Between-subjects Variable Research Articles

Psychosocial and vocational impact of an internship program for people diagnosed with severe mental illnesses

Purpose Unemployment is an obstacle in recovery for people with severe mental illnesses (SMI), both in reducing psychopathological symptoms and in achieving a high quality of life. The aim of this study was to explore the impact of an internship program for people diagnosed with SMI on psychosocial variables using a pre-test and post-test design. Method Four scales were administered to a sample of 127 study participants, all of whom were diagnosed with SMI. The results of standard and sheltered employment outcomes were obtained by comparing the number and type of contracts gained by participants up to one year after program completion. A repeated measures ANOVA analysis was carried out with intervention being an independent intra-subject variable and type of participant diagnosis being a between-subjects variable. Results A limited increase in social functioning was found, as well as a significant decrease in psychiatric distress for users diagnosed with personality disorders. Participants in the internship program obtained a greater number of employment contracts than their peers who did not participate in the program, albeit with a low effect size. Conclusions Though results were positive, extension of internship length and provision of more intensive counselling for participants may be useful.

Herd immunity versus self-interest motives and norms effects on influenza vaccination intention.

Promoting vaccine uptake is challenging. This research aimed to experimentally test the effect of communication strategies on influenza vaccine uptake intention. We hypothesized that the effect of descriptive norm level (10%-50%-90% of others vaccinated) on intention would vary according to whether the benefits are focused on the individual (self-interest motives) or others (herd-immunity motives). In particular, we predicted that low and high levels of norms would be detrimental in the herd-immunity condition (inverted-U pattern). In contrast, intention should increase linearly with the norm in the self-interest condition. A representative sample of the Swiss population answered a survey containing vignettes manipulating norms (within-subjects variable) and motives (between-subjects variable, randomized). Their intention to receive a flu shot was measured for each situation. As expected, a significant simple quadratic effect of norm was obtained in the herd-immunity condition. No linear effect was found in the self-interest condition. A main effect of motives was found: The intention was higher in the herd-immunity condition than in the self-interest condition. Sensitivity analysis showed that our results are robust, except for the simple quadratic effect in the herd-immunity condition. Herd-immunity motive is more motivating to induce intention to vaccinate against influenza. The effect of norms appears to depend on the motive, and average levels of norms seem to be more motivating than very low and very high levels. The way vaccination is presented can influence adoption rates, and this should be considered when vaccination rates are communicated in the media. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Comparison of the Effects of Extracorporeal Shock Wave Therapy and Dry Needing on Spasticity in Poststroke Patients: A Randomized Controlled Trial

Introduction: The effective treatment of spasticity following a stroke is a critical and pressing concern. Various therapeutic approaches, such as physiotherapy (7, 8) and medication (9, 10), have been employed. In recent years, external corporeal shockwave therapy (ESWT) and dry needling (DN) have gained popularity for managing spasticity and post-stroke pain. This study aims to conduct a comparative analysis of the effectiveness of ESWT and DN in addressing spasticity, pain, as well as upper limb function and sensation in individuals with hemiplegia. Methods: In this study, individuals with hemiplegia were randomly assigned in a 1:1 ratio to either the External Corporeal Shockwave Therapy (ESWT) group (n = 10) or the Dry Needling (DN) group (n = 10). We assessed Upper Extremity Functions, Sensation, Spasticity, and Pain. All measurement indicators were evaluated before treatment and immediately after a single treatment session. To determine the presence of a group *time interaction effect on the treatment's impact for each outcome variable, we used mixed-model repeated-measures ANOVAs. The between-subjects variable was the group, and time served as the within-subjects variable. Results: Both Dry Needling (DN) and External Corporeal Shockwave Therapy (ESWT) demonstrated significant reductions in spasticity within the biceps brachii muscle, along with notable improvements in upper extremity function tests. Moreover, both DN and ESWT led to significant enhancements in the forearm, arm, and finger; however, the same level of improvement was not observed for the hand. Tactile sensitivity, pain sensation, and light touch did not show significant improvements in either treatment group. Nonetheless, both groups experienced a significant reduction in pain levels. When we conducted a comparative analysis between these two treatment groups across all measures, no significant differences were observed (p > 0.05). Conclusion: In individuals with hemiplegia, both External Corporeal Shockwave Therapy (ESWT) and Dry Needling (DN) have demonstrated the ability to effectively reduce pain and spasticity while enhancing upper extremity function. As a result, these treatments may be regarded as viable alternative methods for addressing the needs of individuals with hemiplegia.

