Browsing by Author "Cook, Stephanie"
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Item Open Access Brain Responses to Emotional Faces in Natural Settings: A Wireless Mobile EEG Recording Study(Frontiers in Psychology, 2018-10-25) Soto, V.; Tyson-Carr, J.; Kokmotou, K.; Roberts, Hanna; Cook, Stephanie; Fallon, N.; Giesbrecht, T.; Stancak, A.The detection of a human face in a visual field and correct reading of emotional expression of faces are important elements in everyday social interactions, decision making and emotional responses. Although brain correlates of face processing have been established in previous fMRI and electroencephalography (EEG)/MEG studies, little is known about how the brain representation of faces and emotional expressions of faces in freely moving humans. The present study aimed to detect brain electrical potentials that occur during the viewing of human faces in natural settings. 64-channel wireless EEG and eye-tracking data were recorded in 19 participants while they moved in a mock art gallery and stopped at times to evaluate pictures hung on the walls. Positive, negative and neutral valence pictures of objects and human faces were displayed. The time instants in which pictures first occurred in the visual field were identified in eye-tracking data and used to reconstruct the triggers in continuous EEG data after synchronizing the time axes of the EEG and eye-tracking device. EEG data showed a clear face-related event-related potential (ERP) in the latency interval ranging from 165 to 210 ms (N170); this component was not seen whilst participants were viewing non-living objects. The face ERP component was stronger during viewing disgusted compared to neutral faces. Source dipole analysis revealed an equivalent current dipole in the right fusiform gyrus (BA37) accounting for N170 potential. Our study demonstrates for the first time the possibility of recording brain responses to human faces and emotional expressions in natural settings. This finding opens new possibilities for clinical, developmental, social, forensic, or marketing research in which information about face processing is of importance.Item Open Access Data to support observation of late and ultra-late latency components of cortical laser evoked potentials(Elsevier, 2015-11-23) Stancak, A.; Cook, Stephanie; Wright, H.; Fallon, N.Data are provided to document the presence of late and ultra-late latency components of cortical laser evoked potentials (LEPs) following noxious laser stimulus in Stancak et al. (2015) [3]. The latency components, labeled provisionally as N4, N5, and N6, were observed in 16 healthy human participants who were asked to fully attend their painful and non-painful sensations occurring in association with noxious laser stimulus. Individual laser evoked potential waveforms are provided in support of this observation. Data provided demonstrate the cortical sources of the late and ultra-late laser evoked potentials. The cortical sources of LEPs were reconstructed using the standardized Low Resolution Electromagnetic Tomography (sLORETA) method.Item Open Access Effects of loss aversion on neural responses to loss outcomes: an event-related potential study(Elsevier, 2017-04-08) Kokmotou, K.; Cook, Stephanie; Xie, Y.; Wright, H.; Soto, V.; Fallon, N.; Giesbrecht, T.; Pantelous, A.A.; Stancak, A.Loss aversion is the tendency to prefer avoiding losses over acquiring gains of the same amount. To shed light onthe spatio-temporal processes underlying loss aversion, we analysed the associations between individual lossaversion and electrophysiological responses to loss and gain outcomes in a monetary gamble task.Electroencephalographic feedback-related negativity (FRN) was computed in 29 healthy participants as thedifference in electrical potentials between losses and gains. Loss aversion was evaluated using non-linearparametric fitting of choices in a separate gamble task.Loss aversion correlated positively with FRN amplitude (233–263 ms) at electrodes covering the lower face.Feedback related potentials were modelled by five equivalent source dipoles. From these dipoles, strongeractivity in a source located in the orbitofrontal cortex was associated with loss aversion.The results suggest that loss aversion implemented during risky decision making is related to a valuationprocess in the orbitofrontal cortex, which manifests during learning choice outcomes.Item Open Access The experience of long-stay patients in a forensic psychiatric hospital in China: a qualitative study(Springer Nature, 2019-09-02) Wang, Yuan