Complex Span Research Articles

A test of interference versus decay in working memory: Varying distraction within lists in a complex span task

Abstract We tested two competing explanations of the effect of processing on working memory. According to decay models, memory representations decay during processing and can be rehearsed or refreshed in the free time between processing steps. Alternatively, one interference-based model assumes that processing involves encoding of distractor representations in working memory, and free time is used to remove distractors. In several experiments the demand from distractor processing was varied within lists, such that one burst of processing following an item on the list was either particularly demanding or particularly undemanding. The exceptional distractor burst had its greatest effect on the list item that immediately preceded it (a local effect), and it affected items that had not yet been presented as well as preceding items. Both findings are predicted by a computational interference model of working memory, and together are problematic for the viewpoint that refreshing offsets decay.

The relationship between working memory capacity and simultaneous interpreting performance

This experimental study investigated the relationship between signed language interpreters’ working memory capacity (WMC) and their simultaneous interpreting performance. Thirty-one professional Auslan (Australian Sign Language)/English interpreters participated: 14 native signers and 17 non-native signers. They completed simultaneous interpreting tasks from English into Auslan and vice versa, an English listening span task and an Auslan working memory span task; each interpreting task was followed by a short semi-structured interview. Quantitative results for the sample as a whole showed no significant correlations between bilingual WMC and overall simultaneous interpreting performance in either direction. The same trend was established for both the native signers and the non-native signers, considered as two separate groups. The findings thus suggest that professional signed language interpreters’ WMC as measured by complex span tasks is not closely associated with the overall quality of their simultaneous interpreting performance. Data regarding educational and professional background showed mixed patterns in relation to participants’ interpreting performance in each language direction. In the interviews, participants reported various triggers of cognitive overload in the simultaneous interpreting tasks (e.g. numbers, lists of items, a long time lag, dense information, fatigue) and mentioned their coping strategies (e.g. strategic omissions, summarization, generalization, adjusting time lag).

Does Controlling for Temporal Parameters Change the Levels-of-Processing Effect in Working Memory?

The distinguishability between working memory (WM) and long-term memory has been a frequent and long-lasting source of debate in the literature. One recent method of identifying the relationship between the two systems has been to consider the influence of long-term memory effects, such as the levels-of-processing (LoP) effect, in WM. However, the few studies that have examined the LoP effect in WM have shown divergent results. This study examined the LoP effect in WM by considering a theoretically meaningful methodological aspect of the LoP span task. Specifically, we fixed the presentation duration of the processing component a priori because such fixed complex span tasks have shown differences when compared to unfixed tasks in terms of recall from WM as well as the latent structure of WM. After establishing a fixed presentation rate from a pilot study, the LoP span task presented memoranda in red or blue font that were immediately followed by two processing words that matched the memoranda in terms of font color or semantic relatedness. On presentation of the processing words, participants made deep or shallow processing decisions for each of the memoranda before a cue to recall them from WM. Participants also completed delayed recall of the memoranda. Results indicated that LoP affected delayed recall, but not immediate recall from WM. These results suggest that fixing temporal parameters of the LoP span task does not moderate the null LoP effect in WM, and further indicate that WM and long-term episodic memory are dissociable on the basis of LoP effects.

Mind wandering, control failures, and social media distractions in online learning

Mind wandering often leads to performance and accuracy errors during activities that are demanding and require concentration. Students are often asked to concentrate on demanding tasks in their studies, and by the nature of this principle, off-task thinking would inherently be prohibitive to their success. Further, the distracting nature of social media and technology may greatly increase the likelihood of mind wandering when students are engaged in online learning, requiring them to engage with said technology. To examine the relationships among working memory, interest, mind wandering and performance, 126 participants from at a large Midwestern state university completed three complex span tasks, responded to mind-wandering probes while watching two online lectures and rated interest in the lecture topics. Higher levels of mind wandering predicted lower levels of academic performance. Lower levels of working memory capacity predicted higher levels of mind wandering and lower levels of academic performance. Higher levels of topic interest predicted lower levels of mind wandering. A novel mind wandering probe, thinking about or using another technology, accounted for 29% of all off-task thinking.