When and why is faculty mentorship effective for underrepresented students in STEM? A multicampus quasi-experiment.

Faculty mentorship can be one solution to addressing the participation and persistence gaps between underrepresented groups (URGs) and overrepresented group members in science, technology, engineering, and math (STEM). However, little is known about the mechanisms underlying effective STEM faculty mentorship. The present study (a) investigates if faculty mentorship impacts STEM identity, attitudes, belonging, and self-efficacy; (b) compares students' perceptions of women versus men faculty mentorship support functions; and (c) uncovers the mentorship support mechanisms underlying impactful faculty mentorship. The present research sampled ethnic-racial minority URG undergraduate students pursuing STEM majors across eight institutions (N = 362; age = 24.85; 36.6% Latinx, 30.6% Black, and 4.6% multiracial; 60.1% women). The study's overall quasi-experimental design adopted a one-factor two-level (faculty mentorship status: yes, no) between-subjects design. Among the participants who reported having a faculty mentor, we also examined faculty mentor gender (women vs. men) as a between-subjects variable. Faculty mentorship had a positive impact on URG students' STEM identity, attitudes, belonging, and self-efficacy. Furthermore, mentorship support functions indirectly predicted identity, attitudes, belonging, and self-efficacy among URG mentees who had women compared to men faculty mentors. Implications for how STEM faculty, regardless of their gender identity, can be effective mentors to URG students are discussed. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

The Effects of Transparency and Reliability of In-Vehicle Intelligent Agents on Driver Perception, Takeover Performance, Workload and Situation Awareness in Conditionally Automated Vehicles

In the context of automated vehicles, transparency of in-vehicle intelligent agents (IVIAs) is an important contributor to driver perception, situation awareness (SA), and driving performance. However, the effects of agent transparency on driver performance when the agent is unreliable have not been fully examined yet. This paper examined how transparency and reliability of the IVIAs affect drivers’ perception of the agent, takeover performance, workload and SA. A 2 × 2 mixed factorial design was used in this study, with transparency (Push: proactive vs. Pull: on-demand) as a within-subjects variable and reliability (high vs. low) as a between-subjects variable. In a driving simulator, 27 young drivers drove with two types of in-vehicle agents during the conditionally automated driving. Results suggest that transparency influenced participants’ perception on the agent and perceived workload. High reliability agent was associated with higher situation awareness and less effort, compared to low reliability agent. There was an interaction effect between transparency and reliability on takeover performance. These findings could have important implications for the continued design and development of IVIAs of the automated vehicle system.

Effects of emotion on intertemporal decision-making: Explanation from the single dimension priority model

<p id="p00005">Studies show that significant differences are found in intertemporal choice between people in positive and negative emotions. However, the mechanism underlying this effect is underexplored. This study aimed to reveal the process mechanism of emotions on intertemporal decision making on the basis of the single dimension priority model by using a process-oriented method-a visual analog scale. <break/>We conducted three studies, where emotions were induced by video clip-induced technique to trigger target emotions (positive, neutral and negative). In study 1, the effects of emotions on intertemporal choice was investigated. This study used a 3 (emotion: positive, neutral, negative) × 2 (delay amount: 100, 1000 yuan) × 5 (delay time: 10, 30, 90, 180, 360 days) mixed design with emotion as a between-subjects variable. Participants were randomly assigned to positive, neutral, and negative conditions and were asked to complete the delay discounting task. In study 2, the process mechanism of emotions on intertemporal choice with a between-subjects design (emotion: positive, negative) was explored. Participants in each condition were asked to complete the delay discounting task and to compare the difference in the delay dimension with that on the outcome dimension. In studies 3a and 3b, 2 (emotion: positive, negative) × 2 (priming: time priming/money priming, no priming) between-subjects designs were used to manipulate the difference-comparing process and explore whether the effect of emotions on intertemporal choice disappeared. <break/>The results were observed as follows: (1) Emotions affected intertemporal choice significantly. Participants in the positive condition preferred the delay reward more than participants in the negative and neutral condition. (2) The difference-comparing process played a mediating role in the relationship between emotion and intertemporal decision making. Participants in positive emotion perceived that the difference in outcome dimension was greater than that of delay dimension and preferred the delay option. Participants in negative emotions perceived opposite and tended to choose the immediate choice. (3) The effect of emotions on intertemporal decision making disappeared when the difference-comparing process was manipulated. <break/>In summary, this study revealed the psychological mechanism of emotions on intertemporal decision making from the perspective of decision-making process and added important procedural evidence to the single dimension priority model.

