Temporal discrimination deficits as a function of lag interference in older adults

Abstract

A vital component of episodic memory is the ability to determine the temporal order of remembered events. Although it has been demonstrated that the hippocampus plays a crucial role in this ability, the details of its contributions are not yet fully understood. One proposed contribution of the hippocampus is the reduction of mnemonic interference through pattern separation. Prior studies have used behavioral paradigms designed to assess this function in the temporal domain by evaluating the ability to determine the order of remembered events as a function of proximity in time. Results from these paradigms in older adults (OA) have been mixed, possibly due to limitations in controlling elapsed time and narrow range of temporal lags. Here, we introduce a novel behavioral paradigm designed to overcome these limitations. We report that OAs are impaired relative to younger adults at moderate and high temporal lags but not at low lags (where performance approached floor). We evaluated OAs' ability to benefit from primacy (enhanced order judgment on the first few items of any given sequence) and found two distinct subgroups: one group was on par with young adults [aged-unimpaired (AU)] and the other group was two standard deviations below the mean of young adults [aged-impaired (AI)]. Temporal discrimination performance in AU adults was consistent with a pattern separation deficit, while performance in AI adults was consistent with a generalized temporal processing deficit. We propose that the task introduced is a sensitive marker for episodic memory deficits with age, and may have diagnostic value for early detection of age-related pathology.

Age-related deficits in the mnemonic similarity task for objects and scenes

“…The most common version of the MST utilizes simple, everyday objects on a white background and has been a powerful tool for demonstrating decreases in pattern separation behavior in aging and MCI [10,11,13,15,38]. In addition, several variants of the MST or related tasks designed to test pattern separation performance have shown age-related declines manipulating temporal [39], emotional [40,41], verbal [42], and spatial [43-45] dimensions of lure similarity. In this study, we developed a different manipulation: the use of rich, complex scenes in place of simple objects.…”

Mutual Entailment of Temporal Relations in Younger and Older Adults: Reversing Order Judgments

“…From a cognitive perspective, temporal memory concerns the ability to accurately encode and recall the time and order of past events (DuBrow & Davachi, 2014), whereas, to behaviour analysts, temporal memory effects are typically construed as the effects of time and order of stimulus presentation on subsequent stimulus control. Many studies have established age differences in temporal memory tasks (e.g., Roberts, Ly, Murray, & Yassa, 2014;Rotblatt et al, 2015), but these have, in the main, focused on longer term memory effects.. Within the current cognitive literature, there are four main hypotheses about the basis of reduced temporal memory in older adults.…”

The effect of interference on temporal order memory in individuals with Parkinson’s disease

“…Age-related deficits in memory for the temporal order of occurrence of items or events have been well documented in healthy older adults (Blachstein et al, 2012; Kessels et al, 2007; Newman et al, 2001; Old & Naveh-Benjamin, 2008; Roberts et al, 2014; Tolentino et al, 2012; Ulbrich et al, 2009). Recent studies have demonstrated that temporal interference may play a key role in the ability of older adults to remember sequences of stimuli (Roberts et al, 2014; Rotblatt et al, 2015; Tolentino et al, 2012).…”

“…Recent studies have demonstrated that temporal interference may play a key role in the ability of older adults to remember sequences of stimuli (Roberts et al, 2014; Rotblatt et al, 2015; Tolentino et al, 2012). Various human and animal studies reviewed by Kesner and Hopkins (2006) have shown that items occurring further apart in a temporal sequence are easier to remember than items that are temporally adjacent.…”