The effectiveness of unitization in mitigating age-related relational learning impairments depends on existing cognitive status

Abstract

Binding relations among items in the transverse patterning (TP) task is dependent on the integrity of the hippocampus and its extended network. Older adults have impaired TP learning, corresponding to age-related reductions in hippocampal volumes. Unitization is a training strategy that can mitigate TP impairments in amnesia by reducing reliance on hippocampal-dependent relational binding and increasing reliance on fused representations. Here we examined whether healthy older adults and those showing early signs of cognitive decline would also benefit from unitization. Although both groups of older adults had neuropsychological performance within the healthy range, their TP learning differed both under standard and unitized training conditions. Healthy older adults with impaired TP learning under standard training benefited from unitized training. Older adults who failed the Montreal Cognitive Assessment (MoCA) showed greater impairments under standard conditions, and showed no evidence of improvement with unitization. These individuals’ failures to benefit from unitization may be a consequence of early deficits not seen in older adults who pass the MoCA.

Visual integration of objects and scenes increases recollection‐based responding despite differential MTL recruitment in young and older adults

“…Given the well‐documented age‐related decreases in associative memory performance (Naveh‐Benjamin, ; Naveh‐Benjamin, Brav, & Levy, ; Naveh‐Benjamin, Guez, Kilb, & Reedy, ; Old & Naveh‐Benjamin, ) along with an increased reliance on familiarity‐based responding among older adults (Anderson et al, ; Bartlett & Fulton, ; Yonelinas, ), several studies have explored unitization as a method to improve associative memory performance in older adults (Ahmad et al, ; Bastin et al, ; D'Angelo et al, ; D'Angelo et al, ; Zheng et al, ). Across these studies, unitization consistently benefited older adults and reduced, but did not necessarily remove the difference in associative memory performance between age groups (Memel & Ryan, ; Zheng et al, ; Ahmad et al, ; Bastin et al, ; Bader et al, ).…”

“…For example, an arrow turns from facing upward to facing the circle and then compresses the circle. Both healthy older adults (D'Angelo et al, , ) and individuals with MTL amnesia (D.A. in Ryan et al, ; N.C. in D'Angelo et al, ) exhibited better learning of arbitrary relations when provided with a unitizing animation, suggesting that unitized learning does not rely on hippocampus.…”

“…Other studies rely on perceptual unitization by presenting an object word on a colored background and ask the participant either to imagine the word interacting with a different object of that color (e.g., "MONKEY on a red background: Imagine a monkey sitting atop a stop sign"), or for unitized pairs, imagine the object word in that color (e.g., "CLOTH on a green background: Imagine a cloth used to clean up spilled pea soup"; Staresina & Davachi, 2006;Diana et al, 2010). Finally, others have promoted unitization by presenting videos of various shapes interacting in such a way to emphasizes an action/consequence sequence (D'Angelo et al, 2016;D'Angelo, Noly-Gandon, Kacollja, Barense, & Ryan, 2017;Ryan, Moses, Barense, & Rosenbaum, 2013).…”

“…These authors suggest that unitization has limited or no effect on recollection, but instead increases associative memory performance by specifically enhancing familiarity for the pairs. Given the well-documented age-related decreases in associative memory performance (Naveh-Benjamin, 2000;Naveh-Benjamin, Brav, & Levy, 2007;Naveh-Benjamin, Guez, Kilb, & Reedy, 2004;Old & Naveh-Benjamin, 2008) along with an increased reliance on familiarity-based responding among older adults (Anderson et al, 2008; Bartlett & Fulton, 1991;Yonelinas, 2002), several studies have explored unitization as a method to improve associative memory performance in older adults (Ahmad et al, 2015;Bastin et al, 2013;D'Angelo et al, 2016;D'Angelo et al, 2017;Zheng et al, 2015).…”

Transverse patterning, aging, and neuropsychological correlates in humans

“…Critically, the investigators did not indicate any age‐related differences in transverse patterning performance, perhaps because all participants were explicitly trained prior to the task, whereas the Driscoll et al () study required incidental trial and error for skill acquisition. Recent reports have also confirmed that semantic information (Ostreicher et al, ) and unitization (D'Angelo et al, ) improve impaired transverse patterning performance in cognitively normal older adults; unitization does not aid performance in older adults who do not earn passing scores (n ≥ 26/30) on the Montreal Cognitive Assessment (MoCA), however (D'Angelo et al, in press). Although these studies yielded important findings, researchers have not explored transverse patterning performance in a pattern separation context by dichotomizing cognitively normal older adults into impaired and unimpaired subgroups based on the HVLT‐R.…”