behind the VOI in Formosan macaques. Monkeys choose the equal division more often when a conspecific is present than when it is absent, suggesting a degree of impartiality. To better understand this impartiality, we measure a monkey's reactions to two directions of inequity: one regarding inequity to its advantage and the other to its disadvantage. We find that disadvantageous inequity aversion correlates with the degree of impartiality behind the VOI. Therefore, seemingly impartial behavior could result from a primitive negative reaction to being disadvantaged. This suggests a mechanism to explain a tendency toward impartiality.

Faster onset of antidepressant effects of citalopram compared with sertraline in drug-naïve first-episode major depressive disorder in a Chinese population: a 6-week double-blind, randomized comparative study.

Several previous studies, including a meta-analysis, reported no significant differences between various selective serotonin reuptake inhibitors (SSRIs) in the treatment of major depressive disorder. However, because of the different chemical structure of SSRIs and the difference in the frequency of serotonin transporter polymorphisms between ethnic groups, a head-to-head comparative study between SSRIs in different populations may be enlightening. We compared the efficacy and adverse effect profiles of citalopram and sertraline in a double-blinded randomized clinical trial in a Chinese population of drug-naïve patients with first-episode major depressive disorder. Fifty-one patients were randomly assigned to citalopram or sertraline treatment. The Montgomery-Åsberg Depression Rating Scale (MADRS) was used as the primary outcome. Efficacy and adverse effects were analyzed in an intent-to-treat population. Efficacy was analyzed using a last-observation-carried-forward method for early terminators. There were no significant differences in demographic characteristics at baseline. No significant differences were found in MADRS scores between citalopram and sertraline at baseline (36.6 ± 5.5 vs 38.2 ± 4.9; P = 0.322) or at the end of treatment (week 6; 10.8 ± 10.0 vs 16.7 ± 11.3; P = 0.082). However, MADRS scores in the citalopram group were significantly lower at week 1 (25.2 ± 8.5 vs 30.4 ± 6.1; P = 0.029) and week 3 (15.9 ± 10.0 vs 22.1 ± 8.7; P = 0.037). Overall, treatment-emergent adverse effects were reported by 14.3% and 28.6% of patients in the citalopram and sertraline groups, respectively. In conclusion, citalopram and sertraline were both efficacious and well tolerated. However, citalopram exhibited a significantly faster onset than sertraline during the early weeks of treatment and tended to have a better efficacy in overall treatment, although the statistic was not significant.

Interval Laparoscopic Transabdominal Cervical Cerclage (ILTACC) Using Needleless Mersilene Tape for Cervical Incompetence.

Interval Laparoscopic Transabdominal Cervical Cerclage (ILTACC) has become a procedure of choice for many laparoscopic surgeons in nonpregnant patients diagnosed with cervical incompetence (CI) due to the inherent advantages it offers. The study was conducted to describe the feasibility of performing a three-step approach of ILTACC using a needleless mersilene tape in patients diagnosed with CI. A case series of three patients diagnosed with CI who underwent ILTACC using needleless mersilene tape referred at a tertiary hospital for cerclage. Women diagnosed with CI who underwent ILTACC using a needleless mersilene tape were included in the study, and surgical outcomes were measured. Descriptive statistics were used to describe the demographic profile and surgical outcomes of the patients. Three patients with a mean age of 31 (standard deviation [SD] = 4.96) years with a gravidity of 2.67 (SD, 0.82) and parity of 0.33 (SD, 0.47) were selected. The cervical length was 1.98 (SD, 0.76) cm. The average operative time was 149 (SD, 43.87) minutes. All patients had minimal blood loss (≤ 60 ml) without intraoperative blood transfusion. The hospital stay was 1.33 (SD, 0.47) days with a median of 1 and a range of 1-2 days. No intraoperative or postoperative complications were noted. No cases were converted to laparotomy. The result of this article shows the safety and feasibility of ILTACC using needleless mersilene tape. However, it should be evaluated in more cases.

Sentinel Pelvic Lymph Node Dissection by Natural Orifices Transvaginal Endoscopic Surgery Approach after Indocyanine Green Dye Detection in Early Endometrial Cancer of Posthysterectomy Patient.

There was a case of 57-year-old female who was done the natural orifices transvaginal endoscopic surgery (NOTES) hysterectomy and bilateral salpingo-oophorectomy for benign disease. However, her biopsy result was Grade 1 endometrioid adenocarcinoma, and she was incidentally diagnosed as endometrial cancer. She was uneventful apart from that finding. She underwent the sentinel pelvic lymph node dissection with indocyanine green-guided NOTES approach for complete staging. This technique may be helpful to maximize the complete staging in early endometrial cancer as well as it can minimize the morbidity-related lymphadenectomy. In conclusion, in spite of a new technique for NOTEs, it can be safe and cost-effective for patients.

