固著行為（stereotypical behavior ）的起因與功能仍不清楚。學家們大都從操作制約觀點來研究此異常行為。本研究共有三個子研究，採功能分析的方法，試圖找出影響自閉症學童固著行為之原因。研究一、以類似的功能分析（analogue functional analysis ）從操弄四種情境（引起注意、工作要求、單獨、及遊玩情境）來分析該學童固著行為的功能。結果顯示：四種情境都無法對固著行為產生區分性的結果。研究二、以功能分析來操弄四種情境（單獨、聽覺遮蔽、觸覺遮蔽、及視覺遮蔽情境）來分析造成固著行為的感官功能。結果顯示：只有在觸覺遮蔽的情境下，固著行為顯著減少。研究三、繼續以功能分析來操弄五種情境（繩子、單獨、聽覺遮蔽、觸覺遮蔽、及視覺遮蔽情境）來檢視替代性的觸覺刺激能否與固著行為產生對抗的效果。研究顯示：以繩子能成功地替代固著行為。最後，本研究對固著行為的感官功能與感官刺激的來源，進一步地討論，並對未來的研究提出建議。

The current study included three experiments that functionally analyzed stereotypical behavior. An analogue functional analysis was used in Experiment 1 to detect the function of one student' s stereotypy which might serve to escape from task demands, obtain attention from others, or produce sensory self-stimulation. An analysis of sensory modalities was conducted in Experiment 2 to further analyze the possible sensory consequences causing the student's stereotypy. Alternative sensory reinforcer was used in Experiment 3 to compete with specific sensory consequences maintaining the student's stereotypy. Results of the present study demonstrated sensory reinforcement was a determinant of stereotypical behavior in this student. The specific function of stereotypy in this student was maintained by tactile stimulation.