Yuan; Zhong, Shaoling; Guo, Huijuan; Cook, Stephanie; Chen, Yanan; Luo, Chenyuli; Peng, Ke; Wang, Fanglan; Liang, Xiaoxi; Chen, Hui; Li, Qiguang; Zhou, Jiansong; Wang, Xiaoping; Chen, RunsenBackground Long stay in forensic psychiatric hospitals is common in patients who are defined as “not criminally responsible on account of mental disorder”. However, little is known about how these patients experience and perceive the long stay within these settings. The aim of this study is to explore the perception and needs of long-stay patients in forensic psychiatric hospitals in China. Methods In-depth semi-structured interviews were conducted with 21 participants who had lived in the forensic psychiatry hospital for more than 8 years. We used thematic analysis strategies to analyse the qualitative data. Results Participants’ perceptions clustered seven themes: hopelessness, loneliness, worthlessness, low mood, sleep disturbances, lack of freedom, and lack of mental health intervention. Conclusions The views and opinions expressed by long-stay patients showed that psychological distress is prevailing in forensic psychiatric hospitals. Adequate and effective care and mental health interventions are recommended to be tailored for their special needs.Item Open Access Investigating the True Effect of Psychological Variables Measured Prior to Arthroplastic Surgery on Postsurgical Outcomes: A P-Curve Analysis(Elsevier, 2020-10-20) Niederstrasser, Nils; Cook, StephaniePatients’ presurgical psychological profiles have been posited to predict pain and function following arthroplastic surgery of the hip and knee. Nevertheless, findings are conflicting, and this may be rooted in biased reporting that makes the determination of evidential value difficult. This ambiguity may have negative consequences for researchers and governmental agencies, as these rely on findings to accurately reflect reality. P-Curve analyses were used to establish the presence of evidential value and selective reporting in a sample of studies examining the effect of presurgical psychological predictors on outcomes following knee and hip arthroplastic surgery. A systematic search of the literature revealed 26 relevant studies. The examined sets of studies indicate that there is evidential value for the effect of depression on pain intensity and function, anxiety on pain intensity and function, pain catastrophizing on pain intensity, as well as the combined effects of all psychological predictors on pain intensity and function. The presence of evidential value was inconclusive for the effect of optimism on pain intensity. There were no signs that any results were influenced by biased reporting. The results highlight the importance of patients’ psychological profiles in predicting surgical outcomes, which represent a promising avenue for future treatment approaches. Perspective: The effects of P-hacking are difficult to detect and might be at the root of conflicting findings pertaining to the predictive properties of presurgical psychological variables on postsurgical outcomes. P-Curve analysis allows the determination of evidential value underlying these relationships and detection of P-hacking to ensure that findings are not the result of selective reporting.Item Open Access Mapping multidimensional pain experience onto electrophysiological responses to noxious laser heat stimuli(Elsevier, 2015-10-23) Stancak, A.; Cook, Stephanie; Wright, H.; Fallon, N.The origin of the conscious experience of pain in the brain is a continuing enigma in neuroscience. To shed light on the brain representation of a multifaceted pain experience in humans, we combined multivariate analysis of subjective aspects of pain sensations with detailed, single-trial analysis of electrophysiological brain responses. Participants were asked to fully focus on any painful or non-painful sensations occurring in their left hand during an interval surrounding the onset of noxious laser heat stimuli, and to rate their sensations using a set of visual analogue scales. Statistical parametric mapping was used to compute a multivariate regression analysis of subjective responses and single-trial laser evoked potentials (LEPs) at subject and group levels. Standardized Low Resolution Electromagnetic Tomography method was used to reconstruct sources of LEPs. Factor analysis of subjective responses yielded five factors. Factor 1, representing pain, mapped firstly as a negative potential at the vertex and a positive potential at the fronto-temporal region during the 208–260 ms interval, and secondly as a strong negative potential in the right lateral