Dissociations of the number and precision of visual short-term memory representations in change detection

Abstract

The present study dissociated the number (i.e., quantity) and precision (i.e., quality) of visual short-term memory (STM) representations in change detection using receiver operating characteristic (ROC) and experimental manipulations. Across three experiments, participants performed both recognition and recall tests of visual STM using the change-detection task and the continuous color-wheel recall task, respectively. Experiment 1 demonstrated that the estimates of the number and precision of visual STM representations based on the ROC model of change-detection performance were robustly correlated with the corresponding estimates based on the mixture model of continuous-recall performance. Experiments 2 and 3 showed that the experimental manipulation of mnemonic precision using white-noise masking and the experimental manipulation of the number of encoded STM representations using consolidation masking produced selective effects on the corresponding measures of mnemonic precision and the number of encoded STM representations, respectively, in both change-detection and continuous-recall tasks. Altogether, using the individual-differences (Experiment 1) and experimental dissociation (Experiment 2 and 3) approaches, the present study demonstrated the some-or-none nature of visual STM representations across recall and recognition.

Poor Sleep Quality and Compromised Visual Working Memory Capacity

“…Last, traditional measures of performance such as accuracy and response time often confound the quantitative and qualitative aspects of WM representations. This approach is problematic because effects on these compound measures are often interpreted as effects on WM capacity, even though these behavioral measures could reflect effects on WM capacity, precision, or both (see Xie & Zhang, 2016; 2017a; 2017b; Zhang & Luck, 2009; 2011 for some discussions). Using a novel experimental paradigm (Zhang & Luck, 2008), the current study obtained simultaneous assessments of quantity and quality for retained WM representations, making it possible to assess the dissociable effects of the three health-related factors on WM representations.…”

“…Waters & Bucks, 2011; Wee et al, 2013). Although these impairments have been taken as evidence for reduced WM capacity (i.e., the amount of information maintained in WM), a reduction in memory quality might also account for these findings (see Xie & Zhang, 2016; 2017a; 2017b; Zhang & Luck, 2009; 2011 for some discussions). To clarify this issue, Wee and colleagues (2013) recently distinguished the effects of sleep deprivation on the quantitative (e.g., the number of remembered stimuli) and qualitative (e.g., precision, how precisely a given memory representation corresponds to the original to-be-remembered physical stimulus) aspects of visual WM using a procedure and a mathematical model developed by Zhang and Luck (2008).…”

Bias in confidence: A critical test for discrete-state models of change detection.

“…When a test item T with value t is presented, the color is deemed to be the same as the one stored in VWM if x falls within the interval[t − ∆, t + ∆], and different otherwise. The right panel of Figure 7 shows the ratio m munder different values of ∆ and t. This ratio is larger than 1 across all the different values considered, therefore failing to show the condition necessary for the model to predict biased confidence judgments.Casting Working-Memory Slots Through Mixture Signal-DetectionModelingFinally, a discrete-state model extension that can account for biased confidence judgments in a plausible way assumes that people's responses consist of a mixture of guesses and memory-based judgments, the latter being based on a comparison between graded and fallible memory representations with response criteria (e.g.,Nosofsky & Gold, 2018;Xie & Zhang, 2017; see alsoKeshvari, van den Berg, & Ma, 2013;Zhang &…”

Memorability of words in arbitrary verbal associations modulates memory retrieval in the anterior temporal lobe

“…The extent to which stimulus memorability may affect recall, when the to-be-remembered task content is not explicitly perceived, is less clear 14 . As opposed to recognition, recall critically relies on our ability to form and remember associations between items 15 . Once formed, these associations provide a powerful cue for recalling items from memory, even when no perceptual information regarding the to-be-retrieved content is provided 16 .…”