Exploring semantic memory by investigating buildup and release of proactive interference in healthy older adults and individuals with dementia of the Alzheimer type

Abstract

There is debate regarding the integrity of semantic memory in dementia of the Alzheimer type (DAT). One view argues that DAT is associated with a breakdown in semantic memory; the other argues that DAT is associated with predominantly preserved semantic memory and a breakdown in retrieval. The classic release from proactive interference (RPI) paradigm was used to shed light on this debate. Individuals with early-stage DAT (n = 36) and healthy older adult controls (n = 45) participated in an RPI paradigm. Each trial was a Brown-Peterson task in which participants read three-word lists, counted (for 0, 3, 6, or 9 s), and recalled the words. Both groups showed significant proactive interference (PI), but the size of the PI was significantly smaller in the DAT group. The group difference in PI may be due to the faster forgetting rate in the DAT group. Both groups showed significant RPI and there was no group difference in size when RPI was considered in terms of PI levels. Both groups showed PI and RPI in prior list intrusions. The DAT group's significant buildup and release of PI based on semantic categories suggest predominantly preserved semantic memory activity, at least, in early-stage DAT individuals.

An Evaluation of Deficits in Semantic Cueing and Proactive and Retroactive Interference as Early Features of Alzheimer's Disease

“…Bondi and co-workers (19) showed that measures of proactive interference (PI) and retroactive interference (RI), based on overlap of 8 (of 16) targets on two learning lists of the California Verbal Learning Test (CVLT) (20), could distinguish between MCI and cognitively normal patients and between MCI and AD patients. Other investigations have shown the presence of PI in mild AD patients (21, 22,23, 24, 25). In contrast, other studies evaluating the build-up and release from PI have suggested lack of PI effects (26, 27) or even less vulnerability to PI (28) in AD patients as compared to cognitively normal subjects or Parkinson disease subjects (29, 30).…”

“…Previously, there has been controversy in the literature about the importance of semantic proactive interference and retroactive interference as early markers of incipient AD (26,27,24,23,29,30). In our view, discordance in previous findings has been attributed to: the use of relatively passive encoding strategies, assumptions that individuals have implicitly understood overlapping semantic categories and the presence of sufficient retrieval strength to produce proactive and retroactive interference effects.…”

Everyday‐like memory for objects in ageing and Alzheimer's disease assessed in a visually complex environment: The role of executive functioning and episodic memory

“…Compared with older adults, a different memory profile in AD patients emerged from the VR‐based assessment with impairments on all of the HOMES measures that followed, thus replicating the well‐known memory pattern of AD: learning, recognition accuracy, semantic clustering, PI, and increased susceptibility to false recognitions (Aronoff et al ., ; Budson et al ., ; Multhaup, Balota, & Faust, ; Westerberg et al ., ). Our study extends this pattern to naturalistic situations using VR although it should be noted that free‐recall measures from HOMES test suffer from floor effects for our AD patients.…”

Comparative Cognitive and Subjective Side Effects of Immediate-Release Oxycodone in Healthy Middle-Aged and Older Adults

“…Older adults typically evidence greater interference effects than younger adults and our results indicate this may be exacerbated during the peak medication period. 18, 31, 52…”