Aptitude

In total, 234 people from 15 families of Finnish origin with some professional musicians and/or active amateurs were recruited for the study via a nationwide search by sending information leaflets or letters to the families whose members had studied or were studying at Sibelius Academy or music institutes in Finland (supplementary fig 1 online). The family members who first contacted us knew that there were some musicians or active amateurs in their families and informed their families about the study. Among the professional musicians, the two main groups were pianists and violinists. The amateurs were most commonly playing the piano or singing in a choir. The phenotypes of all family members were defined by three tests for musical aptitude: an auditory structuring ability test (the Karma Music test, KMT) designed by one of the authors,13 and the Seashore pitch and time discrimination subtests (SP and ST respectively).14 The KMT has been successfully used for 30 years in Finnish primary schools and music institutes a selection test for students to play an instrument. The KMT is devised to measure auditory structuring in a way that minimises the effects of training and/or culture.15 It uses small, abstract sound patterns that are repeated to form hierarchic structures. The subject’s task is to detect structural changes in these patterns, ie, changes in the order or number of the tones (an example of three items is enclosed in the supplementary material online). In a study that used the Mismatch Negativity (MMN) component of event related brain potentials, persons with high scores in the auditory structuring test were compared with those who had low score. There was a difference when the stimuli were sound patterns but not when mere pitches were used. This supports the validity of the test as a measure of auditory structuring rather than sensory differentiation.16 (link) In contrast, the SP and ST subtests consist of pair-wise comparisons of the physical properties of sound and are used to measure simple sensory capacities, such as ability to detect small differences in tone pitch or length. Testing was performed as a group test that lasted about 1 hour. Groups contained members from one family or from multiple families in each “session”. A total of 224 family members (105 males and 119 females) completed all tests and thus were included in further analyses.
All of the tests used a continuous scoring scale (for KMT, 0–40; for SP and ST, 0–50), with one point obtained for each correct answer. The reliabilities (α coefficients) of the tests were: KMT 0.88, SP 0.91 and ST 0.78. Calculating reliabilities is a standard procedure within the behavioural sciences. This index is an estimate of the share of systematic, non-random variance in measurements (maximum = 1). The correlations between the three tests were: KMT/SP 0.64, KMT/ST 0.41 and SP/ST 0.41. These results show that the tests are reliable and only partially overlapping.
The results of the three music tests were given to the participants if they were interested. Instructions for carrying out the tests are available on request.

The measures are conceptualized as indicators for four task classes. Arguably these task classes tap different aspects of the working memory system. Within each task class indicators relied on either verbal, numerical, or figural-spatial stimuli and responses, or mixtures of two of these content domains. The selected task classes reflect operationalizations of competing WMC accounts and are frequently used measures for the assessment of WMC. Based on these two criteria, four WMC task classes were identified: (1) Complex Span (Cspan) tasks designed to capture simultaneous storage and processing in conditions of high interference, (2) Updating tasks assessing the accuracy of updating in working memory across a series of steps, (3) Recall N-back (RNb) tasks requiring the evaluation of the identity of each stimulus from a sequence to a preceding stimulus presented with a certain lag N, which also captures the updating of temporary bindings in working memory and (4) Binding tasks developed to test the ability to establish and briefly maintain bindings in working memory (see Figure 2 for a schematic representation of an example task for the four task classes).
Besides these four classes for measuring WMC, three covariates were of relevance in the present study. First, we developed three tests for the assessment of SM, capturing the aptitude to establish new associations in memory. These tasks were designed analogous to the binding tasks, except that list lengths were longer in order to exceed the capacity limits of primary memory and that memory for associations was tested over a much longer retention period filled with other tasks to ensure that recall relies entirely on SM. Second, two popular experimental paradigms—the Simon task and the Eriksen flanker task—were included to measure one aspect of cognitive control, the inhibition of strong but wrong response tendencies. Finally, we administered three tests of fluid intelligence as criterion measures.

The following instruments were used for data collection:

SDQ. The SDQ is a 25-item, open-access document that is used to screen youths for behavioral problems. The respondent is asked to reply based on the behavior of the study child over the past 6 months. Five items refer to prosocial skills, and 20 refer to difficulties. These items are divided into five scales: emotional symptoms, conduct problems, hyperactivity/inattention, peer relationship problems, and prosocial behaviors. Each scale consists of five items answered on a scale of “not true,” “somewhat true,” or “certainly true.” The total difficulty score is calculated by adding the results of the scales (excluding the prosocial behavior scale). From the total difficulties score, the SDQ enables researchers to classify subjects as normal, borderline, or abnormal, based on cutoff points. The values proposed by the original study for a Brazilian population for the inclusion of children in each classification are as follows: 0–13 for the normal category, 14–16 for the borderline category, and 17–40 for the abnormal category (Fleitlich et al., 2000 ). Children can be classified into these categories on each scale of the instrument, and the absolute values for this classification vary among the individual scales. The parent version of this scale, which was translated and validated for Portuguese by Fleitlich and Goodman (2001 (link)), was used.

In Brazil, SDQ psychometric properties of reliability and discriminative validity were assessed and satisfactorily attested (Woerner et al., 2004a (link)). To verify the reliability of the instrument, the test-retest method and the calculation of Cronbach's alpha were used, and significant values were reported. In this study, the test-retest reliability (20 days) ranged from 0.77 to 0.79.
For the purposes of this study, the sections of the DAWBA corresponding to the SDQ scales were applied, relative to the diagnostic assessments of depression (Depression), anxiety (Generalized Anxiety), attention and hyperactivity (Attention and Activity), interpersonal relationships (Friendship Questionnaire), difficult behaviors (Awkward and Troublesome Behavior), and social skills (Aptitudes Scale). DAWBA was used as the gold standard for the comparison with the SDQ scales, to analyze its discriminative validity to identify behavioral difficulties and prosocial resources in school-age children.

This study was part of a project on neuroaesthetics, which addressed issues pertaining to domain-general and domain-specific neural organization among art students in a variety of fields (visual arts, dance, piano, strings, vocals, percussions) and non-artist healthy controls. To facilitate inter-group comparisons, we had all of the artists undergo the same psychological assessments and neuroimaging using the same scanning protocols. In the current study, we focused exclusively on VAs and controls. Creativity can be a core mental competence of VA since the process of creating artwork reflects VA’s creativity (Getzels and Csikszentmihalyi, 2020 ). Thus, all participants took the self-reported 40-item Chinese version of the Abbreviated Torrance Test for Adults (ATTA) to assess their aptitude in tasks involving visual (figural) and verbal manipulation (Chen, 2006 ). The ATTA is commonly used for cross-artist group comparisons (not addressed in the current study); however, it includes a figural part that engages creative drawing mirroring the visual art training of VAs. The ATTA measures the ability to think creatively in terms of fluency, originality, elaboration, and flexibility (Chen, 2006 ). Fluency refers to the number of ideas that a participant can generate in a limited time. Originality indicates one’s ability to create unique ideas. Elaboration indicates the ability to embellish ideas with details. Flexibility indicates one’s ability to generate many different ideas (Althuizen et al., 2010 (link); Shen and Lai, 2014 (link)). The ATTA creativity index (CI) score refers to the sum of the four capacity scores. We followed standard protocols in administering and scoring the tests (Chen, 2006 ). SPSS Statistics (v. 23.0, IBM Corp., Armonk, NY, USA) was used for all psychological evaluation analyses. The results of the psychological evaluations were considered significant at p < 0.05.