Significant Main Effect Of Condition Research Articles

Exercise does not cause post-exertional malaise in Veterans with Gulf War Illness: A randomized, controlled, dose–response, crossover study

Chronic multisymptom illnesses (CMI) such as Myalgic Encephalomyelitis/Chronic Fatigue Syndrome, Long-COVID, and Gulf War Illness (GWI) are associated with an elevated risk of post-exertional malaise (PEM), an acute exacerbation of symptoms and other related outcomes following exercise. These individuals may benefit from personalized exercise prescriptions which prioritize risk minimization, necessitating a better understanding of dose–response effects of exercise intensity on PEM. MethodsVeterans with GWI (n = 40) completed a randomized controlled crossover experiment comparing 20 min of seated rest to light-, moderate-, and vigorous-intensity cycling conditions over four separate study visits. Symptoms, pain sensitivity, cognitive performance, inflammatory markers (C-reactive protein and plasma cytokines) were measured before and within 1 h after exercise and seated rest. Physical activity behavior was measured ≥ 7 days following each study visit via actigraphy. Linear mixed effects regression models tested the central hypothesis that higher intensity exercise would elicit greater exacerbation of negative outcomes, as indicated by a significant condition-by-time interaction for symptom, pain sensitivity, cognitive performance, and inflammatory marker models and a significant main effect of condition for physical activity models. ResultsSignificant condition-by-time interactions were not observed for primary or secondary measures of symptoms, pain sensitivity, cognitive performance, and a majority of inflammatory markers. Similarly, a significant effect of condition was not observed for primary or secondary measures of physical activity. ConclusionsUndesirable effects such as symptom exacerbation were observed for some participants, but the group-level risk of PEM following light-, moderate-, or vigorous-intensity exercise was no greater than seated rest. These findings challenge several prior views about PEM and lend support to a broader body of literature showing that the benefits of exercise outweigh the risks.

Ascorbic Acid Infusion Improves Cerebrovascular Reactivity in Middle-Aged and Older Adults

Aging is associated with reductions in cerebrovascular reactivity (CVR) and cerebrovascular conductance (CVC), which may contribute to the development of neurodegenerative disease and stroke. In the peripheral vasculature, increased oxidative stress is linked to vascular dysfunction and is ameliorated following infusion of the antioxidant ascorbic acid (AA). However, oxidative stress’ effect on cerebrovascular function in humans is not entirely understood. PURPOSE: To determine whether oxidative stress reduces CVR and CVC in middle-aged and older adults (MA/O). We hypothesized that AA infusion would increase CVR and CVC in MA/O but not young adults (YA). METHODS: Young (18-29 years) and middle-aged and older (55-79 years) adults were recruited for two identical experimental visits. Each visit consisted of the same measures performed both before and after the infusion of either AA or saline (SAL). Middle cerebral artery blood velocity (MCAv) was recorded using a transcranial Doppler ultrasound probe. CVR was tested using a hypercapnia protocol that was achieved with a computer-based gas blender that increased the subjects’ end-tidal partial pressure of carbon dioxide (PETCO2) 9 mmHg above baseline for a 3-minute period. CVR was defined as the percent change in MCAv during hypercapnia divided by the absolute change in PETCO2. CVC was defined as the percent of CVR normalized for the changes in mean arterial blood pressure. Two-way ANOVAs were used to assess the effects of AA and SAL on CVR and CVC. Fisher’s LSD tests were used to assess main and interaction effects when necessary. RESULTS: 8 YA (25 + 2 years) and 14 MA/O (65 + 6 years) completed the experimental visits. There was a significant main effect of condition (pre/post) on CVR following SAL infusion (p = 0.016), and a significant age x condition interaction effect on CVR following AA infusion (p = 0.016). There were no significant main or interaction effects on CVC following SAL infusion, but there was a significant age x condition interaction effect on CVC following AA infusion (p = 0.012). Post hoc testing indicated that the difference in CVR following SAL infusion was due to an increase in YA (3.0 + 0.5 %/mmHg pre vs. 3.8 + 1.1 %/mmHg post, p = 0.047), whereas the difference in CVR following AA infusion was due to an increase in MA/O (3.3 + 1.7 %/mmHg pre vs. 4.1 + 1.9 %/mmHg post, p = 0.006). The difference in CVC was indicated to be due to both lower baseline CVC in MA/O (2.3 + 0.4 %/mmHg YA pre vs. 1.3 + 1.1 %/mmHg MA/O pre, p = 0.019) and an increase in CVC in MA/O following AA infusion (1.3 + 1.1 %/mmHg pre vs. 2.0 + 0.5 %/mmHg post, p = 0.047). CONCLUSION: Our main finding is that AA infusion restores CVR and CVC in MA/O, but not YA. This finding suggests that age-related increases in oxidative stress may impair cerebrovascular function. Supported by NIH Grant P20 GM113125. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Exploring the Impact of Safer Sports Betting Promotion on Social Media: An Experimental Study.

