2022-2023 Undergraduate Awardee: Lily Reck

“Experienced Emotion: Positive Valence Acquisition of Stimuli Associated with High Cognitive Effort”

Lily Reck, George Washington University


Previous research shows that stimuli associated with a high level of cognitive effort can acquire positive valence. For example, faces that frequently appear with incongruent distractors (e.g., a male face superimposed with the gender word “FEMALE”) are subsequently recognized faster when the faces express positive, rather than negative, emotion. However, it is still unclear whether perceiving emotion in high-effort stimuli impacts participants’ emotional state. The current study examined whether participants’ experienced emotion matched the positivity bias associated with high-effort stimuli. Participants performed a color Stroop task by identifying the color of a color patch, while ignoring a congruent or incongruent (see below), overlapping distractor color word.

Participants in the low-effort condition received 80% congruent trials, and those in the high-effort condition received 20% congruent trials. Throughout this task, participants were occasionally asked to rate their mood on a 5-point visual analogue mood scale, ranging from 1 (very negative) to 5 (very positive). Results show that the high-effort group rated their mood more positively than the low-effort group, implying that the results in the previous study may be due to the change of subjective feeling because of exerting a high level of cognitive effort.


Our emotions regularly dictate the success of our actions, and in turn our actions result in different emotions. For example, if we perform poorly on an academic assessment, then we may feel sad, disappointed, or discouraged. In turn, this presence of negative emotion may affect our short-term success on other measures of skill, such as a presentation in the following class. From this hypothetical scenario, in everyday life, people’s cognitive ability and emotions causally interact both frequently and with high stakes. This interaction between cognitive effort and emotion has been simulated in a laboratory setting using an interference paradigm, in which participants must maintain the task goal, while ignoring task-irrelevant distractors.

A previous research study has shown that the presence of cognitively demanding stimuli can lead to the faster detection of positive emotion in those stimuli. For example, in the first phase of their experiment, Tae et al. (2022) utilized a gender Stroop task, where participants were tasked with recognizing the apparent gender of an emotionless, neutral face while ignoring either a congruent or incongruent overlapping gender word. Half of the stimuli appeared with a congruent gender word 80% of the time, the mostly congruent condition (MC), and the other half of stimuli appeared with an incongruent gender word 80% of the time, the mostly incongruent condition (MI). This phase resulted in participants forming an association between the faces and the level of cognitive effort required to ignore the superimposed distractor word. Overall, the congruency effect (i.e., the difference in response times between congruent and incongruent conditions) was smaller with MI stimuli than MC stimuli, indicating that mostly incongruent stimuli require more cognitive effort. The next phase of Tae et al.’s experiment tasked participants with identifying the emotion, positive (happy) or negative (angry), in the same actors’ faces from the previous phase. The researchers found that participants responded significantly faster to the MI stimuli when the stimuli was portraying positive emotion, as opposed to negative emotion–a concept known as the positivity bias. Additionally, this inclination towards positive emotion was not prevalent with the low-effort MC stimuli. Therefore, the researchers concluded that stimuli requiring increased cognitive effort can become associated with positive valence (Tae et al., 2022).

However, it is still not clear whether detecting emotion in high-effort stimuli impacts the participants’ experienced emotion. In Experiment 1 of the current study, we examined whether participants’ emotional state matches the positive bias associated with high-effort stimuli found in the Tae et al. (2022) study.


131 participants were recruited from The George Washington University for course credit. All provided written informed consent prior to participation.

The present study consisted of one between-subject experiment, conducted online through E-Prime Go. Participants performed 180 total trials of a color Stroop task by identifying the color of a color patch while ignoring an overlapping distractor color word. One group of participants received 80% congruent trials, the MC, low-effort condition, while the other group received 20% congruent trials, the MI, high -effort condition. Approximately every thirty Stroop trials, participants were asked to rate their mood on a 5-point visual analogue mood scale, with 1 being very negative and 5 being very positive, yielding a total of six experienced emotion ratings. By manipulating the list wide proportion congruency of the colors, the two groups of participants elicited differing amounts of cognitive effort, though the task itself was kept constant.

After data collection concluded, individual participant files were downloaded from E-Prime Go before being merged into one data file in E-Merge 3 and processed in E-Data Aid 3. This file was then exported to Excel for preliminary data analysis and entered into SPSS 28 for further statistical testing.


We excluded 25 participants from data analysis due to poor accuracy (lower than 80%), leaving a total of 106 participants (56 in the MC condition and 50 in the MI condition).