frontal and prefrontal scalp regions during the 1292–1340 ms interval. Three other factors, labelled “anticipated pain”, “stimulus onset time”, and “body sensations”, represented non-specific aspects of the pain experience, and explained portions of LEPs in the latency range from 200 ms to 700 ms. The subjective space of pain during noxious laser stimulation is represented by one large factor featuring pain intensity, and by other factors accounting for non-specific parts of the sensory experience. Pain is encoded in two separate latency components with different scalp and brain representations.Item Open Access The neural correlates of economic value and valuation context: An event-related potentials study(American Physiological Society, 2018-05-15) Tyson-Carr, J.; Kokmotou, K.; Soto, V.; Cook, Stephanie; Fallon, N.; Giesbrecht, T.; Stancak, A.The value of environmental cues and internal states is continuously evaluated by the human brain, and it is this subjective value that largely guides decision making. The present study aimed to investigate the initial value attribution process, specifically the spatiotemporal activation patterns associated with values and valuation context, using electroencephalographic event-related potentials (ERPs). Participants completed a stimulus rating task in which everyday household items marketed up to a price of £4 were evaluated with respect to their desirability or material properties. The subjective values of items were evaluated as willingness to pay (WTP) in a Becker-DeGroot-Marschak auction. On the basis of the individual’s subjective WTP values, the stimuli were divided into high- and low-value items. Source dipole modeling was applied to estimate the cortical sources underlying ERP components modulated by subjective values (high vs. low WTP) and the evaluation condition (valuerelevant vs. value-irrelevant judgments). Low-WTP items and valuerelevant judgments both led to a more pronounced N2 visual evoked potential at right frontal scalp electrodes. Source activity in right anterior insula and left orbitofrontal cortex was larger for low vs. high WTP at 200 ms. At a similar latency, source activity in right anterior insula and right parahippocampal gyrus was larger for value-relevant vs. value-irrelevant judgments. A stronger response for low- than high-value items in anterior insula and orbitofrontal cortex appears to reflect aversion to low-valued item acquisition, which in an auction experiment would be perceived as a relative loss. This initial lowvalue bias occurs automatically irrespective of the valuation context.Item Open Access Neural Mechanisms of Attentional Switching Between Pain and a Visual Illusion Task: A Laser Evoked Potential Study(Springer, 2017-12-19) Stancak, A.; Fallon, N.; Fenu, A.; Kokmotou, K.; Soto, V.; Cook, StephaniePrevious studies demonstrated that pain induced by a noxious stimulus during a distraction task is affected by both stimulus-driven and goal-directed processes which interact and change over time. The purpose of this exploratory study was to analyse associations of aspects of subjective pain experience and engagement with the distracting task with attentionsensitive components of noxious laser-evoked potentials (LEPs) on a single-trial basis. A laser heat stimulus was applied to the dorsum of the left hand while subjects either viewed the Rubin vase-face illusion (RVI), or focused on their pain and associated somatosensory sensations occurring on their stimulated hand. Pain-related sensations occurring with every laser stimulus were evaluated using a set of visual analogue scales. Factor analysis was used to identify the principal dimensions of pain experience. LEPs were correlated with subjective aspects of pain experience on a single-trial basis using a multiple linear regression model. A positive LEP component at the vertex electrodes in the interval 294–351 ms (P2) was smaller during focusing on RVI than during focusing on the stimulated hand. Single-trial amplitude variations of the P2 component correlated with changes in Factor 1, representing essential aspects of pain, and inversely with both Factor 2, accounting for anticipated pain, and the number of RVI figure reversals. A source dipole located in the posterior region of the cingulate cortex was the strongest contributor to the attention-related single-trial variations of the P2 component. Instantaneous amplitude variations of the P2 LEP component during switching attention towards pain in the presence of a distracting task are related to the strength of pain experience, engagement with the