Effects of Hearing Status and Sign Language Use on Working Memory

Deaf individuals have been found to score lower than hearing individuals across a variety of memory tasks involving both verbal and nonverbal stimuli, particularly those requiring retention of serial order. Deaf individuals who are native signers, meanwhile, have been found to score higher on visual-spatial memory tasks than on verbal-sequential tasks and higher on some visual-spatial tasks than hearing nonsigners. However, hearing status and preferred language modality (signed or spoken) frequently are confounded in such studies. That situation is resolved in the present study by including deaf students who use spoken language and sign language interpreting students (hearing signers) as well as deaf signers and hearing nonsigners. Three complex memory span tasks revealed overall advantages for hearing signers and nonsigners over both deaf signers and deaf nonsigners on 2 tasks involving memory for verbal stimuli (letters). There were no differences among the groups on the task involving visual-spatial stimuli. The results are consistent with and extend recent findings concerning the effects of hearing status and language on memory and are discussed in terms of language modality, hearing status, and cognitive abilities among deaf and hearing individuals.

Working Memory Models: Insights From Neuroimaging.

FIGURE 1. The Atkinson and Shiffrin Model of memory is diagramed in the gray panel. Sensory information is perceived and suppressed via selective attention processes, then briefly held in the limited-capacity modality-specific sensory register. Information enhanced by selective attention enters into short term memory (STM). The process of rehearsal (maintenance) can sustain information in STM. Information in STM is automatically encoded (stored, consolidated) into long term memory (LTM). Although flawed, this model continues to provide a simple and easy approach to understanding memory. Assumptions that proved to be inconsistent with research included that any information in STM will transfer to LTM and that STM is required

Executive functions and the contribution of short-term memory span in children with specific language impairment.

An increasing number of results show that specific language impairment (SLI) is often associated with impairments in executive functions (EF), but the nature, extent, and generality of these deficits is yet unclear. The aim of the paper is to present results from verbal and nonverbal tasks examining EF in children with SLI and their age-matched typically developing (TD) peers. 31 children with SLI were tested on verbal and nonverbal versions of simple and complex span, fluency, N-back, and Stroop tasks. Their performance was compared with 31 TD children matched on age and nonverbal IQ. The design allows us to examine whether executive functions are similarly affected in SLI in verbal and nonverbal tasks. The SLI group showed difficulties in verbal versions of complex span (listening span task) and fluency but not in inhibition (Stroop tasks) relative to TD age-matched children. Including simple verbal span (digit span) as a covariate eliminated group differences on both verbal tasks. Children with SLI were found to be impaired on several verbal measures of EF, but these differences were largely due to more fundamental deficits in verbal short-term span.

Reconciling Two Computational Models of Working Memory in Aging.

It is well known that working memory performance changes with age. Two recent computational models of working memory, TBRS* and SOB-CS, developed from young adults WM performances are opposed regarding the postulated causes of forgetting, namely time-based decay and interference for TBRS* and SOB-CS, respectively. In the present study, these models are applied on a set of complex span data produced by young and older adults. As expected, these models are unable to account for the older adult data. An investigation on the effect of the main parameters of these models showed that the poorer performance of older adults does not come from a weaker encoding of item but rather from difficulties during the free time that immediately follows each distractor, as well as from a higher level of confusion between items. These results are discussed with respect to the current theories of working memory and aging.

Maintenance Mechanisms in Children’s Verbal Working Memory

<p>Previous research in adults has indicated two maintenance mechanisms of verbal information in working memory, i.e., articulatory rehearsal and attentional refreshing. However, only three studies have examined their joint contribution to children’s verbal working memory. The present study aimed at extending this line of research by investigating the developmental changes occurring from 6 to 9 years old. In two experiments using complex span tasks, children of three different age groups maintained letters or words while performing a concurrent task. The opportunity for attentional refreshing was manipulated by varying the attentional demand of the concurrent task. Moreover, this task was performed either silently by pressing keys or aloud, the latter inducing a concurrent articulation. As expected, recall performance increased strongly with age. More interestingly, concurrent articulation had a detrimental effect on recall even in 6-year-old children. Similarly, introducing a concurrent attention-demanding task impaired recall performance at all ages. Finally, the effect of the availability of rehearsal and of attentional refreshing never interacted at any age. This suggested an independence of the two mechanisms in the maintenance of verbal information in children’s working memory. Implications for the development of rehearsal use and for the role of attention in working memory are discussed.</p>

They can take a hint: Older adults effectively integrate memory cues during recognition.

