Changes in attention
Many older adults notice a decline in their attentional abilities. Attention is a broad construct that refers to "the cognitive ability that allows us to deal with the inherent processing limitations of the human brain by selecting information for further processing" (p. 334). Since the human brain has limited resources, people use their attention to zone in on specific stimuli and block out others. If older adults have fewer attentional resources than younger adults, we would expect that when two tasks must be carried out at the same time, older adults performance will decline more than that of younger adults. However, a large review of studies on cognition and aging suggest that this hypothesis has not been wholly supported. While some studies have found that older adults have a more difficult time encoding and retrieving information when their attention is divided, other studies have not found meaningful differences from younger adults. Similarly, one might expect older adults to do poorly on tasks of sustained attention, which measure the ability to attend to and respond to stimuli for an extended period of time. However, studies suggest that sustained attention shows no decline with age. Results suggest that sustained attention increases in early adulthood and then remains relatively stable, at least through the seventh decade of life. More research is needed on how normal aging impacts attention after age eighty. It is worth noting that there are factors other than true attentional abilities that might relate to difficulty paying attention.
For example, it is possible that sensory deficits impact older adults attentional abilities. In other words, impaired hearing or vision may make it more difficult for older adults to do well on tasks of visual and verbal attention. Changes in memory
Many different types of memory have been identified in humans, such as declarative memory (including episodic memory and semantic memory), working memory, spatial memory, and procedural memory. Studies done, have found that memory functions, more specifically those associated with the medial temporal lobe are especially vulnerable to age-related decline. A number of studies utilizing a variety of methods such as histological, structural imaging, functional imaging, and receptor binding have supplied converging evidence that the frontal lobes and frontal-striatal dopaminergic pathways are especially affected by age-related processes resulting in memory changes. Changes in language
Changes in performance on verbal tasks, as well as the location, extent, and signal intensity of BOLD signal changes measured with functional MRI, vary in predictable patterns with age. For example, behavioral changes associated with age include compromised performance on tasks related to word retrieval, comprehension of sentences with high syntactic and/or working memory demands, and production of such sentences. Genetic changes
Variation in the effects of aging among individuals can be attributed to both genetic, health, and environmental factors. As in so many other science disciplines, the  nature and nurture debate is an ongoing conflict in the field of cognitive neuroscience. The search for genetic factors has always been an important aspect in trying to understand neuro-pathological processes.