Meaning in learning: Contextual cueing relies on objects' visual features and not on objects' meaning

Semantic meaning enhances feature-binding but not quantity or precision of locations in visual working memory

Recent studies showed that real-world items are better remembered in visual working memory (VWM) than visually similar stimuli that are stripped of their semantic meaning. However, the exact nature of this advantage remains unclear. We used meaningful and meaningless stimuli in a location-reproduction VWM task. Employing a mixture-modeling analysis, we examined whether semantic meaning enables more item locations to be remembered, whether it improves the precision of the locations stored in memory, or whether it improves binding between the specific items and their locations. Participants were presented with streams of four (Experiments 1 & 2) or six (Experiment 3) real-world items, or their scrambled, meaningless counterparts. Each item was presented at a unique location, and the task was to reproduce one item's location. Overall, location memory was consistently better for real-world items compared with their scrambled counterparts. Furthermore, the results revealed that participants were less likely to make swap errors for the meaningful items, but there was no effect of conceptual meaning on the guess rate or the precision of the report. In line with previous findings, these results indicate that conceptual meaning enhances VWM for arbitrary stimulus properties such as item location, and this improvement is primarily due to a more efficient identity-location binding rather than an increase in the quantity or quality (precision) of the locations held in memory.

Investigating the Effect of Contextual Cueing with Face Stimuli on Electrophysiological Measures in Younger and Older Adults

Extracting repeated patterns from our surroundings plays a crucial role in contextualizing information, making predictions, and guiding our behavior implicitly. Previous research showed that contextual cueing enhances visual search performance in younger adults. In this study, we investigated whether contextual cueing could also improve older adults' performance and whether age-related differences in the neural processes underlying implicit contextual learning could be detected. Twenty-four younger and 25 older participants performed a visual search task with contextual cueing. Contextual information was generated using repeated face configurations alongside random new configurations. We measured RT difference between new and repeated configurations; ERPs to uncover the neural processes underlying contextual cueing for early (N2pc), intermediate (P3b), and late (r-LRP) processes; and multiscale entropy and spectral power density analyses to examine neural dynamics. Both younger and older adults showed similar contextual cueing benefits in their visual search efficiency at the behavioral level. In addition, they showed similar patterns regarding contextual information processing: Repeated face configurations evoked decreased finer timescale entropy (1-20 msec) and higher frequency band power (13-30 Hz) compared with new configurations. However, we detected age-related differences in ERPs: Younger, but not older adults, had larger N2pc and P3b components for repeated compared with new configurations. These results suggest that contextual cueing remains intact with aging. Although attention- and target-evaluation-related ERPs differed between the age groups, the neural dynamics of contextual learning were preserved with aging, as both age groups increasingly utilized more globally grouped representations for repeated face configurations during the learning process.

The time course of category-based attentional template pre-activation depends on the category framework

When searching for a target defined by a set of objects, attention can be directed toward task-relevant objects by creating a category-based attentional template (CAT). Previous studies have found that CAT can be activated before the onset of the target. However, the time course of CAT pre-activation and whether the category framework (prototypical or semantic) can modulate it remain unclear. To explore the time course of CAT pre-activation, we employed a rapid serial probe presentation paradigm (RSPP) with event-related potentials (ERPs). To investigate the effect of the category framework on the time course of CAT pre-activation, the target category was defined as the prototypical category (Experiment 1) or the semantic category (Experiment 2). The results showed that the prototype-based CAT was pre-activated 300 ms prior to the target, whereas the semantics-based CAT was pre-activated 1500 ms before the onset of the target. The difference in the time course of pre-activation between the two CAT types indicates that the category framework can modulate the time course of CAT pre-activation. Additionally, during the attentional selection phase, an overall comparison of the target revealed that a larger N2pc was elicited by the prototype-based CAT than by the semantics-based CAT, suggesting that the prototype-based CAT could capture more attention than the semantics-based CAT. The findings on the difference between the two CAT frameworks in the preparatory and attentional selection phases provide more evidence for categorical information in visual search and extend our understanding of the mechanism of categorical attentional selection.

