Retrospective cues based on object features improve visual working memory performance in older adults

Research with younger adults has shown that retrospective cues can be used to orient top-down attention toward relevant items in working memory. We examined whether older adults could take advantage of these cues to improve memory performance. Younger and older adults were presented with visual arrays of five colored shapes; during maintenance, participants were presented either with an informative cue based on an object feature (here, object shape or color) that would be probed, or with an uninformative, neutral cue. Although older adults were less accurate overall, both age groups benefited from the presentation of an informative, feature-based cue relative to a neutral cue. Surprisingly, we also observed differences in the effectiveness of shape versus color cues and their effects upon post-cue memory load. These results suggest that older adults can use top-down attention to remove irrelevant items from visual working memory, provided that task-relevant features function as cues.     

Coventry university students’ experience of mental health problems

Growing numbers of university students are reporting mental health problems and using counselling services. The purpose of this study was to examine Coventry University students’ experience of mental health problems. The Department of Health (DoH) Mental Health Survey questionnaire (2003) was used to examine the experience of mental health problems and help seeking behaviour. Within the last 12 months nearly three quarters of students had experienced anxious or depressed moods, or, personal, mental, nervous or emotional problems, with a third of students failing to seek help. Ethnic minority students were more likely to report problems and less likely to seek help when compared to white students. Male students were less likely to seek help compared to female students. There are few existing studies that have focused on the mental health of students at universities established after 1992 from existing polytechnics. Coventry University exceeds the Government benchmark targets for recruiting students from non-traditional backgrounds. Our results show that it is these groups of students who are more likely to experience mental health problems.     

Investigating the childhood development of working memory using sentences: New evidence for the growth of chunk capacity

Child development is accompanied by a robust increase in immediate memory. This may be due to either an increase in the number of items (chunks) that can be maintained in working memory or an increase in the size of those chunks. We tested these hypotheses by presenting younger and older children (7 and 12 years of age) and adults with different types of lists of auditory sentences: four short sentences, eight short sentences, four long sentences, and four random word lists, each read with a sentence-like intonation. Young children accessed (recalled words from) fewer clauses than did older children or adults, but no age differences were found in the proportion of words recalled from accessed clauses. We argue that the developmental increase in memory span was due to a growing number of chunks present in working memory with little role of chunk size.     

Correction to smith, hood, and gilchrist (2010)

Reports an error in "Probabilistic cuing in large-scale environmental search" by Alastair D. Smith, Bruce M. Hood and Iain D. Gilchrist (Journal of Experimental Psychology: Learning, Memory, and Cognition, 2010[May], Vol 36[3], 605-618). This article contained typographical errors in the first paragraph under Experiment 2, Results. The first Analysis of Variance conducted on reaction time data reported incorrect degrees of freedom. This does not affect the interpretation of the article. The corrected paragraph is as follows. "Search times (see Figure 3) were significantly faster for targets in the rich side of the display (mean difference 6.57 s, SD 4.22), F(1, 17) 42.9, p .001. There was also a main effect of block, F(1, 17) 5.73, p .05, and a Probability X Block interaction, F(1, 17) 11.0, p .005, reflecting the slower overall search times for sparse trials in the second block and indicating a larger cuing effect in Block 2 (mean difference 8.10 s, SD 4.93) than Block 1 (mean difference 5.05 s, SD 4.31)." (The following abstract of the original article appeared in record 2010-08037-004.) Finding an object in our environment is an important human ability that also represents a critical component of human foraging behavior. One type of information that aids efficient large-scale search is the likelihood of the object being in one location over another. In this study we investigated the conditions under which individuals respond to this likelihood, and the reference frames in which this information is coded, using a novel, large-scale environmental search paradigm. Participants searched an array of locations, on the floor of a room, for a hidden target by pressing switches at each location. We manipulated the probability of the target being at a particular set of locations. Participants reliably learned target likelihoods when the possible search locations were kept constant throughout the experiment and the starting location was fixed. There was no evidence of such learning when room-based and body-based reference frames were dissociated. However, when this was combined with a more salient perceptual landmark, an allocentric cuing effect was observed. These data suggest that the encoding of this type of statistical contingency depends on the combination of spatial cues. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Searching the same display twice: Properties of short-term memory in repeated search

Consecutive search for different targets in the same display is supported by a short-term memory mechanism: Distractors that have recently been inspected in the first search are found more quickly in the second search when they become the target (Exp. 1). Here, we investigated the properties of this memory process. We found that this recency advantage is robust to a delay between the two searches (Exp. 2) and that it is only slightly disrupted by an interference task between the two searches (Exp. 3). Introducing a concurrent secondary task (Exp. 4) showed that the memory representations formed in the first search are based on identity as well as location information. Together, these findings show that the short-term memory that supports repeated visual search stores a complex combination of item identity and location that is robust to disruption by either time or interference.     

A two-stage search of visual working memory: investigating speed in the change-detection paradigm

A popular procedure for investigating working memory processes has been the visual change-detection procedure. Models of performance based on that procedure, however, tend to be based on performance accuracy and treat working memory search as a one-step process, in which memory representations are compared to a test probe to determine if a match is present. To gain a clearer understanding of how search of these representations operate in the change-detection task, we examined reaction time in two experiments, with a single-item probe either located centrally or at the location of an array item. Contrary to current models of visual working memory capacity, our data point to a two-stage search process: a fast first step to check for the novelty of the probe and, in the absence of such novelty, a second, slower step to search exhaustively for a match between the test probe and a memory representation. In addition to these results, we found that participants tended not to use location information provided by the probe that theoretically could have abbreviated the search process. We suggest some basic revisions of current models of processing in this type of visual working memory task.     

Age differences in visual working memory capacity: not based on encoding limitations

Why does visual working memory performance increase with age in childhood? One recent study ( Cowan et al., 2010b ) ruled out the possibility that the basic cause is a tendency in young children to clutter working memory with less‐relevant items (within a concurrent array, colored items presented in one of two shapes). The age differences in memory performance, however, theoretically could result from inadequate encoding of the briefly presented array items by younger children. We replicated the key part of the procedure in children 6–8 and 11–13 years old and college students (total N = 90), but with a much slower, sequential presentation of the items to ensure adequate encoding. We also required verbal responses during encoding to encourage or discourage labeling of item information. Although verbal labeling affected performance, age differences persisted across labeling conditions, further supporting the existence of a basic growth in capacity.