Alinda Friedman

Hemispheres as Independent Resource Systems: Limited-Capacity Processing and Cerebral Specialization.

In this article, we develop as framework for understanding how cerebral specialization of function contributes to the flexibility of human information processing. We propose that the left and right hemispheres together form a system of two mutually inaccessible and finite pools of resources. Further, we propose that these two types of resources cannot be made available in different amounts at any given time. This framework is essentially a special case of a multiple-resources model of limited-capacity information processing. It accounts for a broad range of data from experiments involving perceptual and cognitive information processing, control of motor performance, and changes in electrical activity of the brain. It also provides insights into why the cerebral specialization literature has been plagued with problems that have made theorizing so difficult. In addition, the theory provides insights into mechanisms that might be responsible for patterns of task interference that are not easily handled by an information-processing model in which processes compete for supplies from a single pool of undifferentiated resources. Thus, the framework we are proposing has important theoretical and methodological implications for researchers in both divided attention and cerebral specialization.

Measuring and predicting visual fidelity

This paper is a study of techniques for measuring and predicting visual fidelity. As visual stimuli we use polygonal models, and vary their fidelity with two different model simplification algorithms. We also group the stimuli into two object types: animals and man made artifacts. We examine three different experimental techniques for measuring these fidelity changes: naming times, ratings, and preferences. All the measures were sensitive to the type of simplification and level of simplification. However, the measures differed from one another in their response to object type. We also examine several automatic techniques for predicting these experimental measures, including techniques based on images and on the models themselves. Automatic measures of fidelity were successful at predicting experimental ratings, less successful at predicting preferences, and largely failures at predicting naming times. We conclude with suggestions for use and improvement of the experimental and automatic measures of visual fidelity.

Bidimensional regression: Assessing the configural similarity and accuracy of cognitive maps and other two-dimensional data sets

Bidimensional regression is a method for comparing the degree of resemblance between 2 planar configurations of points and, more generally, for assessing the nature of the geometry (Euclidean and non-Euclidean) between 2-dimensional independent and dependent variables. For example, it can assess the similarity between location estimates from different tasks or participant groups, measure the fidelity between cognitive maps and actual locations, and provide parameters for psychological process models. The authors detail the formal similarity between uni- and bidimensional regression, provide computational methods and a new index of spatial distortion, outline the advantages of bidimensional regression over other techniques, and provide guidelines for its use. The authors conclude by describing substantive areas in psychology for which the method would be appropriate and uniquely illuminating.

Memorial Comparisons without the "Mind's Eye"

Subjects compared pairs of nonconcrete and nonimageable words along a dimension which has no physical analog—the Evaluative dimension of the semantic differential. Their reaction time to do so was an inverse logarithmic function of the difference between the numerical “goodness” values they had assigned to the words. This result held in both a finite set (Experiment 1) and an infinite set (Experiment 2) paradigm, thus precluding the possibility that only ordinal or rank-order information was used. In addition, the distance effect was apparent regardless of whether an individuals magnitude estimates were normative or idiosyncratic. Further, the serial position and semantic congruity effects obtained in both experiments mirrored those which are typically found when imageable items and/or dimensions are used in this task. These data constrain the use of analog representational structures as constructs underlying the relationship between symbolic distance and reaction time.

Systematic review of sedentary behavior and cognitive development in early childhood

OBJECTIVE To comprehensively review observational and experimental studies examining the relationship between sedentary behavior and cognitive development during early childhood (birth to 5years). METHOD Electronic databases were searched in July, 2014 and no limits were imposed on the search. Included studies had to be peer-reviewed, published, and meet the a priori determined population (apparently healthy children aged birth to 5years), intervention (duration, types, and patterns of sedentary behavior), comparator (various durations, types, or patterns of sedentary behavior), and outcome (cognitive development) study criteria. Data extraction occurred in October and November 2014 and study quality and risk of bias were assessed in December 2014. RESULTS A total of 37 studies, representing 14,487 participants from nine different countries were included. Thirty-one studies used observational study designs and six studies used experimental study designs. Across study designs, increased or higher screen time (most commonly assessed as television viewing (TV)), reading, child-specific TV content, and adult-specific TV content had detrimental (negative) associations with cognitive development outcomes for 38%, 0%, 8%, and 25% of associations reported, respectively, and beneficial (positive) associations with cognitive development outcomes for 6%, 60%, 13%, and 3% of associations reported, respectively. Ten studies were moderate quality and 27 studies were weak quality. CONCLUSIONS The type of sedentary behavior, such as TV versus reading, may have different impacts on cognitive development in early childhood. Future research with reliable and valid tools and adequate sample sizes that examine multiple cognitive domains (e.g., language, spatial cognition, executive function, memory) are needed. Registration no. CRD42014010004.

Global-scale location and distance estimates: common representations and strategies in absolute and relative judgments.

