Ulrich Mayr, Ph.D. - US grants

DESCRIPTION (provided by applicant): Mental sets are high-level representations that regulate lower-level selection of action. Despite the relevance of mental sets for coherent and purposeful action, relatively little is known about how they are selected and maintained in the face of internal or external interference. The central thesis of this proposal is that a better understanding of set-level processes can be attained by looking at interactions between mental sets and lower-level representations that constrain action in a bottom-up manner (i.e., locations of stimuli or response keys). Specifically, an automatic process is proposed that binds action-related lower-level representations (e.g., stimulus or response locations) to the mental set that is in control of the action. Bindings between set-level and low-level codes should usually be in the service of stable and coherent goal-directed action. However, such bindings may get in the way of efficient control when the association between low-level and high-level codes is ambiguous or highly variable. In particular, problems should occur when high-level control is impaired, as in some patient groups and, albeit to lesser degree also in the context of normal aging. Interference elicited from bindings between high-level and low-level codes may also lie at the heart of executive-control deficits observed in old adults. Therefore, in a majority of the proposed experiments I suggest to explore the hypothesis that old adults are much more negatively affected by ambiguous mappings between low-level and set-level aspects than young adults. Such a result would point to age-related difficulties with "keeping apart" high-level representations that share low-level elements. The proposed project promises a bridge between lower-level perceptual/attentional processes and executive processes as well as answers to the important question of age differences in executive control.

[unreadable] DESCRIPTION (provided by applicant): In democracies, individual decisions about voluntary giving and voting determine the type and amount of public goods. Understanding the neural processes that determine these public-good decisions is important for distinguishing between economic theories, which in turn can inform public policy. Recent neuroeconomic work has provided initial evidence that charitable giving may be driven by both "pure altruism" from experiencing increases to the public good regardless of their cause (Harbaugh, Mayr, & Burghart, under review), and "warm glow" from the agency effect of having chosen to give (Moll et la., 2006). This work has also shown that both activity in neural reward centers and in prefrontal regions independently predicts rates of giving to a charity. However, these results come from experiments with predominantly young adults. In practice, the level and type of public goods are determined by the decisions of older adults, who give more and vote more often than the young do. At the same time, there are known neuro-cognitive changes that occur with age that might affect economic decisions. [unreadable] [unreadable] Therefore, our first specific aim is to generalize and extend the existing results on the neural basis of public-good decisions across a large sample of young (age 25-35, n=50) and older adults (age 65- 75, n=50). The experimental protocol will include (a) a condition in which the subjects' payoff and the funding for a public good change in a mandatory, tax-like manner, (b) a voluntary-giving condition where people can accept transfers or not, and (c) a voting condition where majority rule among a group of participants determines if taxes will be levied on all and transferred to the charity. By considering both taxation and contributions from older segments of the society, this design covers the most critical sources of funding for public good. [unreadable] [unreadable] Our second specific aim is to test hypotheses about how neural and psychological changes across the life span translate into age-related changes in public-good decisions. For example, we predict that age-related decline in the ability to represent long-term goals in prefrontal cortex reduces the tendency to voluntarily provide or vote for public goods. However, age-related increases in warm- glow should exert an opposing positive effect on charitable-giving, but not on voting for taxation since, which provides less opportunity for warm glow. In our preliminary work, we also found that the mere opportunity of free choice triggered reward-center responses, but also "neural costs" in terms of substantial prefrontal activity. Given that prefrontal activity should be particularly demanding for old adults, we predict a reduction of the free-choice benefit in old adults, a result with potentially important consequences for comparing welfare benefits of taxation and giving across age groups. [unreadable] [unreadable] In preliminary work on young adults using economic experiments and fMRI scanning we have shown that it is possible to use neural activation in reward centers as a measure of the marginal rate of substitution between payoffs to oneself and to a charity, and that this measure predicts voluntary giving decisions. We propose to apply similar methods to a population of older subjects, and to both charitable giving and voting experiments. The objective is to see if economic models can explain these behaviors in the age groups that are most likely to give and to vote, and to see how age related changes in the brain are related to the observed changes in voting and charitable giving that occur with age. [unreadable] [unreadable] [unreadable]

