Decision making in economic context is an everyday activity but its neuronal correlates are poorly understood. The present study aimed at investigating the electrophysiological brain activity during simulated purchase decisions of technical products for a lower or higher price relative to a mean price estimated in a pilot study. Expectedly, participants mostly decided to buy a product when it was cheap and not to buy when it was expensive. However, in some trials they made counter-conformity decisions to buy a product for a higher than the average price or not to buy it despite an attractive price. These responses took more time and the variability of the response latency was enhanced relative to conformity responses. ERPs showed enhanced conflict related fronto-central N2 during both types of counter-conformity compared to conformity decisions. A reverse pattern was found for the P3a and P3b. The response-locked P3 (r-P3) was larger and the subsequent CNV smaller for counter-conformity than conformity decisions. We assume that counter-conformity decisions elevate the response threshold (larger N2), intensify response evaluation (r-P3) and attenuate the preparation for the next trial (CNV). These effects were discussed in the framework of the functional role of the fronto-parietal cortex in economic decision making.

Error detection is required in order to correct or avoid imperfect behavior. Although error detection is beneficial for some people, for others it might be disturbing. We investigated Gaudreau and Thompson's (Personality and Individual Differences, 48, 532−537, 2010) model, which combines personal standards perfectionism (PSP) and evaluative concerns perfectionism (ECP). In our electrophysiological study, 43 participants performed a combination of a modified Simon task, an error awareness paradigm, and a masking task with a variation of stimulus onset asynchrony (SOA; 33, 67, and 100 ms). Interestingly, relative to low-ECP participants, high-ECP participants showed a better post-error accuracy (despite a worse classification accuracy) in the highvisibility SOA 100 condition than in the two low-visibility conditions (SOA 33 and SOA 67). Regarding the electrophysiological results, first, we found a positive correlation between ECP and the amplitude of the error positivity (Pe) under conditions of low stimulus visibility. Second, under the condition of high stimulus visibility, we observed a higher Pe amplitude for high-ECP-low-PSP participants than for high-ECP-high-PSP participants. These findings are discussed within the framework of the error-processing avoidance hypothesis of perfectionism (Stahl, Acharki, Kresimon, Völler, & Gibbons, International Journal of Psychophysiology, 97, 153-162, 2015).

The effect of coffee without and with caffeine (200 mg) on the performance of "awake" respectively "fatigued" subjects was proved. 5 females and 7 males (22 to 32 years) were chosen for the cross-over double-blind study. Motor reaction time, visual-mental processing time, reading-speed and reading-errors were recorded. Further experiments under aggravated conditions were carried out. In the morning ("awake") caffeine increases the efficiency of all parameters excepted the reading errors. At night ("fatigued") the increase by caffeine is insignificant. Even in some subjects caffeine decreases the speed of reading and increases the number of errors. Under test-conditions, which were aggravated by strong acoustical disturbance, caffeine does not improve efficiency, compared with caffeine-free coffee. Overriding into the range of decreasing performance in spite of increasing central activity was not found under any test-condition.

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