The current study assessed the effectiveness of delivering safer gambling messaging to regular sport bettors on social media. It also assessed whether the content of the message impacted message effectiveness. A 3 × 2 mixed factorial design was employed, with 281 participants randomly assigned to follow one of three Twitter accounts. The accounts either sent out informational messages, self-appraisal messages or emotional self-efficacy messages. Participants reported betting behaviour from the two weeks prior to following the accounts, in addition to during the two-week intervention period, using information from their online gambling accounts. Participants reported readiness to change gambling behaviour pre and post the two-week intervention period. A significant main effect of intervention stage highlighted reductions in betting behaviour and increased readiness to change behaviour. However, there was no significant main effect of condition and no significant interaction between intervention stage and condition upon betting behaviour or readiness to change. The findings suggest receiving safer gambling messages on social media may lead to a reduction in betting behaviour. However, similar reductions in behaviour were observed in the experimental and control conditions. Further research is needed to clarify whether changes in behaviour observed in the current study would extend over a longer period of time.

Effectiveness of a video-feedback intervention to promote positive parenting for foster children

Foster children are at risk for developing disorganized attachment relationships (Van den Dries et al., 2009; Vasileva & Petermann, 2018) and behavioural problems (Goemans et al., 2015; Vanschoonlandt et al., 2012). Video-feedback Intervention to promote Positive Parenting and Sensitive Discipline – Foster Care/Adoption (VIPP-FC/A) is an intervention aimed at improving sensitive parenting in order to promote secure attachment relations and reduce behavioural problems. In this study, a Randomized Controlled Trial (RCT) was used in order to examine the effectiveness of VIPP-FC/A in a Flemish foster care sample ( n = 100), using questionnaires at three measurement moments. The hypothesis was that VIPP-FC/A would increase foster mothers’ sensitive parenting and decrease the externalizing behavioural problems and insecure attachment behaviour of the foster children and parenting stress of the foster mothers. The intervention effects on these four outcome variables were analysed by constructing four multilevel models. After controlling for the baseline measurement, there was no significant main effect of condition for sensitive parenting, externalizing problems, insecure attachment behaviour and parenting stress. There was however a significant effect of condition and age on insecure attachment behaviour: within the group of youngest foster children (under 30 months), children in the intervention group scored lower insecure attachment scores than children in the control group. Additionally, there was a significant effect of condition and type of foster care on externalizing behaviour problems. In the group of children placed in kinship foster care, children in the intervention group had lower external behavior scores than children in the control group.

Mobile Electroencephalography Reveals Differences in Cortical Processing During Exercises With Lower and Higher Cognitive Demands in Preadolescent Children.

