Aging and guided visual search: the role of visual working memory.

In the present study, we examined age-related differences in utilizing learned associations to guide visual search. Participants viewed an object cue that was associated with 1 or 2 target colors, followed by a search array. Older adults showed slower RTs, larger visual search slopes, and reduced cue-target association knowledge than did younger adults. We also found increased search RTs and higher error rates when the cue was associated with 2 colors instead of 1. However, visual search slopes did not vary with the number of associated colors. This indicates that participants could activate multiple templates simultaneously to guide the search or retrieve associative information directly from the long-term memory. Furthermore, regression analyses showed that VWMC can predict both visual search performances and cue-target association knowledge. More broadly, our results demonstrate that VWMC can modify the effects of age on cued visual search performance.

Does constraining memory maintenance reduce visual search efficiency?

We examine whether constraining memory retrieval processes affects performance in a cued recall visual search task. In the visual search task, participants are first presented with a memory prompt followed by a search array. The memory prompt provides diagnostic information regarding a critical aspect of the target (its colour). We assume that upon the presentation of the memory prompt, participants retrieve and maintain hypotheses (i.e., potential target characteristics) in working memory in order to improve their search efficiency. By constraining retrieval through the manipulation of time pressure (Experiments 1A and 1B) or a concurrent working memory task (Experiments 2A, 2B, and 2C), we directly test the involvement of working memory in visual search. We find some evidence that visual search is less efficient under conditions in which participants were likely to be maintaining fewer hypotheses in working memory (Experiments 1A, 2A, and 2C), suggesting that the retrieval of representations from long-term memory into working memory can improve visual search. However, these results should be interpreted with caution, as the data from two experiments (Experiments 1B and 2B) did not lend support for this conclusion.

Making Retrospective Confidence Judgments Improves Learners' Ability to Decide What Not to Study.

Predictions about future retrieval success, known as judgments of learning (JOLs), are often viewed as important for effective control over learning. However, much less is known about how retrospective confidence judgments (RCJs), evaluations of past retrieval success, may affect control over learning. We compared participants' ability to identify items that would benefit from additional study after making either a JOL or an RCJ. Participants completed a cued-recall task in which they made a metacognitive judgment after an initial recall attempt and before making a restudy decision. Participants who made RCJs prior to their restudy decisions were more accurate at identifying items in need of being restudied, relative to participants who made JOLs. The results indicate that having participants assess their confidence in past retrieval success can nudge them toward better utilizing of valid information when deciding which items are in need of further study.

Personality and attention: Levels of neuroticism and extraversion can predict attentional performance during a change detection task.

The present study demonstrates that levels of extraversion and neuroticism can predict attentional performance during a change detection task. After completing a change detection task built on the flicker paradigm, participants were assessed for personality traits using the Revised Eysenck Personality Questionnaire (EPQ-R). Multiple regression analyses revealed that higher levels of extraversion predict increased change detection accuracies, while higher levels of neuroticism predict decreased change detection accuracies. In addition, neurotic individuals exhibited decreased sensitivity A' and increased fixation dwell times. Hierarchical regression analyses further revealed that eye movement measures mediate the relationship between neuroticism and change detection accuracies. Based on the current results, we propose that neuroticism is associated with decreased attentional control over the visual field, presumably due to decreased attentional disengagement. Extraversion can predict increased attentional performance, but the effect is smaller than the relationship between neuroticism and attention.

Using a model of hypothesis generation to predict eye movements in a visual search task.

We used a model of hypothesis generation (called HyGene; Thomas, Dougherty, Sprenger, & Harbison, 2008) to make predictions regarding the deployment of attention (as assessed via eye movements) afforded by the cued recall of target characteristics before the onset of a search array. On each trial, while being eyetracked, participants were first presented with a memory prompt that was diagnostic regarding the target's color in a subsequently presented search array. We assume that the memory prompts led to the generation of hypotheses (i.e., potential target characteristics) from long-term memory into working memory to guide attentional processes and ocular-motor behavior. However, given that multiple hypotheses might be generated in response to a prompt, it has been unclear how the focal hypothesis (i.e., the hypothesis that exerts the most influence on search) affects search behavior. We tested two possibilities using first fixation data, with the assumption that the first item fixated within a search array was the focal hypothesis. We found that a model assuming that the first item generated into working memory guides overt attentional processes was most consistent with the data at both the aggregate and single-participant levels of analysis.

Using the memory activation capture (MAC) procedure to investigate the temporal dynamics of hypothesis generation.

Research investigating top-down capture has demonstrated a coupling of working memory content with attention and eye movements. By capitalizing on this relationship, we have developed a novel methodology, called the memory activation capture (MAC) procedure, for measuring the dynamics of working memory content supporting complex cognitive tasks (e.g., decision making, problem solving). The MAC procedure employs briefly presented visual arrays containing task-relevant information at critical points in a task. By observing which items are preferentially fixated, we gain a measure of working memory content as the task evolves through time. The efficacy of the MAC procedure was demonstrated in a dynamic hypothesis generation task in which some of its advantages over existing methods for measuring changes in the contents of working memory over time are highlighted. In two experiments, the MAC procedure was able to detect the hypothesis that was retrieved and placed into working memory. Moreover, the results from Experiment 2 suggest a two-stage process following hypothesis retrieval, whereby the hypothesis undergoes a brief period of heightened activation before entering a lower activation state in which it is maintained for output. The results of both experiments are of additional general interest, as they represent the first demonstrations of top-down capture driven by participant-established WM content retrieved from long-term memory.