The authors examined whether absolute and relative judgments about global-scale locations and distances were generated from common representations. At the end of a 10-week class on the regional geography of the United States, participants estimated the latitudes of 16 North American cities and all possible pairwise distances between them. Although participants were relative experts, their latitude estimates revealed the presence of psychologically based regions with large gaps between them and a tendency to stretch North America southward toward the equator. The distance estimates revealed the same properties in the representation recovered via multidimensional scaling. Though the aggregated within- and between-regions distance estimates were fitted by Stevenss law (S. S. Stevens, 1957), this was an averaging artifact: The appropriateness of a power function to describe distance estimates depended on the regional membership of the cities. The authors conclude that plausible reasoning strategies, combined with regionalized representations and beliefs about the location of these relative to global landmarks, underlie global-scale latitude and distance judgments.

Penetrating the geometric module: catalyzing children's use of landmarks.

We used a reference memory paradigm to examine whether 4- and 5-year-old children could be trained to use landmark features to relocate targets after disorientation. In Experiment 1, half of the children were pretrained in a small equilateral triangle-shaped room. Each of the three walls was a different color, and the target was always in the middle of the yellow wall. These children and a control group were tested in a small rectangular room with three white walls and one yellow wall; the target was placed in one of the corners. Children with pretraining responded more frequently to the correct corner than to the diagonally congruent corner on their first set of four trials in the rectangular room, whereas the children in the control group used geometric cues exclusively. Three additional groups of children (Experiment 2) showed that the use of landmark features--both salient and subtle--can be learned in as few as four practice trials in a small rectangular room. The data support the view that both geometry and landmark features are adaptively combined in the same representation.

Dividing Attention Between the Hands and the Head: Performance Trade-Offs Between Rapid Finger Tapping and Verbal Memory

We tested a multiple resources approach to time-sharing performance which assumes that each cerebral hemisphere controls its own set of processing resources that it cannot share with the other hemisphere. Right-handed men performed a verbal memory task while concurrently tapping the index finger of either hand as rapidly as possible. Task priority was manipulated with a payoff scheme. Subjects remembered more on the verbal task when concurrently tapping with their left hands than when tapping with their right hands, and their memory performance was much better when the memory task was emphasized than when the tapping task was emphasized, regardless of hand. For the tapping task, decrements from baseline tapping rates and trade-offs between tasks were equal for both hands when subjects were reading the to-be-remembered words aloud. In contrast, during the retention interval, decrements were larger for the right hand than the left, and there were no task trade-offs. The data were interpreted to mean that on right-hand trials, both tasks required exclusively left-hemisphere resources, whereas on left-hand trials, righthemisphere resources were required to execute the tapping movements per se, but left-hemisphere resources were necessary to coordinate those movements with the movements required for overt speech. The data suggest that cognitive and motor resources may be independent types and thus underscore the importance of manipulating task priority to obtain an accurate picture of a tasks resource requirements.

Systematic review of physical activity and cognitive development in early childhood

OBJECTIVES To comprehensively review all observational and experimental studies examining the relationship between physical activity and cognitive development during early childhood (birth to 5 years). DESIGN Systematic review. METHODS Electronic databases were searched in July, 2014. No study design, date, or language limits were imposed on the search. Included studies had to be published, peer reviewed articles that satisfied the a priori determined population (apparently healthy children aged birth to 5 years), intervention (duration, intensity, frequency, or patterns of physical activity), comparator (various durations, intensity, or patterns of physical activity), and outcome (cognitive development) study criteria. Study quality and risk of bias were assessed in December 2014. RESULTS A total of seven studies, representing 414 participants from five different countries met the inclusion criteria, including two observational and five experimental studies. Six studies found increased or higher duration/frequency of physical activity had statistically significant (p<0.05) beneficial effects on at least one cognitive development outcome, including 67% of the outcomes assessed in the executive function domain and 60% in the language domain. No study found that increased or higher duration/frequency of physical activity had statistically significant detrimental effects on cognitive development. Six of the seven studies were rated weak quality with a high risk of bias. CONCLUSIONS This review provides some preliminary evidence that physical activity may have beneficial effects on cognitive development during early childhood. Given the shortage of the information and the weak quality of available evidence, future research is needed to strengthen the evidence base in this area.

Task-sharing within and between hemispheres: a multiple-resources approach

The assumption that there are qualitatively different information-processing resources has important implications for human performance. We first review some issues involved in isolating independent resource types and then present our own model, which proposes that each cerebral hemisphere accesses an independent resource supply that can be shared among many types of tasks, including those with no obvious similarities. The available evidence indicates that the model is viable. Its implications for human factors are, first, that tasks mayor may not overlap in their resource demand, and the only way to determine this reliably is with a task emphasis manipulation. Second, neither modality (visual versus auditory) nor code (verbal versus nonverbal) predicts interference as well as the particular hemisphere(s) involved in processing. Limitations of a multiple-resources approach are also discussed.