This fully editable lesson on Emotion as a Factor Affecting Perception introduces students to how emotional responses influence perceptual processes, such as attention and interpretation. Aligned with the AQA GCSE Psychology Specification, this resource explores perceptual defence and how anxiety-provoking stimuli can delay recognition. The lesson focuses on McGinnies’ (1949) study, which investigates the impact of emotional arousal on perception, highlighting strengths and limitations in its findings. Comprehensive Lesson Slides: The slides outline how emotions shape perception, emphasising perceptual defence and its effect on recognising stimuli. McGinnies’ (1949) study is used to demonstrate emotional influences, encouraging students to evaluate the strengths and weaknesses of the research, such as its use of galvanic skin response (GSR) as an objective measure and concerns about ecological validity. Interactive Activities: Students participate in Think-Pair-Share discussions, analyse emotional influences on perception, and complete application tasks based on exam-style questions. Tasks include summarising McGinnies’ study and evaluating perceptual defence with real-world examples. Evaluation and Assessment: Structured evaluation worksheets guide students in assessing strengths and limitations of McGinnies’ study, including debates over whether delayed recognition reflects embarrassment rather than defence mechanisms. Assessment materials also include 9-mark essay-style questions with model answers and scaffolding.