Explicit awareness supports conditional visual search in the retrieval guidance paradigm.

In four experiments we explored whether participants would be able to use probabilistic prompts to simplify perceptually demanding visual search in a task we call the retrieval guidance paradigm. On each trial a memory prompt appeared prior to (and during) the search task and the diagnosticity of the prompt(s) was manipulated to provide complete, partial, or non-diagnostic information regarding the target's color on each trial (Experiments 1-3). In Experiment 1 we found that the more diagnostic prompts was associated with faster visual search performance. However, similar visual search behavior was observed in Experiment 2 when the diagnosticity of the prompts was eliminated, suggesting that participants in Experiment 1 were merely relying on base rate information to guide search and were not utilizing the prompts. In Experiment 3 participants were informed of the relationship between the prompts and the color of the target and this was associated with faster search performance relative to Experiment 1, suggesting that the participants were using the prompts to guide search. Additionally, in Experiment 3 a knowledge test was implemented and performance in this task was associated with qualitative differences in search behavior such that participants that were able to name the color(s) most associated with the prompts were faster to find the target than participants who were unable to do so. However, in Experiments 1-3 diagnosticity of the memory prompt was manipulated via base rate information, making it possible that participants were merely relying on base rate information to inform search in Experiment 3. In Experiment 4 we manipulated diagnosticity of the prompts without manipulating base rate information and found a similar pattern of results as Experiment 3. Together, the results emphasize the importance of base rate and diagnosticity information in visual search behavior. In the General discussion section we explore how a recent computational model of hypothesis generation (HyGene; Thomas, Dougherty, Sprenger, & Harbison, 2008), linking attention with long-term and working memory, accounts for the present results and provides a useful framework of cued recall visual search.

Working memory dynamics bias the generation of beliefs: the influence of data presentation rate on hypothesis generation.

Although temporal dynamics are inherent aspects of diagnostic tasks, few studies have investigated how various aspects of time course influence hypothesis generation. An experiment is reported that demonstrates that working memory dynamics operating during serial data acquisition bias hypothesis generation. The presentation rate (and order) of a sequence of serially presented symptoms was manipulated to be either fast (180 ms per symptom) or slow (1,500 ms per symptom) in a simulated medical diagnosis task. When the presentation rate was slow, participants chose the disease hypothesis consistent with the symptoms appearing later in the sequence. When the presentation rate was fast, however, participants chose the disease hypothesis consistent with the symptoms appearing earlier in the sequence, therefore representing a novel primacy effect. We predicted and account for this effect through competitive working memory dynamics governing information acquisition and the contribution of maintained information to the retrieval of hypotheses from long-term memory.

Catching a glimpse of working memory: top-down capture as a tool for measuring the content of the mind.

This article outlines a methodology for probing working memory (WM) content in high-level cognitive tasks (e.g., decision making, problem solving, and memory retrieval) by capitalizing on attentional and oculomotor biases evidenced in top-down capture paradigms. This method would be of great use, as it could measure the information resident in WM at any point in a task and, hence, track information use over time as tasks dynamically evolve. Above and beyond providing a measure of information occupancy in WM, such a method would benefit from sensitivity to the specific activation levels of individual items in WM. This article additionally forwards a novel fusion of standard free recall and visual search paradigms in an effort to assess the sensitivity of eye movements in top-down capture, on which this new measurement technique relies, to item-specific memory activation (ISMA). The results demonstrate eye movement sensitivity to ISMA in some, but not all, cases.

The influence of action on visual search: behavioral response toward stimuli modifies the selection process.

In five experiments, we investigated how simple actions (as assessed via a go/no-go task) influence visual search. In Experiments 1 and 2, participants responded (go) when a color name (cue) matched a colored shape (prime), and did not respond (no-go) when they mismatched. Participants then searched a visual array for a tilted line, either embedded within the prime (valid prime) or within a different shape of a different color (invalid prime). For go trials, but not for no-go trials, the validity of the prime influenced search behavior so that faster RTs were observed when the prime was valid as compared with when it was invalid. In Experiment 3, the go/no-go task was based on the shape of the prime. The color of the prime, but not the shape, was re-presented in the search array, and its validity produced a similar pattern as in Experiments 1-2. In Experiment 4, participants responded when the color name and prime mismatched. Reaction times indicated that attentional set had an influence on the validity differences in Experiments 1-3. In Experiment 5, the go/no-go task was based on whether a digit matched a digit appearing within the prime. Go trials produced similar validity effects as observed in Experiments 1-3.

The effect of behavioral response on affective evaluation.

In the present research we investigated how action influences affective evaluation. In three experiments, participants conducted a sequence of go/no-go tasks, then evaluated the pleasantness of a novel shape. The results of Experiments 1 and 2 show that participants evaluated the shapes that appeared in the go trials more positively than the shapes that appeared in the no-go trials. In Experiment 3, the go/no-go task was conducted without the to-be-evaluated shapes present in the display. The results show that the shape stimuli following the go trials were evaluated more positively than the shape stimuli following the no-go trials, even when the shapes were not directly associated with the go/no-go task. Based on the present study, we suggest that activating or inhibiting a motoric action may play a critical role in modifying one's affective evaluation. Additionally, the present results suggest that effortful and non-default responses can negatively modulate affective evaluation by taxing an individual's cognitive load. Furthermore, we argue that individuals can potentially control their affective states through behavioral activation and inhibition.