Effects of ε4 on Object Recognition in the Non-Demented Elderly

Abstract

Previously we reported that Apolipoprotein E (ApoE) ε4 negatively affects performance in the novel-image-novel-location (NINL) object recognition test in healthy non-demented elderly human study participants. In this study, the participants were invited to return for testing sessions 6 and 18 months after the baseline session. Using a longitudinal study design, effects of ε4 on NINL test performance were assessed in study “dropouts”, participants that did not return for the second and/or third session(s), and “finishers”, participants that returned for all sessions. There were effects of ε4 on dropout rates and NINL total scores as well as sub-scores in both dropouts and finishers. NINL total score was a predictor of ε4 participant dropout. Compared to non-ε4 dropouts, ε4 dropouts had lower NINL scores. In contrast, ε4 finishers had higher NINL scores than non-ε4 finishers. Thus, the NINL test could be a valuable tool in detecting pre-clinical signs of age-related cognitive impairments, particularly those associated with ε4 risk.

Novel image–novel location object recognition task sensitive to age-related cognitive decline in nondemented elderly

“…The MMSE was administered at sessions 1, 3, and 4, and the NINL task was administered at all sessions. The sequence of testing was the MMSE, NINL (immediate), health questionnaire, and NINL (delay; (Berteau-Pavy et al 2007; Haley et al 2010)). Logical memory and word recall were performed in the final session [session 5; (Wechsler 1997)] following the NINL test.…”

“…The most widely used cognitive task in the elderly is the mini-mental state examination [MMSE; (Folstein et al 1975; Helkala et al 2002; Soto et al 2005)]. While useful for identifying frank dementia, MMSE may not detect more subtle age-related cognitive changes (Berteau-Pavy et al 2007; Haley et al 2010; Leveille et al 1998). Thus, different tests are needed to identify these changes.…”

“…NINL performance is sensitive to the effects of apolipoprotein E4 (Berteau-Pavy et al 2007; Haley et al 2010), a risk factor for developing age-related cognitive decline (Adak et al 2004; Aggarwal et al 2005; Brayne et al 1996; Howieson et al 2003; Wilson et al 2002) and Alzheimer’s disease (Corder et al 1995; Corder et al 1993; Farrer et al 1997; Poirier et al 1995). Moreover, the NINL test does not assess verbal memory, as do MMSE, word recall lists, and logical memory, but rather visuospatial memory which may be more sensitive to the early effects of mild cognitive impairment or Alzheimer’s disease (Iachini et al 2009).…”

The backup is active in Alzheimer’s disease: A hypothesis from problem theory

“…When the participants had finished an object recognition test, they were asked to return for two more sessions at 6 and 18 months. E4 carriers were 2.7 times more likely to drop out than other participants [21]. This might be attributed to the strategy of avoiding frustrating conditions taking over, as those who failed to return had performed poorly at the task.…”

Neuroscience-based Tests for Assessing Cognitive Changes in Normal Aging and in the Prodromal Phase of Alzheimer’s Disease

“…As emphasized previously, reduction in axons and synapses in the perforant pathway input into hippocampus from the entorhinal cortex is one of the earliest of the neural and synaptic changes in AD [22] and is associated with early Aβ accumulation. Following up 6 to 18 months later on the nondemented older adults assessed by Bertreau-Pavy et al [85] on established tests of memory and on translational tests of spatial cognition, Haley et al [92] assessed effects of APOE ε4 on study "dropouts" (participants that did not return for the second and/or third session[s]) and "finishers" (participants that returned for all sessions). There were effects of APOE ε4 on dropout rates and Novel Image Novel Location total scores as well as subscores in both dropouts and finishers.…”