First, the correct response times to the Stroop stimuli were subjected to a 2-way ANOVA with trial congruence (congruent and incongruent) as a within-subject variable and congruence proportion (MC and MI) as a between-subject variable. While the MC and MI groups were not different in terms of response time,  p >  0.13, both groups responded faster to congruent (M = 528 ms) than to incongruent trials (M = 600 ms), F(1, 104) =  57.02, p  < 0.001, ηp2 = 0.354. Further, the trial congruence effect was different between MC and MI groups, F(1, 104) = 92.464,  p  < 0.001, ηp2 = 0.471. The congruence effect was significant in both the MC condition (M = 164 ms), t(55) = 10.16, p < 0.001, and in the MI condition (M = -20 ms), t(49) = -2.19, p = 0.034, but the former was greater than the latter. The interaction between congruence proportion and trial congruence establishes that the participants in the MI condition exerted more cognitive effort than those in the MC condition.

Second, the mood ratings were compared between the two groups in a 2-way ANOVA with the 6 different emotion rating points as within-subject variables and congruence proportion (MC and MI) as a between-subject variable. The results showed that regardless of the specific rating points, MI participants reported more positive mood (M = 3.12) than MC participants (M = 2.78), F(1, 104), =  4.83  p < 0.001 , ηp2 = 0.044. No other main effect or interaction was significant, p > 0.66.


The purpose of Experiment 1 was to investigate if participants’ emotional state reflects bias towards positive emotion during high cognitive effort tasks. Two groups of participants completed a block of color Stroop trials intermixed with mood rating scales, where the high-effort group faced MI trials, while the low-effort group responded to MC trials. Participants in the high-effort condition rated their moods as significantly more positive than the low-effort group, implying that the results in the Tae et al. (2022) study may be due to the change of subjective feeling because of exerting a high level of cognitive effort.

To further investigate the mechanisms of the positive bias associated with high cognitive effort, we propose two hypotheses. First, the successful performance hypothesis emphasizes that in the high cognitive effort condition, participants simply have more opportunities to resolve the conflict between the color patch and the distractor color word (80% of total trials) than those in the low effort condition (20% of total trials). The sheer increase in the frequency of successful conflict resolution could subsequently result in increased positive mood. Experiment 2 will control task difficulty and manipulate opportunity for conflict resolution. The high-frequency group will undergo a block of 600 color Stroop trials of 50% congruence (300 incongruent trials), while the low frequency group will instead complete 300 Stroop trials (150 incongruent trials), followed by 300 simple color identification trials to equate the number of total trials. Both groups will rate their mood 6 random times throughout the experiment. If opportunity for successful performance is responsible for the positive mood of participants in cognitively challenging blocks, then the high frequency group will report a more positive emotional state than the low frequency group.

Alternatively, but not mutually exclusively, the task difficulty hypothesis proposes that overall task difficulty in high-effort blocks is responsible for participants’ increased mood. When completing an 80% congruent block, the incongruent trials appeared occasionally, reducing the task difficulty, while in a 20% congruent block, the incongruent trials were prevalent, requiring high cognitive effort due to elevated task difficulty. In Experiment 3, opportunities for conflict resolution will be controlled while overall task difficulty is manipulated. This task will involve 600 color Stroop trials of 50% congruence, with the color patch and overlapping word appearing in one of four locations on the screen: top left, bottom left, top right, or bottom right. In the random condition, the congruence of the trials will be randomly distributed across the left two and right two locations. However, in the prediction group, the laterality of locations will serve as a predictor of congruency (e.g., 80% of left trials will appear incongruent). This manipulation will allow the prediction group to partially predict the type of congruence, which will reduce the task difficulty. These Stroop trials will be randomly intermixed with 6 mood scale ratings. If task difficulty is the cause of increased mood associated with high cognitive effort, then the participants in the random group will express more positive moods than the prediction group.

Impact Statement

The current study showed how perceiving positive emotion in a challenging task environment positively influences our own experienced emotions. Firstly, understanding the emotional impact of exerting cognitive effort is crucial for best informing policy decisions, especially in professional settings for optimizing productivity in the presence of frequent distractors. Moreover, the relevance of this research to overall executive function may facilitate outreach to non-academic constituencies. Lastly, previous research has never separately studied successful performance and task difficulty in relation to cognitively challenging tasks, and so the results from Experiment 2 and 3 could greatly impact the field at large in how cognitive conflict is studied and perceived in relation to experienced emotion in the future. This research will be presented in a poster at both the Association for Psychological Science 35th Annual meeting and the Vision Sciences Society 22nd Annual meeting in May 2023, sponsored by the National Eye Institute Early Career Scientist Travel Grant, the George Washington University (GWU) Sigelman Undergraduate Research Enhancement Award, and the GWU Columbian College of Arts & Sciences Scholarly Travel Fund.