Comparison of LigaSure™ tissue fusion system and a conventional bipolar device in hysterectomy via natural orifice transluminal endoscopic surgery (NOTES): A randomized controlled trial.

OBJECTIVE: To evaluate the efficacy and effectiveness of applying LigaSure™ Tissue Fusion System in hysterectomy via transvaginal natural orifice transluminal endoscopic surgery (NOTES) in comparison with using the conventional bipolar device. MATERIALS AND METHODS: Eighty women scheduled for hysterectomy by transvaginal NOTES were prospectively randomized into applying LigaSure (study group) or conventional bipolar instrument (control group) in an intention-to-treat analysis. Primary endpoints were the device-related efficacy; secondary endpoints were surgical effectiveness measured by operative time, blood loss, postoperative pain and adverse events. RESULTS: In the eligibly allocated patients, three in the control group (n = 39) converted to applying LigaSure and one converted to conventional laparoscopy intraoperatively, while none in the LigaSure group (n = 38) found such conversions. Patients who completed full analysis in the LigaSure (n = 36) and control (n = 35) groups did not differ significantly in operative time, estimated blood loss, and the length of hospital stay. In the subgroup of women who underwent hysterectomy only, the LigaSure group (n = 22) showed significantly reduced operative time than the control group (76.50 ± 24.74 min versus 93.96 ± 27.10 min, p = 0.029). Postoperative pain scores were statistically higher in the LigaSure group within 36 h; however, the difference was not clinically significant. The incidence of postoperative adverse events between the groups was not different; nevertheless, device-related adverse events was not found in the LigaSure group. CONCLUSION: LigaSure™ tissue fusion technology was feasible and efficacious without compromising surgical procedures for hysterectomy by transvaginal NOTES compared with the conventional bipolar hemostasis device.

The outcomes of transvaginal NOTES hysterectomy in various uterine sizes.

OBJECTIVES: Natural orifice transluminal endoscopic surgery (NOTES) is an emerging technique in the area of minimally invasive procedures. Preliminary reports have confirmed transvaginal NOTES to be a safe and feasible method for performing hysterectomy and adnexal procedures. However, there are limitations regarding the feasibility of performing transvaginal NOTES hysterectomy in various uterine sizes. MATERIALS AND METHODS: Two hundred and seventy-five women who had undergone transvaginal NOTES hysterectomy for benign pelvic lesions were recruited from May 2012 to May 2016. Their medical records were retrospectively reviewed. All patients were placed into one of three groups depending on weight of the surgical specimen in order to assess surgical outcomes. RESULTS: One hundred ninety-one patients (69.46%) had a uterine weight of <500 g (group 1), 67 (24.36%) had a uterine weight of 500-999 g. (group 2), and 17 (6.18%) had a uterine weight of ≥1000 g. (group 3). The mean age± SD of group 1, group 2, and group 3 were 48.68 ± 6.63, 47.22 ± 3.81, and 46.53 ± 2.96 years, respectively (p value = 0.110). There was no statistical differences in terms of parity, body mass index (BMI), or history of abdominal surgery among the three groups. With regard to surgical outcomes, the mean operative times (Standard error: SE) were 76.70 (0.68), 99.99 (1.14), and 152.88 (3.37) minutes in Group 1, Group 2, and Group 3, respectively. The mean amounts of blood loss (SE) was 180.85 (4.61), 342.57 (6.98), and 532.35 (11.85) ml in Group 1, 2, and 3, respectively. There were statistically significant differences in terms of operative time and blood loss among the three groups (p = 0.0001 and 0.0001, respectively). CONCLUSIONS: Although the size of uterus has a significant effect on operative time and blood loss, NOTES hysterectomy can be successfully performed without any increase in complication rates. Natural orifice transluminal endoscopic surgery hysterectomy is a safe and feasible procedure even in large uteri.

Tenderization effect of whelk meat using ultrasonic treatment.

