Abstract: The Y-maze can be used to assess short term memory in mice. Spontaneous alternation, a measure of spatial working memory, can be assessed by allowing mice to explore all three arms of the maze and is driven by an innate curiosity of rodents to explore previously unvisited areas. A mouse with intact working memory, and hence intact prefrontal cortical functions, will remember the arms previously visited and show a tendency to enter a less recently visited arm. Spatial reference memory, which is underlined by the hippocampus, can also be tested by placing the test mice into the Y-maze with one arm closed off during training. After an intertrial interval of for example 1 h, the mouse should remember which arm it has not explored previously and should visit this arm more often. This chapter describes the pre-test conditions, the materials required and the protocol for conducting and interpreting the results of these two related tests.

Abstract: Traversing sensory environments requires keeping relevant information in mind while simultaneously processing new inputs. Visual information is kept in working memory via feature-selective responses in early visual cortex, but recent work has suggested that new sensory inputs obligatorily wipe out this information. Here we show region-wide multiplexing abilities in classic sensory areas, with population-level response patterns in early visual cortex representing the contents of working memory alongside new sensory inputs. In a second experiment, we show that when people get distracted, this leads to both disruptions of mnemonic information in early visual cortex and decrements in behavioral recall. Representations in the intraparietal sulcus reflect actively remembered information encoded in a transformed format, but not task-irrelevant sensory inputs. Together, these results suggest that early visual areas play a key role in supporting high-resolution working memory representations that can serve as a template for comparison with incoming sensory information.

Abstract: Data from the NICHD Study of Early Child Care (N = 1273) were analyzed to assess the longitudinal relations among executive function (EF) components in early childhood (54 months) and adolescence (15 years) and their prediction of academic achievement. We found that after controlling for early achievement, demographic, and home environment variables, only working memory at 54 months significantly predicted working memory at 15 years and that working memory was the only significant EF predictor of achievement at age 15. In contrast, all early achievement measures were significant predictors of later achievement. Furthermore, no demographic or home environment variables at 54 months significantly predicted EF at 15, and only maternal education significantly explained variance in adolescent math and literacy achievement. These findings demonstrate the predictability of working memory and highlight its importance for academic outcomes across development. However, the lack of associations of preschool inhibition and attention measures, after controlling for early achievement, demographic, and home environment variables, to corresponding measures in adolescence suggests the need for more developmentally sensitive measures of EF. Given that the EF measures used in this study are commonly used in educational and psychological research, more care should go into understanding the psychometric properties across development. (PsycINFO Database Record (c) 2019 APA, all rights reserved)

Abstract: Sequential and persistent activity models are two prominent models of short-term memory in neural circuits. In persistent activity models, memories are represented in persistent or nearly persistent activity patterns across a population of neurons, whereas in sequential models, memories are represented dynamically by a sequential activity pattern across the population. Experimental evidence for both models has been reported previously. However, it has been unclear under what conditions these two qualitatively different types of solutions emerge in neural circuits. Here, we address this question by training recurrent neural networks on several short-term memory tasks under a wide range of circuit and task manipulations. We show that both sequential and nearly persistent solutions are part of a spectrum that emerges naturally in trained networks under different conditions. Our results help to clarify some seemingly contradictory experimental results on the existence of sequential versus persistent activity-based short-term memory mechanisms in the brain.

Abstract: This article reviews contemporary research on multimedia learning that uses cognitive load theory as the major theoretical framework. In particular, we address the extent to which working memory ha...