The aim of this study was to examine whether cortical activity changes during exercise with increasing cognitive demands in preadolescent children. Twenty healthy children (8.75 [0.91]y) performed one movement game, which was conducted with lower and higher cognitive demands. During a baseline measurement and both exercise conditions, cortical activity was recorded using a 64-channel electroencephalographic system, and heart rate was assessed. Ratings of perceived excertion and perceived cognitive engagement were examined after each condition. To analyze power spectral density in the theta, alpha-1, and alpha-2 frequency bands, an adaptive mixture independent component analysis was used to determine the spatiotemporal sources of cortical activity, and brain components were clustered to identify spatial clusters. One-way repeated-measures analyses of variance revealed significant main effects for condition on theta in the prefrontal cluster, on alpha-1 in the prefrontal, central, bilateral motor, bilateral parieto-occipital, and occipital clusters, and on alpha-2 in the left motor, central, and left parieto-occipital clusters. Compared with the lower cognitive demand exercise, cortical activity was significantly higher in theta power in the prefrontal cluster and in alpha-1 power in the occipital cluster during the higher cognitive demand exercise. The present study shows that exercise complexity seems to influence cortical processing as it increased with increasing cognitive demands.

P013 The Effect of Noise Exposure during Sleep on the Cortisol Awakening Response

Abstract Introduction Environmental noise could negatively impact the sleep and well-being of nearby residents. This study tested for overnight noise exposure effects on the cortisol awakening response (CAR), a potential marker of noise-related stress responses, and for differences in CAR and hair cortisol between different prior noise exposure groups. Methods A randomised controlled laboratory trial was conducted in 68 individuals from four groups; including WFN-exposed residents n=14 with and n=18 without WFN-related complaints, n=18 quiet rural control and n=18 urban traffic-noise exposed residents. Across six nights, after an initial adaptation night, participants were exposed in random order to different noise conditions, which included intermittent WFN and road traffic noise (RTN), WFN at average exposure levels throughout wake, sleep or both and a quiet control night. Salivary CAR responses were evaluated from 5 serial saliva samples collected following awakening. Hair cortisol levels were also collected. Mixed effects models were used to examine group and night effects on CAR and group effects on hair cortisol. Results There was a significant main effect of condition on CAR (p=0.038), but no significant pairwise differences between the control night and noise exposure nights, and no further differences between nights or groups on CAR or hair cortisol concentrations. Conclusions Acute in-laboratory noise-related sleep disturbance at the levels used in this study do not appear to alter acute cortisol awakening responses. A better understanding of chronic noise exposure effects and stress responses is important to help clarify and mitigate potential environmental noise exposure effects on nearby residents.

The immediate effect of multidirectional elastic tape on the passive mechanical properties of the ankle joint

ABSTRACTThis study examined the immediate effects of multidirectional elastic tape (MET) on passive ankle joint torque in healthy adults. A randomised crossover trial evaluated four tape conditions (no-tape-NT, low-tension-LT, medium-tension-MT, and high-tension-HT) at two angular speeds on peak dorsiflexion torque, low- (stiffness 1) and high-torque stiffness (stiffness 2), area under the loading curve (AUC) and hysteresis. Twenty-two adults completed the study (17 females; mean (SD): age 26.0 (6.9) years, height 1.7 (0.1) m, body mass 71.1 (20.2) kg. There was no significant condition-by-speed interaction for any ankle torque variable. There was a significant main effect of condition on peak dorsiflexion torque, stiffness 1, and AUC, but not stiffness 2 or hysteresis. Post-hoc tests revealed that peak dorsiflexion torque, stiffness 1 and AUC were significantly lower in the NT condition, compared to the three taped conditions, and between the LT and HT conditions, though the effect sizes were considered small. MET applied with increasing levels of pre-tension, led to a small and incremental increase in stretch resistance and elastic energy stored (range 5.5% to 12.5%) during passive ankle dorsiflexion. Importantly, effect sizes were small and may not translate to measurable improvements in muscle-tendon unit performance during dynamic exercise.

Effects of a Tart Cherry Supplement on Recovery from Exhaustive Exercise.

