Konstantinos Tsetsos

• PhD, Cognitive Science, UCL
• Senior Lecturer at University of Bristol

Investigation into the neural and computational bases of decision-making has proceeded in two parallel but distinct streams. Perceptual decision-making (PDM) is concerned with how observers detect, discriminate, and categorize noisy sensory information. Economic decision-making (EDM) explores how options are selected on the basis of their reinforce...

Human choice behavior exhibits many paradoxical and challenging patterns. Traditional explanations focus on how values are represented, but little is known about how values are integrated. Here we outline a psychophysical task for value integration that can be used as a window on high-level, multiattribute decisions. Participants choose between alt...

Recent research has investigated the process of integrating perceptual evidence toward a decision, converging on a number of sequential sampling choice models, such as variants of race and diffusion models and the non-linear leaky competing accumulator (LCA) model. Here we study extensions of these models to multi-alternative choice, considering ho...

A central puzzle for theories of choice is that people's preferences between options can be reversed by the presence of decoy options (that are not chosen) or by the presence of other irrelevant options added to the choice set. Three types of reversal effect reported in the decision-making literature, the attraction, compromise, and similarity effe...

The way humans and other animals represent the values of alternatives is context-dependent, as it can be distorted by inferior alternatives that are immediately available for choice (immediate context); or that were encountered in previous episodes (temporal context). Yet, the extent to which the immediate and temporal context (co-) shape context-d...

Experimental research in decision making often relies on tasks that provide participants with all the information they need to make their decisions. Here, we consider the process by which decision makers seek information about their choice alternatives when it is not immediately provided. Recent advances in computational theories have proposed that...

Early foundational work in the decision sciences carefully balanced empirical observations and theoretical explanations. Dating back to Daniel Bernoulli, a handful of behavioral regularities observed in theoretical lotteries ignited the refinement of normative theories and the development of new descriptive frameworks of valuation and choice. Howev...

Contrary to the predictions of normative theories, choices between two high-value alternatives can be biased by the introduction of a third low-value alternative (dubbed the distractor effect). Normalization-based theories, like divisive and range normalization, explain different forms of the distractor effect by suggesting that the value of each a...

Experimental research in decision-making often relies on tasks that provide participants with all the information they need to make their decisions. Here we consider the process by which decision-makers seek information about their choice alternatives when it is not immediately provided. Recent advances in computational theories have proposed that...

During decision-making attention plays a pivotal role by guiding information sampling between alternatives. We need to optimally encode different options and compare between them. So far the role of attention in decision-making has only been addressed through saccadic displacements. However, looking is not always attending and attending not always...

Human economic decisions are highly sensitive to contexts. Deciding between two competing alternatives can be notoriously biased by their overall value ('magnitude effect') or by a third decoy option ('distractor effect'). Some prominent explanations appeal to diminishing value sensitivity and divisive normalization in value representations, i.e.,...

Choice transitivity (CT) is a central axiom of rationality. While violating CT is rare, there have been reports of such violations (Tversky, 1969; Tsetsos et al., 2016; but see Regenwetter, 2011). If humans indeed violate CT, an important challenge is understanding the conditions that promote intransitive choices and the mechanisms that support it....

Why do we sometimes spend too much time on seemingly impossible-to-solve tasks instead of just moving on? Masís et al. provide a new perspective on the speed-accuracy trade-off (SAT), showing that, although prolonging deliberation looks suboptimal in the short run, it is a long-term investment that helps organisms reach proficient performance more...

Decisions between two economic goods can be swayed by a third unavailable 'decoy' alternative, which does not compete for choice, notoriously violating the principles of rational choice theory. Although decoy effects typically depend on the decoy's position in a multiattribute choice space, recent studies using risky prospects (i.e., varying in rew...

A central goal in Cognitive Science is understanding the mechanisms that underlie cognition. Here, we contend that Cognitive Science, despite intense multidisciplinary efforts, has furnished surprisingly few mechanistic insights. We attribute this slow mechanistic progress to the fact that cognitive scientists insist on performing underdetermined e...

When making decisions, animals must trade off the benefits of information harvesting against the opportunity cost of prolonged deliberation. Deciding when to stop accumulating information and commit to a choice is challenging in natural environments, where the reliability of decision-relevant information may itself vary unpredictably over time (var...

Influential theories postulate distinct roles of catecholamines and acetylcholine in cognition and behavior. However, previous physiological work reported similar effects of these neuromodulators on the response properties (specifically, the gain) of individual cortical neurons. Here, we show a double dissociation between the effects of catecholami...

Many decisions result from the accumulation of decision-relevant information (evidence) over time. Even when maximizing decision accuracy requires weighting all the evidence equally, decision-makers often give stronger weight to evidence occurring early or late in the evidence stream. Here, we show changes in such temporal biases within participant...