Adaptively biasing recognition judgments in light of environmental cues improves net accuracy. Based on previous work suggesting that strategically shifting biases on a trial-wise basis should be cognitively demanding, the authors predicted that older adults would not achieve the same accuracy benefits from environmental cues as the young. However, despite showing clear declines in cognitive control as indexed by complex span, older adults demonstrated similar accuracy gains and similar alterations of response probabilities with cues of 75% reliability (Experiment 1) and more complex cues spanning 3 levels of reliability (Experiment 2). Despite preserved gains in accuracy, older adults clearly demonstrated disproportionate slowing that was specific to trials in which cues were invalid. This slowing may reflect impairments in behavioral inhibition that could impinge upon accuracy were responding increasingly sped and future work manipulating response speed and measures of inhibition may yield further insights.

Promoting the experimental dialogue between working memory and chunking: Behavioral data and simulation.

Working memory (WM) is a cognitive system allowing short-term maintenance and processing of information. Maintaining information in WM consists, classically, in rehearsing or refreshing it. Chunking could also be considered as a maintenance mechanism. However, in the literature, it is more often used to explain performance than explicitly investigated within WM paradigms. Hence, the aim of the present paper was (1) to strengthen the experimental dialogue between WM and chunking, by studying the effect of acronyms in a computer-paced complex span task paradigm and (2) to formalize explicitly this dialogue within a computational model. Young adults performed a WM complex span task in which they had to maintain series of 7 letters for further recall while performing a concurrent location judgment task. The series to be remembered were either random strings of letters or strings containing a 3-letter acronym that appeared in position 1, 3, or 5 in the series. Together, the data and simulations provide a better understanding of the maintenance mechanisms taking place in WM and its interplay with long-term memory. Indeed, the behavioral WM performance lends evidence to the functional characteristics of chunking that seems to be, especially in a WM complex span task, an attentional time-based mechanism that certainly enhances WM performance but also competes with other processes at hand in WM. Computational simulations support and delineate such a conception by showing that searching for a chunk in long-term memory involves attentionally demanding subprocesses that essentially take place during the encoding phases of the task.

Implicit and explicit measures of spider fear and avoidance behavior: Examination of the moderating role of working memory capacity

Background and objectivesAvoidance behavior is central to several anxiety disorders. The current study tested whether avoidance behavior for spiders depends on a dynamic interplay between implicit and explicit processes, moderated by the availability to exert control through working memory capacity (WMC). MethodsA total of 63 participants completed an approach-avoidance task, an implicit association test, a spider fear questionnaire and a behavioral avoidance test that included an assessment of approach distance as well as approach speed. WMC was measured by a complex operation span task. It was hypothesized that in individuals with low WMC, implicit avoidance tendencies and implicit negative associations predict avoidance behavior for a spider better than the explicit measure, whereas in high WMC individuals, the explicit measure should better predict avoidance behavior than the implicit measures. ResultsResults revealed that WMC moderated the influence of implicit negative associations, but not implicit avoidance tendencies, on spider approach distance but not the speed of approaching. Although explicit spider fear directly influenced avoidance behavior, its impact was not modulated by WMC. LimitationsParticipants in our study were from a non-clinical sample, which limits the generalizability of our findings. ConclusionsThese findings suggest that implicit processes might become more pertinent for fear behavior as the ability to control such processes wanes, which may be particularly relevant for anxiety disorders given their association with lowered executive control functioning. As such, training procedures that specifically target implicit processes or control abilities might improve treatment outcomes for anxiety disorders.