Abstract: Chunking is the recoding of smaller units of information into larger, familiar units. Chunking is often assumed to help bypassing the limited capacity of working memory (WM). We investigate how chunks are used in WM tasks, addressing three questions: (a) Does chunking reduce the load on WM? Across four experiments chunking benefits were found not only for recall of the chunked but also of other not-chunked information concurrently held in WM, supporting the assumption that chunking reduces load. (b) Is the chunking benefit independent of chunk size? The chunking benefit was independent of chunk size only if the chunks were composed of unique elements, so that each chunk could be replaced by its first element (Experiment 1), but not when several chunks consisted of overlapping sets of elements, disabling this replacement strategy (Experiments 2 and 3). The chunk-size effect is not due to differences in rehearsal duration as it persisted when participants were required to perform articulatory suppression (Experiment 3). Hence, WM capacity is not limited to a fixed number of chunks regardless of their size. (c) Does the chunking benefit depend on the serial position of the chunk? Chunks in early list positions improved recall of other, not-chunked material, but chunks at the end of the list did not. We conclude that a chunk reduces the load on WM via retrieval of a compact chunk representation from long-term memory that replaces the representations of individual elements of the chunk. This frees up capacity for subsequently encoded material. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Abstract: Everyday life is defined by goal states that are continuously reprioritized based on available, often affective information. To pursue these goals, individuals need to process and maintain goal-relevant information, while ignoring potentially salient information that distracts resources from these goals. Empirically, this ability has typically been operationalized as working memory (WM) capacity. A growing body of research is investigating the impact of information's affective salience on WM capacity. In the present review we address this question by exploring the potential differential impact of affective compared with neutral information on WM, and the underlying neural substrates. One-hundred and 65 studies (N = 7,433) were included in the meta-analysis. Results showed negligible to small (d = -.07-.20) effects of affective information on behavioral measures of WM in healthy individuals (n = 4,936) that varied as a function of valence and task-relevance. Heterogeneity analyses were significant, demonstrating the need to identify further study-specific factors and individual differences that moderate affective WM. At the neural level (33 studies; n = 683), processing affective versus neutral material during WM tasks was associated with more frequent recruitment of the vlPFC, the amygdala, and the temporo-occipital cortex. In contrast to healthy individuals, across behavioral studies those suffering from mental health problems (n = 2,041) showed impaired WM accuracy (d = -0.21) in the presence of affective material. These findings highlight the importance of integrating behavioral and neural levels of analysis. Finally, these findings suggest that affective WM capacity may be a transdiagnostic mechanism associated with poor mental health. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Abstract: Executive function is foundational for cognitive development. Previous research has shown both gross motor skills and physical activity to be related to executive function. However, evidence for these relationships in the preschool years, as well as in low- and middle-income countries is lacking. Therefore, this study aimed to investigate the relationships between components of executive function (inhibition, shifting and working memory) and gross motor skills (locomotor skills and object control skills) in a sample of preschool children from urban and rural low-income settings in South Africa. Results revealed that inhibition and working memory, but not shifting, were associated with gross motor skills. More specifically: inhibition was associated with both locomotor [β = 0.20, p = 0.047] and object control skills [β = 0.24, p = 0.024], whereas working memory was only associated with locomotor skills [β = 0.21, p = 0.039]. Physical activity was not associated with inhibition and shifting but was negatively associated with working memory. These results elaborate a growing evidence base linking executive function and gross motor skills in the early years, and it is the first to look at specific associations of locomotor and object control skills with executive function in the South African context (a low- and middle-income country).

Abstract: The literature on individual differences in long-term memory (LTM) is organized and reviewed. This includes an extensive review of the factor structure of LTM abilities as well as specific individual differences in criterial tasks such as free recall, paired associates recall, and recognition. It is demonstrated that individual differences in LTM abilities are represented by various lower order factors based on criterial tasks as well as by a more general higher-order LTM factor. These individual differences are linked with multiple different constructs including working memory, intelligence, and attention control. Individual differences in forgetting, interference control, false memory, testing effects, general retrieval abilities, and the influence of strategies are also examined. Overall, it is clear that there are substantial and robust individual differences in LTM abilities and that these abilities demonstrate important relations with other cognitive abilities. Future directions and an integration of individual differences in a general framework of memory are discussed, and it is suggested that combined experimental and correlational approaches are needed to better understand individual differences in LTM and that individual differences in LTM should be used to better test and revise theories of LTM processes. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Abstract: This study investigated the effects of bilingualism on set-shifting and working memory in children with autism spectrum disorders (ASD). Bilinguals with ASD were predicted to display a specific bilingual advantage in set-shifting, but not working memory, relative to monolinguals with ASD. Forty 6- to 9-year-old children participated (20 ASD, 20 typically-developing). Set-shifting was measured using a computerized dimensional change card sort (DCCS) task, and by parent report of executive functioning in daily life. Results showed an advantage for bilingual relative to monolingual children with ASD on the DCCS task, but not for set-shifting in daily life. Working memory was similar for bilinguals and monolinguals with ASD. These findings suggest that bilingualism may mitigate some set-shifting difficulties in children with ASD.