Significance Imagine you are deciding between two goods: A is simple but inexpensive, B is luxurious but more costly. Introducing a less advantageous option (e.g., lower quality than A, same price) should not alter your choice between A and B. However, this principle is often violated; three classic biases known as “decoy effects” have been identif...

Influential accounts postulate distinct roles of the catecholamine and acetylcholine neuromodulatory systems in cognition and behavior. But previous work found similar effects of these modulators on the response properties of individual cortical neurons. Here, we report a double dissociation between catecholamine and acetylcholine effects at the le...

Decisions are often made by accumulating ambiguous evidence over time. The brain’s arousal systems are activated during such decisions. In previous work in humans, we found that evoked responses of arousal systems during decisions are reported by rapid dilations of the pupil and track a suppression of biases in the accumulation of decision-relevant...

Decisions are often made by accumulating ambiguous evidence over time. The brain’s arousal systems are activated during such decisions. In previous work in humans, we found that evoked responses of arousal systems during decisions are reported by rapid dilations of the pupil and track a suppression of biases in the accumulation of decision-relevant...

Decisions are often made by accumulating ambiguous evidence over time. The brain’s arousal systems are activated during such decisions. In previous work in humans, we found that evoked responses of arousal systems during decisions are reported by rapid dilations of the pupil and track a suppression of biases in the accumulation of decision-relevant...

Human decisions can be biased by irrelevant information. For example, choices between two preferred alternatives can be swayed by a third option that is inferior or unavailable. Previous work has identified three classic biases, known as the attraction, similarity and compromise effects, which arise during choices between economic alternatives defi...

Decisions are typically made after integrating information about multiple attributes of alternatives in a choice set. Where observers are obliged to consider attributes in turn, a computational framework known as "selective integration" can capture salient biases in human choices. The model proposes that successive attributes compete for processing...

Decisions do not occur in isolation, but are embedded in sequences of other decisions, often pertaining to the same source of evidence. Here, we characterized the impact of intermittent choices on the accumulation of a protracted stream of decision-relevant evidence towards a final decision. Human participants performed two versions, based on perce...

When making decisions, animals must trade off the benefits of information harvesting against the opportunity cost of prolonged deliberation. Deciding when to stop accumulating information and commit to a choice is challenging in natural environments, where the reliability of decision-relevant information may itself vary unpredictably over time (var...

Human choice behavior shows a range of puzzling anomalies. Even simple binary choices are modified by accept/reject framing and by the presence of decoy options, and they can exhibit circular (i.e., intransitive) patterns of preferences. Each of these phenomena is incompatible with many standard models of choice but may provide crucial clues concer...

Perceptual choices depend not only on the current sensory input but also on the behavioral context, such as the history of one’s own choices. Yet, it remains unknown how such history signals shape the dynamics of later decision formation. In models of decision formation, it is commonly assumed that choice history shifts the starting point of accumu...

Decisions are typically made after integrating information about multiple attributes of alternatives in a choice set. The computational mechanisms by which this integration occurs have been a focus of extensive research in humans and other animals. Where observers are obliged to consider attributes in turn, a framework known as “selective integrati...

A bstract Perceptual choices depend not only on the current sensory input, but also on the behavioral context. An important contextual factor is the history of one’s own choices. Choice history often strongly biases perceptual decisions, and leaves traces in the activity of brain regions involved in decision processing. Yet, it remains unknown how...

We show that the benchmark Bayesian framework that Rahnev & Denison (R&D) used to assess optimality is actually suboptimal under realistic assumptions about how noise corrupts decision making in biological brains. This model is therefore invalid qua normative standard. We advise against generally forsaking optimality and argue that a biologically c...

Humans display a number of puzzling choice patterns that contradict basic principles of rationality. For example, they show preferences that change as a result of task framing or of adding irrelevant alternatives into the choice set. A recent theory has proposed that such choice and risk biases arise from an attentional mechanism that increases the...

Neuromodulatory brainstem systems controlling the global arousal state of the brain are phasically recruited during cognitive tasks. The function of such task-evoked neuromodulatory signals is debated. Here, we uncovered a general principle of their function, across species and behavioral tasks: counteracting maladaptive biases in the accumulation...

People's assessments of the state of the world often deviate systematically from the information available to them [1]. Such biases can originate from people's own decisions: committing to a categorical proposition, or a course of action, biases subsequent judgment and decision-making. This phenomenon, called confirmation bias [2], has been explain...

In accounting for phenomena present in preferential choice experiments, modern models assume a wide array of different mechanisms such as lateral inhibition, leakage, loss aversion, and saliency. These mechanisms create interesting predictions for the dynamics of the deliberation process as well as the aggregate behavior of preferential choice in a...