Psychological, psychophysiological and behavioural effects of participant-selected vs. researcher-selected music in simulated urban driving

We investigated the effect of participant-selected (PSel) and researcher-selected (RSel) music on urban driving behaviour in young men (N = 27; Mage = 20.6 years, SD = 1.9 years). A counterbalanced, within-subjects design was used with four simulated driving conditions: PSel fast-tempo music, PSel slow-tempo music, RSel music and an urban traffic-noise control. The between-subjects variable of personality (introverts vs. extroverts) was explored. The presence of PSel slow-tempo music and RSel music optimised affective valence and arousal for urban driving. NASA Task Load Index scores indicated that the urban traffic-noise control increased mental demand compared to PSel slow-tempo music. In the PSel slow-tempo condition, less use was made of the brake pedal. When compared to extroverts, introverts recorded lower mean speed and attracted lower risk ratings under PSel slow-tempo music. The utility of PSel slow-tempo and RSel music was demonstrated in terms of optimising affective state for simulated urban driving.

Information Overload Effects in Sequential Information Acquisition for Investment Decision-Making

This paper experimentally investigates structured investment decision-making with sequential information provision. Subjects were asked to rank investment alternatives using a scoring model. A mixed design with information provision as the within-subject variable and initial information load as the between-subjects variable was employed. A computer-based process tracing technology provided insights into the underlying information acquisition process – information cues were covered by boxes for the second step of the decision. Moving the cursor over a box uncovered the information. Duration and frequency of uncovering the different information cues was recorded in a database. The main variables of interest were decision accuracy, decision confidence, and measures characterizing the information acquisition process. The main findings were the following: the amount of information provided in the first step significantly impacted decision accuracy and decision confidence, which decreased for the high initial information load group. In addition, receiving a high number of information cues in the first step led to a reduction in the attention devoted to the information received in the second step. Confirmatory information search behavior could not be observed. Findings help further our understanding on how the amount and timing of information provision impact decision quality and confidence.

Effects of frequency and signal-to-noise ratio on accuracy of target sound detection with varied inferences among Taiwanese hearing-impaired individuals

This study investigated the effects of interference type (i.e., no interference, auditory interference, and visual interference), target sound frequency (i.e., 125, 1000, and 6000 Hz), and signal-to-noise ratio (SNR) (i.e., 5, 10, and 15 dB) on the accuracy of target sound detection in Taiwanese hearing-impaired individuals. The mixed design consisted of sound frequency and SNR, with the type of interference as a between-subjects variable. A total of 45 hearing-impaired individuals participated in this study. The accuracy of target sound detection was analyzed using three-way repeated-measures. The results revealed that the accuracy was significantly higher when the participants were interfered by auditory information than when they were not interfered or interfered by visual information. The analysis indicated that the accuracy of the target sound detection at a frequency of 6000 Hz was lower than those at frequencies of 125 and 1000 Hz; moreover, the accuracy at 125 Hz was lower than that at 1000 Hz. The SNR also affected the accuracy; the SNRs of 10 and 15 dB were associated with higher accuracy than that of 5 dB; moreover, the SNR of 15 dB yielded higher accuracy than that of 10 dB. Our findings are beneficial in the design of devices for the hearing-impaired, who need to detect a signal in a noisy environment, such as the siren of an ambulance on the road or a signal warning or alarm in the workplace.

Influence of Acculturation on Emotional Learning and Memory in Spanish and English Speakers

Abstract Objective The Emotional Verbal Learning Test-Spanish (EVLT-S) is a novel list learning test similar in structure to traditional verbal memory tests but contains words from 4 discrete emotional categories. Influence of acculturation on emotional learning was examined on EVLT-S learning trials 1 to 5. Participants and Method Participants included 50 bilingual healthy individuals in the Spanish-dominant group (Age M = 20.3years; 72% female) and 27 in the English-dominant group (Age M = 23.4years, 51.9% female). They were administered a battery of tests including the EVLT, a non-emotional verbal list learning test (LLT), Vocabulary (VC), Digit Span (DS), and The Short Acculturation Scale for Hispanics (SASH) in their dominant language. To examine learning curves a mixed model ANOVA was conducted with test (EVLT-S/EVLT, LLT-S/LLT) and trial as within-subjects variables and group (Spanish, English) as a between-subjects variable. Results There were significant main effects (p &amp;lt; .005) for test, trial, and group. The Spanish-dominant group had the lowest overall performance on the EVLT-S (main effect for group). Post hoc comparisons of the Spanish-dominant group’s LLT-S and EVLT-S performance indicated significant differences at each trail (p &amp;lt; .01), with the EVLT-S scores being lower than the LLT-S scores. The ANOVA was repeated with VC, DS, and SASH included as covariates. When controlling for these variables, the main effect for group was no longer significant. A significant trial by acculturation interaction effect emerged (p&amp;lt;.05), with the English-dominant group generally performing better than the Spanish-dominant group. Conclusions Results suggest that Spanish and English language group differences were largely accounted for by word knowledge (VC), working memory (DS), and acculturation differences (SASH) between the groups. The role of these variables is discussed further in the context of acculturation.

