Uma R. Karmarkar
Assistant Professor of Business Administration
Uma Karmarkar is an assistant professor of business administration in the Marketing Unit and teaches the first year marketing course in the required MBA curriculum.
Professor Karmarkar's research examines the neural and psychological factors that underlie consumer decision-making. Some of her recent work targets how timing and/or uncertainty influence perceptions of value. Her findings have been published in the Journal of Consumer Research, Neuron, and Learning and Memory. In addition, her work has attracted coverage by media outlets including Newsweek, Reuters, Scientific American, and The New York Times.
Professor Karmarkar holds two Ph.D. degrees – one in neuroscience from the University of California, Los Angeles, and more recently, another in marketing from the Stanford University Graduate School of Business.
Should You Sleep on It? The Effects of Overnight Sleep on Subjective Preference-based Choice
Conventional wisdom and studies of unconscious processing suggest that sleeping on a choice may improve decision-making. Though sleep has been shown to benefit several cognitive tasks, including problem solving, its impact on everyday choices remains unclear. Here we explore the effects of "sleeping on it" on preference-based decisions among multiple options. In two studies, individuals viewed several attributes describing a set of items and were asked to select their preferred item after a 12-hour interval that either contained sleep or was spent fully awake. After an overnight period including sleep, individuals showed increases in positive perceptions of the choice set. This finding contrasts with previous research showing that sleep selectively enhances recall for negative information. In addition, this increase in positive recall did not translate into a greater desire to purchase their preferred item or into an overall benefit for choice satisfaction. Time-of-day controls were used to confirm that the observed effects could not be explained by circadian influences. Thus we show that people may feel more positive about the choice options, but not more confident about the choice after "sleeping on" a subjective decision. We discuss how the valence of recalled choice set information may be important in understanding the effects of sleep on multi-attribute decision making, and suggest several avenues for future research.
Keywords: decision making;
Asymmetric Effects of Favorable and Unfavorable Information on Decision-making Under Ambiguity
Most daily decisions involve uncertainty about outcome probabilities arising from incomplete knowledge, i.e., ambiguity. We explore how the addition of partial information affects these types of choices using theoretical and empirical methods. Our experiments in both gain and loss domains demonstrate that when such information supports a favorable outcome, it strongly increases valuation of an ambiguous financial prospect. However, when information supports an unfavorable outcome, it has significantly less impact. We find that two mechanisms drive this asymmetry. First, unfavorable information decreases estimates of a good outcome occurring but also reduces aversive uncertainty. These factors act in opposition, minimizing the effects of unfavorable information. Second, when information can be subjectively interpreted, unfavorable information is less likely to be integrated into evaluations. Our findings reveal mechanisms not captured by traditional models of decision making under uncertainty and highlight the importance of increasing the salience of unfavorable information in uncertain contexts to promote unbiased decision making.
Decision Choices and Conditions;
Outcome or Result;
BYOB: How Bringing Your Own Shopping Bags Leads to Treating Yourself, and the Environment
As concerns about pollution and climate change have become more central in public discourse, shopping with reusable grocery bags has been strongly promoted as environmentally and socially conscious. In parallel, firms have joined policy makers in using a variety of initiatives to reduce the use of plastic bags. However, little is known about how these initiatives might alter consumers' in-store behavior. Using scanner panel data from a single California location of a major grocery chain, and completely controlling for consumer heterogeneity, we demonstrate that bringing your own bags simultaneously increases purchases of environmentally friendly as well as indulgent (hedonic) items. We use experimental methods to further demonstrate causality and to consider the effects of potential moderators. These findings have implications for decisions related to product pricing, placement and assortment, store layout, and the choice of strategies to increase the use of reusable bags.
Keywords: grocery shopping;
Cost Conscious? The Neural and Behavioral Impact of Price Primacy on Decision-Making
Price is a key factor in most purchases, but it can be presented at different stages of decision making prior to a purchase. We examine the sequence-dependent effects of price and product information on the decision-making process at both neural and behavioral levels. During functional magnetic resonance imaging, the price of a product was shown to participants either before or after the product itself was presented. Early exposure to price, or price primacy, altered the process of valuation, as seen via altered patterns of activity in medial prefrontal cortex immediately prior to purchase decisions. Specifically, whereas viewing products first resulted in evaluations strongly related to products' attractiveness or desirability, viewing prices first appeared to promote overall evaluations related to products' monetary worth. Consistent with this framework, we show that price primacy can increase purchase of bargain priced products when their worth is easily recognized. Together, these results suggest that price primacy highlights considerations of product worth and can thereby influence purchasing.