The aim of this study was to investigate the effects of a tart cherry supplement on recovery from exercise-induced muscle damage. Seventeen recreationally active women (mean age ± SD = 22.2 ± 3.3 years, height = 162.0 ± 6.0 cm, body mass = 65.1 ± 11.1 kg, BMI = 24.7 ± 3.5 kg·m2) supplemented with 1000 mg of concentrated tart cherry or a placebo for eight consecutive days. An overload protocol of 8 sets of 10 repetitions of maximal effort concentric and eccentric muscle actions of the leg extensors at a velocity of 60°·s-1 was performed on the fourth day of supplementation. Testing sessions consisted of a muscle function test (MFT) to examine pre- and post-testing peak torque, peak power, total work, time-to-peak torque, mean power, muscle activation of the quadriceps, and muscle soreness at baseline and post-testing at 0 h, 24 h, 48 h, and 72 h. A second trial of testing was repeated two weeks later using the opposite supplement to the one assigned for the first trial. No significant interaction for time × condition × velocity (p = 0.916) and no significant main effect for condition (p = 0.557) were demonstrated for peak torque. However, there were main effects for time and velocity for concentric quadriceps peak torque (p < 0.001). For muscle soreness, there was no two-way interaction for time x condition (p > 0.05) and no main effect for condition (p > 0.05), but there was a main effect for time (p < 0.001). In conclusion, a tart cherry supplement did not attenuate losses in isokinetic muscle peak torque, peak power, total work, time-to-peak torque, muscle soreness, or quadriceps muscle activation.

Change in Views of Aging, Physical Activity, and Physical Health Over 8 Weeks: Results From a Randomized Study.

The AgingPLUS program targets motivational barriers, including negative views of aging, as mechanisms to increase adult physical activity. A pilot study was conducted to test the efficacy of this new program against a generic successful aging program. Fifty-six participants were randomly assigned to the AgingPLUS group, and 60 participants were assigned to the active control group. Repeated-measures multivariate analyses of variance assessed changes in views of aging, physical activity, blood pressure, and hand-grip strength from pretest (Week 0) to delayed posttest (Week 8). The Condition × Occasion interactions were nonsignificant; however, significant main effects for condition and occasion were found. Follow-up tests showed that views of aging were more positive, and physical activity had significantly increased at Week 8 for all participants. In addition, in the treatment group, elevated blood pressure had significantly decreased and hand-grip strength had significantly increased at Week 8. Despite the nonsignificant multivariate findings, the main effect findings provided partial support for the efficacy of the AgingPLUS program.

On the move: The impact of breaking up sitting during the day on driving performance when sleep restricted

ObjectiveSleep restriction and prolonged sitting are both associated with reduced cognitive performance which is detrimental to safe driving. Regular bouts of walking to break up prolonged sitting have been shown to improve cognitive performance. It is unknown if breaking up sitting with walking may improve cognitive performance related to driving, particularly when drivers are sleep restricted. MethodsHealthy participants (n = 81, age 23.6 ± 4.5 years, 49% female) participated in a 7-day laboratory study (1 Adaptation day, 5 Experimental days, 1 Recovery day). Participants were randomly allocated to a condition: sitting 9 h sleep (Sit9), breaking up sitting 9 h sleep (Break9), sitting 5 h sleep (Sit5) and breaking up sitting 5 h sleep (Break5). Participants allocated to the Break9 and Break5 conditions completed 3-min of light-intensity walking on a treadmill every 30 min between 09:00–17:00 h, while participants in Sit9 and Sit5 groups remained seated during these times. Each participant completed a 20-min monotonous simulated driving commute at 08:10 h and 17:30 h on each of the 5 Experimental days. ResultsThere was a significant main effect of condition with decreased speed variability for Break9 compared to Sit9, Sit5 and Break5 (p < 0.0001) for both commutes. Break5 had significantly higher lane variability compared to Sit9 and Break9, and Sit5 (p = <0.05) for both commutes. Break5 reported greater subjective sleepiness before each commute compared to Sit9, Break9 and Sit5 (p < 0.001). Cox Proportional Hazards model showed a significant increase in time to first crash for Sit5 and Break5 compared to Sit9 (p= <0.005). There were no significant two- or three-way interaction effects by condition, day or commute time for any of the outcome measures. ConclusionThe findings from this study highlight that breaking up sitting with light-intensity walking may improve driving performance in areas such as speed maintenance, but may not extend to lane keeping performance. The findings also show that the benefits of breaking up sitting with light-intensity walking may not be sufficient to overcome detrimental impacts of sleep restriction for all areas of driving performance. Future research should focus on increased intensity of activity as a possible means to extend the benefits more comprehensively across additional areas of driving performance.