Atypical Functional Connectivity Associated with Autonomous Sensory Meridian Response: An Examination of Five Resting-State Networks.

Autonomous sensory meridian response (ASMR) is a perceptual phenomenon in which specific auditory and/or visual stimuli consistently elicit tingling sensations on the neck, scalp, and shoulders, as well as a positive and relaxed emotional state. The “ASMR triggers” that initiate these responses generally consist of soft sounds (e.g., whispering), repetitive noises (e.g., tapping sounds), or videos of people performing socially intimate acts (e.g., watching someone brush her hair). Despite being a relatively common phenomenon, little is known about the neural substrates of ASMR. In the current research, resting-state functional magnetic resonance imaging (fMRI) was used to examine whether ASMR was associated with atypical patterns of functional connectivity. Seventeen individuals with ASMR and 17 matched control participants underwent an anatomical MRI scan and a resting-state fMRI scan. An independent components analysis was used to identify the default mode, salience, central executive, sensorimotor, and visual networks. An analysis of variance with group (ASMR vs. control) as a between-subjects variable was performed to contrast the functional connectivity of each of these networks. The results demonstrated that ASMR was associated with reduced functional connectivity in the salience and visual networks, and with atypical patterns of connectivity in the default mode, central executive, and sensorimotor networks.

Tropicamide has limited clinical effect on cycloplegia and mydriasis when combined with cyclopentolate and phenylephrine

To examine the cycloplegic and mydriatic effect of tropicamide omission from a common pediatric eye drop combination. Consecutive children examined at the Ann & Robert H. Lurie Children's Hospital of Chicago from June 8, 2017 to September 6, 2017 were enrolled prospectively. Tropicamide, cyclopentolate, and phenylephrine (TCP) was instilled in one eye; cyclopentolate and phenylephrine (CP), in the other. Spherical equivalent, maximum pupil size, and pupillary constriction in response to photostimulation were measured before and 30minutes after instillation using an autorefractor and pupillometer. Iris pigmentation was examined as a between-subjects variable. A total of 75 children 4-11years of age were included. Mean differences in spherical equivalent between TCP and CP were not statistically significant (P=0.95). Significant interactions between eye drop regimen and iris pigmentation were observed for pupil size (P=0.001) and constriction percentage (P=0.02). Among only patients with dark irides, TCP yielded slightly larger pupils (7.70 vs 7.31mm [P<0.001]) that were less responsive to light (5.75% vs 8.07% [P=0.002]). All pupils dilated to ≥6.0mm, with equivalent proportions achieving ≥7.0mm for TCP and CP (P=0.18). TCP and CP elicited equivalent cycloplegic effects. Mydriatic differences between the regimens, although statistically significant in dark irides, were of limited clinical magnitude, and all pupils achieved sufficient dilation for funduscopy.

Effects of age and visual attention demands on optokinetic nystagmus suppression

IntroductionThe utility of optokinetic nystagmus suppression as an index of visual attention has been demonstrated; however, a gap exists in our understanding of the effects of aging on attentional division. The purpose of this study was to explore the effect of a subject's age upon their ability to allocate visual attention among multiple salient elements which varied in location and complexity. MethodLarge-field optokinetic nystagmus (OKN)-inducing animations were presented along with a central flashing fixation point to 27 subjects: 15 younger adults (range 19–23, mean age 21.4); and 12 older adults (range 65–89, mean age 74). Subjects were instructed to fixate on a central point while attending to either moving features of the background or solely to the fixation target. Failure of subjects to accurately divide their attention was quantified by optokinetic gain (eye velocity/background velocity). Gain was analysed in two separate 3-way ANOVAs: one at the central location with the between-subjects variable of age and within-subjects variables of complexity and dynamism; and one using only the dynamic tasks, including a between-subjects variable of age and within-subjects variables of complexity and location. ResultsA strong effect of age was found between subjects during the more attentionally demanding dynamic tasks, but there was only a marginal effect during the static tasks. All within-subjects variables were highly significant, and there were several significant 2- and 3-way interactions. ConclusionThis study provides strong evidence for the compounding effects of senescence and stimulus characteristics on an adult's ability to accurately allocate visual attention. These findings show that OKN suppression may be a useful framework for quantification of attentional resources in older subjects.

