The LJDM seminar series is supported by
University College London
City University London
Originally established at UCL in the early 1970’s as a weekly Cognition and Reasoning seminar, it later became an intercollegiate seminar on Language and Cognition in the early 1980’s.
The name LJDM was finally coined in 1990, and the group has been running seminars under this name ever since, with lecturers and researchers in and around the UK meeting on a regular basis to discuss judgment and decision making, judgments of likelihood, reasoning, thinking, problem solving, forecasting, risk perception and communication, and other related topics.
If you would like to present your research to the group or to suggest a speaker, please contact the organizers:
Unless specified otherwise, all seminars take place on Wednesdays at 5pm, in Room 313 at the Psychology Department, University College London (on the corner of Bedford Way, Gordon Square and Torrington Place, London WC1H 0AP). Map.
To get updates on the current schedule and weekly reminders of the seminars, please subscribe to the Risk and Decision mailing list.
All are welcome to attend.
Term 2 Seminar Schedule
January – March 2019
Wandi Bruine de Bruin
University of Leeds
Age differences in decision-making competence: Emerging research and policy implications
Population age is steadily increasing in countries around the world. Decisions about personal finances, retirement, and health are becoming increasingly complex, perhaps especially in older age. My programme of research on decision-making competence across the life span combines insights from behavioural decision making and life-span developmental psychology to examine how and why aspects of decision-making competence change with adult age. (It is not all bad news for the ageing decision maker!) I will discuss the implications of my findings for behavioural decision research as well as the development of interventions and policy to support decision-making competence in people of all ages.
Tel Aviv University
The formation of preference in risky choice
A key question in decision-making is how people integrate amounts and probabilities to form preferences between risky alternatives. I will present a study in which we rely on the general principle of integration-to-boundary to develop several process models of risky choice that account for both choices and response-times. These models allowed to contrast between two influential competing theories: i) within-alternative evaluations, based on a multiplicative interaction between amounts and probabilities, ii) within-attribute comparisons across alternatives. To constrain the preference formation process, we monitored eye-fixations during decisions between pairs of lotteries, designed to systematically span the decision-space. Behavioral results indicate that the participants' eye-scanning patterns were associated with risk-preferences and expected-value maximization. Crucially, model comparisons showed that within-alternative process models decisively outperformed within-attribute ones, in accounting for choices and response-times. These findings elucidate the psychological processes underlying preference formation when making risky-choices, and suggest that within-alternative integration is an adaptive mechanism lying at the heart of it.
University of Edinburgh
Tracking referring expressions across time
In 2002, the New York Times referred to Google in one of its articles as `Google, the company behind the popular Web search engine'. Now, when we refer to Google, as we speak or write, we hardly ever describe what Google does. Ever wondered how long it took for `Google' to become common knowledge and everyday parlance?
In this talk, I will present a large corpus study of how expressions that refer to the same entity develop over time. When a reader is first introduced to an entity, the expressions must describe the entity. For entities that are widely known, a single word or phrase often suffices. We track thousands of people and organizations mentioned over 20 years of New York Times (NYT). As entities move from first introduction to the NYT audience to a common knowledge status, we show empirically that the expressions along this trajectory depend on the type of the entity, and exhibit linguistic properties related to becoming common knowledge (e.g., they get shorter, involve more definite articles). These properties can also be used to build a model to predict how long it will take for an entity to reach common knowledge status. Our results reach 10-30% absolute improvement over a majority-class baseline.
13/02/2019 READING WEEK (No Seminar)
University of Leicester
Persuading with confidence: Evidence for the Confidence Heuristic
According to the confidence heuristic, when people communicate beliefs to one another, they generally express confidence proportional to their degree of certainty, based on their relevant knowledge, and recipients tend to judge the persuasiveness of the communication according to the confidence with which it is expressed. Previous experiments have investigated the confidence–persuasiveness aspect of the heuristic but not the full knowledge–confidence–persuasiveness hypothesis. I report 3 experiments to test the confidence heuristic using incentivized interactive decisions with financial outcomes in which participants attempted to identify target stimuli after conferring with a partner who was also seeking the right answer and who had either stronger or weaker information about the target. Experiment 1, using a facial identification task, confirmed the confidence heuristic. Experiment 2, using geometric shapes as stimuli, found a much larger confidence heuristic effect. Experiment 3 found similar confidence heuristic effects through face-to-face and computer-mediated communication channels, suggesting that verbal rather than nonverbal communication drives the heuristic. Suggesting an answer first was typical of pair members with strong evidence and may therefore be a dominant cue that persuades. The results establish the confidence heuristic with dissimilar classes of stimuli and through different communication channels.
