Humans spend a considerable portion of their lives engaged in ‘stimulus-independent thoughts' (SIT), or mental activity that occurs independently of input from the immediate external environment. Although such SITs are, by definition, different from thoughts that are driven by stimuli in one's external environment (i.e. stimulus-dependent thoughts; SDTs), at times, the phenomenology of these two types of thought appears to be deceptively similar. But how similar are they? We address this question by comparing the content of two types of SIT (dreaming and waking SITs) with the content of SDTs. In this 7 day, smartphone-based experience-sampling procedure, participants were intermittently probed during the day and night to indicate whether their current thoughts were stimulus dependent or stimulus independent. They then responded to content-based items indexing the qualitative aspects of their experience (e.g. My thoughts were jumping from topic to topic). Results indicate substantial distinctiveness between these three types of thought: significant differences between at least two of the three mental states were found across every measured variable. Implications are discussed.

This article is part of the theme issue ‘Offline perception: voluntary and spontaneous perceptual experiences without matching external stimulation’.

人类一生中有相当一部分时间从事“独立于刺激的思维”（SIT），即独立于直接外部环境输入而发生的心理活动。尽管根据定义，此类 SIT 不同于由外部环境中的刺激驱动的思想（即依赖于刺激的思想；SDT），但有时，这两种思想的现象学似乎看似相似。但它们有多相似？我们通过将两种类型的 SIT（做梦和醒着的 SIT）的内容与 SDT 的内容进行比较来解决这个问题。在这个为期 7 天、基于智能手机的体验抽样过程中，参与者在白天和晚上被间歇性地探查，以表明他们当前的想法是依赖刺激还是不依赖刺激。然后，他们对基于内容的项目做出回应，这些项目索引了他们体验的定性方面（例如，我的想法从一个主题跳到另一个主题）。结果表明这三种思想之间存在显着差异：在每个测量变量中都发现了三种心理状态中至少两种之间的显着差异。讨论了影响。

这篇文章是主题问题“离线感知：没有匹配外部刺激的自愿和自发的感知体验”的一部分。