**2. Methods**

Participants of the study were 10 right-handed second-grade female students aged 8–9 years (mean = 8.50, SD = 0.53). All of the participants were native Finnish speakers and students from a Finnish public elementary school, namely, the Viikki Teacher Training School of the University of Helsinki, where the student teachers practice under the guidance of mentors who are highly skilled in teaching. Additionally, research, practice, and development activities have a crucial role in Viikki Teacher Training School. The school has learning resources available for different learners with advanced pedagogies in use. Elementary school students in Viikki School are in general local children from the neighborhood, which can be described as a medium socioeconomic status district when compared to other areas in Helsinki [26].

The students' participation in this pilot study was voluntary, and parental, school principal, and municipal officials' written consents were obtained. The study was part of a bigger research project, which had already been reviewed and approved by University of Helsinki Ethical Review Board before. The participants had the right to cancel their participation at any moment of the study and measurements.

Participants had previously been classified as growth or fixed mindset students in the following manner: during individual interviews a researcher had asked the students 10 questions of a 5-point Likert-type scale questionnaire based on Gunderson and colleagues' mindset questionnaire used among children in previous research [27, 28]. They were also asked to describe how they understand the words "intelligence" and "giftedness." During that interview the participants were encouraged to bring up examples or questions related to the questionnaire.

The experiment was conducted by two experimenters during the school day in a separate space at the school premises. Before the experiment, the students were briefed about the process; they were encouraged to ask questions about the experiment and were reminded that they can cancel their participation at any moment. Participants then completed the task on a laptop. After the task, participants were debriefed about the experiment and compensated. The whole procedure lasted for approximately 1 h per participant.

The task was an age-appropriate go/no-go task adapted from Grammer and colleagues' study [29]. Participants were told that the task was a game in which they had to help a zookeeper catch animals and were instructed to press a button every time they saw a picture of an animal (go trial) except when the animal was an orangutan (no-go trial), because orangutans were also helping the zookeeper. The task consisted of a practice block (9 go trials, 3 no-go trials) followed by 16 blocks (30 go trials, 10 no-go trials) making up a total of 640 trials. Each stimulus was presented for 750 ms followed by a blank screen for 500 ms (response window 1250 ms). The participants were allowed small breaks between blocks and a longer one between blocks 8 and 9.

The task was conducted with presentation software (Neurobehavioral Systems, Inc., Albany, CA). EEG data were recorded with portable equipment (BrainVision QuickAmp amplifier) using 32 Ag-AgCl active electrodes (ActiCap, Brain Products, Germany) including two mastoid electrodes, one nose and one vertical eye movement electrode. Electrolyte gel (Signa Gel, Bio-Medical Instruments, Inc., Warren, MI) was used at each electrode. The data were recorded with BrainVision Recorder at 500 Hz sampling rate.

After recording, the EEG data were processed with Matlab R2017b software (Mathworks, Natick, MA) with EEGLAB 14.1.2b toolbox. The signal was high-pass filtered at 0.1 Hz and epoched 1250 ms before and 500 ms after response. In addition to visual inspection, artifactual epochs were rejected by detecting abnormal trends and abnormal spectra, and eye movement artifacts were removed using independent component analysis (ICA) [30]. The data were re-referenced to the average of the two mastoid electrodes. Response-locked grand average ERPs for

*Mindsets and Failures: Neural Differences in Reactions to Mistakes among Second-Grade Finnish… DOI: http://dx.doi.org/10.5772/intechopen.85421*

channels Fz and Pz were calculated and baseline corrected by subtracting the mean amplitude from −150 to −50 ms pre-response. For figures, the waveforms were lowpass filtered using a Butterworth filter of order 3 with a cutoff frequency of 30 Hz.

Behavioral data from the go/no-go task included response accuracy and reaction time measures for each trial. These were further processed in R statistical software (version 3.4.3) and used to compute measures for post-error adjustments, following Moser and colleagues [14].