Previous work has shown significant gender differences in the likelihoood to compete, with men being about twice as willing as women. More recent work suggests that these differences are driven by hormonal levels within an individual over time. This proposal will assess the relationship between hormones and both competitive and cooperative choices in a larger sample of men and women. Estrogen, progesterone (in women) and testosterone (in men and women) will be measured. A second study will add neuroimaging to test the hypothesis that gender and individual differences in competitive/cooperative choices result from hormonal modulation of activity in the brain's reward areas.

In terms of broader impacts, the results showing that men are more willing to compete than women have been and have been offered as a partial explanation for gender differences in outcomes in earnings and careers, including the scarcity of women in top executive and academic positions. This research will shed light on the causes of this result, and will help to evaluate the desirability and design of policy interventions to address such differences. A better understanding of the reasons for the wide variations in competitive behavior can also help individuals make more informed decisions about education and careers on their own as well.

DESCRIPTION (provided by applicant): Cognitive control over perception, thought, and action allows us to stay on task by keeping irrelevant information at bay. Whether control is successful or not largely depends on its dynamic properties. It needs to respond promptly to upcoming challenges, such as the need for flexible change, or to critical triggering events, such as the experience of conflict, but it also needs to be able to profit from past control events. Deficits i dynamic control are linked to prevalent clinical disorders, including attention deficit/hyperactiviy disorder, schizophrenia, or depressive symptoms. Moreover, control dynamics change across the adult life span in ways that are not well understood and that become particularly relevant in multi-tasking situations. In order to fully understand both intact and deficient control we need to track how the dynamics of control actually unfold over time. One central claim of this application is that eye tracking combined with adequate experimental paradigms and analytic techniques can provide dynamic information with the necessary precision. With these analytic tools, we examine here the general hypothesis that local control dynamics are profoundly affected global control settings. Specifically, we propose that control operates either in a maintenance mode, emphasizing stable behavioral patterns, or in an updating mode, emphasizing flexible change. Furthermore, we hypothesize that older adults' specific difficulties in multi-tasking situations arise from on overuse of the updating mode, which in turn has pervasive down-stream effects on local control phenomena. Using our eye-tracking based analytic tools; we test these general hypotheses in three different ways. First, we look at the precise short-term and longer-term temporal dynamics of adopting attentional settings and how these dynamics change as a function of control modes and age. Second, we examine for the first time how exactly interruptions affect cognitive activity in young and old adults. Third, we use eye-movements to directly assess when individuals engage in updating, thus allowing us to determine both antecedents and consequences of updating operations, as well as why older adults often dramatically over-engage in updating. Thus, this work addresses substantive questions about flexible control of thought and action and about the nature of age differences therein, but also brings a new set of methodological tools to the study of control. These tools will substantially enhance the precision with which researchers can capture the dynamic nature of control. Multitasking and interruptions are an omnipresent reality in the way we use modern digital media. Difficulties with multitasking in older adults contribute to the emerging digital divide, potentially constraining seniors' societal participation or access to important health-care tools. The information gained in this project will be useful for the design of multi-task environments or targeted training procedures.

Many of the most interesting human activities result from basic building blocks of behavior being structured into appropriate sequences. For example, speaking involves the combination of individual syllables into words and sentences; while, performing music involves the combination of notes into melody. The mind must represent these activities in terms of the hierarchical structures that combine the basic elements. Deficits in the ability to implement such structures, due to neurological disorders or aging, can have wide-ranging consequences for real-world functioning. Little is currently known about the mental representations that enable these sequential skills, or about how deficits in fluent sequential performance arise from disruptions to these representations. This project develops new methods for tracking these mental representations using electrophysiological signals recorded at the scalp (EEG). These methods will allow the pinpointing of the exact sources of individual and age-related differences and provide initial hints for the origin of deficits due to disease or brain insults. The project provides training and educational opportunities in sophisticated brain-imaging and data-analytic techniques for undergraduate and graduate students and contains a science-education component for underprivileged high-school students.