task, and the level of anticipated pain. Results provide neurophysiological underpinning for the use of distraction analgesia acute pain relief.Item Metadata only P31-028-23 Sensory Perception of Food and Its Influence on Snacking Behaviours Among Adults Residing in the UK(Elsevier, 2023-07-27) Jin, Yannan; Johnson, Hannah; Cook, StephanieSensory perception of food and its influence on snacking behaviours among adults residing in the UK Hannah Johnson1, Stephanie Cook1, Yannan Jin1 1 De Montfort University Objectives Understanding the factors driving food overconsumption is key to tackling the worldwide obesity issue. The link of body weight status with sensory preferences of foods (e.g. sweet and fatty foods) has been suggested, but remains inconclusive as to mixed evidence thus far. The socio-demographic factors’ potential influence on food choices further increases the complexity of the unsolved puzzle. The study aimed to look at the sensory perception of foods and snacking behaviours among adults of different socio-demographic characteristics and body weight statuses in the UK. Study methods It was a cross-sectional study. An online survey was used to determine the participants’ socio-demographic information (age, sex and occupation), Body Mass Index (BMI), sensory-attribute’s liking (e.g. taste and texture) of 45 snack items, frequency of eating snacks (salty, sweet, bitter, sour and savoury) using a 5-point Likert-scale (1 never to less than once a week – 5 more than 3 times a day), and their perceived importance of the appearance, smell, taste and texture of snacks in determining how much they eat, using a 5-point Likert-scale (1 not at all important – 5 extremely important). Data were analysed using Mann-Whitney U test and Kruskal-Wallis Test, SPSS v28.0. Results 56 participants (Mean age 44.6 y; SD 16.2) completed the survey (17 males and 39 females). Their BMI ranged from 15.8 to 39.9 kg/m2 (Mean 27.3, SD 5.6) and was classified into four groups, including underweight (N = 2); normal-weight (N = 22); overweight (N = 16) and obese (N = 16). The results showed that gender variation existed in the frequency of snack intakes including salty (U = 205, P = 0.012, r = 0.3) and bitter (U = 223, P = 0.025, r = 0.3). The frequency of sour-snack intake significantly differed between normal-weight and obese groups (H (3) = 10.3, P = 0.023). Age tended to exert a notable influence on almost all types of snack-intakes, including sweet (H (5) = 12.9, P = 0.024); bitter (H (5) = 11.0, P = 0.049); salty (H (5) = 18.7, P = 0.004) and sour (H (5) = 15.3, P = 0.009). Conclusion Demographic characteristics and body weight status were evidently shown to interplay with individuals’ food preferences and intake behaviours. The growing knowledge in this research area will benefit the future exploration in finding personalised solutions to prevent and manage adulthood obesity. Fund source The study was not funded.Item Open Access Pleasant and Unpleasant Odors Influence Hedonic Evaluations of Human Faces: An Event-Related Potential Study(Frontiers, 2015-12-16) Cook, Stephanie; Fallon, N.; Wright, H.; Thomas, A; Giesbrecht, T.; Field, M.; Stancak, A.Odors can alter hedonic evaluations of human faces, but the neural mechanisms of such effects are poorly understood. The present study aimed to analyze the neural underpinning of odor-induced changes in evaluations of human faces in an odor-priming paradigm, using event-related potentials (ERPs). Healthy, young participants (N = 20) rated neutral faces presented after a 3 s pulse of a pleasant odor (jasmine), unpleasant odor (methylmercaptan), or no-odor control (clean air). Neutral faces presented in the pleasant odor condition were rated more pleasant than the same faces presented in the no-odor control condition, which in turn were rated more pleasant than faces in the unpleasant odor condition. Analysis of face-related potentials revealed four clusters of electrodes significantly affected by odor condition at specific time points during longlatency epochs (600950 ms). In the 620640 ms interval, two scalp-time clusters showed greater negative potential in the right parietal electrodes in response to faces in the pleasant odor condition, compared to those in the no-odor and unpleasant odor conditions. At 926 ms, face-related potentials showed greater positivity in response to faces in the pleasant and unpleasant odor conditions at the left and right lateral frontal-temporal electrodes, respectively. Our data shows that odor-induced shifts in evaluations of faces were associated with amplitude changes in the late (>600) and ultra-late (>900 ms) latency epochs. The observed amplitude changes during the ultralate epoch are consistent with a left/right hemisphere bias towards pleasant/unpleasant odor effects. Odors alter evaluations of human faces, even when there is a temporal lag between presentation of odors and faces. Our results provide an initial understanding of the neural mechanisms underlying effects of odors on hedonic evaluations.Item Open Access Pleasant and unpleasant odour-face combinations influence face and odour perception: An event-related potential study.