When making decisions humans often violate the principles of rational choice theory. Recent experiments, involving rapid experiential decisions, uncovered a mechanism that is responsible for various rationality violations. According to this selective gating mechanism, incoming value samples are accumulated across time, but prior to their accumulati...

People often have to make decisions based on many pieces of information. Previous work has found that people are able to integrate values presented in a rapid serial visual presentation (RSVP) stream to make informed judgements on the overall stream value (Tsetsos et al. Proceedings of the National Academy of Sciences of the United States of Americ...

Humans deviate from rational choice theory if their estimates of the attribute values for one alternative change as a function of the attribute values of competing alternatives (1). In our paper (2), we report such “context-dependent” (CD) deviations from rationality in the form of a frequent winner (FW) effect and the corresponding weak stochastic...

Humans are often observed to make optimal sensorimotor decisions but to be poor judges of situations involving explicit estimation of magnitudes or numerical quantities. For example, when drawing conclusions from data, humans tend to neglect the size of the sample from which it was collected. Here, we asked whether this sample size neglect is a gen...

Significance Healthy individuals appear to display inconsistent preferences, preferring A over B , B over C , and C over A . Inconsistent, intransitive preferences of this form are hallmark manifestations of irrational choice behavior and breach the very assumptions of economic theory. Nevertheless, the neurocognitive mechanisms that mediate the fo...

Trueblood, Brown, and Heathcote (2014) provide a new model of multiattribute choice, which accounts for 3 contextual reversal effects (similarity, attraction and compromise). We review the details of the model and highlight some novel predictions. First, we show that the model works by setting a "fine balance" between 2 opposing factors that influe...

Behavioural studies over half a century indicate that making categorical choices alters beliefs about the state of the world. People seem biased to confirm previous choices, and to suppress contradicting information. These choice-dependent biases imply a fundamental bound of human rationality. However, it remains unclear whether these effects exten...

Perceptual decisions are based on the temporal integration of sensory evidence for different states of the outside world. The timescale of this integration process varies widely across behavioral contexts and individuals, and it is diagnostic for the underlying neural mechanisms. In many situations, the decision-maker knows the required mapping bet...

Perceptual decisions are based on the temporal integration of sensory evidence for different states of the outside world. The timescale of this integration process varies widely across behavioral contexts and individuals, and it is diagnostic for the underlying neural mechanisms. In many situations, the decision-maker knows the required mapping bet...

There are errors in the Funding section. The correct funding information is as follows: This work was funded by the Amsterdam Brain and Cognition priority program; grant number: ABC2014-01 (http://abc.uva.nl/research/nav), the European Union 7th Framework Programme (FP7/2007-2013) under grant agreement no. 604102 (Human Brain Project; http://www.h...

Human performance on perceptual classification tasks approaches that of an ideal observer, but economic decisions are often inconsistent and intransitive, with preferences reversing according to the local context. We discuss the view that suboptimal choices may result from the efficient coding of decision-relevant information, a strategy that allow...

Highlights •Humans show biased integration of decision-relevant evidence •Later and more expected evidence wields more impact over choices •Adaptive gain control accounts for decision biases during serial integration •Expected evidence elicits markers of gain control using fMRI and pupillometry Summary Neural systems adapt to background levels of s...

Decision-making is a dynamic process that begins with the accumulation of evidence and ends with the adjustment of belief. Each step is itself subject to a number of dynamic processes, such as planning, information search and evaluation. Furthermore, choice behavior reveals a number of challenging patterns, such as order effects and contextual pref...

A key computation underlying perceptual decisions is the temporal integration of "evidence" in favor of different states of the world. Studies from psychology and neuroscience have shown that observers integrate multiple samples of noisy perceptual evidence over time toward a decision [1-11]. An influential model posits perfect evidence integration...

Previous research suggests that voting in elections is influenced by appearance-based personality inferences (e.g., whether a political candidate has a competent-looking face). However, since voters cannot objectively evaluate politicians’ personality traits, it remains to be seen whether appearance-based inferences about a characteristic continue...

When people make decisions, do they give equal weight to evidence arriving at different times? A recent study (Kiani et al., 2008) using brief motion pulses (superimposed on a random moving dot display) reported a primacy effect: pulses presented early in a motion observation period had a stronger impact than pulses presented later. This observatio...

Research on the psychology and neuroscience of simple, evidence-based choices has led to an impressive progress in capturing the underlying mental processes as optimal mechanisms that make the fastest decision for a specified accuracy. The idea that decision-making is an optimal process stands in contrast with findings in more complex, motivation-b...

In this post scrit, the authors discuss an article by Hotaling, Busemeyer, and Li (see record 2010-22285-008) which provided a valuable reply to the challenges the current authors raised for the decision field theory (DFT) account of preference reversal in multiattribute choice. They agree with Hotaling, Busemeyer, and Li's observation that with th...