Effect of exposure to aggressive stimuli on aggressive driving behavior at pedestrian crossings at unmarked roadways

BackgroundAggressive driving, influenced by the proneness of driving aggression, angry state and provoking situation, is adversely affecting traffic safety especially in developing countries where pedestrians frequently cross an unmarked crosswalk. Exposure to aggressive stimuli causes driving anger and aggressive driving behaviors, but the exposure effect on higher and lower aggression drivers and their cumulative changes under successive exposures need more investigation. ObjectivesAn experiment was conducted to examine (1) driving behaviors of individuals with higher and lower aggressive driving traits when approaching pedestrian crossings at unmarked roadways with and without aggressive provocation; and (2) cumulative changes of driving performance under repeated provocations. MethodWe conducted a driving simulator study with 50 participants. Trait of aggressive driving served as a between-subjects variable: participants with an Aggressive Driving Scale (ADS) total score of 30 or more (for men) or 23 or more (for women) were regarded as higher aggressive drivers; lower aggressive drivers were those individuals whose ADS total scores were 21 or less (for men) or 13 or less (for women). Exposure to aggressive stimuli (provoked vs. non-provoked condition) served as a within-subjects variable. Several aspects of the participants’ minimum driving speed, lateral distance from a simulated pedestrian, lateral deviation, and subjective measures were collected. ResultsWe found that drivers with higher aggressive driving traits were more likely to feel irritated and fail to give way for pedestrians and drove closer to pedestrians when exposed to sustained honking and improper passing compared to the non-provoked condition. This trait×state interaction only occurred when pedestrians crossed the street from the right roadway edge line. In addition, we observed an accumulation effect of exposure to aggressive stimuli on driver's aggressive behaviors at pedestrian crossings. ConclusionsEnvironmental design, law enforcement, and educational campaign may have practical value for reducing pedestrian and driver conflicts at unmarked roadways.

Family Income Affects Children’s Altruistic Behavior in the Dictator Game

This study aimed to examine how family income and social distance influence young rural Chinese children’s altruistic behavior in the dictator game (DG). A total of 469 four-year-old children from eight rural areas in China, including many children left behind by parents who had migrated to urban areas for work, played the DG. Stickers comprised the resource, while recipients in the game were assumed to be either their friends or strangers, with the social distance (i.e., strangers compared to friends) as a between-subjects variable. Children donated significantly more stickers to their friends than to strangers. Moreover, children from lower income families donated more stickers than children from higher income families. However, no gender and parental migrant status differences in children’s prosocial behaviors were evident in this sample. Findings of this study suggest that children’s altruistic behaviours to peers are influenced by family characteristics since preschool age. The probable influence of local socialization practices on development and the possible adaptive significance were discussed.

Incidental vocabulary acquisition from stories: Second and fourth graders learn more from listening than reading

Both reading and language experiences contribute to vocabulary development, but questions remain as to what effect each has and when. This article investigates the effects that reading, telling and sharing a story have on vocabulary acquisition. Children ( N = 37) were told nine stories in a randomized, single-blind and counterbalanced 2 × 3 mixed design. The between-subjects variable was grade (2 vs 4) and the within-subjects factor was the story condition, being either read (adult read aloud) or told (free story telling) to the children, or read silently by the children (independent reading). Each story contained two rare target words that were unlikely to have been previously known to the children. Measures of receptive vocabulary, decoding, reading comprehension and target vocabulary acquisition from the story were also administered. Children in grade 4 performed better on the vocabulary acquisition test and there was a main effect for story condition; children learnt the least number of words when reading the stories independently and the most from the free story telling condition. Implications for vocabulary learning and the importance of oral language exposure – even for established readers in primary school – are discussed.

