Background We developed a novel delayed reproduction task, the “What was where?” task, which obtains a continuous measure of localization error and is more sensitive compared to conventional span measures of Short‐term Memory (STM). Method We recruited 44 MCI (Mild Cognitive Impairment), 41 AD (Alzheimer’s Disease) patients and 109 healthy elderly controls (EHCs) from memory clinics in Oxford, UK and Jena, Germany, where they performed the “What was where?” task (Figure 1). We extracted the following metrics: Identification Accuracy (percentage correctly identified items), Absolute Localization Error (how far the object was misplaced), Misbinding rate (erroneously localizing an item to the remembered location of another item in memory) and Guessing response rate. Result Absolute Localization Error and Misbinding rates were greater in MCI and AD patients (p < 0.001) compared to EHCs, while AD and MCI performed similarly on these metrics. However, Identification Accuracy as well as Guessing (p = 0.003) were greater in MCI (p < 0.001) compared to AD patients. Moreover, EHCs identified the correct object more often (p < 0.001) and guessed less (p < 0.001) than MCI patients. Conclusion This novel task is able to detect STM impairment in MCI cases on a continuous scale, and is a sensitive memory measure which might be a useful index of memory for future clinical trials in AD in its earliest stages.

External warning cues temporarily increase the brain's sensitivity for upcoming events. Such increased levels of phasic alertness help individuals to flexibly adapt their reactions to the fast-changing requirements of highly complex visual environments. Previous studies reported that both healthy younger and older adults profit from phasic alerting cues. Arguably, such an intact phasic alerting mechanism could be even more relevant in pathologically aging individuals who are characterized by pronounced reductions of general processing capacity. The present study employed a theory of visual attention based whole report paradigm with auditory cues in order to investigate phasic alerting effects in amnestic mild cognitive impairment (aMCI) on a purely perceptual level. In addition, aMCI patients were compared to a previously reported sample of healthy older adults. The analysis in aMCI patients indicated that their visual processing speed was significantly higher in the cue compared to the no-cue condition. Across groups, auditory alerting cues significantly increased visual processing speed. Further, visual processing speed was reduced in aMCI patients compared to healthy older adults, replicating prior findings. Taken together, the results suggest that the processing system of aMCI patients exhibits general declines but can still flexibly integrate auditory warning signals. Phasic alerting cues facilitate a temporary increase in processing speed, enabling an efficient handling of upcoming sensory information.