Alan D. Castel

Perceiving numbers causes spatial shifts of attention

Number symbols are part of our everyday visual world. Here we show that merely looking at numbers causes a shift in covert attention to the left or right side, depending upon the numbers magnitude. This observation implies obligatory activation of number meaning and signals a tight coupling of internal and external representations of space.

Memory Predictions Are Influenced by Perceptual Information : Evidence for Metacognitive Illusions

Although perceptual information is utilized to judge size or depth, little work has investigated whether such information is used to make memory predictions. The present study examined how the font size of to-be-remembered words influences predicted memory performance. Participants studied words for a free-recall test that varied in font size and made judgments of learning (JOLs) for each item. JOLs were influenced by font size, as larger font sizes were given higher JOLs, whereas little relationship was evident between font size and recall. The effect was modified when other, more valid, sources of information (e.g., associative strength) were available when JOLs were made and persisted despite experience with multiple study-test sessions, use of a forgetting scale to assess predictions, and explicit warning of participants that font size has little effect on memory performance. When ease of reading was manipulated, such that large font size words were made less fluent, the effect was eliminated. Thus, highly accessible perceptual cues can strongly influence JOLs, likely via encoding fluency, and this effect can lead to metacognitive illusions

Memory for grocery prices in younger and older adults: the role of schematic support.

The present study examined how younger and older adults remember price information. Participants studied grocery items that were priced at market value or were well above or below market value. Although younger adults displayed better recall performance for unrealistic prices than older adults, there was no age difference for realistic prices, and both groups were equally accurate at remembering the general price range of the items. The results suggest that when older adults can rely on prior knowledge and schematic support, and tasks involve naturalistic materials, memory for associative information can be as good as that of younger adults.

The effects of aging on selectivity and control in short-term recall

The ability to control encoding and retrieval processes strategically is critical for the efficient use of memory. We examined the ability of younger and older adults to selectively remember words on the basis of their arbitrary point values by using a technique developed by Watkins and Bloom (1999). In the first three experiments, younger subjects recalled more words than did older subjects, but an independent index of recall selectivity showed that older subjects were apparently more successful in selecting higher valued words. However, a fourth experiment showed that this superior selectivity on the part of older adults was attributable to their greater proportional reliance on primary memory recall. Overall, the data suggest that although older adults recall fewer words than do younger adults, they exert as much control over some aspects of encoding.

The Ease-of-Processing Heuristic and the Stability Bias Dissociating Memory, Memory Beliefs, and Memory Judgments

Judgments about memory are essential in promoting knowledge; they help identify trustworthy memories and predict what information will be retained in the future. In the three experiments reported here, we investigated the mechanisms underlying predictions about memory. In Experiments 1 and 2, single words were presented once or multiple times, in large or small type. There was a double dissociation between actual memory and predicted memory: Type size affected predicted but not actual memory, and future study opportunities affected actual memory but scarcely affected predicted memory. The results of Experiment 3 suggest that beliefs and judgments are largely independent, and neither consistently resembles actual memory. Participants’ underestimation of future learning—a stability bias—stemmed from an overreliance on their current memory state in making predictions about future memory states. The overreliance on type size highlights the fundamental importance of the ease-of-processing heuristic: Information that is easy to process is judged to have been learned well.

Metacognitive illusions for auditory information: Effects on monitoring and control

Prior work has demonstrated that the perceptual features of visually presented stimuli can have a strong influence on predictions of memory performance, even when those features are unrelated to recall (Rhodes & Castel, 2008). The present study examined whether this finding would hold in an auditory domain and influence study-choice allocation. Participants listened to words that varied in volume, made judgments of learning (JOLs) for each item, and were then administered a test of free recall. In Experiment 1, we showed that JOLs were influenced by volume, with loud words given higher JOLs than quiet words, and that volume had no influence on recall, illustrating a metacognitive illusion based on auditory information. In Experiment 2, we extended these findings to control processes and showed that participants were more likely to choose to restudy quiet words than loud words. These findings indicate that highly accessible auditory information is integrated into JOLs and restudy choices, even when this information does not influence actual memory performance.

Spatial attention and response control in healthy younger and older adults and individuals with Alzheimer's disease : Evidence for disproportionate selection impairments in the simon task

The authors examined the degree to which aging and Alzheimers disease (AD) influence the ability to control attention when conflict is presented in terms of incongruent mapping between a stimulus and the appropriate response. In a variant of the Simon task, healthy older adults and older adults with mild or very mild AD showed disproportionately larger reaction time (RT) costs when the stimulus and response were in conflict relative to RT costs of healthy younger adults. Analyses of RT distributions provide support for a 2-process model of the Simon effect in which there is a short-lived transient effect of the irrelevant dimension in younger adults and a more sustained influence across the RT distribution in older adults. An analysis of error rates showed that the older adults with mild and very mild AD made more errors on incongruent trials, suggesting that AD leads to increased likelihood of selecting the prepotent pathway. The findings are discussed in terms of the special nature of the response requirements of the Simon task to better illuminate the attentional decrements in both healthy aging and early stage AD.

Illusions of competence and overestimation of associative memory for identical items: Evidence from judgments of learning

The relation between subjects’ predicted and actual memory performance is a central issue in the domain of metacognition. In the present study, we examined the influence of item similarity and associative strength on judgments of learning (JOLs) in a cued recall task. We hypothesized that encoding fluency would cause a foresight bias, so that subjects would overestimate recall of identical pairs (scale-scale), as compared with strong associates (weight-scale) or unrelated pairs (mask-scale). In Experiment 1, JOLs for identical word pairs were higher than those for related and unrelated pairs, but later recall of identical pairs was lower than recall of related pairs. In Experiment 2, the effect of encoding fluency (inferred from self-paced study time) was examined, and a similar pattern of results was obtained, with subjects spending the least amount of time studying identical pairs. We conclude that overconfidence for identical pairs reflects an assessment of item similarity when JOLs are made, despite associative strength being a better predictor of later retrieval.

Memory for general and specific value information in younger and older adults: Measuring the limits of strategic control

The ability to selectively remember important information is a critical function of memory. Although previous research has suggested that older adults are impaired in a variety of episodic memory tasks, recent work has demonstrated that older adults can selectively remember high-value information. In the present research, we examined how younger and older adults selectively remembered words with various assigned numeric point values, to see whether younger adults could remember more specific value information than could older adults. Both groups were equally good at recalling point values when recalling the range of high-value words, but younger adults outperformed older adults when recalling specific values. Although older adults were more likely to recognize negative value words, both groups exhibited control by not recalling negative value information. The findings suggest that although both groups retain high-value information, older adults rely more on gist-based encoding and retrieval operations, whereas younger adults are able to remember specific numeric value information.

The role of spatial working memory in inhibition of return: evidence from divided attention tasks.

Inhibition of return (IOR) refers to a bias against returning attention to a location that has been recently attended. In the present experiments, we examined the role of working memory in IOR by introducing secondary tasks (in the temporal interval between the cue and the target) that involved a working memory component. When the secondary task was nonspatial in nature (monitoring odd digits or adding digits), IOR was present, although overall reaction times were greater in the presence of the secondary task. When the task involved a spatial working memory load (remembering the directionality of arrows or the orientation of objects), IOR was eliminated. However, when the participants had incentive to process the directionality of an arrow but did not have to use any memory system, IOR persisted at peripheral locations. Overall, the results suggest that IOR is partially mediated by a spatial working memory system.