Abstract: Purpose Compared to children with typical development, children with dyslexia, developmental language disorder (DLD), or both often demonstrate working memory deficits. It is unclear how pervasive ...

Abstract: How does visual working memory (WM) store the binding between different features of a visual object (like colour, orientation, and location), and does memorizing these bindings require additional resources beyond memorizing individual features? These questions have traditionally been addressed by comparing performance across different types of change detection task. More recently, experimental tasks such as analogue (cued) recall, combined with analysis methods including Bayesian hypothesis testing and formal model comparison, have shed new light on the properties of WM. A significant new perspective is that noise in neural representation limits the precision of recall, and several recent models incorporate this view to account for failures of binding in WM. We review the literature on feature binding with a focus on these new developments and discuss their implications for the interpretation of classical findings.

Abstract: Disorders of reading, math, and attention frequently co-occur in children. However, it is not yet clear which cognitive factors contribute to comorbidities among multiple disorders and which uniquely relate to one, especially because they have rarely been studied as a triad. Thus, the present study considers how reading, math, and attention relate to phonological awareness, numerosity, working memory, and processing speed, all implicated as either unique or shared correlates of these disorders. In response to findings that the attributes of all three disorders exist on a continuum rather than representing qualitatively different groups, this study employed a dimensional approach. Furthermore, we used both timed and untimed academic variables in addition to attention and activity level variables. The results supported the role of working memory and phonological awareness in the overlap among reading, math, and attention, with a limited role of processing speed. Numerosity was related to the comorbidity between math and attention. The results from timed variables and activity level were similar to those from untimed and attention variables, although activity level was less strongly related to cognitive and academic/attention variables. These findings have implications for understanding cognitive deficits that contribute to comorbid reading disability, math disability, and/or attention-deficit/hyperactivity disorder.

Abstract: [Correction Notice: An Erratum for this article was reported in Vol 45(9) of Journal of Experimental Psychology: Learning, Memory, and Cognition (see record 2019-48991-001). In the article, the copyright attribution was incorrectly listed and should have published under the Creative Commons CC-BY license. The correct copyright is "© 2018 The Author(s)." All versions of this article have been corrected.] Theories of working memory often disagree on the relationships between processing and storage, particularly on how heavily they rely on an attention-based limited resource. Some posit separation and specialization of resources resulting in minimal interference to memory when completing an ongoing processing task, while others argue for a greater overlap in the resources involved in concurrent tasks. Here, we present four experiments that investigated the presence or absence of dual-task costs for memory and processing. The experiments were carried in an adversarial collaboration in which researchers from three opposing theories collaboratively designed a set of experiments and provided differential predictions in line with each of their models. Participants performed delayed recall of aurally and visually presented letters and an arithmetic verification task either as single tasks or with the arithmetic verification task between presentation and recall of letter sequences. Single- and dual-task conditions were completed with and without concurrent articulatory suppression. A consistent pattern of dual-task and suppression costs was observed for memory, with smaller or null effects on processing. The observed data did not fit perfectly with any one framework, with each model having partial success in predicting data patterns. Implications for each of the models are discussed, with an aim for future research to investigate whether some combination of the models and their assumptions can provide a more comprehensive interpretation of the pattern of effects observed here and in relevant previous studies associated with each theoretical framework. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Abstract: I propose that the capacity of working memory places a specific limit on the maintenance of temporary bindings. Two experiments support this binding hypothesis: Participants remembered word lists of varying length. When tested on a randomly selected word, their error rates increased with the length of the list, reflecting a limited capacity for short-term maintenance. This increase in errors was predominantly due to binding errors: People confused the correct word with other words of the current memory list, but very rarely with words not in the list. The frequencies of response choices were analyzed through two measurement models – one based on the assumption of discrete memory states, one on the assumption of continuous memory strength – that capture memory for items and for bindings in separate parameters. Increasing memory set size impaired binding memory but not item memory, supporting the binding hypothesis.

