Current neurobiological models of adolescent decision-making suggest that heightened risk taking during adolescence is a result of the asynchronous development of neural regions underlying cognitive control and reward processing, particularly during periods of heightened social and affective arousal (e.g., Casey, Getz, & Galván, 2008; Steinberg, 2008). Despite the emphasis on the interplay of cognitive and emotional processes during adolescence, the developmental literature has largely overlooked the potential importance of maturational changes in the anterior insular cortex (AIC), a region known for its role as a cognitive-emotional hub. In a recent review we proposed a theory of adolescent risk-taking in which development of the AIC, and its connectivity to other regions, biases adolescents towards engagement in risky behaviors (Smith, Steinberg, & Chein, 2014b). The current studies provide a test of the proposed model through an examination of specific aspects of AIC development and functioning, including the trajectory of structural development within the AIC, the role of AIC engagement in adolescents' risky decision-making, and the impacts of affective arousal on AIC recruitment. Results from Study 1 suggest that the AIC exhibits continued developmental changes during adolescence that likely affect its involvement in cognitive processes. Using a risk-taking task, Study 2 demonstrates the flexible role of the AIC during adolescent decision-making and explores how affective arousal biases the AIC towards engagement in risky behaviors. Implications for both the proposed model and the developmental literature are discussed. / Psychology

This study utilized the theories of David C. McClelland and associates regarding affective arousal, concept of cues arousing motives, and neutral testing procedures. The problem was to study the influence of color and/ or movement, as cues added to the McClelland four-picture Thematic Apperception Test, to evoke need achievement responses to determine whether or not the added stimuli of color and/or movement might evoke increased need achievement responses. Four treatment variations of the test were made: Treatment A, consisted of the standard McClelland test, in black and white pictures. This treatment served as the control. Treatment B used the black and white pictures, but with movement added to the standard test. Treatment C added color to the pictures, but no movement. Treatment D added both color and movement to the test. A special effects apparatus was used to create the color and/or movement added to the pictures. The treatment variations of the four pictures were recorded on motion picture film in order to standardize the experimental procedures of the study. A sample of 120 male college students was tested, and subdivided into groups of 30 subjects each. Each group of 30 students saw only one of the four treatment variations. The testing was accomplished by projecting the filmed, four-picture McClelland test, with each of the four pictures being shown for 20 seconds. After each picture was shown, five minutes were allowed for the subjects to write a story about the picture. The stories were scored for need achievement by the McClelland and associates (1953) scoring system C. Statistical comparisons were made among the three experimental groups (Treatment B, C, D), as compared with the control group (Treatment A) in terms of the subject's mean scores in need achievement. No significant differences were found in any of the statistical comparisons. It was, therefore, concluded that the study subjects did not respond to the addition of color and/or movement as significant cues related to achievement motivation.