Muscle Tension in Generalized Anxiety Disorder During a Stressful Mental Arithmetic Task

Introduction: The purpose of this study was to compare muscle tension between individuals with and without generalized anxiety disorder (GAD) during a resting state and a stressful mental arithmetic task. Methods: A total of 95 undergraduate students (68 females and 27 males; mean age=19.6, SD=3.5) completed an online survey on GAD symptoms and pathological worry, a diagnostic interview, and two laboratory tasks (resting and mental arithmetic tasks) while electromyography (EMG) signals were being recorded. Results: We found a significant main effect of condition, F(1,93) = 24.13, p&lt;.001, and group, F(1,93) = 4.55, p=.036. Furthermore, there was a significant interaction effect between condition and group, F(1,93) = 5.85, p=.017. A post-hoc analysis revealed that the increase in EMG activity from the resting period, 95% CI [.002398 .003474], to the mental arithmetic task, 95% CI [.003850 .005086], was significant for the GAD group, but not for the non-GAD group. Conclusions: Individuals with and without GAD did not show significant differences in physiologically measured muscle tension at baseline. However, the GAD group showed higher levels of muscle tension during stressful situations when compared to the non-GAD group.

Behavioural approach-avoidance tendencies among individuals with elevated blood pressure.

The online version contains supplementary material available at 10.1007/s12144-023-04337-2.

Metabolic impact of feeding prior to a 60-min bout of moderate-intensity exercise in females in a fasted state.

The metabolic impact of pre-exercise feeding of protein or carbohydrate on fat oxidation and energy expenditure rates, especially, in females, is poorly understood. Recreationally active females (n = 15, 32 ± 10 years, 164.8 ± 5.6 cm, 63.5 ± 9.3 kg, 23.4 ± 3.2 kg/m2) completed four testing sessions in a randomized, double-blind, crossover fashion after fasting overnight. Participants ingested isovolumetric and isoenergetic solutions containing either 25 g of whey protein, casein protein, carbohydrate (CHO), or a non-caloric placebo (PLA). Participants then completed 60 min of treadmill exercise at 15% below ventilatory threshold 30 min after ingestion. Respiratory exchange ratio (RER) was evaluated throughout exercise and resting energy expenditure (REE) was assessed pre-exercise, and 0-, 60-, and 120-min post-exercise. A significant condition x time interaction was observed for RER (p = 0.008) during exercise, with CHO exhibiting higher RER values (vs. PLA) at four time points. A significant main effect for condition was observed for carbohydrate (p = 0.001) and fat (p = 0.02) oxidation rates during exercise, with fat oxidation rates being higher in PLA vs. CHO (p = 0.01). When total fat oxidized was calculated across the entire exercise bout, a significant main effect for condition was observed (p = 0.01), with PLA being greater than CHO (p = 0.04). A significant condition x time interaction (p = 0.02) was found for both absolute and normalized REE, with casein and whey protein having significantly higher values than CHO (p < 0.05) immediately post-exercise. When compared to a fasted control (PLA), consuming CHO, but not protein, decreased total fat oxidation prior to a 60-min bout of moderate-intensity exercise in females.

