Marius Usher

• Professor of Psychology
• Professor at Tel Aviv University

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...

Humans learn both directly, from own experience, and via social communication, from the experience of others. They also often integrate these two sources of knowledge to make predictions and choices. We hypothesized that when faced with the need to integrate communicated information into personal experience, people would represent the average of ex...

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...

Real-life decisions typically involve multiple options, each with multiple attributes affecting value. In such complex cases, sequential shifts of attention to specific options and attributes are thought to guide the decision process. We designed a task that allowed us to monitor attention in monkeys engaged in such multi-attribute decisions. We re...

In this paper, we revisit the debate surrounding the Unfolding Argument (UA) against causal structure theories of consciousness (as well as the hard-criteria research program it prescribes), using it as a platform for discussing theoretical and methodological issues in consciousness research. Causal structure theories assert that consciousness depe...

Models of multi-attribute decision making vary on whether all or only part of the information available is being processed, as well as on whether preference formation is based on within-option or within-attribute processing. Here we carry out a combined empirical and computational study in which we rely on lottery-options with varying task complexi...

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....

Individual differences in cognitive processing have been the subject of intensive research. One important type of such individual differences is the tendency for global versus local processing, which was shown to correlate with a wide range of processing differences in fields such as decision making, social judgments and creativity. Yet, whether th...

Evidence integration is a normative algorithm for choosing between alternatives with noisy evidence, which has been successful in accounting for vast amounts of behavioural and neural data. However, this mechanism has been challenged by non-integration heuristics, and tracking decision boundaries has proven elusive. Here we first show that the deci...

Integration to boundary is an optimal decision algorithm that accumulates evidence until the posterior reaches a decision boundary, resulting in the fastest decisions for a target accuracy. Here, we demonstrated that this advantage incurs a cost in metacognitive accuracy (confidence), generating a cognition/metacognition trade-off. Using computatio...

Many situations in life (such as considering which stock to invest in, or which people to befriend) require averaging across series of values. Here, we examined predictions derived from construal level theory, and tested whether abstract compared with concrete thinking facilitates the process of aggregating values into a unified summary representat...

We examine the ability of observers to extract summary statistics (such as the mean and the relative-variance) from rapid numerical sequences of two digit numbers presented at a rate of 4/s. In four experiments (total N = 100), we find that the participants show a remarkable ability to extract such summary statistics and that their precision in the...

The unfolding argument (UA) was advanced as a refutation of prominent theories, which posit that phenomenal experience is determined by patterns of neural activation in a recurrent (neural) network (RN) structure. The argument is based on the statement that any input–output function of an RN can be approximated by an “equivalent” feedforward-networ...

Individual differences in cognitive processing have been the subject of intensive research. An important type of such individual differences is the tendency for global vs. local processing, which was shown to correlate with a wide range of processing differences in fields such as decision making, social judgments and creativity. Yet, whether these...

We examine the ability of human observers to estimate the average of rapid serial visual presentational (RSVP) sequences of numerical symbols at rates of up to 30 items/sec. In three experiments (2 pilots and 1 pre-registered replication), we find that observers extract the average of fast RSVP sequences (which they “barely see”) with a precision t...

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...

Recent research has established that humans can extract the average perceptual feature over briefly presented arrays of visual elements or the average of a rapid temporal sequence of numbers. Here we compared the extraction of the average over briefly presented arrays, for a perceptual feature (orientations) and for numerical values (1-9 digits), u...

Traditional models of decision making under uncertainty explain human behavior in simple situations with a minimal set of alternatives and attributes. Some of them, such as prospect theory, have been proven successful and robust in such simple situations. Yet, less is known about the preference formation during decision making in more complex cases...

When choosing between options, such as food items presented in plain view, people tend to choose the option they spend longer looking at. The prevailing interpretation is that visual attention increases value. However, in previous studies, 'value' was coupled to a behavioural goal, since subjects had to choose the item they preferred. This makes it...

Evidence-integration is a normative algorithm for choosing between alternatives with noisy evidence, which has been successful in accounting for a vast amount of behavioral and neural data. However, this mechanism has been challenged as tracking integration boundaries sub-serving choice has proven elusive. Here we first show that the decision bound...

Humans and animals are capable of estimating and discriminating nonsymbolic numerosities via mental representation of magnitudes—the approximate number system (ANS). There are two models of the ANS system, which are similar in their prediction in numerosity discrimination tasks. The log-Gaussian model, which assumes numerosities are represented on...

Integration-to-boundary is an optimal decision algorithm that takes samples of evidence until the posterior reaches a decision boundary, resulting in the fastest decisions for a target accuracy. For example, integration-to-boundary achieves faster mean-RT compared with taking a fixed number of samples that result in the same choice-accuracy. Here w...

