were either related or unrelated to the target stimuli, which was a letter Q. Young and older adults completed a target-counting task which required a search of a visual display. The number of distractor items remained constant throughout the displays, but the distractor type (i.e. whether it was categorically related to the target, numerically related, or not related at all) was varied in order to observe possible differences performance to do with age. Researchers found that older adults were slower at counting targets than younger adults, regardless of distractor presence in the display. Counting performance slowed for both young and older adults when distractors appeared in the display, and when distractors were incongruent with regards to the required response, interference was highest for both young and older adults. With regards to selective attention performance, no evidence suggested that there was an age difference in the effects of the type of distractor. The lack of interaction between age and condition suggests an age-related deficit in inhibitory processes, and this can be seen in the increased response times in the experimental conditions in which targets were presented without distractors, compared to targets presented with distractors. This increase in response time is greater for older adults than for younger adults, suggesting that attention allocation over trials is sensitive to age-related decline, and therefore it is possible that there is an age-related decline in ability to switch between a situation that requires the use of inhibitory processes and situations that do not require selective attention. Mild cognitive impairment Mild cognitive impairment (MCI) is considered the transitional stage between normal aging and Alzheimer's disease, though it is noted that not all individuals diagnosed with MCI progress to dementia. It is possible that there would be some small changes in visual selective attention at this stage, as even in early stages of Alzheimer's disease, such deficits are observed. Deficits in MCI are consistent with the neurological changes seen in brain areas such as the prefrontal cortex, parietal lobes, cholinergic system, and the decreased connectivity in the frontoparietal network in the early stages of AD. These changes, which have been shown to result in inefficient processing speed and difficulties in shifting focus, suggest that patients with MCI have more difficulty attending to the target stimuli when distractors are present, compared to healthy controls. Individuals with MCI who progressed to dementia within 2.5 years showed significantly more inefficient