Cognitive scientists have long assumed that the critical, hierarchically-organized structures that support sequenced behaviors rely on a special set of mental representations that organize complex sequences into smaller parts (often referred to as chunks), or that mark the position within a chunk. Yet, because of their abstract nature, it has been very difficult to empirically track these hidden representations. The central hypothesis tested in this project is that rhythmic, electrophysiological signals contain robust information about how strongly these mental representations are activated at a given point in time. The planned experiments will examine the validity and robustness of new, EEG-based methods of tracking mental representations. Individual experiments will determine how exactly positions or chunks are represented and will test specific hypotheses about how individual or adult, age-related differences in cognitive resources (e.g., working-memory capacity) affect sequential representations. This project will equip researchers with refined theories about how sequential information is processed, and more generally with a novel set of analytic tools to characterize complex, cognitive performance.

While giving a presentation, we can speak freely from memory, but with some danger of losing our train of thought. Alternatively, we can rely on notes but risk a dysfluent and stilted presentation. This is one example of a type of decision that we need to make almost constantly; namely whether to rely on internal representations – that is, our knowledge and memory – or on information from the environment to guide our actions in the world. Suboptimal internal/external decisions can have important consequences. For example, previous work has shown that older adults have a strong tendency to search the environment for clues, even when they know perfectly well what to do next, which in turn leads to highly inefficient performance. Other vulnerable populations, such as individuals with attention deficit and hyperactivity disorder (ADHD), are likely to rely either too much or too little on external information and therefore can appear either distracted or hyper-focused. Adequate balancing between information sources is particularly important when people interact with modern and emerging technologies. For example, the increasing salience of information-rich displays in newer-model cars can pose a serious distraction danger for individuals with a strong tendency to rely primarily on external information. Yet, little is known about how internal/external decisions are being made, what kind of information is used for such decisions, and what exactly explains the suboptimal pattern in certain subgroups, such as in older adults or individuals with ADHD. The current project will use computational modeling and eye-tracking experiments to address this gap in the research literature. The long-term goal of this work is to inform technological solutions that support optimal internal/external information calibration, in particular in vulnerable populations.

The investigators use eye-tracking technology to monitor human participants in experimental situations that require performing one of several, simple tasks at any given point in time (e.g., responding to an arrow cue by indicating either its spatial location or the direction in which it is pointing). The currently most appropriate task can be determined either by utilizing the participant’s own knowledge (internal representations) or by examining simple reminders that indicate what to do next (external information). In Aim 1, the focus is on aspects that can “irrationally” influence the internal/external decision process and that “pull” the decision process towards relying on the environment, even when there is no objective need to use external information. For example, preliminary results have shown that both the saliency of external prompts and how frequently an individual had inspected external signals in the recent past, strongly influence the current use of information in the environment. Aim 2 focuses on situations in which there is an optimal balance between relying on external or internal information that participants need to try to achieve. The goal here is to determine to what degree external/internal decisions can be explained by a simple, rational model, and if not, how such a model would have to be amended in order to explain participants’ behavior. For example, preliminary evidence suggests that the subjective cost involved in making internal/external decisions itself is a factor that can steer individuals towards suboptimal patterns of information use. Aim 3 combines the experimental paradigms from the previous aims to characterize internal/external decisions within a larger, heterogenous sample of young and older adults, as well as individuals diagnosed with ADHD. The project also includes an education and outreach component directed towards increasing accessibility of STEM education for students with ADHD. Students from the University of Oregon’s School of Journalism will develop animated material about the nature of ADHD that will be tested in the University’s Accessible Education Center. Combined, this work will generate new theoretical and empirical knowledge about how individuals use internal versus external sources of information and will lead to a better understanding of suboptimal information use in vulnerable populations.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.