This study was conducted to assess the potential application of ultrasonic treatment to enhance the tenderness of whelk (Buccinum undatum) meat. The optimum ultrasonic conditions for the maximum tenderization effect were determined using response surface methodology by a three-level factorial Box-Behnken design for the optimization of three variables. The optimum conditions for the three variables found were as follows: ultrasound power at 200 W, treatment time for 9.6 min, and temperature at 45°C. The resulted tenderization effect was comparable to traditional enzymatic methods. Furthermore, disruption of muscle microstructure was observed in the ultrasonic-treated whelk meat by scanning electron microscopy, while evaluations on physicochemical properties indicated the ultrasonic treatment has no significant undesirable effects on the quality of whelk meat including pH, water-holding capacity, and lipid oxidation. In conclusion, this study showed the feasibility of ultrasonic treatment as a promising tenderization method for whelk meat without detrimental effects on its quality.

Unexpected epithelial ovarian cancers arising from presumed endometrioma: A 10-year retrospective analysis.

OBJECTIVE: To evaluate the incidence and prognosis of unexpected epithelial ovarian cancers (EOCs) occurring in presumed benign endometrioma. MATERIALS AND METHODS: Patients who underwent primary surgery at Chang Gung Memorial Hospital between November 2003 and October 2013 were searched with the Systematized Nomenclature of Medicine code followed by chart review. RESULTS: The incidence of unexpected EOCs in presumed ovarian endometrioma was 0.14%, as 11 patients were revealed after reviewing 497 patients of pathology-proven EOCs in the current series. All patients were aged ≥ 40 years; seven (63.6%) had inward mass within ovarian cyst in preoperative images, six had cancer antigen-125 (CA-125) > 200 U/mL, and two with CA-125 > 1500 U/mL. Ten patients underwent laparoscopy initially, including five with ovarian preservation at the beginning. Ten patients subsequently completed concurrent or secondary staging surgery, including four totally with laparoscopy. The histologic subtypes had clear-cell (8/11), endometrioid (1/11), mixed clear-cell and endometrioid (1/11), and low-grade serous adenocarcinoma (1/11). Seven patients had endometriosis-associated ovarian carcinoma (EAOC), while the other four were non-EAOC with no endometriosis component. The only mortality was a patient of non-EAOC in Stage IIIc, whereas the other 10 in Stage I were alive. The overall survival rate was 90.9% (10/11) with follow-up ranging from 23 months to 130 months. CONCLUSION: Unexpected EOCs occurring in presumed ovarian endometrioma was rare and, if present, the prognosis was good in Stage I disease with laparoscopic management. Combining parameters of patient's age, CA-125 level, and inward solid mass at imaging could help to raise the precautions.

Subtotal hysterectomy by natural orifice transluminal endoscopic surgery.

STUDY OBJECTIVE: To introduce the innovative surgical procedure of treating benign uterine pathology with subtotal hysterectomy by natural orifice transluminal endoscopic surgery (NOTES). DESIGN: Prospective observational study. SETTING: Tertiary referral medical center. METHODS: From June 2014 to May 2016, three patients with benign uterine diseases who were eligible for laparoscopic subtotal hysterectomy were recruited to undergo transvaginal NOTES at a tertiary referral medical center. Intraoperative and postoperative surgical outcomes were measured. RESULTS: Subtotal hysterectomy by transvaginal NOTES was successfully completed in all patients without any conversion to conventional laparoscopy. The operative time was 144 ± 4.5 (138-149) minutes with an average estimated blood loss of 133 ± 62 (50-200) mL. None of the patients required an intraoperative blood transfusion. The mean specimen weight was 140 ± 59 (56-188) g. The final histology reports were uterine leiomyoma and adenomyosis in these three cases. There were no intraoperative or postoperative complications. No case required intraoperative or postoperative blood transfusion. No cases were converted to traditional laparoscopy or laparotomy. CONCLUSION: Our preliminary results showed the safety and feasibility of subtotal hysterectomy by transvaginal NOTES in selected patients. It is one of the most minimally invasive surgeries and results in invisible scars.

Robot-assisted natural orifice transluminal endoscopic surgery for hysterectomy.

OBJECTIVE: To describe the surgical procedures of robot-assisted natural orifice transluminal endoscopic surgery (NOTES) for hysterectomy and to evaluate its feasibility. MATERIALS AND METHODS: From December 2014 to February 2015, four patients with benign diseases who were eligible for robot-assisted NOTES at Chang Gung Memorial Hospital were recruited to this study. Intraoperative and postoperative surgical outcomes were evaluated. RESULTS: Robot-assisted NOTES hysterectomy was successfully performed in all these patients. None of the patients had vaginal delivery, with two being nulliparous. The mean ± standard error of the mean uterine weight was 365.5 ± 69.2 g, the mean operative time was 198.8 ± 39.0 minutes, the mean docking time was 38.3 ± 2.4 minutes, the mean blood loss was 180.0 ± 56.1 mL, and the mean postoperative hospital stay was 2.5 ± 0.3 days. The final pathologic diagnoses were adenomyosis and/or leiomyomas. CONCLUSION: The novel robot-assisted NOTES technology created scarless skin wounds. More importantly, the device allows the surgeon to reach deeper places to achieve hemostasis, and perform surgery on larger tumors using the curved cannulae-wristed instrument. However, its implementation is limited by the lack of appropriate instrumentation, which requires further development and break through. At this stage, robot-assisted NOTES is only useful for limited applications in highly selected patients.

