BackgroundWhile optimally activities are provided at those moments when the individual with profound intellectual and multiple disabilities (PIMD) is ‘focused on the environment’ or ‘alert’, detailed information about the impact that the design and timing of the activity has on alertness is lacking. Therefore, the aim of the present study is to shed light on the sequential relationship between different stimuli and alertness levels in individuals with PIMD.MethodVideo observations were conducted for 24 participants during one‐on‐one interactions with a direct support person in multisensory environments. Time‐window sequential analyses were conducted for the 120 s following four different stimuli.ResultsFor the different stimuli, different patterns in terms of alertness became apparent. Following visual stimuli, the alertness levels of the individuals with PIMD changed in waves of about 20 s from ‘active alert’ to ‘passive alert’. While auditory and tactile stimuli led to ‘alert’ reactions shortly after the stimulation, alertness levels decreased between seconds 20 and 120. Reactions to vestibular stimuli were only visible after 60 s; these were ‘active alert’ or ‘withdrawn’.ConclusionsThe results of the present study show that individuals with PIMD show their reactions to stimuli only slightly, so that ‘waves’ might reflect the optimal alertness pattern for learning and development. Consequently, it is especially important that direct support persons follow and stimulate these individual ‘waves’ in the activities they provide to their clients.