Division and spreading of attention across color.

Biological systems must allocate limited perceptual resources to relevant elements in their environment. This often requires simultaneous selection of multiple elements from the same feature dimension (e.g. color). To establish the determinants of divided attentional selection of color, we conducted an experiment that used multicolored displays with four overlapping random dot kinematograms that differed only in hue. We manipulated (i) requirement to focus attention to a single color or divide it between two colors; (ii) distances of distractor hues from target hues in a perceptual color space. We conducted a behavioral and an electroencephalographic experiment, in which each color was tagged by a specific flicker frequency and driving its own steady-state visual evoked potential. Behavioral and neural indices of attention showed several major consistencies. Concurrent selection halved the neural signature of target enhancement observed for single targets, consistent with an approximately equal division of limited resources between two hue-selective foci. Distractors interfered with behavioral performance in a context-dependent fashion but their effects were asymmetric, indicating that perceptual distance did not adequately capture attentional distance. These asymmetries point towards an important role of higher-level mechanisms such as categorization and grouping-by-color in determining the efficiency of attentional allocation in complex, multicolored scenes.

How the Effect of Virtual Reality on Cognitive Functioning Is Modulated by Gender Differences.

Virtual reality (VR) can be a promising tool to simulate reality in various settings but the real impact of this technology on the human mental system is still unclear as to how VR might (if at all) interfere with cognitive functioning. Using a computer, we can concentrate, enter a state of flow, and still maintain control over our surrounding world. Differently, VR is a very immersive experience which could be a challenge for our ability to allocate divided attention to the environment to perform executive functioning tasks. This may also have a different impact on women and men since gender differences in both executive functioning and the immersivity experience have been referred to by the literature. The present study aims to investigate cognitive multitasking performance as a function of (1) virtual reality and computer administration and (2) gender differences. To explore this issue, subjects were asked to perform simultaneous tasks (span forward and backward, logical-arithmetic reasoning, and visuospatial reasoning) in virtual reality via a head-mounted display system (HDMS) and on a personal computer (PC). Our results showed in virtual reality an overall impairment of executive functioning but a better performance of women, compared to men, in visuospatial reasoning. These findings are consistent with previous studies showing a detrimental effect of virtual reality on cognitive functioning.

Walking (and talking) the plank: dual-task performance costs in a virtual balance-threatening environment.

We evaluated the effects of engaging in extemporaneous speech in healthy young adults while they walked in a virtual environment meant to elicit low or high levels of mobility-related anxiety. We expected that mobility-related anxiety imposed by a simulated balance threat (i.e., virtual elevation) would impair walking behavior and lead to greater dual-task costs. Altogether, 15 adults (age = 25.6 ± 4.7 yrs, 7 women) walked at their self-selected speed within a VR environment that simulated a low (ground) and high elevation (15 m) setting while speaking extemporaneously (dual-task) or not speaking (single-task). Likert-scale ratings of cognitive and somatic anxiety, confidence, and mental effort were evaluated and gait speed, step length, and step width, as well as the variability of each, was calculated for every trial. Silent speech pauses (> 150 ms) were determined from audio recordings to infer the cognitive costs of extemporaneous speech planning at low and high virtual elevation. Results indicated that the presence of a balance threat and the inclusion of a concurrent speech task both perturbed gait kinematics, but the virtual height illusion led to increased anxiety and mental effort and a decrease in confidence. The extemporaneous speech pauses were longer on average when walking, but no effects of virtual elevation were reported. Trends toward interaction effects arose in self-reported responses, with participants reporting more comfort walking at virtual heights if they engaged in extemporaneous speech. Walking at virtual elevation and while talking may have independent and significant effects on gait; both effects were robust and did not support an interaction when combined (i.e., walking and talking at virtual heights). The nature of extemporaneous speech may have distracted participants from the detrimental effects of walking in anxiety-inducing settings.

Processing Speed and Attentional Shift/Mental Flexibility in Patients with Stroke: A Comprehensive Review on the Trail Making Test in Stroke Studies.