(Elsevier, 2017-07-14) Cook, Stephanie; Fallon, N.; Soto, V.; Tyson-Carr, J.; Kokmotou, K.; Thomas, A.; Giesbrecht, T.; Field, M.; Stancak, A.Odours alter evaluations of concurrent visual stimuli. However, neural mechanisms underlying the effects of congruent and incongruent odours on facial expression perception are not clear. Moreover, the influence of emotional faces on odour perception is not established. We investigated the effects of one pleasant and one unpleasant odour paired with happy and disgusted faces, on subjective ratings and ERP responses to faces. Participants rated the pleasantness of happy and disgusted faces that appeared during 3 s pleasant or unpleasant odour pulses, or without odour. Odour pleasantness and intensity ratings were recorded in each trial. EEG was recorded continuously using a 128-channel system. Happy and disgusted faces paired with pleasant and unpleasant odour were rated as more or less pleasant, respectively, compared to the same faces presented in the other odour conditions. Odours were rated as more pleasant when paired with happy faces, and unpleasant odour was rated more intense when paired with disgusted faces. Unpleasant odour paired with disgusted faces also decreased inspiration. Odour-face interactions were evident in the N200 and N400 components. Our results reveal bi-directional effects of odours and faces, and suggest that odour-face interactions may be represented in ERP components. Pairings of unpleasant odour and disgusted faces resulted in stronger hedonic ratings, ERP changes, increased odour intensity ratings and respiratory adjustment. This finding likely represents heightened adaptive responses to multimodal unpleasant stimuli, prompting appropriate behaviour in the presence of danger.Item Open Access The relationship between childhood trauma and Internet gaming disorder among college students: A structural equation model(AKJournals, 2020-04-07) shi, Lijuan; Wang, Yuanyuan; Yu, Hui; Wilson, Amanda; Cook, Stephanie; Duan, Zhizhou; Peng, Ke; Hu, Zhishan; Ou, Jianjun; Duan, Suqian; Yang, Yuan; Ge, Jiayu; Wang, Hongyan; Chen, Li; Zhao, Kaihong; Chen, RunsenBackground The aim of this study was to investigate the mechanisms of Internet gaming disorder (IGD) and the associated interaction effects of childhood trauma, depression and anxiety in college students. Methods Participants were enrolled full-time as freshmen at a University in the Hunan province, China. All participants reported their socio-demographic characteristics and undertook a standardized assessment on childhood trauma, anxiety, depression and IGD. The effect of childhood trauma on university students' internet gaming behaviour mediated by anxiety and depression was analysed using structural equation modelling (SEM) using R 3.6.1. Results In total, 922 freshmen participated in the study, with an approximately even male-to-female ratio. A mediation model with anxiety and depression as the mediators between childhood trauma and internet gaming behaviour allowing anxiety and depression to be correlated was tested using SEM. The SEM analysis revealed that a standardised total effect of childhood trauma on Internet gaming was 0.18, (Z = 5.60, 95% CI [0.02, 0.05], P < 0.001), with the direct effects of childhood trauma on Internet gaming being 0.11 (Z = 3.41, 95% CI [0.01, 0.03], P = 0.001), and the indirect effects being 0.02 (Z = 2.32, 95% CI [0.00, 0.01], P = 0.020) in the pathway of childhood trauma-depression-internet gaming; and 0.05 (Z = 3.67, 95% CI [0.00, 0.02], P < 0.001) in the pathway of childhood trauma-anxiety-Internet gaming. In addition, the two mediators anxiety and depression were significantly correlated (r = 0.50, Z = 13.54, 95% CI [3.50, 5.05], P < 0.001). Conclusions The study revealed that childhood trauma had a significant impact on adolescents' Internet gaming behaviours among college students. Anxiety and depression both significantly mediated the relationship between childhood trauma and internet gaming and augmented its negative