Mesozoic orogenic gold deposits in Mexico

Although orogenic gold deposits in Mexico were mostly formed during the Cenozoic, they started forming during the Late Cretaceous, or perhaps even earlier. Mylonitic zones in the Oaxacan metamorphic complex span either Permo-Triassic or Triassic-Jurassic ages, but none of these have been formally associated with the existing orogenic gold occurrences. Given the current scarcity of age data for them, any interpretation concerning the age patterns or distribution of orogenic gold deposits in Mexico other than those in the Sonoran belt is hitherto deemed to be precarious. A few known Mesozoic examples are part of the Quitovac–La Choya deposits in the Caborca Orogenic Gold Belt (COGB) in Sonora, and Los Uvares in the Los Cabos Block (southernmost part of the Baja California Peninsula). The COGB constitutes the most economically important and geologically consistent mineralized area in Mexico with respect to orogenic gold deposits. Also, the COGB arguably correlates with the Mother Lode trend in California and Nevada, whereas the cluster of deposits in the Los Cabos Block may have correspondent similarly mineralized areas in mainland southwestern Mexico (Jalisco Block). Other areas with orogenic gold deposits in Mexico, which have been traditionally overlooked or scantly mentioned, are the northernmost part of the Baja California Peninsula, and the Arteaga and Oaxacan metamorphic complexes, although no geochronological data are available from these. Besides the overly lack of such data, one of the typical problems concerning the characterization and metallogenesis of orogenic deposits in Mexico has been their inaccurate or incorrect ascription to other genetic paradigms or types of deposits, such as epithermal or porphyry Cu–Au deposits, therefore misguiding exploration efforts.The formation of orogenic gold deposits in Mexico has been commonly associated with the Laramide orogeny, in association with cataclastic or mylonitic deformation and shear zones. Their depth of formation, under lithostatic pressure, has ben estimated at a range between ~3 and ~10km. Alteration assemblages in them are generally dominated by quartz±“sericite”±pyrite, and may be carbonate-rich. The hypogene mineralogy of orogenic gold deposits in Mexico is normally dominated by sulfides like pyrite, galena, sphalerite and whereas gold normally occurs as “electrum”, also known as unspecified Ag-rich gold, Au-rich silver, or as free gold. The latter may either be a hypogene or supergene mineral, in which case it is likely to be due mostly to the leaching-off of Ag from “electrum”. Te-rich associations are rare and have complex parageneses that consist typically of silver and/or gold tellurides. The mineralizing fluid precipitation into quartz veins occurred at temperatures ~350°C and are CO2-rich deeply seated crustal brines from metamorphic sources, with salinities typically ranging between ~2 and ~10wt.% NaCl equiv. but attaining up to ~33wt.% NaCl equiv.

Working memory still needs verbal rehearsal.

The causal role of verbal rehearsal in working memory has recently been called into question. For example, the SOB-CS (Serial Order in a Box-Complex Span) model assumes that there is no maintenance process for the strengthening of items in working memory, but instead a process of removal of distractors that are involuntarily encoded and create interference with memory items. In the present study, we tested the idea that verbal working memory performance can be accounted for without assuming a causal role of the verbal rehearsal process. We demonstrate in two experiments using a complex span task and a Brown-Peterson paradigm that increasing the number of repetitions of the same distractor (the syllable ba that was read aloud at each of its occurrences on screen) has a detrimental effect on the concurrent maintenance of consonants whereas the maintenance of spatial locations remains unaffected. A detailed analysis of the tasks demonstrates that accounting for this effect within the SOB-CS model requires a series of unwarranted assumptions leading to undesirable further predictions contradicted by available experimental evidence. We argue that the hypothesis of a maintenance mechanism based on verbal rehearsal that is impeded by concurrent articulation still provides the simplest and most compelling account of our results.

The developmental influence of primary memory capacity on working memory and academic achievement.

In this study, we investigate the development of primary memory capacity among children. Children between the ages of 5 and 8 completed 3 novel tasks (split span, interleaved lists, and a modified free-recall task) that measured primary memory by estimating the number of items in the focus of attention that could be spontaneously recalled in serial order. These tasks were calibrated against traditional measures of simple and complex span. Clear age-related changes in these primary memory estimates were observed. There were marked individual differences in primary memory capacity, but each novel measure was predictive of simple span performance. Among older children, each measure shared variance with reading and mathematics performance, whereas for younger children, the interleaved lists task was the strongest single predictor of academic ability. We argue that these novel tasks have considerable potential for the measurement of primary memory capacity and provide new, complementary ways of measuring the transient memory processes that predict academic performance. The interleaved lists task also shared features with interference control tasks, and our findings suggest that young children have a particular difficulty in resisting distraction and that variance in the ability to resist distraction is also shared with measures of educational attainment.

