Why would repeating a cue seem like it should help more?
Targeted memory reactivation works on a simple premise: a sound or smell that was paired with something you learned can be played again during sleep to nudge the sleeping brain to replay that memory. If replay is the mechanism, it is intuitive that replaying the cue more often would drive more replay and therefore a bigger benefit. One review of hippocampal contributions to sleep-based consolidation notes that some processes in the brain require numerous repetitions to produce their effects, which is part of why repeated cueing is discussed as a strategy [2].
But that same discussion does not establish that each additional cue buys a proportional gain in memory. The review addresses repeated cue presentations as a topic and their potential impact, without clearly detailing measured memory benefits from adding more repetitions [2]. So the plausibility of a dose-response effect is a hypothesis, not a demonstrated result.
What seems to matter more than how many times a cue is played
In a nap study where sounds were paired with pictures and replayed during sleep, the benefit depended on two things: how accurately the participant had learned the picture in the first place, and whether the sound was directly associated with that specific picture [1]. In other words, a cue that is only loosely tied to a memory, or a memory that was never well formed, is a weak candidate for reactivation regardless of how often it is presented.
This reframes the question. If the limiting factor is the quality of the cue-memory link rather than the number of cue deliveries, then piling on repetitions would not be expected to scale the benefit smoothly. The nap study supports this emphasis on accuracy and direct associations, though it did not vary the number of cue presentations, so it cannot tell us what extra repetitions would do [1].
Timing and the window around a cue may matter as much as count
Work on overnight consolidation has focused on delivering cues during specific sleep phases, such as particular slow-oscillation states, and has reported memory benefits from cueing timed to those states [3]. That line of research treats when a cue arrives as a central variable, not how many times it arrives.
A more recent study manipulated the duration of the reactivation window rather than the number of cue presentations, and found that memory benefits tracked the link between sound onset and later gains, with benefits able to be disrupted under some conditions [4]. This suggests the effective unit may be a well-timed reactivation event rather than a raw count of cue deliveries. Separately, a study presenting snack names during non-REM sleep to test updating of social-learning-based evaluations considered cueing repetition in its analysis, but its aim was evaluation updating rather than a repetition dose-response for memory [5]. Across these studies, the number of cue presentations is not the variable that was systematically varied and measured against memory size.
What a real answer would require
To know whether more cue presentations produce proportionally larger benefits, a study would need to hold the cue-memory association and timing constant while varying the number of presentations, then measure memory change across those levels. None of the studies here did that. The nap study explicitly did not explore multiple cue presentations [1], the overnight slow-oscillation work examined phase-specific cueing rather than repetition count [3], and the reactivation-window study varied duration rather than count [4].
So the practical takeaway for now is modest: cueing during sleep is associated with memory changes, and the strength of that link appears to hinge on how well the cue is bound to the memory and when it is delivered [1][3][4]. Whether adding more cue presentations yields proportionally more memory is an open question that the current evidence does not resolve.
Sources used in this answer
The benefits of targeted memory reactivation for consolidation in sleep are contingent on memory accuracy and direct cue-memory associations
In a nap study replaying picture-associated sounds, memory benefits depended on initial memory accuracy and on direct cue-memory associations; the study did not test multiple cue presentations.
Hippocampal contributions to declarative memory consolidation during sleep
A review of hippocampal contributions to sleep consolidation discusses repeated cue presentations and their potential impact, but does not clearly detail measured memory benefits from repetition.
Shaping overnight consolidation via slow-oscillation closed-loop targeted memory reactivation
Overnight targeted memory reactivation timed to specific slow-oscillation phases was associated with memory benefits, but the study did not examine multiple cue presentations during a nap.
Manipulating memory processing during sleep to explore the critical duration of reactivation events
Varying the duration of reactivation windows rather than cue count, memory benefits correlated with sound-onset-linked reactivation and could be disrupted under some conditions.
Modulating social learning-induced evaluation updating during human sleep
Presenting snack names as cues during non-REM sleep was used to test social-learning-based evaluation updating, and the study considered cueing repetition in analysis without testing a repetition dose-response for memory.