The drift-diffusion model (DDM) is widely used and broadly accepted for its ability to account for binary choices (in both the perceptual and preferential domains) and for their response times (RT), as a function of the stimulus or the option values. The DDM is built on an evidence accumulation to bound concept, where, in the value domain, a decisi...

Recent research has established that humans can extract average of perceptual features from sets of briefly and simultaneously presented elements or the average of rapid temporal sequences of numerical values. Here we compare the extraction of the average of simultaneously presented sets of perceptual features (orientations) and of numerical values...

We examine the ability of observers to extract summary statistics (such as the mean and the relative-variance) from rapid numerical sequences (two digit numbers presented at a rate of 4/sec). In four experiments, we find that the participants show a remarkable ability to extract such summary statistics and that their precision in the estimation of...

How do people judge the degree of causal responsibility that an agent has for the outcomes of her actions? We show that a relatively unexplored factor – the robustness (or stability) of the causal chain linking the agent’s action and the outcome – influences judgments of causal responsibility of the agent. In three experiments, we vary robustness b...

When choosing between options, such as food items presented in plain view, people tend to choose the option they spend longer looking at. The prevailing interpretation is that visual attention increases value. However, in previous studies, 'value' was coupled to a behavioural goal, since subjects had to choose the item they preferred. This makes it...

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...

Associative processes, such as the encoding of associations between words in a list, can enhance episodic memory performance and are thought to deteriorate with age. Here, we examine the nature of age-related deficits in the encoding of associations, by using a free recall paradigm with visual arrays of objects. Fifty-five participants (26 young st...

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...

A key question in decision-making is how people integrate amounts and probabilities to form preferences between risky alternatives. Here we rely on the general principle of integration-to-boundary to develop several biologically plausible process models of risky-choice, which account for both choices and response-times. These models allowed us to c...

Integration-to-boundary is a prominent normative principle used in evidence-based decisions to explain the speed-accuracy trade-off and determine the decision-time. Despite its prominence, however, the decision boundary is not directly observed, but rather is theoretically assumed, and there is still an ongoing debate regarding its form: fixed vs....

The formation of attitudes or preferences for alternatives that consist of rapid numerical sequences has been suggested to reflect either a summation or an averaging principle. Previous studies indicate the presence of two mechanisms, accumulators (that mediate summation) and population-coding (that mediate averaging), which operate in preference f...

The formation of attitudes or preferences for alternatives that consist of rapid numerical sequences has been suggested to reflect either a summation or an averaging principle. Previous studies indicate the presence of two mechanisms, accumulators (that mediate summation) and population-coding (that mediate averaging), which operate in preference f...

An enduring debate in decision-making and social cognition concerns the algorithm governing the formation of intuitive preferences and attitudes. Here we contrast 2 principles that are considered central to such judgments: averaging versus summation. Participants in 4 experiments were prompted to rely on their intuition when rating the Hall of Fame...

Although ageing is known to affect memory, the precise nature of its effect on retrieval and encoding processes is not well understood. Here, we examine the effect of ageing on the free recall of word lists, in which the semantic structure of word sequences was manipulated from unrelated words to pairs of associated words with various separations (...

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...

The question of whether conscious experience is restricted by cognitive access and exhausted by report, or whether it overflows it—comprising more information than can be reported—is hotly debated. Recently, we provided evidence in favor of Overflow, showing that observers discriminated the color‐diversity (CD) of letters in an array, while their w...

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...

I propose a compatibilist theory of agency and responsibility, according to which an agent is responsible for an effect, if and only if, she is the earliest source of robust causation over it, via an action she carried out in the service of her long term interests. This theory deploys a notion of teleological control, which is a type of guidance‐co...

We contrast two theoretical positions on the relation between phenomenal and access consciousness. First, we discuss previous data supporting a mild Overflow position, according to which transient visual awareness can overflow report. These data are open to two interpretations: (i) observers transiently experience specific visual elements outside a...

The cognitive mechanism underlying decisions based on sequential samples has been found to be affected by whether multiple alternatives are evaluated together or whether each alternative is evaluated individually. In this experiment, we examined whether evaluation format can also lead to different preference orders among risky alternatives. We hypo...

Is it possible to carry out complex multi-attribute decisions (which require an estimation of the weighted average) intuitively, without resorting to simplifying heuristics? Over the course of 600 trials, 26 participants had to choose the better-suiting job-candidate, a task requiring comparison of two alternatives over three/four/five dimensions w...

Humans possess a remarkable ability to rapidly form coarse estimations of numerical averages. This ability is important for making decisions that are based on streams of numerical or value-based information, as well as for preference formation. Nonetheless, the mechanism underlying rapid approximate numerical averaging remains unknown, and several...

