Abstract: Suicide is among the leading causes of death among adolescents in China. Suicidal ideation is the early psychological activity of suicide attempts and actual acts of suicide. Clinical studies suggest that 80 percent of suicides show some forms of suicidal ideation. Therefore, analyzing the adolescents’ suicidal ideation and actively intervening their suicide attempts become one of the major measures to prevent them from committing suicide.
Researches on the detection rate of the adolescents’ suicidal ideation, influential factors, and interventions from the perspectives of psychology, physiology, and sociology deepen our understandings of suicidal ideation among adolescents. However, at present, researches in the field mainly focus on the origin of teenagers’ suicidal ideation and interventions on the manifestations of the suicidal ideation. There are few systemic researches on the mental mechanism of adolescents’ suicidal ideation from the point of the social information coding.
The current research surveyed 3014 high school students by questionnaires and interviews, selected 306 participants based on their responses, and examined three aspects of social information coding (i.e., reaction time to passive or active vocabulary, perceptual processing, and semantic processing) among these adolescents. For the adolescents who got high marks (HM group) on the Positive and Negative Suicide Ideation Scale (PANSI), the reaction time of the detection stimulation on passive vocabulary is significantly shorter than that on active vocabulary; whereas for adolescents who got low marks (LM group) on the PANSI, the reaction time of the detection stimulation on passive vocabulary is significantly longer than that on active vocabulary.
On the perceptual processing level, no significant differences were found between the number of passive, active and neutral words the participants could recall among either HM group or the LM group.
On the semantic processing level, the number of active words that the HM group adolescents can recall is significantly lower than LM group adolescents; however, the number of passive words that the HM group adolescents can recall is significantly higher than LM group adolescents.
In summary, that current study suggests that the adolescents with higher level of suicidal ideation have attentional bias for passive words, whereas the adoelscents with lower level of suicidal ideation have attentional bias for active words; both of the groups have no bias for specific words on the perceptual processing level. However, the two groups have entirely different biases for specific words on the semantic processing level.

Key words: high school student, suicide ideation, social information coding