The use of Tholos software for combining measures of mental workload: Toward theoretical and methodological improvements

Mental workload is a concept central to a range of disciplines (including cognitive psychology and ergonomics) that has given rise to various theoretical and methodological debates. As a result, researchers have used a number of techniques for measuring mental workload. Traditionally, three categories of measurement technique have been recognized: performance measures (e.g., the dual-task paradigm), subjective measures (e.g., rating scales), and physiological measures (e.g., heart, respiration, and blink rates). Each technique has advantages and limitations; however, some limitations may prevent an accurate evaluation of the mental workload. In this article, we focus on the benefits of combining multiple measures of mental workload. However, because combining several techniques is a very complex process, we have developed the Tholos software in an attempt to reduce this complexity. This software package uses measures from each of the three categories: a dual-task paradigm with auditory signals; the National Aeronautics and Space Administration task load index (NASA-TLX) scale and its simplified version, the “raw” task load index (RTLX); and physiological (such as pupil-dilation) measurements with which our software can merge results from the dual-task paradigm. To illustrate the benefits of using Tholos, we describe a puzzle-solving experiment in which we combined multiple measures of mental workload. The results indicate the importance of combining multiple measures to build upon the theoretical and methodological foundations of mental workload.     

Division of Household and Childcare Labor and Relationship Conflict Among Low-Income New Parents

We examine the relationships among the division of housework and childcare labor, perceptions of its fairness for two types of family labor (housework and childcare), and parents’ relationship conflict across the transition to parenthood. Perceived fairness is examined as a mediator of the relationships between change in the division of housework and childcare and relationship conflict. Working-class, dual-earner couples (n?=?108) in the U.S Northeast were interviewed at five time points from the third trimester of pregnancy and across the first year of parenthood. Research questions addressed whether change in the division of housework and childcare across the transition to parenthood predicted mothers’ and fathers’ relationship conflict, with attention to the mediating role of perceived fairness of these chores. Findings for housework indicated that perceived fairness was related to relationship conflict for mothers and fathers, such that when spouses perceived the change in the division of household tasks to be unfair to either partner, they reported more conflict, However, fairness did not significantly mediate relations between changes in division of household tasks and later relationship conflict. For childcare, fairness mediated relations between mothers’ violated expectations concerning the division of childcare and later conflict such that mothers reported less conflict when they perceived the division of childcare as less unfair to themselves; there was no relationship for fathers. Findings highlight the importance of considering both childcare and household tasks independently in our models and suggest that the division of housework and childcare holds different implications for mothers’ and fathers’ assessments of relationship conflict.     

Perceptual span,visual span,and visual attention span: Three potential ways to quantify limits on visual processing during reading

Many lines of evidence have revealed limitations of the human visual system, most notably that only a portion of available information is processed in a single glance. A degree of conceptual confusion has emerged, however, regarding the underlying concepts or mechanisms explaining limited visual processing in reading; perceptual span, visual span, or visual attention span. While the original definitions of these three concepts are clear and well-differentiated, they are routinely used inconsistently in the literature. The primary goal of the present review is to re-specify these three concepts in terms of what they correspond to and how they are determined. Further, we investigate whether these three spans refer to vision-related measurements and/or are based on general cognitive abilities. This review should lead to a better understanding of the involvement of visual functions in reading performance.     

Adolescents' evaluations of those who challenge exclusive and inclusive peer norms

Early and middle adolescents' judgements and reasonings about peers who challenge exclusive and inclusive peer group norms were examined across three studies with varying intergroup contexts. Study 1 participants included (N = 199) non-Arab American participants responding to an Arab American/non-Arab American intergroup context. Study 2 included (N = 123) non-Asian and (N = 105) Asian American participants responding to an Asian/non-Asian American intergroup context. Study 3 included (N = 275) Lebanese participants responding to an American/Lebanese intergroup context. Across all three studies participants responded to ingroup and outgroup deviant group members who challenged their peer groups to either include or exclude an outgroup peer with similar interests. Findings indicated that adolescents approved of peers who challenged exclusive peer norms and advocated for inclusion of an ethnic and cultural outgroup, and disapproved of peers who challenged inclusive group norms and advocated for exclusion. Non-Arab and non-Asian American adolescents displayed ingroup bias when evaluating a deviant advocating for exclusion. Additionally, age differences were found among Asian American adolescents. Findings will be discussed in the light of intergroup research on those who challenge injustices.     

When to intervene and take a stand: Evaluating bystander roles in intergroup name-calling contexts

Children (n = 121, M = 9.86 years, SD = 0.64) and adolescents (n = 101, M = 12.84 years, SD = 0.69) evaluated proactive and passive bystander behaviour to intergroup name-calling (N = 222, 54% female). Scenarios depicted ingroup perpetrators and outgroup victims who were from a stigmatized group (ethnicity) or a non-stigmatized group (school affiliation), with bystanders depicted as being proactive (intervening to help) or passive (failing to challenge the aggression), counter to their own group's norm. Children and adolescents personally evaluated proactive bystanders more favourably than passive bystanders. However, adolescents, more than children, expected their peers to be more positive about proactive bystanders than passive bystanders in the stigmatized context. Results are discussed in terms of the complexities of bystander decisions and implications for anti-bullying interventions.     