The Stroop task is a central experimental paradigm used to probe cognitive control by measuring the ability of participants to selectively attend to task-relevant information and inhibit automatic task-irrelevant responses. Research has revealed variability in both experimental manipulations and individual differences. Here, we focus on a particula...

An enduring debate in decision-making and social cognition concerns the algorithm governing the formation of intuitive preferences and attitudes. Here we contrast 2 principles that are considered central to such judgments: averaging versus summation. Participants in 4 experiments were prompted to rely on their intuition when rating the Hall of Fame...

We show that our item-based model, competitive guided search, accounts for the empirical patterns that H&O invoke against item-based models and we highlight recently reported diagnostic data that challenges H&O's approach. We advise against 'forsaking the item' until and unless a full fixation-based model is shown to be superior to extant item-base...

This commentary focuses on two related, open questions in Hulleman & Olivers’ proposal: (i) the nature of the parallel attentive process that determines target presence within, and thus presumably the size of, the functional visual field, and (ii) how the pre-attentive guidance mechanism must be conceived to also account for search performance in t...

Numbers play a major role in decisions about vital life issues. This study compared the relative advantage of analytical vs. intuitive numerical processing in numerical average evaluations, while varying information load, complexity of the task and the information presentation formats. Thinking manipulation was based on Dehaene’s [5] model, which p...

The parietal cortex has been implicated in a variety of numerosity and numerical cognition tasks and was proposed to encompass dedicated neural populations that are tuned for analogue magnitudes as well as for symbolic numerals. Nonetheless, it remains unknown whether the parietal cortex plays a role in approximate numerical averaging (rapid, yet c...

Visual search is central to the investigation of selective visual attention. Classical theories propose that display items are identified as focal attention is deployed serially to their locations based on their salience. While this accounts for set-size effects over a continuum of task difficulties, it has been suggested that parallel models can a...

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...

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...

Making decisions based on relative rather than absolute information processing is tied to choice optimality via the accumulation of evidence differences, and to canonical neural processing via accumulation of evidence ratios. These theoretical frameworks predict invariance of decision latencies to absolute intensities that maintain differences and...

Making decisions based on relative rather than absolute information processing is tied to choice optimality via the accumulation of evidence differences, and to canonical neural processing via accumulation of evidence ratios. These theoretical frameworks predict invariance of decision latencies to absolute intensities that maintain differences and...

Author An important process that supports decision-making is the integration of evidence over time, which optimizes decision quality by enhancing the signal to noise ratio. The nature of this process depends critically on the weight given to evidence across time: which information has more impact—early, intermediate or late? We used a novel psycho...

Evidence for expanded integration. As discussed in the main text, our observation that accuracy increased with trial duration can be accounted for by a non-integration-based model, such as probability-summation (Watson, 1979). However, integration-based and non-integration-based models provide diverging predictions regarding accuracy in the differe...

Observed and predicted temporal-weighting in Experiment 4 (N = 8), which was identical to Exp. 3, only with 5-sec trials rather than 3-sec trials. As can be see, observed weights are monotonically increasing indicating recency-biased integration. This pattern is predicted by the DLCA model. Simulation was conducted using the best-fitting parameters...

Experiment 4. To test the predictions of the DLCA model, we have conducted an experiment (Exp. 4; N = 8), which was identical to Exp. 2, only with trial duration of 5-sec, rather than 3-sec. We find that, as predicted by the DLCA, but not by the two alternative accounts described above, temporal weighting in 5-sec trials is monotonic and recency-bi...

Observed and simulated accuracy in baseline congruent- and incongruent-perturbation trials. Experimental data shows that accuracy did not differ between baseline, congruent and incongruent trials (black line). This pattern is captured by an integration-based model (red line; here the DLCA with the best-fitting parameters reported in the main text)....

Logistic regression weights with high temporal resolution (200 ms of perceptual evidence per window). Statistical analyses of the weighting functions reveal no evidence for non-monotonicity in 1- and 2-sec trials [1-sec: the 2nd temporal-window is not significantly different from the 4th or 5th window; p = 0.63; p = 0.38, respectively; 2-sec: the 4...

Simulated temporal weights for 1- and 2-sec trials using a model, in which on some trials integration is primacy-biased (p_inhibition_dominance = 0.16; noise = 0.5; leak = 0.04; inhibition = 0.2) and on other recency-biased (p_leak_dominance = 0.84; noise = 0.5; leak = 0.2; inhibition = 0.025). Parameters were manually chosen to meet the non-monoto...

