Reaction Time Bias Research Articles

Limited time horizons lead to the positivity effect in attention, but not to more positive emotions: An investigation of the socioemotional selectivity theory.

A positivity effect in attention (i.e., an attentional bias in favor of positive over negative stimuli) has been frequently reported in older adults. Based on the postulates of socioemotional selectivity theory (SST), the present study tested whether this positivity effect: (a) depends on the subjective perception of a limited future time perspective (FTP) independently of chronological age, (b) involves controlled processes, and (c) contributes to optimizing positive emotions. Thirty-one older adults (aged 75-93) and 92 younger adults (aged 18-23) were recruited. Young adults were divided into a control group (N = 52) and a group with limited FTP (N = 40), where their subjective perception of the time left to live was experimentally reduced. All participants performed a dot-probe task involving positive, negative and neutral pictures displayed with different presentation durations (500 ms, 1,000 ms). Reaction time bias scores were calculated, and emotional state was measured several times during the task. Analyses revealed attentional biases toward positive (compared to negative) pictures in older adults and young adults with limited FTP, but not in young adults in the control group. These positivity effects appeared from 500 ms of stimulus presentation, did not increase over time, and did not correlate with participants' emotions. These findings support SST predictions that positivity effects occur when individuals perceive a limited FTP, regardless of their actual age. However, our data also suggest that the positivity effect may be a more automatic than controlled process that does not influence emotional state. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Modulation of rhythmic visual stimulation on left-right attentional asymmetry.

The rhythmic visual stimulation (RVS)-induced oscillatory brain responses, namely steady-state visual evoked potentials (SSVEPs), have been widely used as a biomarker in studies of neural processing based on the assumption that they would not affect cognition. However, recent studies have suggested that the generation of SSVEPs might be attributed to neural entrainment and thus could impact brain functions. But their neural and behavioral effects are yet to be explored. No study has reported the SSVEP influence on functional cerebral asymmetry (FCA). We propose a novel lateralized visual discrimination paradigm to test the SSVEP effects on visuospatial selective attention by FCA analyses. Thirty-eight participants covertly shifted their attention to a target triangle appearing in either the lower-left or -right visual field (LVF or RVF), and judged its orientation. Meanwhile, participants were exposed to a series of task-independent RVSs at different frequencies, including 0 (no RVS), 10, 15, and 40-Hz. As a result, it showed that target discrimination accuracy and reaction time (RT) varied significantly across RVS frequency. Furthermore, attentional asymmetries differed for the 40-Hz condition relative to the 10-Hz condition as indexed by enhanced RT bias to the right visual field, and larger Pd EEG component for attentional suppression. Our results demonstrated that RVSs had frequency-specific effects on left-right attentional asymmetries in both behavior and neural activities. These findings provided new insights into the functional role of SSVEP on FCAs.

The Hierarchical Relationship Between the Relational-Self and the Collective-Self During Attention Processing.

BackgroundUnder the Chinese collectivist cultural system, people emphasize social connections with close others and members of in-groups. Collectivism can be divided into the following two forms: relational collectivism (privileges relational self [RS]) and group collectivism (emphasizes collective self [CS]). Previous researchers have found a hierarchy between the RS and CS, resulting in different degrees of recognition advantages. However, the hierarchy between the RS and CS is unclear and may depend on the specific processing stage. Therefore, this research compared the hierarchy between these two selves during different processing stages using an eye-movement method.MethodsThe sample consisted of thirty-eight young adults aged between 18 and 24 years old (M = 20.45, SD= 1.62). Each participant finished a dot-probe task featuring high-relevant (HR, ie one’s mother’s name and China) and low-relevant (LR, ie, name of a famous person and USA) information about the RS and CS and neutral information. Further, the eye-movement (EM) indices were collected simultaneously.ResultsA stronger reaction time bias and longer total gaze duration revealed that young people in China focus more on RS information, indicating that Chinese people prioritize the RS over the CS at late stages of attentional processing.ConclusionInformation on interpersonal relationships and information on the in-group both catch people’s attention quickly and easily, but only RS information can maintain attention for longer. Understanding the hierarchy of the RS and the CS may provide more evidence for self-construal in the Chinese collectivist cultural context. The importance of the RS prompting that the interpersonal and close relationships are more important to the development of the self, suggesting that it is necessary to pay more attention to the impact of interpersonal support on people’s mental health in clinical applications.