Evidence for a role of action in colour perception

Action is not usually considered to play a role in colour perception. However, sensorimotor theories of perception (eg O'Regan and No?, 2001 Behavior and Brain Science 24 939-1011) suggest that, on the contrary, the transformations created by action in the sensory input are a necessary condition for all perception. In the case of colour vision, eye movements may explain how a retina with significant irregularities in resolution and cone arrangement (Roorda and Williams, 1999 Nature 397 520-522) could permit the perception of a richly coloured world (Clark and O'Regan, 2000 15th International Conference on Pattern Recognition volume 2: Pattern Recognition and Neural Networks pp 503-506; Skaff et al, 2002 16th International Conference on Pattern Recognition volume 2, pp 681-684). We provide evidence that perception of colour is modified when an artificial coupling is introduced linking eye movements and colour changes. After 40 min of wearing left-field-blue/right-field-yellow spectacles, observers' colour vision adapts so that, after removing the spectacles, white patches seem to become bluer when the eyes move rightwards and yellower when the eyes move leftwards. This induced dependence of colour perception on the direction of eye saccade is shown to be related to the amount of eye movements during exposure. This result, which cannot be explained either by retinal adaptation, or by a conditioned association between colour and side, constitutes first clear evidence for a role of eye movements in perceived colour and argues for the involvement in colour perception of neural mechanisms continuously tuned to sensorimotor contingencies.     

Truth table tasks: Irrelevance and cognitive ability

Two types of truth table task are used to examine people's mental representation of conditionals. In two within-participants experiments, participants either receive the same task-type twice (Experiment 1) or are presented successively with both a possibilities task and a truth task (Experiment 2). Experiment 3 examines how people interpret the three-option possibilities task and whether they have a clear understanding of it. The present study aims to examine, for both task-types, how participants' cognitive ability relates to the classification of the truth table cases as irrelevant, and their consistency in doing so. Looking at the answer patterns, participants' cognitive ability influences their classification of the truth table cases: A positive correlation exists between cognitive ability and the number of false-antecedent cases classified as “irrelevant”, both in the possibilities task and the truth task. This favours a suppositional representation of conditionals.     

Prospective memory across the lifespan: Investigating the contribution of retrospective and prospective processes

Prospective memory performance follows an inverted U-shaped function across the lifespan. Findings on the relative contribution of purely prospective memory and retrospective memory processes within prospective memory to this trajectory are scarce and inconclusive. We analyzed age-related differences in prospective memory performance across the lifespan in a cross-sectional design including six age groups (N = 99, 7–83 years) and investigated possible mechanisms by experimentally disentangling the relative contributions of retrospective memory and purely prospective memory processes. Results confirmed the inverted U-shaped function of prospective memory performance across the lifespan. A significant interaction between process type and age group was observed indicating differential relative contributions of retrospective memory and purely prospective memory processes on the development of prospective memory performance. Our results showed that mainly the pure prospective memory processes within prospective memory lead to lower prospective memory performance in young children and old adults. Moreover, the relative contributions of the retrospective memory and purely prospective memory processes are not uniform at both ends of the lifespan, i.e., in later adulthood the purely prospective memory processes seem to determine performance to an even greater extent than in childhood. Nevertheless, age effects were also observed in the retrospective component which thus contributed to the prospective memory performance differences between the age groups.     

Diet and gender influences on processing and discrimination of speech sounds in 3- and 6-month-old infants: a developmental ERP study

Early post-natal nutrition influences later development, but there are no studies comparing brain function in healthy infants as a function of dietary intake even though the major infant diets differ significantly in nutrient composition. We studied brain responses (event-related potentials; ERPs) to speech sounds for infants who were fed either breast milk (BF), milk-based formula (MF), or soy formula (SF) during the first 6 months of life. Two syllables presented in an oddball paradigm elicited a late positive wave (P350) from temporal and frontal brain regions involved in language processes. All groups showed significantly greater response amplitudes to the infrequent syllable across sites at 3 months and frontally at 6 months, but significant discrimination at temporal sites was only observed at 6 months in BF infants. Decreases in response amplitudes from 3 to 6 months were greater for the frequently presented syllable, most prominent in BF infants, and greater in females than males. The results indicate greater syllable discrimination in BF than formula-fed infants, but whether this can be attributed to dietary influences alone remains unclear. Feeding method and background factor differences between breastfed and formula-fed infants may also contribute to the observed differences. The general absence of differences between formula-fed groups is notable and suggests that milk-based formula and soy formula equally support brain development and function during the first post-natal 6 months. Finally, the results indicate gender differences in the development of neural and temporal processes involved in sensory discrimination, and suggest that at 6 months these processes are better developed in females.