Abstract: Objective To test for associations between long-term anabolic-androgenic steroid (AAS) use and cognitive functioning, and establish a candidate neuronal basis by assessing the associations between cognitive performance and brain morphology both in users and nonusers. Method Eighty four previous or current AAS-users and 69 non-AAS-using male weightlifters aged 19-75 years (mean 32.6, SD 8.8) underwent MRI of the brain and a comprehensive neuropsychological test battery. Performance on fine motor speed, speed of processing, learning and memory, working memory, executive functioning, and problem solving was compared between the groups, and between AAS users with short versus long AAS exposure. Associations between cognitive scores and regional cortical thickness and arealization defined using FreeSurfer were tested using linear models. Results Relative to nonexposed, AAS-exposed weightlifters performed significantly worse on several cognitive domains, independent of age, education, verbal IQ, and exposure to classical drugs of abuse. Strongest effects were observed for speed of processing (ηp2 = .07), working memory (ηp2 = .08) and problem solving (ηp2 = .09). Longer duration of AAS-use was associated with poorer memory function (ηp2 = .11). Within AAS users, individuals with better memory and working memory performance had with thicker frontoparietal cortex and larger medial frontal surface area, respectively. Conclusions Prolonged high-dose AAS use is associated with poorer cognitive function across multiple domains, and the observed regional associations between cortical brain morphometry and memory and working memory performance may suggest differential brain-based mechanisms. The public, health care professionals, and policymakers should be aware that use of AAS in large doses potentially could lead to poorer brain health and cognition. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Abstract: Captions provide a useful aid to language learners for comprehending videos and learning new vocabulary, aligning with theories of multimedia learning. Multimedia learning predicts that a learner’s working memory (WM) influences the usefulness of captions. In this study, we present two eye-tracking experiments investigating the role of WM in captioned video viewing behavior and comprehension. In Experiment 1, Spanish-as-a-foreign-language learners differed in caption use according to their level of comprehension and to a lesser extent, their WM capacities. WM did not impact comprehension. In Experiment 2, Englishas-a-second-language learners differed in comprehension according to their WM capacities. Those with high comprehension and high WM used captions less on a second viewing. These findings highlight the effects of potential individual differences and have implications for the integration of multimedia with captions in instructed language learning. We discuss how captions may help neutralize some of working memory’s limiting effects on learning.

Abstract: BACKGROUND: Exposure to nature may be particularly beneficial for the brain regions that support spatial working memory, a strong correlate of academic achievement. AIMS: To explore whether children living in greener neighbourhoods (wards) have better spatial working memory. SAMPLE: Drawn from the UK's Millennium Cohort Study, the sample was 4,758 11-year-olds living in urban areas in England. METHODS: We fitted two-level regression models, with children nested in wards, before and after adjustment for confounders, including poverty, parental education, sports participation, neighbourhood deprivation, and neighbourhood history. Spatial working memory was measured using the Cambridge Neuropsychological Test Automated Battery Spatial Working Memory task. Greenspace was measured as the percentage of greenery in the child's ward. RESULTS: Even after controlling for confounders, lower quantity of neighbourhood greenspace was related to poorer spatial working memory. Importantly, neighbourhood deprivation did not modify this relationship. Therefore, lower quantity of greenspace was related to poorer spatial working memory similarly in deprived and non-deprived neighbourhoods. CONCLUSIONS: Children living in greener urban neighbourhoods have better spatial working memory. If this association is causal, then our findings can be used to inform policy decisions about both education and urban planning.