The Trail Making Test (TMT) is one of the most commonly administered tests in clinical and research neuropsychological settings. The two parts of the test (part A (TMT-A) and part B (TMT-B)) enable the evaluation of visuoperceptual tracking and processing speed (TMT-A), as well as divided attention, set-shifting and cognitive flexibility (TMT-B). The main cognitive processes that are assessed using TMT, i.e., processing speed, divided attention, and cognitive flexibility, are often affected in patients with stroke. Considering the wide use of TMT in research and clinical settings since its introduction in neuropsychological practice, the purpose of our review was to provide a comprehensive overview of the use of TMT in stroke patients. We present the most representative studies assessing processing speed and attentional shift/mental flexibility in stroke settings using TMT and applying scoring methods relying on conventional TMT scores (e.g., time-to-complete part A and part B), as well as derived measures (e.g., TMT-(B-A) difference score, TMT-(B/A) ratio score, errors in part A and part B). We summarize the cognitive processes commonly associated with TMT performance in stroke patients (e.g., executive functions), lesion characteristics and neuroanatomical underpinning of TMT performance post-stroke, the association between TMT performance and patients' instrumental activities of daily living, motor difficulties, speech difficulties, and mood statue, as well as their driving ability. We also highlight how TMT can serve as an objective marker of post-stroke cognitive recovery following the implementation of interventions. Our comprehensive review underscores that the TMT stands as an invaluable asset in the stroke assessment toolkit, contributing nuanced insights into diverse cognitive, functional, and emotional dimensions. As research progresses, continued exploration of the TMT potential across these domains is encouraged, fostering a deeper comprehension of post-stroke dynamics and enhancing patient-centered care across hospitals, rehabilitation centers, research institutions, and community health settings. Its integration into both research and clinical practice reaffirms TMT status as an indispensable instrument in stroke-related evaluations, enabling holistic insights that extend beyond traditional neurological assessments.

The effects of forewarning and divided attention on context retrieval in false recognition.

After studying a list of words that are semantically associated to a critical lure, participants are more likely to attribute a falsely recognised critical lure to the context of its strong than weak semantic associates. This is known as the source-strength effect. The current study investigated the roles of automatic and controlled processing in context retrieval in false recognition that is demonstrated by the source-strength effect. The results revealed that the source-strength effect was impervious to forewarning (Experiment 1) and remained intact when attentional resources at encoding were reduced (Experiment 2), suggesting that context retrieval in false recognition is based on automatic processes that are not amenable to conscious control and do not require many attentional resources. This interpretation is consistent with the associative activation theory, which proposes that context retrieval in false recognition is based on memory associations between contexts and critical lures that are automatically created when critical lures become automatically activated via spreading activation process.

Running together influences where you look.

To read this article, you have to constantly direct your gaze at the words on the page. If you go for a run instead, your gaze will be less constrained, so many factors could influence where you look. We show that you are likely to spend less time looking at the path just in front of you when running alone than when running with someone else, presumably because the presence of the other runner makes foot placement more critical.

Severe processing capacity limits for sub-lexical features of letter strings.

When reading, the visual system is confronted with many words simultaneously. How much of that information can a reader process at once? Previous studies demonstrated that low-level visual features of multiple words are processed in parallel, but lexical attributes are processed serially, for one word at a time. This implies that an internal bottleneck lies somewhere between early visual and lexical analysis. We used a dual-task behavioral paradigm to investigate whether this bottleneck lies at the stage of letter recognition or phonological decoding. On each trial, two letter strings were flashed briefly, one above and one below fixation, and then masked. In the letter identification experiment, participants indicated whether a vowel was present in a particular letter string. In the phonological decoding experiment, participants indicated whether the letter string was pronounceable. We compared accuracy in a focused attention condition, in which participants judged only one of the two strings, with accuracy in a divided attention condition, in which participants judged both strings independently. In both experiments, the cost of dividing attention was so large that it supported a serial model: participants were able to process only one letter string per trial. Furthermore, we found a stimulus processing trade-off that is characteristic of serial processing: When participants judged one string correctly, they were less likely to judge the other string correctly. Therefore, the bottleneck that constrains word recognition under these conditions arises at a sub-lexical level, perhaps due to a limit on the efficiency of letter recognition.

The neural oscillations in delta- and theta-bands contribute to divided attention in audiovisual integration.