Measuring Food-Related Attentional Bias.

Objective: Food-related attentional bias has been defined as the tendency to give preferential attention to food-related stimuli. Attentional bias is of interest as studies have found that increased attentional bias is associated with obesity; others, however, have not. A possible reason for mixed results may be that there is no agreed upon measure of attentional bias: studies differ in both measurement and scoring of attentional bias. Additionally, little is known about the stability of attentional bias over time. The present study aims to compare attentional bias measures generated from commonly used attentional bias tasks and scoring protocols, and to test re-test reliability.Methods: As part of a larger study, 69 participants (67% female) completed two food-related visual probe tasks at baseline: lexical (words as stimuli), and pictorial (pictures as stimuli). Reaction time bias scores (attentional bias scores) for each task were calculated in three different ways: by subtracting the reaction times for the trials where probes replaced (1) neutral stimuli from the trials where the probes replaced all food stimuli, (2) neutral stimuli from the trials where probes replaced high caloric food stimuli, and (3) neutral stimuli from low caloric food stimuli. This resulted in three separate attentional bias scores for each task. These reaction time results were then correlated. The pictorial visual probe task was administered a second time 14-days later to assess test-retest reliability.Results: Regardless of the scoring use, lexical attentional bias scores were minimal, suggesting minimal attentional bias. Pictorial task attentional bias scores were larger, suggesting greater attentional bias. The correlation between the various scores was relatively small (r = 0.13–0.20). Similarly, test-retest reliability for the pictorial task was poor regardless of how the test was scored (r = 0.20–0.41).Conclusion: These results suggest that at least some of the variation in findings across attentional bias studies could be due to differences in the way that attentional bias is measured. Future research may benefit from either combining eye-tracking measurements in addition to reaction times.

Recoiling from Threat: Anxiety is Related to Heightened Suppression of Threat, Not Increased Attention to Threat.

Increased attention to threat is considered a core feature of anxiety. However, there are multiple mechanisms of attention and multiple types of threat, and the relationships among attention, threat, and anxiety are poorly understood. The present study used event-related potentials (ERPs) to separately isolate attentional selection (N2pc) and suppression (PD) of pictorial threats (photos of weapons, snakes, etc.) and conditioned threats (colored shapes paired with electric shock). In a sample of 48 young adults, both threat types were initially selected for increased attention (an N2pc), but only conditioned threats elicited subsequent suppression (a PD) and a reaction time (RT) bias. Levels of trait anxiety were unrelated to N2pc amplitude, but increased anxiety was associated with larger PDs (i.e., greater suppression) and reduced RT bias to conditioned threats. These results suggest that anxious individuals do not pay more attention to threats, but rather engage more attentional suppression to overcome threats.

Aberrant attentional bias to sad faces in depression and the role of stressful life events: Evidence from an eye-tracking paradigm

Attentional biases are thought to be involved in the etiopathogenesis of depressive disorders. Recent studies indicate eye-tracking techniques could overcome methodological issues of traditional reaction time bias measures and be used to reliably quantify biases in attention. In the current study, 50 participants with a current depressive disorder and 31 never-depressed individuals performed a free-viewing eye-tracking paradigm with two counterbalanced blocks; one contained four-by-four arrays of happy and neutral faces, the other arrays of sad and neutral faces. Average dwell-times were analyzed, and internal consistency was examined. Dwell-time measures had good to excellent internal consistency. Both groups were characterized by increased dwell-time to happy compared to neutral faces (i.e., bias toward positive faces). Never-depressed participants showed a bias away from sad stimuli (i.e., increased dwell-time to neutral compared to sad faces), that was not evident in the depressed group. Moreover, depressed individuals dwelled longer on sad stimuli than never-depressed participants. Within depressed participants, bias to sad faces was associated with both childhood trauma and recent negative life events. Results demonstrate that an attentional bias towards sad faces in depression can be reliably assessed using free-viewing eye-tracking technique and its magnitude is exacerbated by the experience of stressful life events.