Accessibility and surgical outcomes of transumbilical single-port laparoscopy using straight instruments for hysterectomy in difficult conditions.

OBJECTIVES: To evaluate the accessibility of transumbilical single-port laparoscopy for hysterectomy in difficult conditions. MATERIALS AND METHODS: This prospective observational study recruited patients with benign diseases who were scheduled for laparoscopic hysterectomy between March 2010 and October 2011 to undergo the transumbilical single-port approach with straight instruments and a laparoscope. RESULTS: In total, 109 patients were included with a mean [± standard error of the mean (SEM)] age of 45.9 ± 0.4 years and mean body mass index of 23.9 ± 0.3 kg/m(2). The yielded mean uterine weight was 403.4 ± 25.3 g, with 28 (25.7%) weighing ≥500 g, including four specimens >1000 g, and 44 (40.4%) needed concurrent adhesiolysis. The operative time was 117.2 ± 4.2 minutes, estimated blood loss was 270.3 ± 22.9 mL, and the postoperative hospital stay was 2.8 ± 0.1 days. Patients with a uterus weighing ≥500 g had a higher intraoperative blood loss in comparison with those with a uterus weighing <500 g (375.4 ± 55.3 mL vs. 234.0 ± 23.0 mL; p < 0.05) and a higher incidence of blood transfusion (17.9% and 6.2%, respectively). The single-port approach was abandoned in four (3.7%) patients with severe pelvic adhesion--an additional port was opened for extensive adhesiolysis. None of the patients with a voluminous uterus needed an additional port. There were no major intraoperative or postoperative complications. CONCLUSION: The single-port approach using straight, conventional laparoscopic instruments was feasible and safe in the majority of the patients undergoing hysterectomy, and was found to be accessible even in cases with a large uterus. The patients benefitted from this approach and had less abdominal wounds. However, patients with a voluminous uterus tended to have more intraoperative blood loss, and in some cases with severe adhesions, additional port(s) were required for surgical effectiveness.

Comparison of morcellator and culdotomy for extraction of uterine fibroids laparoscopically.

OBJECTIVE: To define a rational guideline for the removal of uterine fibroids after laparoscopic myomectomy (LM) by culdotomy or morcellator in multiparae. STUDY DESIGN: A total of 416 multiparae receiving LM were retrospectively studied between November 1997 and January 2014. Of these, 335 had fibroids removed by culdotomy and 81 by a laparoscopic 15mm electromechanical morcellator. Data on parity, number, size and weight of fibroids, operating time, specimen removal time, blood loss, postoperative stay, hospital charges and complications were recorded. The patients were analyzed in four subgroups stratified by main fibroid size and type of procedure. RESULTS: There was no significant difference in body mass index, number of fibroids removed, blood loss, complications, and hospitalization duration between the groups. For fibroids below 10cm, the morcellator was significantly faster compared to culdotomy (10min versus 12min, p<0.001). For fibroids 10cm and above, there was no significant difference in time by culdotomy compared to morcellator (24min versus 20min, p=0.497). The electromechanical morcellator was significantly more expensive. CONCLUSION: Fibroid size of 10cm may be used as a guide for the route of fibroid removal; below 10cm the morcellator is faster but more expensive, for fibroids 10cm and above, culdotomy can be considered as it has a similar removal time to the morcellator in multiparae.

Intuition and deliberation: two systems for strategizing in the brain.

Dual-process theories distinguish between intuition (fast and emotional) and reasoning (slow and controlled) as a basis for human decision-making. We contrast dominance-solvable games, which can be solved by step-by-step deliberative reasoning, with pure coordination games, which must be solved intuitively. Using functional magnetic resonance imaging, we found that the middle frontal gyrus, the inferior parietal lobule, and the precuneus were more active in dominance-solvable games than in coordination games. The insula and anterior cingulate cortex showed the opposite pattern. Moreover, precuneus activity correlates positively with how "effortful" a dominance-solvable game is, whereas insula activity correlates positively with how "effortless" a coordination game is.