Vision and hearing become less sensitive with age. But most of this deterioration is cumulative, beginning early in life. The sensitivity of the other sense of taste, touch, smell and balance also decline with age, though the implications of these changes are generally less serious than for vision and hearing (Schaie & Wills, 1996 & Peterson, 1989). The motor system: The brain’s rate of electrical activity declines during old age and the conduction speed of the impulses along neuronal fibers throughout the body also decreases.
There is slowing down in reaction time-the ability to quickly and accurately take action after a signal to respond appears- with age. It has three major components: sensory transmission time; motor execution time, and central processing time, which involves interpretation, decision, and association. The decreasing speed of processing information could account for many of the observed age differences in learning, memory, perception, and intelligence (Schaie & Willis, 1996; Peterson, 1989; Belsky, 1999).
Cognitive changes: There are several changes that occur with aging, one of which is cognitive slowing. The slowing that occurs in all cognitive tasks where speed of response is a component is considered the most pervasive cognitive change in developmental aging. The probable locus of slowing is in the central nervous system (Bob & McCallum, 1998). Pigment lipofuscin builds up in the brain during old age and it gradually results in brain degeneration.
The aged brain weighs less, the lateral ventricles tend to be dilated, and the ribbon of cortical tissue is narrowed (Hurlock, 1986). Such degeneration is held accountable for a decline in the brain’s capacity to function. But the average person’s intelligence is not likely to be seriously impaired before age 70 or 75 (Peterson, 1989). With good physical and mental health, adequate educational levels, and intellectual stimulation, it appears that there is not as a great decline in intellectual abilities with age as previously thought, especially in the 60 to 75 age group.
Emotional changes: Emotional changes over the adult life span are a topic of considerable importance for psychotherapists working with older adults. At the psychological level, the older adults are more difficult to arouse but also have more difficulty returning to a state of calm once aroused (Woodruff, 1985). The accumulation of experiences leads to more complex and less extreme emotional experiences in later life.
A review of research, using the Minnesota Multiphasic Personality Inventory with older adults, noted that older adults were lower on scales associated with anger, impulsivity, and confusion and argued that people may become less impulsive with maturity (Gynther, 1979, in Bob & McCallum, 1998). It was concluded that as a whole, emotionality in older adults may be both more complex and subtler than that of younger adults.