The effect of expertise on Air Traffic controller's situation awareness

This research examined air traffic controller performance on situation awareness (SA) tasks for routine and non-routine situations. Additionally, the difference of working memory capacity between novices and experts was analyzed. To assess SA performance, participants were asked to answer the query after the simulation was frozen. We employed 2*2*2 mixed factorial design including the between-subjects variable of air traffic controller expertise (novices, experts) and the within-subjects variables of the normality of situation (routine, non-routine), and the distracter task (yes, no) and then assessed the capacity of working memory. The results suggest that experts' performance significantly remained higher than novices for non-routine situations. When the distracter task was given, experts' SA accuracy was significantly higher than novices for both routine and non-routine situations. However, there is no difference in working memory capacity between experts and novices. These findings suggest that the performance on SA task was affected by the expertise of the professional development and training.

The Effect of Expertise on Air Traffic Controller's Situation Awareness

This research examined air traffic controller performance on situation awareness (SA) tasks for routine and non-routine situations. Additionally, the difference of working memory capacity between novices and experts was analyzed. To assess SA performance, participants were asked to answer the query after the simulation was frozen. We employed 2*2*2 mixed factorial design including the between-subjects variable of air traffic controller expertise (novices, experts) and the within-subjects variables of the normality of situation (routine, non-routine), and the distracter task (yes, no) and then assessed the capacity of working memory. The results suggest that experts' performance significantly remained higher than novices for non-routine situations. When the distracter task was given, experts' SA accuracy was significantly higher than novices for both routine and non-routine situations. However, there is no difference in working memory capacity between experts and novices. These findings suggest that the performance on SA task was affected by the expertise of the professional development and training.

Effect of caffeine on RPE and perceptions of pain, arousal, and pleasure/displeasure during a cycling time trial in endurance trained and active men

Caffeine has been reported to alter perceptions of exertion, muscle pain, and mood, yet the majority of existing data were obtained in resting volunteers or during steady-state exercise. The primary aim of this study was to examine the effects of caffeine on rating of perceived exertion (RPE) and perceptions of leg pain, arousal, and pleasure/displeasure during a simulated cycling time trial. Endurance-trained (n=8, VO2max=57.5±3.9mL/kg/min) and active (n=8, VO2max=46.5±6.3mL/kg/min) men initially completed two familiarization trials separated by at least 48h. Over the next three trials, they completed a 10km time trial preceded by ingestion of drinks containing caffeine (5mg/kg ingested on 2 separate days) or placebo. Treatments were ingested using a single-blind, crossover design, and participants were deceived as to the content of all drinks. During exercise, RPE (6–20 scale), leg pain (0–10 scale), arousal (Felt Arousal Scale), and pleasure/displeasure (Feeling Scale) were recorded using various categorical scales. Repeated measures analysis of variance was used to assess differences in all variables across time and treatments, with fitness level used as a between-subjects variable. Pleasure/displeasure was altered (p<0.05, partial eta-squared (η2)=0.23) with caffeine compared to placebo, although leg pain, RPE, and arousal were similar (p>0.05) across treatments. Caffeine increased (p<0.05, η2=0.27) cycling performance by 0.3–2.0% versus placebo, with no effect (p>0.05) of fitness level. Only in trained men; however, was there a significant caffeine-mediated improvement in cycling performance, which was consequent with diminished mood in trained and improved mood in active individuals.

Ergogenic Effects of Caffeine on Simulated Time-Trial Performance Are Independent of Fitness Level

Background: The primary aim of this study was to compare the ergogenic effects of caffeine on cycling performance in endurance-trained and recreationally active participants. Methods: Endurance-trained [n=8, VO2max=57.5±3.9 mL/(kg·min)] and active [n=8, VO2max=46.5±6.3 mL/(kg·min)] participants initially completed two familiarization trials separated by at least 48 hours. Over the next three trials, they completed a 10 km cycling time trial preceded by ingestion of drinks containing caffeine (5 mg/kg ingested on 2 separate days) or placebo. Treatments were ingested using a single-blind, crossover design, and participants were deceived as to the content of all drinks. During exercise, heart rate (HR), rating of perceived exertion (RPE), and time were recorded every 1.6 km. Repeated measures analysis of variance was used to assess differences in cycling time, HR, and RPE between treatments, with fitness level used as a between-subjects variable. Results: Caffeine increased (p<0.05) cycling performance by 0.3%–2.0% versus placebo, with no effect (p>0.05) of fitness level. Magnitude of performance improvement in both caffeine trials (−0.21 and −0.23 minutes, respectively) was similar versus placebo. Compared with placebo, exercise HR was higher (p<0.05) with caffeine, although RPE was similar (p>0.05) across treatments. Conclusions: In active men of varying fitness, data reveal a small caffeine-mediated improvement in cycling performance that was similar in magnitude.