Abstract: The relationship of verbal fluency to executive functions (EFs) remains somewhat unclear. Verbal fluency is sometimes considered an EF ability, but is not often included in the same models as other well-studied EFs (inhibition, shifting, and working memory updating). We examined the associations between verbal fluency and EFs at 2 ages with the unity/diversity model, which includes common and domain-specific EF factors. Participants were 813 adolescent twins from the Colorado Longitudinal Twin Sample (mean age 17 years) and 1,290 middle-aged twins from the Vietnam Era Twin Study of Aging (mean age 56 years) who completed multiple measures of EFs, verbal fluency, vocabulary, and nonverbal cognitive ability. Results revealed that, in both samples, a General Fluency factor (i.e., comprising both phonemic and semantic fluency measures) was associated with the Common EF factor, but also with variance unique to working memory updating, working memory span, and set-shifting. In adolescents, semantic fluency also had unique associations with shifting beyond its shared variance with phonemic fluency and Common EF. After accounting for EFs and other cognitive abilities, there were unique genetic and environmental influences on the General Fluency and Semantic-Specific latent factors. These results suggest that verbal fluency ability may best be viewed as an amalgamation of general EF variance (i.e., Common EF ability), variance shared with other EFs (e.g., Updating-Specific ability), and multiple sources of unique genetic/environmental variance (i.e., General Fluency and Semantic-Specific abilities). These associations between verbal fluency and EFs generalize to populations that differ in age by approximately 40 years. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Abstract: Creative thinking shares many characteristics with traditional complex tasks. We investigated whether implicit theories of creativity would affect creative thinking in a way similar to the impact o...

Abstract: Visual working memory (VWM) is limited in both the capacity of information it can retain and the rate at which it encodes that information. We examined the influence of stimulus complexity on these 2 limitations of VWM. Observers performed a change-detection task with English letters of various fonts or letters from unfamiliar alphabets. Average perimetric complexity (κ)-an objective correlate of the number of features comprising each letter-differed among the fonts and alphabets. Varying the time between the memory array and mask, we used change-detection performance to estimate the number of items held in VWM (K) as a function of encoding time. For all alphabets, K increased over 270 ms (indicating the rate of encoding) before reaching an asymptote (indicating capacity). We found that rate and capacity for each alphabet were unrelated to complexity: Performance was best modeled by assuming that both were limited by number of items (K), rather than by number of features (K × κ). We also found a higher encoding rate and capacity for familiar alphabets (∼45 items s-1; ∼4 items) than for unfamiliar alphabets (∼12 items s-1; ∼1.5 items). We then compared the familiar English alphabet to an unfamiliar artificial character set matched in complexity. Again, rate and capacity was higher for the familiar than for the unfamiliar stimuli. We conclude that rate and capacity for encoding into visual working memory is determined by the number of familiar feature-integrated object representations. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Abstract: Cognitive ability is a key selection criterion for entry into many elite professions. Herein, we investigate whether mindfulness training (MT) can enhance cognitive performance in elite military forces. The cognitive effects of a short-form 8-h MT program contextualized for military cohorts, referred to as Mindfulness-Based Attention Training (MBAT), were assessed. Servicemembers received either a 2-week (n=40) or 4-week (n=36) version of MBAT or no training (NTC, n=44). Sustained attention and working memory task performance along with self-reported cognitive failures were assessed at study onset (T1) and 8-weeks later (T2). In contrast to both the NTC and 2-week MT groups, the 4-week MT group significantly improved over time on attention and working memory outcome measures. Among the 4-week more so than the 2-week MBAT participants, working memory performance improvements were correlated with their amount of out-of-class MT practice. In addition to these group-wise effects, all participants receiving MBAT decreased in their self-reported cognitive failures from T1 to T2. Importantly, none of these improvements were related to self-reported task motivation. Together, these results suggest that short-form MT, when delivered over a 4-week delivery schedule, may be an effective cognitive training tool in elite military cohorts.

Abstract: Classical views of the medial temporal lobe (MTL) have established that it plays a crucial role in long-term memory (LTM). Here we demonstrate, in a sample of patients who have undergone anterior temporal lobectomy for the treatment of pharmacoresistant epilepsy, that the MTL additionally plays a specific, causal role in short-term memory (STM). Patients (n=22) and age-matched healthy control participants (n=26) performed a STM task with a sensitive continuous report measure. This paradigm allowed us to examine recall memory for object identity, location and object-location binding, independently on a trial-by-trial basis. Our findings point to a specific involvement of MTL in object-location binding, but, crucially, not retention of either object identity or location. Therefore the MTL appears to perform a specific computation: binding disparate features that belong to a memory. These results echo findings from previous studies, which have identified a role for the MTL in relational binding for LTM, and support the proposal that MTL regions perform such a function for both STM and LTM, independent of the retention duration. Furthermore, these findings and the methodology employed here may provide a simple, sensitive and clinically valuable means to test memory dysfunuction in MTL disorders.