Reducing perceptual interference improves visual discrimination in mild cognitive impairment: Implications for a model of perirhinal cortex function

Abstract

ABSTRACT:Memory loss resulting from damage to the medial temporal lobes (MTL) is traditionally considered to reflect damage to a dedicated, exclusive memory system. Recent work, however, has suggested that damage to one MTL structure, the perirhinal cortex (PRC), compromises complex object representations that are necessary for both memory and perception. These representations are thought to be critical in shielding against the interference caused by a stream of visually similar input. In this study, we administered a complex object discrimination task to two memory-impaired populations thought to have brain damage that includes the PRC [patients diagnosed with amnestic mild cognitive impairment (MCI), and older adults at risk for MCI], as well as agematched controls. Importantly, we carefully manipulated the level of interference: in the High Interference condition, participants completed a block of consecutive perceptually similar complex object discriminations, whereas in the Low Interference condition, we interspersed perceptually dissimilar objects such that there was less buildup of visual interference. We found that both memory-impaired populations were impaired on the High Interference condition compared with controls, but critically, by reducing the degree of perceptual interference, we were largely able to improve their performance. These findings, when taken together with convergent evidence from animals with selective PRC lesions and amnesic patients with focal damage to the PRC, provide support for a representational-hierarchical model of PRC function and suggest that memory loss following PRC damage may reflect a heightened vulnerability to perceptual interference. V

The perirhinal cortex modulates V2 activity in response to the agreement between part familiarity and configuration familiarity

“…The observation that top-down feedback from PRC suppressed part-based responses in lower-level visual regions is consistent with a recent series of findings suggesting that the PRC may be critical in resolving perceptual interference (McTighe et al, 2010;Burke et al, 2010;Romberg et al, 2012;Barense et al, 2012;Newsome et al, 2012). For example, patients with PRC damage were impaired at perceptual discrimination under conditions of high visual interference (a series of complex object discriminations for which object parts were repeatedly presented across trials), but performed normally under conditions of low visual interference (fewer object parts repeated across trials) Newsome et al, 2012).…”

“…For example, patients with PRC damage were impaired at perceptual discrimination under conditions of high visual interference (a series of complex object discriminations for which object parts were repeatedly presented across trials), but performed normally under conditions of low visual interference (fewer object parts repeated across trials) Newsome et al, 2012). These findings suggest that PRC damage rendered these individuals vulnerable to interference from object parts processed by lower-levels in the visual stream.…”

Famous Landmark Identification in Amnestic Mild Cognitive Impairment and Alzheimer's Disease

“…We could not exclude problems with familiarity assessment as an influencing factor, similarly like the other studies on familiarity cited in this article. We acknowledge that some studies in aMCI reported difficulties with assessing familiarity in these subjects [55] and over-reliance on familiarity as well [56]. However other studies did not find impaired familiarity-based recognition in contrary to impaired recognition based on recollection in MCI subjects, suggesting that recollection and familiarity might be independent processes associated with distinct anatomical substrates [57], [58].…”

A retroactive spatial cue improved VSTM capacity in mild cognitive impairment and medial temporal lobe amnesia but not in healthy older adults

“…. Our Our Our Our previous work suggests that t previous work suggests that t previous work suggests that t previous work suggests that the memory impaired he memory impaired he memory impaired he memory impaired cases cases cases cases in the present study in the present study in the present study in the present study may be may be may be may be particularly vulnerable to interference from a particularly vulnerable to interference from a particularly vulnerable to interference from a particularly vulnerable to interference from a barrage of visual information barrage of visual information barrage of visual information barrage of visual information (Barense, Groen, et al, 2012;Newsome, et al, 2012) (Barense, Groen, et al, 2012;Newsome, et al, 2012) (Barense, Groen, et al, 2012;Newsome, et al, 2012) (Barense, Groen, et al, 2012;Newsome, et al, 2012). .…”

“…In addition, recent evidence suggests that both MCI patients and MTL amnesics may be disproportionately vulnerable to interference relative to their age-matched counterparts. Indeed, recent work has shown that removing irrelevant visual information altogether improves performance on memory tasks (Dewar, Alber, Cowan, & Della Sala, 2014;Dewar, Della Sala, Beschin, & Cowan, 2010;Dewar, Garcia, Cowan, & Della Sala, 2009;Dewar, Hoefeijzers, Zeman, Butler, & Della Sala, 2015), as well as perceptual discrimination tasks (Barense, Groen, et al, 2012;Newsome, Duarte, & Barense, 2012). Thus, to the extent that MCI patients and MTL amnesia cases can use spatial information from the retrocue to reduce interference from irrelevant items, it may disproportionately benefit their performance relative to that observed in agematched controls.…”