The Benefit of Attention-to-Memory Depends on the Interplay of Memory Capacity and Memory Load.

Sung-Joo Lim,Malte Wöstmann,Jonas Obleser,Frederik Geweke

doi:10.3389/fpsyg.2018.00184

Sung-Joo Lim, Malte Wöstmann + Show 2 more

Open Access

https://doi.org/10.3389/fpsyg.2018.00184

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Abstract

Humans can be cued to attend to an item in memory, which facilitates and enhances the perceptual precision in recalling this item. Here, we demonstrate that this facilitating effect of attention-to-memory hinges on the overall degree of memory load. The benefit an individual draws from attention-to-memory depends on her overall working memory performance, measured as sensitivity (d′) in a retroactive cue (retro-cue) pitch discrimination task. While listeners maintained 2, 4, or 6 auditory syllables in memory, we provided valid or neutral retro-cues to direct listeners’ attention to one, to-be-probed syllable in memory. Participants’ overall memory performance (i.e., perceptual sensitivity d′) was relatively unaffected by the presence of valid retro-cues across memory loads. However, a more fine-grained analysis using psychophysical modeling shows that valid retro-cues elicited faster pitch-change judgments and improved perceptual precision. Importantly, as memory load increased, listeners’ overall working memory performance correlated with inter-individual differences in the degree to which precision improved (r = 0.39, p = 0.029). Under high load, individuals with low working memory profited least from attention-to-memory. Our results demonstrate that retrospective attention enhances perceptual precision of attended items in memory but listeners’ optimal use of informative cues depends on their overall memory abilities.

Highlights

Internal representations of perceptual information held in memory are not perfectly precise, but inherently noisy – that is, our neural representations do not perfectly match the sensory information (Green and Swets, 1966; Wilken and Ma, 2004; Bays and Husain, 2008; Ma et al, 2014; Bays, 2015)
We further examined the correlation of individual differences in the change of cuerelated precision benefit and overall memory performance
We further examined whether individuals’ working memory span was related to overall memory performance, and to the extent of recall benefits from the valid retro-cues

Summary

Introduction

Internal representations of perceptual information held in memory are not perfectly precise, but inherently noisy – that is, our neural representations do not perfectly match the sensory information (Green and Swets, 1966; Wilken and Ma, 2004; Bays and Husain, 2008; Ma et al, 2014; Bays, 2015). Selective attention to the relevant representation in memory can effectively reduce such noise, by neurally prioritizing the attended representation (Serences and Kastner, 2014; see below for discussion of the possible mechanisms). This attentional enhancement of relevant memory items is referred to as retrospective attention (Griffin and Nobre, 2003; Gazzaley and Nobre, 2012). Auditory memory should benefit from selective attention to relevant signals in midst of irrelevant noise (Gazzaley and Nobre, 2012; Wilsch and Obleser, 2016)

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