Test-retest reliability of attention bias for food: Robust eye-tracking and reaction time indices

This study assessed internal reliability and test-retest reliability of attention bias scores for food derived from the dot probe task. A visual dot probe task with food and non-food pictures (presented for 3000 ms) was administered to 53 healthy women on two occasions. Attention bias scores for food were calculated based on manual response latencies (reaction time bias) and concurrent assessment of eye-movements (direction bias and dwell-time bias). Subjective hunger and blood glucose levels were measured on both testing occasions. Dietary restraint and eating disorder symptoms were assessed during the second session. Results showed that direction bias had poor internal and test-retest reliability. Dwell time bias had excellent internal and acceptable test-retest reliability. Reaction time bias had acceptable internal and good test-retest reliability. Exploratory correlational analyses found that hunger, blood glucose, dietary restraint and eating disorder symptoms were not consistently significantly correlated with indices of attention bias for food. Overall, these findings contradict previous studies that reported low reliability of attention bias indices derived from the visual dot probe task. The implications are that a longer stimulus presentation time (i.e. ≥ 3000 ms), the use of eye-tracking and the use of appetizing stimuli can yield reliable attention bias scores for food. However, the interpretation of dot-probe scores of attention bias for food based on a dot probe task with 3000 ms presentation time and the score's relationship to theoretically relevant constructs such as hunger, eating restraint and eating disorder symptoms, require further clarification.

Attentional bias in MDD: ERP components analysis and classification using a dot-probe task

Background and ObjectiveStrands of evidence have supported existence of negative attentional bias in patients with depression. This study aimed to assess the behavioral and electrophysiological signatures of attentional bias in major depressive disorder (MDD) and explore whether ERP components contain valuable information for discriminating between MDD patients and healthy controls (HCs). MethodsElectroencephalography data were collected from 17 patients with MDD and 17 HCs in a dot-probe task, with emotional-neutral pairs as experimental materials. Fourteen features related to ERP waveform shape were generated. Then, Correlated Feature Selection (CFS), ReliefF and GainRatio (GR) were applied for feature selection. For discriminating between MDDs and HCs, k-nearest neighbor (KNN), C4.5, Sequential Minimal Optimization (SMO) and Logistic Regression (LR) were used. ResultsBehaviorally, MDD patients showed significantly shorter reaction time (RT) to valid than invalid sad trials, with significantly higher bias score for sad-neutral pairs. Analysis of split-half reliability in RT indices indicated a strong reliability in RT, while coefficients of RT bias scores neared zero. These behavioral effects were supported by ERP results. MDD patients had higher P300 amplitude with the probe replacing a sad face than a neutral face, indicating difficult attention disengagement from negative emotional faces. Meanwhile, data mining analysis based on ERP components suggested that CFS was the best feature selection algorithm. Especially for the P300 induced by valid sad trials, the classification accuracy of CFS combination with any classifier was above 85%, and the KNN (k = 3) classifier achieved the highest accuracy (94%). ConclusionsMDD patients show difficulty in attention disengagement from negative stimuli, reflected by P300. The CFS over other methods leads to a good overall performance in most cases, especially when KNN classifier is used for P300 component classification, illustrating that ERP component may be applied as a tool for auxiliary diagnosis of depression.

Vigilant attention to threat, sleep patterns, and anxiety in peripubertal youth.

Vigilant attention to threat is commonly observed in anxiety, undergoes developmental changes in early adolescence, and has been proposed to interfere with sleep initiation and maintenance. We present one of the first studies to use objective measures to examine associations between vigilant attention to threat and difficulties initiating and maintaining sleep in an early adolescent anxious sample. We also explore the moderating role of development (age, puberty) and sex. Participants were 66 peripubertal youth (ages 9-14) with a primary anxiety disorder and 24 healthy control subjects. A dot-probe task was used to assess attentional bias to fearful relative to neutral face stimuli. Eye-tracking indexed selective attentional bias to threat, and reaction time bias indexed action readiness to threat. Sleep was assessed via actigraphy (e.g. sleep onset delay, wake after sleep onset, etc.), parent report (Children's Sleep Habits Questionnaire), and child report (Sleep Self-Report). The Pediatric Anxiety Rating Scale assessed anxiety severity. Eye-tracking initial threat fixation bias (β=.33, p=.001) and threat dwell time bias (β=.22, p=.041) were positively associated with sleep onset latency. Reaction time bias was positively associated with wake after sleep onset (β=.24, p=.026) and parent-reported sleep disturbance (β=.25, p=.019). Anxiety (severity, diagnosis) was not associated with these outcomes. Sex (β=-.32, p=.036) moderated the relation between initial threat fixation bias and sleep onset latency, with a positive association for males (p=.005), but not for females (p=.289). Age and pubertal status did not moderate effects. Vigilant attention to threat is related to longer sleep onset and reduced sleep maintenance. These associations are not stronger in early adolescents with anxiety. Implications for early intervention or prevention that targets vigilant attention to threat to impact sleep disturbance, and vice versa, are discussed.