Sebastian Bobadilla Suarez
Rethinking heuristics and optimal decision making
Are we rational animals or predictably irrational? Two different lines of research have dominated the narrative for explaining decision making. One line of research celebrates the brilliance of (optimal) decision makers while the other emphasizes their (heuristic) limitations. The former derives its predictions from computational descriptions of a task while the latter proceeds in a more bottom-up fashion, hypothesizing classes of algorithmic strategies and fitting them to experimental outcomes. I will present two studies that showcase how misleading this dichotomy can be. Specifically, the studies will attempt to debunk the notion that just because an algorithm is coined as a heuristic, this does not mean it is easily implemented given our cognitive constraints. I will show how two famous heuristics (Tallying and Take-the-Best) can fail under time pressure by manipulating presentation formats. To complement this perspective, I will also discuss work that shows how heuristics can be framed as special cases within principled statistical frameworks.
University of Leeds
Risk, Time, and Psychological Distance
Previous research on the effects of probability (risk) and delay on decision making has focused on examining each dimension separately, and hence little is known about when these dimensions are combined into a single choice option. For this talk, I will present results from behavioural experiments and computational modelling analyses aiming to disentangle the cognitive and psychological underpinnings of risky intertemporal choice, including the application of sequential accumulator modelling (Linear Ballistic Accumulator) and the use of process-tracing designs. We examined the order in which information is acquired (payoff, probability, delay), transitions between information items, and how preferences are constructed across time. The results point towards a dimension-wise evaluation of risky and delayed prospects. We used these observations to inform the development of new models for risky intertemporal choice and to provide novel experimental and behavioural directions for the study of the combined effect of risk and delay on preferential choice.
University of East London
Brain stimulation of the dorso-lateral prefrontal cortex increases cognitive reflection performance
TDCS is a non-invasive brain stimulation (NIBS) method which modulates cortical excitability (Nitsche & Paulus, 2000). TDCS generates a weak electrical current (usually 0.5 - 2 mA) which modulates resting membrane potentials. In three experiments transcranial direct current stimulation was used for either anodal stimulation of the right-dorsolateral prefrontal cortex (DLPFC), left-DLPFC, or sham conditions for 20 minutes (during or) after which participants worked on a number of judgment and decision-making tasks. Right but not left DLPFC stimulation increased performance in an extended cognitive reflection test (CRT), and in judgment tasks measuring heuristic thinking. An additional 2nd stimulation session in one experiment increased performance again, but only for the CRT. These results imply a specific role of the right DLPFC in overcoming pre-potent responses in judgment tasks.
Ariel Cecci, Shari de Baets
UCL, Ghent University
How does financial information impact judgment in forecasting company stocks?
Investors, particularly those who trade every day, are constantly confronted with short-term forecasting decisions based on graphically presented time series. These forecasts are often subject to trend damping; the tendency to underestimate future values for upward trends (under-forecasting) and overestimate them for downward trends (over-forecasting). We investigated this in an experimental study where we manipulated the influence of financial news presented before the estimate of stock prices. We ran a study where participants were presented with two sets of 55-day time series company stocks and asked to indicate their predictions of the price for the next 5 days. The first set of graphs was forecast based solely on the information in the graphs. Before the second set of time series, participants were provided with financial news regarding some of the companies they were going to forecast. These pieces of news resulted from a combination of either positive or negative and integral (related to the company's performance) or incidental (related to the companies' products) information. We will present our findings and discuss their implications.