Memory of Ensemble Representation Was Independent of Attention.

Shenli Peng,Ping Hu,Beibei Kuang

doi:10.3389/fpsyg.2019.00228

Abstract

The hierarchical view of working memory suggested that object ensemble could also be stored into working memory by treating ensemble properties as single “unit.” However, it remains unclear whether ensemble representation in working memory is vulnerable to attention demanding. The present study designed a dual-task paradigm constituting of a memory retaining task and an attention-demanding arrow flanker task. Participants were firstly presented an array (4 or 9) of facial images with neutral expressions and then shown a left- or right-orientated arrow surrounded by four congruent or incongruent oriented arrows or short lines. Participants judged the orientation of the target arrow and then indicated whether a probe facial image was present or absent in the preceding facial array. The probe face consisted of four conditions: (1) a morphed average face of prior face set, (2) a morphed average face of another face set, (3) an exemplar face of prior set, and (4) an exemplar face of another face set. Results confirmed that participants implicitly coded the average facial image of preceding set and retained in working memory. More importantly, the memory representation of ensemble property (e.g., average facial identity) was independent of flanker type. In sum, this study provided further evidence of the hierarchical view of working memory and suggested that attention was not a pre-requisite for the retaining of ensemble properties in working memory.

Highlights

A number of previous studies have demonstrated that people can automatically extract summary statistics from abundant of stimuli, with a surprising precision (Alvarez, 2011; Whitney and Leib, 2018)
We adopted a dual-task paradigm consisted of a memory retaining task and a classical arrow flanker task to investigate whether or not the retaining of ensemble properties in working memory was independent of attention
Consistent with previous studies (Fan et al, 2002; Verbruggen et al, 2006), the results found that participants did show attentional conflict effect during the flanker task, with the lowest ACC and slower

Summary

Introduction

A number of previous studies have demonstrated that people can automatically extract summary statistics (mean, variability, etc.) from abundant of stimuli, with a surprising precision (Alvarez, 2011; Whitney and Leib, 2018). Haberman and Whitney (2007, 2009) demonstrated that ensemble coding occurred for faces—observers could rapidly extract mean emotional valence of a set of facial expressions, even in a glance (50 or 100 ms). In addition to the universality of object ensembles in our daily life, the rapid course of ensemble coding frees people from the working memory and attentional capacity limitation in representing objects (Luck and Vogel, 1997; Alvarez and Cavanagh, 2004). Puzzle derived from the evidenced working memory capacity limitation and the fact that we can map the substantial world have been resolved through the ensemble coding (Lanzoni et al, 2014)

Objectives

Results

Conclusion