Temporal weights in Exp. 2 and Exp. 3. In each experiment seperately, we find numerical trends of non-monotonic weighting functions [Exp. 2: 1st vs. 2nd window; t(9) = 1.16; p = 0.27; 5th vs. 2nd window; t(9) = 1.91; p = 0.08; Exp. 3: 1st vs. 2nd window; t(9) = 1.99; p = 0.08; 5th vs. 2nd window; t(9) = 1.56; p = 0.15]. (DOCX)

Models’ parameter-space. Description of the parameter-space. (DOCX)

Searching for an object among distracting objects is a common daily task. These searches differ in efficiency. Some are so difficult that each object must be inspected in turn, whereas others are so easy that the target object directly catches the observer's eye. In four experiments, the difficulty of searching for an orientation-defined target was...

Using a Stroop task, we investigated the effect of task-irrelevant emotional distractors on attentional proactive control and its interaction with trait anxiety. On the basis of recent findings showing opposed neural responses in the dorsal-executive versus the ventral-emotional systems in response to emotional distractors and of the attentional co...

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...

Visual search is central to the investigation of selective visual attention. Classical theories propose that items are identified by serially deploying focal attention to their locations. While this accounts for set-size effects over a continuum of task difficulties, it has been suggested that parallel models can account for such effects equally we...

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...

We investigated the mechanism with which humans estimate numerical averages. Participants were presented with 4, 8 or 16 (two-digit) numbers, serially and rapidly (2 numerals/second) and were instructed to convey the sequence average. As predicted by a dual, but not a single-component account, we found a non-monotonic influence of set-size on accur...

Confidence judgments are pivotal in the performance of daily tasks and in many domains of scientific research including the behavioral sciences, psychology and neuroscience. Positive resolution i.e., the positive correlation between choice-correctness and choice-confidence is a critical property of confidence judgments, which justifies their ubiqui...

1) Best fitting parameter values for average observer and individual subjects for each of the models tested in the main article. 2) Quantile Probability Choice Response Time Distribution Plots for best fitting parameters of different models tested in the main article

Performance on the Stroop task reflects two types of conflict-informational (between the incongruent word and font color) and task (between the contextually relevant color-naming task and the irrelevant, but automatic, word-reading task). According to the dual mechanisms of control theory (DMC; Braver, 2012), variability in Stroop performance can r...

The rate of exceptionally slow reaction times (RTs), described by the long tail of the RT distribution, was found to be amplified in a variety of special populations with cognitive deficits (e.g., early-stage Alzheimer’s disease, attention-deficit/hyperactivity disorder, low intelligence, elderly). Previous individual differences studies found high...

Evidence from neuropsychology and neuroimaging indicate that the pre-frontal cortex (PFC) plays an important role in human memory. Although frontal patients are able to form new memories, these memories appear qualitatively different from those of controls by lacking distinctiveness. Neuroimaging studies of memory indicate activation in the PFC und...

The distinction between access consciousness and phenomenal consciousness is a subject of intensive debate. According to one view, visual experience overflows the capacity of the attentional and working memory system: We see more than we can report. According to the opposed view, this perceived richness is an illusion-we are aware only of informati...

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...

Historically, visual search models were mainly evaluated based on their account of mean reaction times (RTs) and accuracy data. More recently, Wolfe, Palmer, and Horowitz (2010) have demonstrated that the shape of the entire RT distributions imposes important constraints on visual search theories and can falsify even successful models such as guide...

Identifying which thinking mode, intuitive or analytical, yields better decisions has been a major subject of inquiry by decision-making researchers. Yet studies show contradictory results. One possibility is that the ambiguity is due to the variability in experimental conditions across studies. Our hypothesis is that decision quality depends criti...

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...

A multitude of models have been proposed to account for the neural mechanism of value integration and decision making in speeded decision tasks. While most of these models account for existing data, they largely disagree on a fundamental characteristic of the choice mechanism: independent versus different types of competitive processing. Five model...

Performance of the Stroop task reflects two conflicts-informational (between the incongruent word and ink colour) and task (between relevant colour naming and irrelevant word reading). This is supported by findings showing that the anterior cingulate cortex is more activated by congruent and incongruent stimuli than by nonword neutral stimuli. Prev...

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...

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...

Models of neural networks which include dynamical thresholds can display motion in pattern space, the space of all memories. We investigate this motion in a particular model which is based on a feedback network of excitatory and inhibitory neurons. We find that small variations in the parameters of the model can lead to big qualitative changes of i...

We investigate feedback networks containing excitatory and inhibitory neurons. The couplings between the neurons follow a Hebbian rule in which the memory patterns are encoded as cell assemblies of the excitatory neurons. Using disjoint patterns, we study the attractors of this model and point out the importance of mixed states. The latter become d...

Action selection is the task of doing the right thing at the right time. It requires the assessment of available alternatives, executing those most appropriate, and resolving conflicts among competing goals and possibilities. Using advanced computational modelling, this book explores cutting-edge research into action selection in nature from a wide...

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...