The chapter explores the relationship between novelty, complexity, and hedonic value through a series of experiments. The studies investigate how these factors influence ratings of "pleasingness" and "interestingness" of visual stimuli. Key findings include: 1. **Pleasingness and Interestingness Increase with Novelty**: Both pleasingness and interestingness ratings generally increase with the level of novelty, contrary to some previous findings that suggested an inverse relationship. 2. **Homogeneous Sequences and Familiarization**: Homogeneous sequences (sequences with multiple identical stimuli) declined in judged pleasantness more than sequences with varied stimuli. Simple stimuli became less pleasant as they became less novel, while complex stimuli declined less or became more pleasant. 3. **Complexity and Hedonic Value**: The hedonic value of complex stimuli tends to rise as they become less novel, while the opposite holds for simple stimuli. Monotonous, homogeneous sequences are more likely to lead to a decline in hedonic value after familiarization. 4. **Influence of Familiarization and Attention**: Familiarization and the requirement to make judgments during familiarization can affect ratings. In one experiment, ratings of simple stimuli declined over time, while those of complex stimuli initially declined and then rose. 5. **Wundt Curve Interpretation**: The findings are consistent with the Wundt curve, which suggests that positive hedonic value reaches a maximum with moderate arousal potential and then decreases as arousal potential increases. Simple stimuli, which have high novelty but low complexity, experience a decline in hedonic value as they become familiar. Complex stimuli, which have both high novelty and complexity, initially decline and then rise. 6. **General Discussion**: The chapter concludes that the hedonic value of complex stimuli tends to rise as they become less novel, while simple stimuli decline. Monotonous sequences and the requirement to make judgments during familiarization can influence these trends. The Wundt curve provides a useful framework for understanding these dynamics.The chapter explores the relationship between novelty, complexity, and hedonic value through a series of experiments. The studies investigate how these factors influence ratings of "pleasingness" and "interestingness" of visual stimuli. Key findings include: 1. **Pleasingness and Interestingness Increase with Novelty**: Both pleasingness and interestingness ratings generally increase with the level of novelty, contrary to some previous findings that suggested an inverse relationship. 2. **Homogeneous Sequences and Familiarization**: Homogeneous sequences (sequences with multiple identical stimuli) declined in judged pleasantness more than sequences with varied stimuli. Simple stimuli became less pleasant as they became less novel, while complex stimuli declined less or became more pleasant. 3. **Complexity and Hedonic Value**: The hedonic value of complex stimuli tends to rise as they become less novel, while the opposite holds for simple stimuli. Monotonous, homogeneous sequences are more likely to lead to a decline in hedonic value after familiarization. 4. **Influence of Familiarization and Attention**: Familiarization and the requirement to make judgments during familiarization can affect ratings. In one experiment, ratings of simple stimuli declined over time, while those of complex stimuli initially declined and then rose. 5. **Wundt Curve Interpretation**: The findings are consistent with the Wundt curve, which suggests that positive hedonic value reaches a maximum with moderate arousal potential and then decreases as arousal potential increases. Simple stimuli, which have high novelty but low complexity, experience a decline in hedonic value as they become familiar. Complex stimuli, which have both high novelty and complexity, initially decline and then rise. 6. **General Discussion**: The chapter concludes that the hedonic value of complex stimuli tends to rise as they become less novel, while simple stimuli decline. Monotonous sequences and the requirement to make judgments during familiarization can influence these trends. The Wundt curve provides a useful framework for understanding these dynamics.