Keywords: consumer behavior;
Decision Choices and Conditions;
Advancing Consumer Neuroscience
In the first decade of consumer neuroscience, strong progress has been made in understanding how neuroscience can inform consumer decision making. Here, we sketch the development of this discipline and compare it to that of the adjacent field of neuroeconomics. We describe three new frontiers for ongoing progress at both theoretical and applied levels. First, the field will broaden its boundaries to include genetics and molecular neuroscience, each of which will provide important new insights into individual differences in decision making. Second, recent advances in computational methods will improve the accuracy and out-of-sample generalizability of predicting decisions from brain activity. Third, sophisticated meta-analyses will help consumer neuroscientists to synthesize the growing body of knowledge, providing evidence for consistency and specificity of brain activations and their reliability as measurements of consumer behavior.
Keywords: Consumer neuroscience;
Smidts, Ale, Ming Hsu, Alan G. Sanfey, Maarten A. S. Boksem, Richard B. Ebstein, Scott A. Huettel, Joe W. Kable, et al. "Advancing Consumer Neuroscience." Marketing Letters
25, no. 3 (September 2014): 257–267. View Details
Defining the Contributions of Network Clock Models to Millisecond Timing
Believe Me, I Have No Idea What I Am Talking About: The Effects of Source Certainty on Consumer Involvement and Persuasion
This research explores the effect of source certainty-that is, the level of certainty expressed by a message source-on persuasion. The authors propose an incongruity hypothesis, suggesting that source certainty effects depend on perceived source expertise. In three experiments, consumers receive persuasive messages from sources of varying expertise and certainty. Across studies, low expertise sources violate expectancies, stimulate involvement, and promote persuasion when they express certainty, whereas high expertise sources violate expectancies, stimulate involvement, and promote persuasion when they express uncertainty. Thus, nonexpert (expert) sources can gain interest and influence by expressing certainty (uncertainty).
Experience and Expertise;
Risk and Uncertainty;
Power and Influence;
Evaluating Dedicated and Intrinsic Models of Temporal Encoding by Varying Context
Timing in the Absence of Clocks: Encoding Time in Neural Network States
Experience Dependent Plasticity in Adult Visual Cortex
Temporal Specificity of Perceptual Learning in an Auditory Discrimination Task
Mechanisms and Significance of Spike-timing Dependent Plasticity
How Do We Tell Time?
Functional MRI in Children with Epilepsy
Keywords: Health Disorders;
Consumer Neuroscience: Revealing Meaningful Relationships Between Brain and Consumer Behavior
The goal of this chapter is to give an overview of the nascent field of consumer neuroscience and discuss when and how it is useful to integrate the "black box" of the consumer's brain into consumer psychology. To reach this goal, we first briefly outline several methods that are part of the consumer neuroscience toolkit and how they are currently used. We then provide an overview of the research that has laid the foundation of consumer neuroscience, showcasing studies that highlight the concrete promises of applying neuroscience to consumer psychology. Building from this, we focus on using brain data to predict consumer behavior, a topic that has recently generated a lot of excitement from academics and practitioners alike. Last, we take a look at newer developments we think will have an important future impact on our understanding of consumer psychology.
Appetite, Consumption, and Choice in the Human Brain
Although linked, researchers have long distinguished appetitive from consummatory phases of reward processing. Recent improvements in the spatial and temporal resolution of neuroimaging techniques have allowed researchers to separately visualize different stages of reward processing in humans. These techniques have revealed that evolutionarily conserved circuits related to affect generate distinguishable appetitive and consummatory signals, and that these signals can be used to predict choice and subsequent consumption. Review of the literature surprisingly suggests that appetitive rather than consummatory activity may best predict future choice and consumption. These findings imply that distinguishing appetite from consumption may improve predictions of future choice and illuminate neural components that support the process of decision making.
Knutson, Brian, and Uma R. Karmarkar. "Appetite, Consumption, and Choice in the Human Brain."
Chap. 9 in The Interdisciplinary Science of Consumption
, edited by Stephanie D. Preston, Morten L. Kringelbach, and Brian Knutson, 163–184. Cambridge, MA: MIT Press, 2014. View Details
Customer Experience and Service Design
While services already dominate economic activity in all major economies in the world, there has been curiously little investigation into many aspects of service management. For example, while product design and development have received a great deal of attention, the subject of service design has not been very visible in the research literature. There are many individual designers and design firms famous for their contributions to product design, but the same cannot be said for services. Undoubtedly many examples of outstanding service design exist, and we will mention some later in this work. But recognition of service design as a discipline, as a management function, or a job description still seems to be rare.