Chewing Stimulation Reduces Appetite Ratings and Attentional Bias toward Visual Food Stimuli in Healthy-Weight Individuals.

Based on the theory of incentive sensitization, the exposure to food stimuli sensitizes the brain’s reward circuits and enhances attentional bias toward food. Therefore, reducing attentional bias to food could possibly be beneficial in preventing impulsive eating. The importance of chewing has been increasingly implicated as one of the methods for reducing appetite, however, no studies to investigate the effect of chewing on attentional bias to food. In this study, we investigated whether chewing stimulation (i.e., chewing tasteless gum) reduces attentional bias to food as well as an actual feeding (i.e., ingesting a standardized meal) does. We measured reaction time, gaze direction and gaze duration to assess attentional bias toward food images in pairs of food and non-food images that were presented in a visual probe task (Experiment 1, n = 21) and/or eye-tracking task (Experiment 2, n = 20). We also measured appetite ratings using visual analog scale. In addition, we conducted a control study in which the same number of participants performed the identical tasks to Experiments 1 and 2, but the participants did not perform sham feeding with gum-chewing/actual feeding between tasks and they took a rest. Two-way ANOVA revealed that after actual feeding, subjective ratings of hunger, preoccupation with food, and desire to eat significantly decreased, whereas fullness significantly increased. Sham feeding showed the same trends, but to a lesser degree. Results of the visual probe task in Experiment 1 showed that both sham feeding and actual feeding reduced reaction time bias significantly. Eye-tracking data showed that both sham and actual feeding resulted in significant reduction in gaze direction bias, indexing initial attentional orientation. Gaze duration bias was unaffected. In both control experiments, one-way ANOVAs showed no significant differences between immediately before and after the resting state for any of the appetite ratings, reaction time bias, gaze direction bias, or gaze duration bias. In conclusion, chewing stimulation reduced subjective appetite and attentional bias to food, particularly initial attentional orientation to food. These findings suggest that chewing stimulation, even without taste, odor, or ingestion, may affect reward circuits and help prevent impulsive eating.

The N2pc component reliably captures attentional bias in social anxiety.

We systematically compared different measures of attentional bias (i.e., reaction times, the N2pc component in the EEG, and explicit stimulus ratings) on their ability to reveal attentional engagement to threatening versus neutral facial stimuli in a Dot Probe Task and tested their relation to trait measures of general and social anxiety. We found that the N2pc component reflects a bias toward angry faces with excellent internal consistency. Similar results were obtained for explicit ratings. Reaction time (RT) differences, however, were not indicative of attentional biases and showed zero odd-even reliability. We further found that both higher (i.e., more negative) N2pc amplitudes and earlier peak latencies were associated with more severe symptoms of social anxiety even when controlling for general trait anxiety. The explicit rating biases were also specifically associated with social anxiety. Conversely, the RT bias was not related to social anxiety levels but to general trait anxiety. This highlights the importance of valid and reliable outcome measures for interventions such as attentional bias modification protocols. Mutual exclusivity of different bias operationalizations is discussed.

