Table 1 Thought categories, frequencies, and examples

Environmental distractions

“It is warm in this room,” “What are those red things in the monitor of the computer,” “A high pitch tone outside.”

Task-related interferences

“If the experimenters chose this text because it is very boring and they want us to zone out a lot,” “If I am going to be quizzed on this,” “I was wondering how much time was left.”

Stimulus

“I was thinking that the red balloon had to have been CGI or something,” “Is this really a book,” “How cute the little boy is.”

Semantic memories

“I thought about a scene from both “The Mummy” and “The Return of the Mummy”,” “A story about someone injuring their eyes when diving in with them open,” “Trying to remember which Millais painting had a bubble in it.”

Autobiographical memories

“I remember walking in lines like that in grade school,” “When I visited the Louvre and saw the Greek and Etruscan vases,” “Jumping into the lake last Saturday morning.”

Unspecific memories

“Friends potentially in a class together,” “My roommate playing in the marching band,” “My new swimsuit.”

Fantasies

“Imagining my friend asking me “so chem[istry] is your easiest class right?”,” “What would happen if there were some sort of emergency while I were taking this study,” “What if everyone all the time spoke out their thoughts out loud like I am typing right now. What would happen.”

Prospection

“Cheer practice tonight,” “School work that I have to complete,” “I need to activate my card.”

Introspection

“I am about to fall asleep,” “How much I hate math,” “I cannot believe how many random thoughts I have.”

Vague

“Sleeping,” “Water,” “Nothing in particular.”