How do associative and phonemic overlap interact to boost illusory recollection?

This project investigated the underlying mechanisms that boost false remember responses when participants receive study words that are both semantically and phonologically similar to a critical lure. Participants completed a memory task in which they were presented with a list of words all associated with a critical lure. Included within the list of semantic associates was a target that was either semantically associated (e.g., yawn) to the critical lure (e.g., sleep) or shared the initial (e.g., slam) or final (e.g., beep) phoneme(s) with the critical lure. After hearing the list, participants recalled each list item and indicated whether they just knew it was on the list or if they instead recollected specific contextual details of that item’s presentation. We found that inserting an initial phonemic overlap target boosted experiences of recollection, but only when semantically related associates were presented beforehand. The results are consistent with models of spoken word recognition and show that established semantic context plus initial phonemic overlap play important roles in boosting false recollection.     

“I'm Moderna,what are you?” Evidence that people favor those who received their same brand COVID-19 vaccine

In two studies, we investigated the extent to which people are biased toward people with the same COVID-19 vaccine brand using a monetary allocation task. Informed by theoretical approaches to intergroup bias and the minimal-groups paradigm, we expected that, when deciding how to allocate financial resources among three different people—each with an equal need for assistance but a different COVID-19 vaccine brand—people would allocate more money, on average, to those who received the same versus different vaccine brand than participants personally received. We found in Study 1 (N = 94) that people given a hypothetical $10.00 experimental endowment allocated an average of $2.00 more when a person was a member of their vaccine ingroup than to those from their vaccine brand outgroup. We replicated this effect in Study 2 (N = 219), finding that people continued to allocate more money ($1.42) to a person from their vaccine brand ingroup versus those from their vaccine brand outgroup. Taken together, this work suggests that, among vaccinated people, the brand of another person's vaccine meaningfully influences the allocation of monetary resources and that people are biased toward people with the same COVID-19 vaccine brand. Implications for social identity theories are discussed.     

Legitimate lies: The relationship between omission,commission, and cheating

Across four experiments, we show that when people can serve their self‐interest, they are more likely to refrain from reporting the truth (lie of omission) than actively lie (lie of commission). We developed a novel online “Heads or Tails” task in which participants can lie to win a monetary prize. During the task, they are informed that the software is not always accurate, and it might provide incorrect feedback about their outcome. In Experiment 1, those in the omission condition received incorrect feedback informing them that they had won the game. Participants in commission condition were correctly informed that they had lost. Results indicated that when asked to report any errors in the detection of their payoff, participants in the omission condition cheated significantly more than those in the commission condition. Experiment 2 showed that this pattern of results is robust even when controlling for the perceived probability of the software error. Experiments 3 and 4 suggest that receiving incorrect feedback makes individuals feel more legitimate in withholding the truth, which, in turn, increases cheating.     

Activating the critical lure during study is unnecessary for false recognition

Participants studied lists of nonwords (e.g., froost, floost, stoost, etc.) that were orthographic-phonologically similar to a nonpresented critical lure, which was also a nonword (e.g., ploost). Experiment 1 showed a high level of false recognition for the critical lure. Experiment 2 showed that the false recognition effect was also present for forewarned participants who were informed about the nature of the false recognition effect and told to avoid making false recognition judgments. The present results show that false recognition effects can be obtained even when the critical lure itself is not stored during study. This finding is problematic for accounts that attribute false memories to implicit associative responses or spreading activation but is easily explained by global familiarity models of recognition memory.     

A procedure for studying the within-session onset of human drug discrimination.

The purpose of the present study was to develop a procedure for measuring the within-session onset of human drug discrimination. During daily sessions, under double-blind conditions, caffeine-abstinent adults ingested a letter-coded capsule containing 178 mg caffeine or placebo. Trials were presented at 30-s intervals, beginning immediately after drug ingestion and continuing for 60 min. On each trial, subjects could guess which of their two letter-coded drugs they had received by pressing a left button (for one drug) or right button (for the other drug); subjects could also press a center "no guess" button instead of guessing. Each trial ended after one button press. After each session, subjects were told which drug they had received. Subjects earned one point (worth $0.10 per point) for each correct guess. Subjects lost either 0, 1, or 10 points for each incorrect guess; the point-loss contingencies were varied in random order across sessions. Discrimination earnings accumulated across all sessions. The point-loss contingencies decreased random responding and delayed the discrimination time course. Overall, this procedure provided an orderly and relatively continuous measure of the within-session onset of drug discrimination and should have a range of applications in understanding the human behavioral pharmacology of drugs.     