Adopting a holistic focus of attention promotes adherence and improves performance in college track and field athletes

Research on novices suggests that an external focus improves performance over an internal focus. For experienced performers the results on attentional focus have been mixed. Recently Becker, Georges, and Aiken (2019) suggested that a holistic focus may be a useful substitute when an external focus is not appropriate. The purpose of this study was to investigate attentional focus within track and field athletes performing an underhand shot throw. 18 female athletes performed an underhand shot throw (4 kg) under three focus conditions: internal, external, and holistic. Participants also rated their adherence to each attentional focus manipulation. Repeated-measures ANOVAs with Sidak post-hoc were used to analyze both underhand shot throw distance and focus adherence. A significant main effect for condition was observed for distance (F = 6.14, p = .005). A holistic threw farther than an internal focus (p < .001) with no difference between internal and external (p = .380), or holistic and external foci (p = .312). For adherence, a significant main effect for condition was observed (F = 4.56, p = .018) with holistic focus adhering to the cue significantly more than internal focus (p < .019). The results of this study are in line with research that found a benefit for a holistic focus with novice performers (Becker et al., 2019). Mullen and Hardy (2010) also found a benefit for the golf putt, basketball shot, and long jump with skilled performers adopting a focus on the global or holistic aspect of the skill.

Advantage conferred by overnight sleep on schema-related memory may last only a day.

Sleep contributes to declarative memory consolidation. Independently, schemas benefit memory. Here we investigated how sleep compared with active wake benefits schema consolidation 12 and 24 hours after initial learning. Fifty-three adolescents (age: 15-19 years) randomly assigned into sleep and active wake groups participated in a schema-learning protocol based on transitive inference (i.e. If B > C and C > D then B > D). Participants were tested immediately after learning and following 12-, and 24-hour intervals of wake or sleep for both the adjacent (e.g. B-C, C-D; relational memory) and inference pairs: (e.g.: B-D, B-E, and C-E). Memory performance following the respective 12- and 24-hour intervals were analyzed using a mixed ANOVA with schema (schema, no-schema) as the within-participant factor, and condition (sleep, wake) as the between-participant factor. Twelve hours after learning, there were significant main effects of condition (sleep, wake) and schema, as well as a significant interaction, whereby schema-related memory was significantly better in the sleep condition compared to wake. Higher sleep spindle density was most consistently associated with greater overnight schema-related memory benefit. After 24 hours, the memory advantage of initial sleep was diminished. Overnight sleep preferentially benefits schema-related memory consolidation following initial learning compared with active wake, but this advantage may be eroded after a subsequent night of sleep. This is possibly due to delayed consolidation that might occur during subsequent sleep opportunities in the wake group. Name: Investigating Preferred Nap Schedules for Adolescents (NFS5) URL: https://clinicaltrials.gov/ct2/show/NCT04044885. Registration: NCT04044885.

Approach to impaired corollary discharge in patients with schizophrenia: An analysis of self-induced somatosensory evoked potentials and fields.

BackgroundDifficulty in distinguishing between self-generated actions and those generated by others is a core feature of schizophrenia. This is thought to be underpinned by the failure of corollary discharge. However, few studies have investigated these events using somatosensory evoked potentials (SEPs) and somatosensory evoked magnetic fields (SEFs).MethodsThe study included 15 right-handed patients with schizophrenia and 16 healthy controls. SEP and SEF were elicited by electrical stimuli to the left median nerve at intervals of 1–3 s. In the external condition, stimuli were externally induced by a machine. In the self-condition, stimuli were induced by tapping the participants’ own right index finger. Peak amplitude at C4’ in SEP and root mean square in 10 channels on the right primary somatosensory area in SEF were analyzed.ResultsAlthough there was a significant main effect of condition at N20m, and a significant main effect of condition and group at P30m, no significant interactions of condition and group were found in either N20m or P30m. The post-hoc Wilcoxon signed-rank test revealed that the peak value of P30m in the external condition was significantly higher than that in the self-condition in the healthy control group only. In addition, there was a significant positive correlation between the peak value of P30m in the self-condition and a positive symptom score.ConclusionIn the current study, we did not find abnormalities of corollary discharge in primary sensory areas in patients with schizophrenia. Further investigations with more cases may reveal the possibility of corollary discharge disturbance in the primary sensory cortex.