One of key mechanisms implicated in multisensory processing is neural oscillations in distinct frequency band. Many studies explored the modulation of attention by recording the electroencephalography signals when subjects attended one modality, and ignored the other modality input. However, when attention is directed toward one modality, it may be not always possible to shut out completely inputs from a different modality. Since many situations require division of attention between audition and vision, it is imperative to investigate the neural mechanisms underlying processing of concurrent auditory and visual sensory streams. In the present study, we designed a task of audiovisual semantic discrimination, in which the subjects were asked to share attention to both auditory and visual stimuli. We explored the contribution of neural oscillations in lower-frequency to the modulation of divided attention on audiovisual integration. Our results implied that theta-band activity contributes to the early modulation of divided attention, and delta-band activity contributes to the late modulation of divided attention to audiovisual integration. Moreover, the fronto-central delta- and theta-bands activity is likely a marker of divided attention in audiovisual integration, and the neural oscillation on delta- and theta-bands is conducive to allocating attention resources to dual-tasking involving task-coordinating abilities.

Preseason Measures of Cervical Spine Function, Vestibulo-Ocular Reflex, Dynamic Balance, and Divided Attention in Youth Ice Hockey Players.

OBJECTIVES: Report typical scores and examine preseason cervical spine, vestibulo-ocular reflex, dynamic balance, and divided attention measures in competitive youth ice hockey players aged 10 to 18 years with and without a previous concussion history. DESIGN: Cross-sectional secondary analysis. METHODS: The exposure of interest was self-reported history of concussion. The main outcomes were cervical spine measures (Cervical Flexor Endurance [CFE; seconds], Cervical Flexion-Rotation Test [normal/abnormal], Anterolateral Cervical Spine Strength [kilograms], Head Perturbation Test (/8), and Joint Position Error [JPE; centimeters]), vestibulo-ocular reflex (Dynamic Visual Acuity [logMAR], Head Thrust Test [Positive/Negative]), dynamic balance (Functional Gait Assessment [/30]) and divided attention (Walking While Talking Test [seconds]). Multivariable linear or logistic regression, adjusted for age-group, sex, level of play, and clustered by team, were used to assess potential differences by concussion history. RESULTS: We included data from 2311 participants in this study (87.2% male, 12.8% female, 39.0% reported a previous concussion). No differences by concussion history were found across any of the measures (P values range: 0.17-0.99). Measures of cervical spine function and divided attention differed by age group (eg, Median Left Anterolateral Cervical Spine Strength [kilograms] for males: U13 = 7.46, U15 = 9.10, U18 = 9.67). CONCLUSION: Clinical outcomes scores in youth ice hockey players did not differ by concussion history. Performance on cervical spine strength, CFE, and JPE test outcomes may improve with age, highlighting the importance of developmental considerations when interpreting test scores. J Orthop Sports Phys Ther 2024;54(3):1-11. Epub 30 November 2023. doi:10.2519/jospt.2023.11958.

Measuring the Contributions of Perceptual and Attentional Processes in the Complete Composite Face Paradigm.

Theories of holistic face processing vary widely with respect to conceptualizations, paradigms, and stimuli. These divergences have left several theoretical questions unresolved. Namely, the role of attention in face perception is understudied. To rectify this gap in the literature, we combined the complete composite face task (allowing for predictions of multiple theoretical conceptualizations and connecting with a large body of research) with a secondary auditory discrimination task at encoding (to avoid a visual perceptual bottleneck). Participants studied upright, intact faces within a continuous recognition paradigm, which intermixes study and test trials at multiple retention intervals. Within subjects, participants studied faces under full or divided attention. Test faces varied with respect to alignment, congruence, and retention intervals. Overall, we observed the predicted beneficial outcomes of holistic processing (e.g., higher discriminability for Congruent, Aligned faces relative to Congruent, Misaligned faces) that persisted across retention intervals and attention. However, we did not observe the predicted detrimental outcomes of holistic processing (e.g., higher discriminability for Incongruent, Misaligned faces relative to Incongruent, Aligned faces). Because the continuous recognition paradigm exerts particularly strong demands on attention, we interpret these findings through the lens of resource dependency and domain specificity.

Relationships between age, fMRI correlates of familiarity and familiarity-based memory performance under single and dual task conditions.