The role of rehearsal and generation in false memory creation

The current research investigated one possible mechanism underlying false memories in the Deese-Roediger-McDermott (DRM) paradigm. In the DRM paradigm, participants who study lists of related words (e.g., “table, sitting, bench …”) frequently report detailed memories for the centrally related but non-presented critical lure (e.g., “chair”). One possibility is that participants covertly call to mind the critical non-presented lure during the study phase, and later misattribute memory for this internally generated event to its external presentation. To investigate this, the DRM paradigm was modified to allow collection of on-line thoughts during the study phase. False recognition increased following generation during study. False recognition also increased following study of longer lists; this effect was partially explained by the fact that longer lists were more likely to elicit generations of the critical lure during study. Generation of the lure during study contributes to later false recognition, although it does not explain the entire effect.     

Escalating schedules of incentives increase physical activity with no differences between deposit and no-deposit groups: A systematic replication

Physical inactivity has increasingly affected public health in the United States during the COVID-19 pandemic as it is associated with chronic diseases such as arthritis, cancer, and heart disease. Contingency management has been shown to increase physical activity. Therefore, the present study sought to evaluate the effects of an escalating schedule of monetary reinforcement with a reset contingency on physical activity, as compared between 2 counterbalanced groups in which a monetary deposit of $25 was either required (deposit group) or not (no-deposit group). Twenty-five adults wore Fitbit accelerometers to monitor step counts. An ABA reversal design was used; in the 2 baseline phases, no programmed contingencies were in place for step counts. During intervention, step goals were set using a modified 70^th percentile schedule with a 7-day window: Reaching the first goal would result in $0.25, and incentives increased by $0.25 for each subsequent day in which the goal was met. Failure to reach a goal resulted in a reset of the monetary incentive value to $0.25. Ten out of 12 participants from the deposit group were determined to be responders to intervention, whereas 8 out of 13 participants from the no-deposit group were determined to be responders to intervention. Overall, there were no significant differences between the groups' step counts. However, the deposit group's intervention was cheaper to implement, which suggests that deposit contracts are a viable modification for physical activity interventions.     

When false memories do not occur: not thinking of the lure or remembering that it was not heard?

The aim of the present study was to evaluate two explanations for the non-occurrence of false memories in the Deese-Roediger-McDermott (DRM) paradigm. One explanation was that a critical lure is not recalled because the list failed to evoke it in the participant's mind. Another possible explanation was that the participant would identify the critical lure and would remember, at the time of recall, that the lure was not produced by an external source. In order to explore these two possible explanations for the non-occurrence of false memories, an experimental phase was added to the usual DRM paradigm: participants were asked to recall items they thought of but did not recall because these items were not members of the list presented by the experimenter. Among participants who did not recall the critical lure during the standard recall task, those who recalled the critical lure during the additional phase outnumbered those who did not recall it. This result is more consistent with the second explanation than with the first one.     

The role of rehearsal and generation in false memory creation

The current research investigated one possible mechanism underlying false memories in the Deese-Roediger-McDermott (DRM) paradigm. In the DRM paradigm, participants who study lists of related words (e.g., "table, sitting, bench ...") frequently report detailed memories for the centrally related but non-presented critical lure (e.g., "chair"). One possibility is that participants covertly call to mind the critical non-presented lure during the study phase, and later misattribute memory for this internally generated event to its external presentation. To investigate this, the DRM paradigm was modified to allow collection of on-line thoughts during the study phase. False recognition increased following generation during study. False recognition also increased following study of longer lists; this effect was partially explained by the fact that longer lists were more likely to elicit generations of the critical lure during study. Generation of the lure during study contributes to later false recognition, although it does not explain the entire effect.     

What you don’t know won’t hurt me: Costly (but quiet) exit in dictator games

We used simple economic games to examine pro-social behavior and the lengths that people will take to avoid engaging in it. Over two studies, we found that about one-third of participants were willing to “exit” a $10 dictator game and take $9 instead. The exit option left the receiver nothing, but also ensured that the receiver never knew that a dictator game was to be played. Because most social utility models are defined over monetary outcomes, they cannot explain choosing the ($9, $0) exit outcome over the dominating $10 dictator game, since the game includes outcomes of ($10, $0) and ($9, $1). We also studied exiting using a “private” dictator game. In the private game, the receiver never knew about the game or from where any money was received. Gifts in this game were added innocuously to a payment for a separate task. Almost no dictators exited from the private game, indicating that receivers’ beliefs are the key factor in the decision to exit. When, as in the private game, the receivers’ beliefs and expectations cannot be manipulated by exit, exit is seldom taken. We conclude that giving often reflects a desire not to violate others’ expectations rather than a concern for others’ welfare per se. We discuss the implications of our results for understanding ethical decisions and for testing and modeling social preferences. An adequate specification of social preferences should include “psychological” payoffs that directly incorporate beliefs about actions into the utility function.     

