My research interests include:
1. Attentional and other cognitive effects of incentives
2. Individual differences in decision making
3. Cognitive enhancement
Here are examples of some of my research contributions:
a. Losses and gains (A Youtube movie)
The idea of “loss attention” (Yechiam & Hochman, 2013a; 2013b, 2014; Yechiam et al., 2015) is simply that losses lead to more task attention. This model is different from “loss aversion” (Kahneman & Tversky, 1979) which assumes that losses are given more subjective weight than gains. Instead, under loss attention, losses increase the sensitivity to the task incentive structure as a whole . This model can explain previous phenomena which have been attributed to loss aversion, and clarifies several puzzles.
Specifically, it explains the increased arousal following losses (due to the increased attention), the increased response time in tasks with losses, and the increased cognitive performance typically observed when the outcomes include potential losses. All of these findings were found simultaneously with no loss aversion (as originally defined). Loss attention also explains the findings that tasks with losses induce greater reliability in task performance, and that the positive effect of losses on performance occurs even when better performance does not reduce the chance of getting losses.
Indeed, loss attention appears to be robust and to occur for very small losses and also for large losses. By contrast, loss aversion – if it exists – occurs only for rather large losses (see Yechiam, 2019; Zeif & Yechiam, 2022), and for such large losses it is difficult to differentiate it from risk aversion.
My studies suggest that the way we think about losses should be thus changed from a “tilted scales” metaphor (where the subjective weight of losses is larger than that of respective gains) to an attention investment framework where losses increase the allocation of cognitive effort to a task yielding losses. For instance, a couple of years ago my belt had broken during a scientific conference . I don’t think this was specifically hurting (e.g., that it hurt 2.5 times the price of the belt) but the event certainly did capture my attention.
b. Seeing what could have happened: Effect of foregone payoffs
Imagine a driver who decides to follow the speed-limits and is alone on the road. In this case, there is no temptation to speed. But when this driver also sees other drivers who speed she observes that the common outcome of speeding is positive (they get to their destination faster and with no negative repercussion) and negative outcomes such as a fine are infrequent (in most settings).
Information from unmade choices or strategies – known as foregone outcomes – may increase the tendency to follow strategies that are commonly rewarding, and leads to ignoring or underweighting rare events (such as the possibility of an accident in the example above). Our findings with laboratory tasks reveal that in experimental conditions with foregone payoffs decision makers show super-underweighting of small probability events, even compared to other “experience based” decision tasks (e.g., Yechiam & Busemeyer, 2005; 2006; Yechiam, Rakow, & Newell, 2015). Our explanation for this is that foregone payoffs increase the regret associated with making the option that is less rewarding most of the time (e.g., not speeding), which tempts people to pick the option that is better most of the time (i.e., speeding) but is exposed to rare repercussions.
c. Individual differences in decision making
Many people in the area of decision making discuss the effect of context on behavior and ignore individual differences. My earlier studies with Jerome Busemeyer used cognitive modeling to disentangle different factors affecting choices in repeated experiential decisions, so as to better pinpoint what drives individual differences. My more recent work uses behavioral indices to examine to what extent people behave consistently in different decision situations.
Our recent work suggests that the most consistent factor in such tasks is in fact the consistency of making a selection time and again versus switching to a different option. This “choice switching” was more consistent than any other aspect of decision behavior (see Yechiam, 2020): Being consistent across in tasks performed months apart and also in different tasks.
d. Cognitive enhancement
I am interested in a variety of manipulations that improve cognitive performance, including behavioral economics enhancers (Yechiam, 2023; Submitted) but also pharmaceutical ones. In the past we examined three types of medicine that are presumed to have positive effects on human cognitive processing.
Methylphenidate (Ritalin/Concerta)- Methylphenidate belongs to a series of nootropics that indirectly increase extracellular dopamine and noradrenaline levels in the brain. In my studies with Nirit Agay (Agay et al., 2010; 2014; 2016) and Dana Zeif (Zeif & Yechiam, 2022), we’ve found that methylphenidate positive affected adults without ADHD and adults with ADHD to a similar extent . This was found for working memory and sustained attention task (e.g., the TOVA) and for other tasks including memory tasks and judgment tasks. The effect was larger for individuals who performed poorly in the task. Yet although individuals with ADHD tended to score lower in some of these tasks (especially the TOVA), the key variable determining the cognitive enhancing potential of methylphenidate was not the diagnosis of ADHD per se, but rather one’ task performance off-medication.
DHEA – Dehydroepiandrosterone (DHEA) is an endogenous neurosteroid which acts as a prohormone for both male and female sex hormones. We’ve shown that administering it to cocaine-dependent addicts considerably reduced the relapse to drug use 16 months following treatment in a rehabilitation center (Ohana et al., 2016).
Hypericum perforatum – Considered an antidepressant and anti-anxiety agent, Hypericum perforatum affects multiple neurotransmitters in a non-competitive synergistic manner. Our initial analysis suggests that healthy rodents who are administered with Hypericum show improved memory performance (Ben-Eliezer & Yechiam, 2016). We subsequently found that Hypericum perforatum increased short term memory performance in healthy non-depressed adults. (Yechiam, Ben-Eliezer et al., 2018).