Using fMRI, we investigated the effects of age and divided attention on the neural correlates of familiarity and their relationship with memory performance. At study, word pairs were visually presented to young and older participants under the requirement to make a relational judgment on each pair. Participants were then scanned while undertaking an associative recognition test under single and dual (auditory tone detection) task conditions. The test items comprised studied, rearranged (words from different studied pairs) and new word pairs. fMRI familiarity effects were operationalized as greater activity elicited by studied pairs incorrectly identified as 'rearranged' than by correctly rejected new pairs. The reverse contrast was employed to identify 'novelty' effects. Behavioral familiarity estimates were equivalent across age groups and task conditions. Robust fMRI familiarity effects were identified in several regions, including medial and superior lateral parietal cortex, dorsal medial and left lateral prefrontal cortex, and bilateral caudate. fMRI novelty effects were identified in the anterior medial temporal lobe. Both familiarity and novelty effects were largely age-invariant and did not vary, or varied minimally, according to task condition. In addition, the familiarity effects correlated positively with a behavioral estimate of familiarity strength irrespective of age. These findings extend a previous report from our laboratory, and converge with prior behavioral reports, in demonstrating that the factors of age and divided attention have little impact on behavioral and neural estimates of familiarity.

Perceptual Learning of Noise-Vocoded Speech Under Divided Attention.

Speech perception performance for degraded speech can improve with practice or exposure. Such perceptual learning is thought to be reliant on attention and theoretical accounts like the predictive coding framework suggest a key role for attention in supporting learning. However, it is unclear whether speech perceptual learning requires undivided attention. We evaluated the role of divided attention in speech perceptual learning in two online experiments (N = 336). Experiment 1 tested the reliance of perceptual learning on undivided attention. Participants completed a speech recognition task where they repeated forty noise-vocoded sentences in a between-group design. Participants performed the speech task alone or concurrently with a domain-general visual task (dual task) at one of three difficulty levels. We observed perceptual learning under divided attention for all four groups, moderated by dual-task difficulty. Listeners in easy and intermediate visual conditions improved as much as the single-task group. Those who completed the most challenging visual task showed faster learning and achieved similar ending performance compared to the single-task group. Experiment 2 tested whether learning relies on domain-specific or domain-general processes. Participants completed a single speech task or performed this task together with a dual task aiming to recruit domain-specific (lexical or phonological), or domain-general (visual) processes. All secondary task conditions produced patterns and amount of learning comparable to the single speech task. Our results demonstrate that the impact of divided attention on perceptual learning is not strictly dependent on domain-general or domain-specific processes and speech perceptual learning persists under divided attention.

Cortical Tracking of Continuous Speech Under Bimodal Divided Attention.

Speech processing often occurs amid competing inputs from other modalities, for example, listening to the radio while driving. We examined the extent to which dividing attention between auditory and visual modalities (bimodal divided attention) impacts neural processing of natural continuous speech from acoustic to linguistic levels of representation. We recorded electroencephalographic (EEG) responses when human participants performed a challenging primary visual task, imposing low or high cognitive load while listening to audiobook stories as a secondary task. The two dual-task conditions were contrasted with an auditory single-task condition in which participants attended to stories while ignoring visual stimuli. Behaviorally, the high load dual-task condition was associated with lower speech comprehension accuracy relative to the other two conditions. We fitted multivariate temporal response function encoding models to predict EEG responses from acoustic and linguistic speech features at different representation levels, including auditory spectrograms and information-theoretic models of sublexical-, word-form-, and sentence-level representations. Neural tracking of most acoustic and linguistic features remained unchanged with increasing dual-task load, despite unambiguous behavioral and neural evidence of the high load dual-task condition being more demanding. Compared to the auditory single-task condition, dual-task conditions selectively reduced neural tracking of only some acoustic and linguistic features, mainly at latencies >200 ms, while earlier latencies were surprisingly unaffected. These findings indicate that behavioral effects of bimodal divided attention on continuous speech processing occur not because of impaired early sensory representations but likely at later cognitive processing stages. Crossmodal attention-related mechanisms may not be uniform across different speech processing levels.

Male attention allocation depends on social context.

Allocation of attention, typically a limited capacity, is a mechanism used to filter large amounts of information and determine what stimuli are most relevant at a particular moment. In dynamic social environments as found in almost all species, including humans, multiple individuals may play a pivotal role in any given interaction where a male's attention may be divided between a rival, a current mate, and/or future potential mates. Although clearly important, the role of the social environment on attention in animals is not well understood. Here, we investigated impacts of the social environment on attention allocation using male sailfin mollies, Poecilia latipinna, which are a part of a sexual-unisexual mating system with the Amazon molly, Poecilia formosa. We asked: 1) Does the species of female influence the amount of attention a male allocates to her? And 2) Is a male's attention towards his mate influenced by different social partners? We show that males perceive a larger male as a more relevant stimulus to pay attention to compared to a smaller male, and a conspecific female (either a partner or audience) as a more relevant stimulus compared to a heterospecific female. Our results show that differential allocation of attention is dependent upon multiple components of the social environment in which an individual interacts. Understanding what qualities of rival males or potential mates provide enough meaning to males to cause a shift in attention away from a mating opportunity is essential to understanding the influence of the social environment in sexual selection.