When false memories do not occur: Not thinking of the lure or remembering that it was not heard?

The aim of the present study was to evaluate two explanations for the non-occurrence of false memories in the Deese-Roediger-McDermott (DRM) paradigm. One explanation was that a critical lure is not recalled because the list failed to evoke it in the participant's mind. Another possible explanation was that the participant would identify the critical lure and would remember, at the time of recall, that the lure was not produced by an external source. In order to explore these two possible explanations for the non-occurrence of false memories, an experimental phase was added to the usual DRM paradigm: participants were asked to recall items they thought of but did not recall because these items were not members of the list presented by the experimenter. Among participants who did not recall the critical lure during the standard recall task, those who recalled the critical lure during the additional phase outnumbered those who did not recall it. This result is more consistent with the second explanation than with the first one.     

Tests of an indifference rule in variable‐delay and double‐reward choice procedures with humans

Four hundred and fifty participants were recruited from Amazon Mechanical Turk across 3 experiments to test the predictions of a hyperbolic discounting equation in accounting for human choices involving variable delays or multiple rewards (Mazur, 1984, 1986). In Experiment 1, participants made hypothetical choices between 2 monetary alternatives, 1 consisting of a fixed delay and another consisting of 2 delays of equal probability (i.e., a variable‐delay procedure). In Experiment 2, participants made hypothetical monetary choices between a single, immediate reward and 2 rewards, 1 immediate and 1 delayed (i.e., a double‐reward procedure). Experiment 3 also used a double‐reward procedure, but with 2 delayed rewards. Participants in all 3 experiments also completed a standard delay‐discounting task. Finally, 3 reward amounts were tested in each type of task ($100, $1000, and $5000). In the double‐reward conditions (Experiments 2 and 3), the results were in good qualitative and quantitative agreement with Mazur's model (1984, 1986). In contrast, when participants made choices involving variable delays (Experiment 1), there was relatively poor qualitative and quantitative agreement with this model. These results, along with our previous findings, suggest the structure of questions in hypothetical tasks with humans can be a strong determinant of the choice pattern.     

On the dual effects of repetition on false recognition

The effects of study-list repetition on false recognition of semantic associates were examined using aging (Experiment 1) and recognition time pressure (Experiment 2). Participants studied word lists, each of which was composed of high associates to a single, unstudied word (the critical lure). Under normal testing circumstances, young adult participants (ages 19-26) falsely endorsed fewer critical lures associated with lists that had been presented multiple times than lists presented only once. However, young participants tested under time pressure and older participants (ages 67-85) endorsed a greater number of critical items associated with lists presented thrice than with lists presented once. The results suggest dual bases for the recognition decision, one of which is based on the rapid spread of activation within domains of semantic similarity and the other of which functions to attribute that activation to likely sources and set appropriate decision criteria. The latter capacity is compromised both under conditions of time pressure and in the elderly.     

Influence of paper color and a monetary incentive on response rate

This study examined whether survey response rate differed based on the color of the paper the survey was printed on (blue vs green) and presence of a monetary incentive. A 4-page survey on eating disorders was mailed to Division 1A and 1AA college head athletic trainers (N=223) with half of the surveys on blue paper and half on green paper. Half of the athletic trainers (n = 111) received a $1.00 monetary incentive, and half (n = 112) received no monetary incentive. A total of 166 (71%) athletic trainers returned completed surveys. Response rates did not differ based on survey color but did differ based on presence of a monetary incentive. Athletic trainers who received a monetary incentive were significantly more likely than those who did not to return completed surveys (86% vs 63%, respectively).     

Can false memories prime alternative solutions to ambiguous problems?

Research has demonstrated that false memories are capable of priming and facilitating insight-based problem-solving tasks by increasing solution rates and decreasing solution times. The present research extended this finding by investigating whether false memories could be used to bias ambiguous insight-based problem-solving tasks in a similar manner. Compound remote associate task (CRAT) problems with two possible correct answers, a dominant and a non-dominant solution, were created and normed (Experiment 1). In Experiment 2, participants were asked to solve these CRAT problems after they were given Deese/Roediger-McDermott lists whose critical lures were also the non-dominant solution to half of the corresponding CRATs. As predicted, when false memories served as primes, solution rates were higher and solution times were faster for non-dominant than dominant CRAT solutions. This biasing effect was only found when participants falsely recalled the critical lure, and was not found when participants did not falsely recall the critical lure, or when they were not primed. Results are discussed with regard to spreading activation models of solution competition in problem-solving tasks and current theories of false memory priming effects.     