Naturalistic Assessment of Everyday Memory Performance Among Older Adults

Background/Study Context: Memory performance in everyday life (EDL) and its change through aging is still unclear because laboratory results are often not transferable to real-life situations. Therefore, a naturalistic memory task was designed to investigate memory performance in older adults in a representative task design.Methods: The memory performance of 23 older (70.28 ± 4.65 years) and 20 younger adults (24.89 ± 3.16 years) was assessed by using four established tasks of short-term and working memory (Digit Simple Span, Digit Complex Span, Grid Simple Span, and Grid Complex Span) that differed in difficulty and domain (verbal vs. visual-spatial). To simulate an EDL context, a “Supermarket” was constructed within the laboratory.Results: The results showed that memory performance presents alterations in older adults. This was especially true for the “Supermarket” task, in which the younger adults showed benefits in the common environment as opposed to older adults. A factor analysis showed that the four memory laboratory tasks measured different memory processes as compared with the EDL task.Conclusion: These findings suggest that memory performance in EDL is a different construct than when it is measured in the laboratory and that memory alterations in older adults are especially pronounced in EDL tasks. Following these findings, the authors recommend an EDL approach to measure memory performance further to the well-established laboratory approaches.

The Digit Span Backwards Task

Abstract. The “digit span backwards” (DSB) is the most commonly used test in clinical neuropsychology to assess working memory capacity. Yet, it remains unclear how the task is solved cognitively. The present study was conducted to examine the use of visual and verbal cognitive strategies in the DSB. Further, the relationship between the DSB and a complex span task, based on the Simultaneous Storage and Processing task ( Oberauer et al., 2003 ), was investigated. Visualizers performed better than verbalizers in the dual task condition (rPB = .23) only when the relevant digits were presented optically. Performance in the DSB correlated only weakly with the complex span task in all conditions (all τ ≤ .21). The results indicate that the processing modality is determined by the preference for a cognitive strategy rather than the presentation modality and suggest that the DSB measures different working aspects than commonly used experimental working memory tasks.

Working memory's workload capacity.

We examined the role of dual-task interference in working memory using a novel dual two-back task that requires a redundant-target response (i.e., a response that neither the auditory nor the visual stimulus occurred two back versus a response that one or both occurred two back) on every trial. Comparisons with performance on single two-back trials (i.e., with only auditory or only visual stimuli) showed that dual-task demands reduced both speed and accuracy. Our task design enabled a novel application of Townsend and Nozawa's (Journal of Mathematical Psychology 39: 321-359, 1995) workload capacity measure, which revealed that the decrement in dual two-back performance was mediated by the sharing of a limited amount of processing capacity. Relative to most other single and dual n-back tasks, performance measures for our task were more reliable, due to the use of a small stimulus set that induced a high and constant level of proactive interference. For a version of our dual two-back task that minimized response bias, accuracy was also more strongly correlated with complex span than has been found for most other single and dual n-back tasks.

Using the process dissociation procedure to estimate recollection and familiarity in working memory: An experimental and individual differences investigation

Although complex span tasks are believed to require controlled attention, many studies have indicated the effects of automaticity on working memory (WM) measures. In two experiments, we disentangled recollection and familiarity using an adaptation of the process dissociation procedure). In two blocks of reasoning span (Experiment 1) and Brown–Peterson span (Experiment 2) tasks, participants studied five discrete to-be-remembered digits (0–9) for either 1 or 3 sec while also solving reasoning problems (Does B follow C? BC). Participants were instructed to report the five presented digits (inclusion) or the five digits that were not presented (exclusion). Estimates of recollection but not familiarity differed as a function of presentation rate. Furthermore, recollection was more reliable than the typically used inclusion performance and strongly related to fluid intelligence. These results help to elucidate the functionally distinct roles of recollection and familiarity in WM.

Working memory capacity and the scope and control of attention.

Complex span and visual arrays are two common measures of working memory capacity that are respectively treated as measures of attention control and storage capacity. A recent analysis of these tasks concluded that (1) complex span performance has a relatively stronger relationship to fluid intelligence and (2) this is due to the requirement that people engage control processes while performing this task. The present study examines the validity of these conclusions by examining two large data sets that include a more diverse set of visual arrays tasks and several measures of attention control. We conclude that complex span and visual arrays account for similar amounts of variance in fluid intelligence. The disparity relative to the earlier analysis is attributed to the present study involving a more complete measure of the latent ability underlying the performance of visual arrays. Moreover, we find that both types of working memory task have strong relationships to attention control. This indicates that the ability to engage attention in a controlled manner is a critical aspect of working memory capacity, regardless of the type of task that is used to measure this construct.