Inhibitory Changes After Age 60 and Their Relationship to Measures of Attention and Memory

Abstract

This study examined the relationship between age and inhibitory functioning within a sample of older adults ranging in age from 60 to 85 years old. On the basis of earlier research, and confirmed by factor analysis, measures typically referred to as frontal lobe tasks were used as measures of inhibitory functioning. Findings demonstrated that inhibitory processes continued to decline with advancing age within the older sample. In addition, the role of inhibition in age-related performance deficits on a verbal list learning measure and an attention measure was examined. Hierarchical regression analyses showed that inhibition accounted for a significant proportion of the age-related variance on the two cognitive measures, whereas measures of reading speed accounted for a smaller proportion of the variance. In addition, when inhibition was first covaried out, reading speed no longer accounted for a significant proportion of the age-related variance. It is argued that inhibition is an important contributor to age-related performance decrements in cognition.AN increasingly central notion in attention theory is that inhibitory processes act in concert with excitatory processes to control the contents of working memory. Inhibitory processes help prevent irrelevant stimuli from interfering with the efficient processing of target information in a number of ways (e.g., Hasher & Zacks, 1988;Tipper, 1985;Tipper, Weaver, & Houghton, 1994). Specifically, inhibition can prevent the allocation of attention to irrelevant or distracting information in the internal or external environment, thereby allowing for a focus on the relevant task or goal. Further, as task demands change, inhibition serves to suppress activation of stimuli that were previously important but now are no longer the target of processing (Hasher & Zacks, 1988;. Finally, more recently it has been proposed that inhibition serves to restrain prepo-tent responses from occurring immediately, allowing for an initial evaluation as to their appropriateness (Hasher, Zacks, & May, 1999). When inhibitory processes are not operating efficiently, irrelevant or distracting information can invade working memory, possibly resulting in lowered performance due to interference effects and response competition. These interfering effects can occur at both the encoding and retrieval stages.It has recently been postulated that deficits in inhibitory functioning may account for agerelated performance decrements exhibited in a variety of cognitive tasks (Hasher & Zacks, 1988; Hasher et al., 1999;. This view maintains that inhibitory mechanisms become inefficient with age, causing a disruption to working memory. Working memory has been theorized to be important for successful performance in many cognitive domains, including memory, language comprehension and speech production, and planning and problem solving, among others (Baddeley & Hitch, 1994). Given the importance of Address correspondence to Carol Persad, Neuropsychology Division, University of Michigan, C480 Med Inn, 1500...

Association between memory impairment and insomnia among older adults

“…The results reveal significant differences between older adult insomniac subjects and older adult noninsomniac subjects on three memory processes-learning rate, resistance to proactive interference, and temporal order judgment-all of which have many implications for daily life. The findings of the present study are consistent with results of other studies that show a particularly pronounced age-related decline in the ability to learn (Kessels et al 2003), the ability to inhibit irrelevant information (Persad et al 2002) and the ability to temporally code information (NavehBenjamin et al 2000).…”

Cognitive Ability, Expertise, and Age Differences in Following Air-Traffic Control Instructions.

“…In turn, age differences in WM could be explained by age-related differences in processing speed and interference control. This study adds to the growing body of literature that argues for the importance of both speed and interference control as separable factors that may contribute to age-related differences in cognitive performance (Braver et al, 2001;Kramer, Hahn, & Gopher, 1999;Kray & Lindenberger, 2000;Kwong See & Ryan, 1995;Meiran, Gotler, & Perlman, 2001;Persad, Abeles, Zacks, & Denburg, 2002;Spieler, Balota, & Faust, 1996;Van der Linden et al, 1999;Verhaeghen & De Meersman, 1998;Wecker, Kramer, Wisniewski, Delis, & Kaplan, 2000;West & Baylis, 1998). Especially important is the question of the life span development of processing speed and control of interference.…”

Effect of a structured course involving goal management training in older adults: A randomised controlled trial

“…Working memory functions less well [1], inhibitory mechanisms become less efficient [2,3], and performance in dual task situations is reduced [4]. Working memory, inhibition, and shifting between two tasks are frequently seen as aspects of executive functioning [5].…”