influence. Discussion of the need to understand the subtypes of childhood traumatic experience in relationship to addictive behaviours is included.Item Open Access Simultaneous odour-face presentation strengthens hedonic evaluations and event-related potential responses influenced by unpleasant odour(Elsevier, 2018-02-18) Kokmotou, K.; Soto, V.; Wright, H.; Fallon, N.; Thomas, A; Giesbrecht, T.; Field, M.; Stancak, A.; Cook, StephanieOdours alter evaluations of concurrently presented visual stimuli, such as faces. Stimulus onset asynchrony (SOA) is known to affect evaluative priming in various sensory modalities. However, effects of SOA on odour priming of visual stimuli are not known. The present study aimed to analyse whether subjective and cortical activation changes during odour priming would vary as a function of SOA between odours and faces. Twenty-eight participants rated faces under pleasant, unpleasant, and no-odour conditions using visual analogue scales. In half of trials, faces appeared one-second after odour offset (SOA 1). In the other half of trials, faces appeared during the odour pulse (SOA 2). EEG was recorded continuously using a 128-channel system, and event-related potentials (ERPs) to face stimuli were evaluated using statistical parametric mapping (SPM). Faces presented during unpleasant-odour stimulation were rated significantly less pleasant than the same faces presented one-second after offset of the unpleasant odour. Scalp-time clusters in the late-positive-potential (LPP) time-range showed an interaction between odour and SOA effects, whereby activation was stronger for faces presented simultaneously with the unpleasant odour, compared to the same faces presented after odour offset. Our results highlight stronger unpleasant odour priming with simultaneous, compared to delayed, odour-face presentation. Such effects were represented in both behavioural and neural data. A greater cortical and subjective response during simultaneous presentation of faces and unpleasant odour may have an adaptive role, allowing for a prompt and focused behavioural reaction to a concurrent stimulus if an aversive odour would signal danger, or unwanted social interaction.Item Open Access Tracking Economic Value of Products in Natural Settings: A Wireless EEG Study(Frontiers in Neuroscience, 2018-12-20) Roberts, Hannah; Soto, V.; Tyson-Carr, J.; Kokmotou, K.; Cook, Stephanie; Fallon, N.; Giesbrecht, T.; Stancak, A.Economic decision making refers to the process of individuals translating their preference into subjective value (SV). Little is known about the dynamics of the neural processes that underpin this form of value-based decision making and no studies have investigated these processes outside of controlled laboratory settings. The current study investigated the spatio-temporal dynamics that accompany economic valuation of products using mobile electroencephalography (EEG) and eye tracking techniques. Participants viewed and rated images of household products in a gallery setting while EEG and eye tracking data were collected wirelessly. A Becker-DeGroot-Marschak (BDM) auction task was subsequently used to quantify the individual’s willingness to pay (WTP) for each product. WTP was used to classify products into low, low medium, high medium and high economic value conditions. Eye movement related potentials (EMRP) were examined, and independent component analysis (ICA) was used to separate sources of activity from grand averaged EEG data. Four independent components (ICs) of EMRPs were modulated by WTP (i.e., SV) in the latency range of 150–250 ms. Of the four value-sensitive ICs, one IC displayed enhanced amplitude for all value conditions excluding low value, and another IC presented enhanced amplitude for low value products only. The remaining two value-sensitive ICs resolved inter-mediate levels of SV. Our study quantified, for the first time, the neural processes involved in economic value based decisions in a natural setting. Results suggest that multiple spatio-temporal brain activation patterns mediate the attention and aversion of products which could reflect an early valuation system. The EMRP parietal P200 component could reflect an attention allocation mechanism that separates the lowest-value products (IC7) from products of all other value (IC4), suggesting that low-value items are categorized early on as being aversive. While none of the ICs showed linear amplitude changes that parallel SV’s of products, results suggest that a combination of multiple components may sub-serve a fine-grained resolution of the SV of products.