Characteristics of interpretation bias and relationship with suicidality in a psychiatric hospital sample

BackgroundInterpretation bias, the tendency to interpret ambiguous situations negatively (or to lack a positive bias), is a cognitive vulnerability associated with psychopathology. However, there is a lack of research characterizing this bias in psychiatric samples, including whether it is also a risk factor for suicidality. This study characterized interpretation bias in a psychiatric sample at risk for suicide and examined the relationship between interpretation bias and suicidality cross-sectionally and prospectively. MethodsPatients (N=65) attending a partial hospital program completed the Word-Sentence Association Paradigm (WSAP), which results in four variables reflecting different types of interpretation bias: endorsement rates and reaction time bias scores for negative and benign interpretations. We conducted logistic regression models to predict high suicidality (ideation, plans, attempts, etc. assessed via a structured interview at admission) and suicidal ideation (assessed via self-report at admission and discharge). ResultsLogistic regression models predicting suicide outcomes upon admission and discharge indicated that benign interpretation endorsement was the most robust predictor of suicidality concurrently and prospectively, controlling for baseline suicidal ideation. LimitationsLack of gold standard self-report suicide assessment. Unable to assess additional constructs such as hopelessness or perfectionism, which may better elucidate how lacking a benign bias influences suicidality. Modest sample size. ConclusionsA lower endorsement of positive interpretations was the strongest predictor of prospective suicidal ideation, even after controlling for baseline suicidal ideation. Future research should examine how targeting interpretation bias influences suicidality.

Negative mood disrupts self- and reward-biases in perceptual matching.

There are established effects of self- and reward-biases even on simple perceptual matching tasks [Sui, J., He, X., & Humphreys, G. W. (2012). Perceptual effects of social salience: Evidence from self-prioritization effects on perceptual matching. Journal of Experimental Psychology, Human Perception and Performance, 38, 1105-1117]; however we know little about whether these biases can be modulated by particular interventions, and whether the biases then change in the same way. Here we assessed how the biases alter under conditions designed to induce negative mood. We had participants read a list of self-related negative or neutral mood statements [Velten, E. (1968). A laboratory task for induction of mood states. Behavior Research and Therapy, 6, 473-482] and also listen for 10 min to a passage of negative or neutral music, prior to carrying out perceptual matching with shapes associated to personal labels (self or stranger) or reward (£12 or £1). Responses to the self- and high-reward-associated shapes were selectively slower and less sensitive (d') following the negative mood induction procedures, and the decrease in mood correlated with decreases in the reaction time bias across "high saliency" (self and high-reward) stimuli. We suggest that negative mood may decrease self- and reward-biases through reducing attention to salient external stimuli.

Angry-happy interpretations of ambiguous faces in social anxiety disorder

Social Anxiety Disorder (SAD) is characterized by a tendency to interpret ambiguous social cues as negative. Here we tested whether interpretation of ambiguous faces differs between participants with SAD and non-anxious controls. Twenty-seven individuals with SAD and 21 non-anxious control participants completed an emotion recognition task in which they judged ambiguous morphed faces as happy or angry. Participants with SAD judged a higher proportion of the faces as angry compared to non-anxious participants, and were slower to judge faces as angry compared to happy, while no such reaction time bias manifested in the control group. Finally, happy judgments were slower in the SAD group compared to the control group, while angry judgments were faster in the SAD group compared to the control group. These findings provide evidence for a negative bias in resolving emotional ambiguity in facial expressions among individuals with SAD.

What happens during the stimulus onset asynchrony in the dot-probe task? Exploring the role of eye movements in the assessment of attentional biases.

The dot-probe paradigm is one of the most often used paradigms to investigate attentional biases towards emotional information. However, a large number of the dot-probe studies so far used a long stimulus onset asynchrony allowing for eye movements to occur, which might increase the error variance. This study aimed at addressing this methodological issue by varying the instructions with regard to the gaze behavior and calculating the reaction time (RT) bias score (i.e., RTs for targets presented at the location of the emotional compared to the neutral stimulus) separately for trials with eye movements and trials without eye movements. Results of Experiment 1 (using typical instructions, i.e., instructions that are lenient with regard to eye movements) showed an RT bias, but only in the trials without eye movements The overall RT bias (calculated “blind” for eye movements) was non-significant. In Experiment 2, stricter instructions and small changes in the procedure led to a sharp decrease in the number of eye movements, such that both the RT bias in the trials without eye movements as well as the RT bias across all trials was significant.