La modalidad de actividad físico-deportiva practicada determina el nivel de atención dividida en adultos jóvenes / O tipo de atividade físico-esportiva praticada determina o nível de atenção dividida em adultos jovens / The type of physical-sports activity practised determis the level of divided attention among young adults

El propósito del presente estudio fue determinar las diferencias en el nivel de atención dividida en función de la modalidad de práctica físico-deportiva realizada. La muestra estuvo compuesta por 610 deportistas (66.55% género femenino), con edades entre 20 y 35 años (M ± DT = 22.53 ± 2.72). Para evaluar la atención dividida se utilizó el Test de Círculos, el cual pertenece al software Procesos Atencionales y que está alojado en la plataforma de evaluación online MenPas 1.0 (www.menpas.com). Los resultados obtenidos pusieron de relieve que la práctica de actividad físico-deportiva de tipo colectiva estuvo asociada a una mejor puntuación en el Test de Círculos, encontrándose las mayores diferencias entre las modalidades colectivas e individuales. Estos hallazgos sugieren que practicar actividades físico-deportivas de tipo colectivo, debido a las características de estos deportes, podría contribuir a un mejor desarrollo de capacidades cognitivas como la atención dividida. (AU)

This study aims to determine the differences in levels of dividided attention according to the type of physical-sports activity practised. The sample consisted of 610 athletes (66.55% females) aged between 20 and 35 years (M ± DT = 22.53 ± 2.72). Divided attention was assessed using The Circles Test of the Attentional Processes software hosted on the MenPas 1.0 online assessment platform (www.menpas.com). The result show that the practice of collective physical-sport activity was associated with a better score in the Circles Test, with the greatest differences being between collective and individual modalities. These findings suggest that due to the characteristics of these collective physical-sports, they may contribute to improve Development of cognitive abilities such as divided attention. (AU)

O objetivo do presente estudo foi determinar as diferenças no nível de atenção dividido de acordo com a modalidade de prática físico-esportiva realizada. A amostra foi composta por 610 atletas (66,55% do sexo feminino), com idade entre 20 e 35 anos(M ± SD = 22,53 ± 2,72). Para avaliar a atenção dividida, foi utilizado o Teste dos Círculos, que pertence ao software Processos de Atenção e está hospedado na plataforma de avaliação online MenPas 1.0 (www.menpas.com). Os resultados obtidos destacaram que a prática de atividade físico-esportiva coletiva esteve associada a uma melhor pontuação no Teste de Círculos, sendo as maiores diferenças encontradas entre as modalidades coletiva e individual. Esses achados sugerem que a prática de atividades físico-esportivas coletivas, devido às características desses esportes, poderia contribuir para um melhor desenvolvimento de habilidades cognitivas como a atenção dividida. (AU)

Investigating features that contribute to evaluations of intrusiveness for thoughts and memories.

What makes a thought feel intrusive? One possibility is that traumatic experiences are the primary cause of intrusive thoughts and memories. Another possibility is that experiences of intrusiveness arise from the features involved with re-experiencing. We investigated several features that may lead a thought to feel intrusive: task-congruence, repetition, and affective content. In Experiment 1, participants listened to popular song clips expected to become stuck in one's head. In Experiment 2, participants were cued to recall their own autobiographical memories. We found that both songs and autobiographical memories replaying mentally felt more intrusive when they were incongruent with the current task, cued repeatedly, and had negative emotional content. Additionally, even liked songs and positive autobiographical memories were evaluated as highly intrusive under some conditions. Based on these findings, we argue that intrusiveness is not limited to traumatic thoughts, but rather is a context-dependent evaluation influenced by a variety of features.

Path Configuration Complexity Affects Spatial Memory Span on the eCorsi Task but Does Not Influence Performance of a Concurrent Auditory Discrimination Task.