Awareness of the false memory manipulation and false recall for people's names as critical lures in the Deese-Roediger-McDermott paradigm

In the present study, people's names were used as Critical Lures (central concept not on the lists) in the Deese-Roediger-McDermott (DRM) paradigm for studying false recall. Following Mukai, the transparency of false memory manipulation in the paradigm was manipulated to explore its influence on false recall. 80 volunteers (age range 17-30 years, M age = 20.9 yr., SD = 1.6) took part. Analyses showed that making the critical lure inconspicuous did not significantly increase false recall. However, the proportion of falsely recalled Critical Lures was significantly lower and the proportion of critical lures produced on a postrecall test (asking participants to report items that they had thought of but did not recall) was significantly higher when they spontaneously realized the nature of false memory manipulation. However, there was no effect on veridical recall of study items. These results suggest that participants strategically avoided reporting false recall for people's names as Critical Lures even without forewarning about false memory.     

A second type of magnitude effect: Reinforcer magnitude differentiates delay discounting between substance users and controls

Basic research on delay discounting, examining preference for smaller–sooner or larger–later reinforcers, has demonstrated a variety of findings of considerable generality. One of these, the magnitude effect, is the observation that individuals tend to exhibit greater preference for the immediate with smaller magnitude reinforcers. Delay discounting has also proved to be a useful marker of addiction, as demonstrated by the highly replicated finding of greater discounting rates in substance users compared to controls. However, some research on delay discounting rates in substance users, particularly research examining discounting of small‐magnitude reinforcers, has not found significant differences compared to controls. Here, we hypothesize that the magnitude effect could produce ceiling effects at small magnitudes, thus obscuring differences in delay discounting between groups. We examined differences in discounting between high‐risk substance users and controls over a broad range of magnitudes of monetary amounts ($0.10, $1.00, $10.00, $100.00, and $1000.00) in 116 Amazon Mechanical Turk workers. We found no significant differences in discounting rates between users and controls at the smallest reinforcer magnitudes ($0.10 and $1.00) and further found that differences became more pronounced as magnitudes increased. These results provide an understanding of a second form of the magnitude effect: That is, differences in discounting between populations can become more evident as a function of reinforcer magnitude.     

Re-exposure to studied items at test does not influence false recognition

In two experiments, we investigated whether re-exposure to previously studied items at test affects false recognition in the DRM paradigm. Furthermore, we examined whether exposure to the critical lure at test influences memory for subsequently presented study items. In Experiment 1, immediately following each studied DRM list, participants were given a recognition test. The tests were constructed such that the number of studied items preceding the critical lure varied from zero to five. Neither false recognition for critical lures nor accurate memory for studied items was affected by this manipulation. In Experiment 2, we replicated this pattern of results under speeded conditions at test. Both experiments confirm that exposure to previously studied items at test does not affect true or false recognition in the DRM paradigm. This pattern strongly suggests that retrieval processes do not influence false recognition in the DRM paradigm.     

Re-exposure to studied items at test does not influence false recognition

In two experiments, we investigated whether re-exposure to previously studied items at test affects false recognition in the DRM paradigm. Furthermore, we examined whether exposure to the critical lure at test influences memory for subsequently presented study items. In Experiment 1, immediately following each studied DRM list, participants were given a recognition test. The tests were constructed such that the number of studied items preceding the critical lure varied from zero to five. Neither false recognition for critical lures nor accurate memory for studied items was affected by this manipulation. In Experiment 2, we replicated this pattern of results under speeded conditions at test. Both experiments confirm that exposure to previously studied items at test does not affect true or false recognition in the DRM paradigm. This pattern strongly suggests that retrieval processes do not influence false recognition in the DRM paradigm.     

Heightened interpersonal security diminishes the monetary value of possessions

People may value their possessions, in part, because ownership of goods promotes feelings of security. If so, increasing their sense of security should reduce the value they place on possessions. In two studies we tested this prediction. In Study 1, participants who were assigned randomly to write about an instance of receiving social support placed less monetary value on a blanket they owned relative to participants who were assigned randomly to write about a pleasant restaurant experience. In Study 2, participants who were unobtrusively primed with security-related words placed less monetary value on a pen they just received relative to participants who were primed with positive or neutral words. Results suggest that enhancing interpersonal security reduces valuing possessions.