Visual memory of a co-actor's target during joint search

Studies on joint action show that when two actors turn-takingly attend to each other's target that appears one at a time, a partner's target is accumulated in memory. However, in the real world, actors may not be certain that they attend to the same object because multiple objects often appear simultaneously. In this study, we asked participant pairs to search for different targets in parallel from multiple objects and investigated the memory of a partner's target. We employed the contextual cueing paradigm, in which repetitive search forms associative memory between a target and a configuration of distractors that facilitates search. During the learning phase, exemplars of three target categories (i.e., bird, shoe, and tricycle) were presented among unique objects, and participant pairs searched for them. In Experiment 1, it was followed by a memory test about target exemplars. Consequently, the partner's target was better recognized than the target that nobody searched for. In Experiments 2a and 2b, the memory test was replaced with the transfer phase, where one individual from the pair searched for the category that nobody had searched for while the other individual searched for the category the partner had searched for in the learning phase. The transfer phase did not show search facilitation underpinned by associative memory between the partner's target and distractors. These results suggest that when participant pairs search for different targets in parallel, they accumulate the partner's target in memory but may not form its associative memory with the distractors that facilitates its search.

Raising awareness about measurement error in research on unconscious mental processes

Experimental psychologists often neglect the poor psychometric properties of the dependent measures collected in their studies. In particular, a low reliability of measures can have dramatic consequences for the interpretation of key findings in some of the most popular experimental paradigms, especially when strong inferences are drawn from the absence of statistically significant correlations. In research on unconscious cognition, for instance, it is commonly argued that the lack of a correlation between task performance and measures of awareness or explicit recollection of the target stimuli provides strong support for the conclusion that the cognitive processes underlying performance must be unconscious. Using contextual cuing of visual search as a case study, we show that given the low reliability of the dependent measures collected in these studies, it is usually impossible to draw any firm conclusion about the unconscious character of this effect from correlational analyses. Furthermore, both a psychometric meta-analysis of the available evidence and a cognitive-modeling approach suggest that, in fact, we should expect to see very low correlations between performance and awareness at the empirical level, even if both constructs are perfectly related at the latent level. Convincing evidence for the unconscious character of contextual cuing and other effects will most likely demand richer and larger data sets, coupled with more powerful analytic approaches.

A Metacognitive Perspective of Visual Working Memory With Rich Complex Objects

Visual working memory (VWM) has been extensively studied in the context of memory capacity. However, less research has been devoted to the metacognitive processes involved in VWM. Most metacognitive studies of VWM studies tested simple, impoverished stimuli, whereas outside of the laboratory setting, we typically interact with meaningful, complex objects. Thus, the present study aimed to explore the extent to which people are able to monitor VWM of real-world objects that are more ecologically valid and further afford less inter-trial interference. Specifically, in three experiments, participants viewed a set of either four or six memory items, consisting of images of unique real-world objects that were not repeated throughout the experiment. Following the memory array, participants were asked to indicate where the probe item appeared (Experiment 1) whether it appeared at all (Experiment 2) or whether it appeared and what was its temporal order (Experiment 3). VWM monitoring was assessed by subjective confidence judgments regarding participants’ objective performance. Similar to common metacognitive findings in other domains, we found that subjective judgments overestimated performance and underestimated errors, even for real-world, complex items held in VWM. These biases seem not to be task-specific as they were found in temporal, spatial, and identity VWM tasks. Yet, the results further showed that meaningful, real-world objects were better remembered than distorted items, and this memory advantage also translated to metacognitive measures.

Contingent capture during search for alphanumerical characters: A case of feature-based capture or of conceptual category membership?

To distinguish if search for alphanumerical characters is based on features or on conceptual category membership, we conducted two experiments where we presented upright and inverted characters as cues in a contingent-capture protocol. Here, only cues matching the top-down search template (e.g., a letter cue when searching for target letters) capture attention and lead to validity effects: shorter search times and fewer errors for validly than invalidly cued targets. Top-down nonmatching cues (e.g., a number cue when searching for target letters) do not capture attention. To tell a feature-based explanation from one based on conceptual category membership, we used both upright (canonical) and inverted characters as cues. These cues share the same features, but inverted cues cannot be conceptually categorized as easily as upright cues. Thus, we expected no difference between upright and inverted cues when search is feature-based, whereas inverted cues would elicit no or at least considerably weaker validity effects if search relies on conceptual category membership. Altogether, the results of both experiments (with overlapping and with separate sets of characters for cues and targets) provide evidence for search based on feature representations, as among other things, significant validity effects were found with upright and inverted characters as cues. However, an influence of category membership was also evident, as validity effects of inverted characters were diminished.