Acute effects of ballistic and non-ballistic conditioning activities on the punching impact of amateur boxers

Objectives This study investigated the postactivation performance enhancement (PAPE) effects of medicine ball throwing (MBT) and bench pressing (BP) on punching impact at different recovery times. Methods Fourteen amateur boxers performed three lead-hand (lead-hand) and rear-hand straight punches (rear-hand) at 3, 6, 9, 12, and 15 min after MBT or BP exercise. Peak force, time to the peak force, and rate of force development (RFD) of each punch was measured by a force plate. Results There was no significant condition × time interaction effect for any variables (lead-hand: F = 0.744–0.913, p = 0.448–0.542; rear-hand: F = 0.240–1.355, p = 0.245–0.944). No significant main effect for condition for any variables (lead-hand: F = 0.103–0.219, p = 0.644–0.751; rear-hand: F = 0.070–0.459, p = 0.504–0.793). The time effect was significant on peak force ( F = 4.411, p = 0.005) and RFD ( F = 5.002, p = 0.002) of lead-hand, time to the peak force ( F = 5.791, p = 0.001) and RFD ( F = 5.514, p = 0.001) of rear-hand. Peak force and RFD of the lead-hand, as well as time to the peak force and RFD of the rear-hand enhanced significantly at 6–15 min ( p = 0.001–0.042), compared to the baseline. Conclusions MBT and BP may equally enhance punching impact for amateur boxers; moreover, there was no difference in recovery time between conditioning activities.

Emotional Dysregulation and Altered Reward Processing in Self-Harm

IntroductionSelf-Harm (SH) is any act of self-injury carried out by somebody irrespective of motivation. SH most commonly functions to relieve negative affect (NA). Tentative evidence suggests reward processing is altered in SH. NA may trigger reward hypersensitivity and therefore SH. Whether NA influences reward processing in SH remains unclear.ObjectivesTo investigate whether self-harmers differ in motivation to obtain SH stimuli than healthy controls (HCs) following NA induction.HypothesisAfter NA induction, SH participants will have a significantly shorter reaction latency (RL) and greater reaction accuracy (RA) than HCs in the SH condition of the Incentive Delay (ID) task.Methods16-25-year-old SH (n=35) and HC (n=20) participants were recruited online and underwent the Trier Social Stress Test, to induce NA, followed by the ID task, where participants were cued to respond to a target as quickly as possible. On responding, an image of either a SH act (SH Condition), people socializing (Social Condition) or money (Monetary Condition) appeared. Each condition included control trials showing a neutral image. RA was the percentage of trials responded to within the target’s presentation time. RL was the time (seconds) between target appearance and participants’ response.ResultsThere was no significant main effect of group, condition or group x condition interaction for RL. There was a significant main effect of condition (p &lt; 0.05) but not of group nor a group x condition interaction for RA.ConclusionsReward processing did not differ in the SH group compared to HCs post-NA induction. Future studies could investigate reward processing in longitudinal and larger SH samples.DisclosureNo significant relationships.

