Final answer:
Yan's arousal of the PNS and feelings of worthlessness and helplessness suggest he is experiencing an emotion related to depression, influenced by his physiological state and cognitive appraisal of his situation.
Step-by-step explanation:
Yan is experiencing an arousal of the Parasympathetic Nervous System (PNS) and is considering feelings of worthlessness and helplessness, which likely indicates he is experiencing an emotion related to depression. The James-Lange theory suggests that emotional experiences are the result of physiological arousal; however, it's the cognitive appraisal of this arousal - how we interpret the physical symptoms - that leads to the specific emotional experience according to Schachter and Singer's two-factor theory of emotion. In Yan's case, the feelings of worthlessness and helplessness may be interpreted as signs of physiological arousal, which then contribute to the experience of a depressive emotion.
Martin Seligman's theory of learned helplessness also provides insight into Yan's emotional state. When individuals experience repeated negative events that they feel they cannot control, they may develop a sense of learned helplessness, which is a state where a person feels unable to change their situation and may lead to depression. The arousal Yan is experiencing, coupled with his cognitive appraisal of his situation as one of worthlessness and helplessness, suggests that he is likely experiencing an emotion on the depressive spectrum.