Visuospatial working memory is often assessed using the Corsi block-tapping task where set size is used to estimate capacity. It is well established that characteristics of the Corsi task path configuration such as length, crossings, and angles influence recall accuracy suggesting that more complex path configurations increase the load on working memory. However, the interaction between set size and path configuration is not well understood. Here we used a secondary auditory task to probe if set size and path configuration impose a similar type of load on the system. Nineteen participants (age = 25.3 ± 3.9 years) performed a computerized version of the Corsi test either alone (single) or simultaneously with an auditory tone discrimination task (dual). The eCorsi task involved a set of simple (no crosses, shorter lengths, larger angles) or complex (>2 crosses, longer lengths, smaller angles) paths at set sizes of five to eight blocks. Results showed significantly lower recall accuracy for the complex compared to the simple paths (63.32% vs. 86.38%, p < 0.001) at all set sizes, regardless of task condition (single, dual). Auditory performance (accuracy and response time) was significantly lower in the dual compared to single task (85.34% vs. 99.67%, p < 0.001), but performance was not affected by the complexity of the eCorsi path configuration. These findings suggest that set size and path complexity impose a different type of load on the working memory system and may rely on different resources.

Can divided attention at retrieval improve memory? Effects of target detection during recognition.

The attentional boost effect (ABE) is an improvement of memory under divided attention conditions in which stimulus encoding is enhanced when a target is detected in a simultaneous target-monitoring distracting task. Here we asked whether memory is similarly improved when the target-monitoring task occurs at the time of retrieval. In four experiments, participants encoded words under full attention then completed a recognition test under either divided attention, during which participants made recognition judgments while performing the target-monitoring task, or full attention, in which the target-monitoring task was not performed. Relative to distractor rejection, target detection increased hits and false alarms under divided attention with no net effect on discrimination. Targets and distractors had no effect on recognition under full attention. The target-related increase in hits and false alarms occurred regardless of whether the target-monitoring material matched or mismatched the test material and regardless of the target-to-distractor ratio and the target response. A change in bias accounts for the phenomenon, in which participants adopt a more lenient criterion for target-paired words than for distractor-paired words. The same divided attention manipulation that enhances memory at encoding does not similarly enhance memory at retrieval. Theoretical explanations are discussed.

An ecological investigation of the capacity to follow simultaneous speech and preferential detection of ones' own name.

Many situations require focusing attention on one speaker, while monitoring the environment for potentially important information. Some have proposed that dividing attention among 2 speakers involves behavioral trade-offs, due to limited cognitive resources. However the severity of these trade-offs, particularly under ecologically-valid circumstances, is not well understood. We investigated the capacity to process simultaneous speech using a dual-task paradigm simulating task-demands and stimuli encountered in real-life. Participants listened to conversational narratives (Narrative Stream) and monitored a stream of announcements (Barista Stream), to detect when their order was called. We measured participants' performance, neural activity, and skin conductance as they engaged in this dual-task. Participants achieved extremely high dual-task accuracy, with no apparent behavioral trade-offs. Moreover, robust neural and physiological responses were observed for target-stimuli in the Barista Stream, alongside significant neural speech-tracking of the Narrative Stream. These results suggest that humans have substantial capacity to process simultaneous speech and do not suffer from insufficient processing resources, at least for this highly ecological task-combination and level of perceptual load. Results also confirmed the ecological validity of the advantage for detecting ones' own name at the behavioral, neural, and physiological level, highlighting the contribution of personal relevance when processing simultaneous speech.

Information interference and loss in a dual task situation: Task 1, choice reaction time; Task 2, unspeeded recall.

The extraction and maintenance of second task information was explored in four dual task experiments. A variant of the psychological refractory period procedure was used with the first task, a speeded choice reaction to a tone and the second task, the unspeeded recall of letter triplets. Prior research had shown that recall accuracy dropped as the stimulus-onset asynchrony (SOA) decreased and task overlap increased. This could be due to interference with extracting perceptual information or to loss of the information while awaiting central resources. All four experiments showed evidence of interference, with the accuracy of recall for the first letter recalled relatively unaffected by SOA but with accuracy for later letters dropping as SOA decreased. Two of the experiments showed evidence for loss of second task information, with accuracy lower on trials with longer first task reaction times. The two other experiments showed loss of information when either the response complexity of Task 1 or the perceptual encoding difficulty was increased, increasing the processing time. The observed interference was attributed to slowed extraction of perceptual information. The observed loss was consistent with the encoded information being held in a fragile temporary store, susceptible to loss until consolidated into short-term memory. The evidence showed that the interference and the loss were independent processes.