Emotional Dysregulation and Altered Reward Processing in Self-Harm

AimsSelf-Harm (SH) is defined as “any act of self-injury or poisoning carried out by a person irrespective of their motivation”. SH increases the risk of adverse outcomes including suicide attempts, necessitating early intervention. The most widely reported reason for SH is to relieve negative affect (NA), with NA precipitating SH engagement. SH participants show altered reward processing, particularly reward hypersensitivity. NA could trigger reward hypersensitivity and therefore SH engagement. However, the interaction between NA and reward processing in SH remains unclear.Aim: To investigate whether those who SH show differences in processing SH stimuli compared to healthy controls (HCs) following NA induction.Hypothesis: NA induction will result in SH participants having significantly shorter reaction latency (RL) and significantly greater reaction accuracy (RA) in the SH condition of the Incentive Delay task (IDT) than HCs.Methods16–25-year-old SH (n = 35) and HC (n = 20) participants were recruited on social media. Participants completed the Trier Social Stress Test, to induce NA, followed by the IDT. In the latter, participants were cued to respond to a target as quickly as possible, and on responding were shown images of either a SH act (SH condition), people socializing (social condition) or money (monetary condition), where each condition had control trials where a neutral image was shown, which participants also had to respond to (SH neutral, social neutral and monetary neutral conditions respectively). RA was the percentage of IDT trials in which participants responded within the target's presentation time. RL in the IDT was the time (seconds) between the target appearance and the participant's response.ResultsA linear mixed effects model showed no significant main effect of group on RL (SH vs HC), condition (Social, SH or Monetary) or group x condition interaction (p &gt; 0.05). There was a significant main effect of condition on RA (p &lt; 0.05) but not group or group x condition interaction (p &gt; 0.05). Past-week SH frequency and RA were significantly and positively correlated in social, social neutral and monetary conditions (p &lt; 0.05).ConclusionOverall, there was a non-significant effect of NA on reward processing. However, as greater past-week SH frequency was significantly associated with greater RA, understanding how reward processing and NA interact in SH can provide greater insight into its triggers. Given this study's limited sample size and cross-sectional nature, future studies should investigate how NA and reward processing interact longitudinally and in larger samples to understand how SH can be reduced.

0658 Slow-Wave Sleep Disruption Decreases Ability to Recognize Certain Negative Emotions

Abstract Introduction Research has demonstrated that sleep deprivation may alter emotion recognition. Given that emotion recognition is critical for effective human communication, it is essential to understand how sleep is involved in this process. Slow-wave sleep (SWS) has been suggested to be important for the consolidation and processing of emotional memories and neuroplasticity. This study aimed to examine the impact of experimental disruption of SWS on emotion recognition to further understand the contribution of SWS. Methods 31 participants (20 individuals diagnosed with Major Depressive Disorder (MDD), 11 healthy controls (HC)) completed two overnight sleep studies spaced one week apart. One night served as baseline (BL) and on the other night participants underwent slow-wave disruption (SWD), where SWS was disrupted using auditory stimulation. In the morning following each overnight visit, participants completed an emotion recognition task. Accuracy scores were computed as the percentage correct in each of 10 categories of emotions (anger, contempt, disgust, embarrassment, fear, joy, neutral, pride, sadness, and surprise). Repeated measures ANOVA was used to assess the impact of SWD on emotion recognition with group (HC, MDD) as the between subjects factor and condition (BL, SWD) as the within subjects factor. Results Results revealed a significant main effect of condition for disgust (F=13.72, p&amp;lt; .001), embarrassment (F=6.23, p=.019), and surprise (F=8.06, p=.008), with follow-up t-tests demonstrating that accuracy for the recognition of disgust and embarrassment decreased following SWD and accuracy for surprise increasing following SWD. No significant interactions were found for group*condition (ps&amp;gt;.105). Conclusion These results suggest that while SWD decreases the ability to recognize certain negative emotions, it also increases the ability to recognize surprise, which is in line with previous research examining acute total sleep deprivation. Interestingly, there appears to be no difference in the ability to recognize emotions between individuals with and without depression. Slow-wave sleep deficits, common in disorders such as depression and schizophrenia, may therefore contribute to poor communication abilities through decreased ability to recognize emotions, increasing the risk of interpersonal distress and mental health problems. Support (If Any) Goldschmied: K23MH118580 (NIMH)