Tracing the formation of perceptual decisions in the human brain: A new approach to the study of visuospatial attention asymmetries

Event Abstract Back to Event Tracing the formation of perceptual decisions in the human brain: A new approach to the study of visuospatial attention asymmetries Daniel P. Newman1*, Gerard M. Loughnane2, Simon P. Kelly3, Redmond G. O'Connell4 and Mark Bellgrove1 1 Monash University, School of Psychology and Psychiatry, Australia 2 Trinity College Dublin, Trinity Centre for Bioengineering, Ireland 3 City College of New York, Department of Biomedical Engineering, United States 4 Trinity College Dublin, Institute of Neuroscience and School of Psychology, Ireland BACKGROUND Healthy individuals tend to exhibit a subtle processing bias favouring stimuli in the left over the right visual hemifield, termed pseudoneglect, which is thought to reflect a dominant role of the right hemisphere for attention. Reversal of this leftward advantage marks neurological vulnerability across a number of disorders, including unilateral neglect, ADHD and dyslexia. These disorders share a qualitatively similar behavioural phenotype-leftward inattention- yet this label speaks little to the underlying pathophysiological processes. This study aimed to develop an electrophysiological paradigm to differentiate between attentional, perceptual decision making, and motoric processing asymmetries in relation to visuospatual bias. METHODS A random dot motion patch was continuously presented in each hemifield while healthy participants fixated centrally and reacted via button press to instances of coherent motion occurring on either the left or right at pseudorandom times. Since detecting coherence requires sampling from the entire array of dots, the decision regarding coherent motion is gradual and reflects an accumulation of sensory evidence. Further, the continuous stimuli eliminate sensory-evoked deflections in the ERP trace due to stimulus onset. This allows us to track robust brain signals that index sensory evidence accumulation up to an action-triggering threshold. RESULTS A significant leftward reaction time bias confirmed the task’s sensitivity to pseudoneglect in healthy subjects. Analysis of the decision signal revealed that coherent motion in the left and right visual fields was associated with identical build-up rates and decision thresholds but there was a significant ~23ms lag in the onset of evidence accumulation for right versus left targets. The EEG results suggest that pseudoneglect cannot be attributed to hemispheric differences in motoric processing, evidence accumulation rate or threshold, but are indicative of more efficient attentional orienting towards the left shortly after motion onset- before the coherent motion is consciously perceived. DISCUSSION This paradigm provides a way to identify the specific stages of the perceptual decision process that are related to visuospatial attention asymmetries. This approach has obvious value for clinical populations, such as neglect, ADHD and dyslexia, as a means of ruling out non-attentional influences on spatial asymmetry. Keywords: spatial attention, pseudoneglect, perceptual decision making, hemispheric asymmetry, individual differences Conference: ACNS-2013 Australasian Cognitive Neuroscience Society Conference, Clayton, Melbourne, Australia, 28 Nov - 1 Dec, 2013. Presentation Type: Poster Topic: Attention Citation: Newman DP, Loughnane GM, Kelly SP, O'Connell RG and Bellgrove M (2013). Tracing the formation of perceptual decisions in the human brain: A new approach to the study of visuospatial attention asymmetries. Conference Abstract: ACNS-2013 Australasian Cognitive Neuroscience Society Conference. doi: 10.3389/conf.fnhum.2013.212.00132 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 18 Nov 2013; Published Online: 25 Nov 2013. * Correspondence: Mr. Daniel P Newman, Monash University, School of Psychology and Psychiatry, Melbourne, Australia, dan.newman86@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Daniel P Newman Gerard M Loughnane Simon P Kelly Redmond G O'Connell Mark Bellgrove Google Daniel P Newman Gerard M Loughnane Simon P Kelly Redmond G O'Connell Mark Bellgrove Google Scholar Daniel P Newman Gerard M Loughnane Simon P Kelly Redmond G O'Connell Mark Bellgrove PubMed Daniel P Newman Gerard M Loughnane Simon P Kelly Redmond G O'Connell Mark Bellgrove Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Food-related Stroop interference in obese and normal-weight individuals: Behavioral and electrophysiological indices

The primary objective of the present study was to investigate differences in the attentional processing of food-related words in a Stroop task, as assessed by means of behavioral (reaction times) and electrophysiological (P200 and P300 amplitudes) indices, between obese and normal-weight individuals. Results revealed a P200 bias to food-related words in obese participants, which was not seen in normal-weight participants. This indicates that, in an early, automatic stage of information processing, obese participants already tend to engage more attention towards food-related stimuli than to neutral stimuli. With respect to reaction times and P300 scores, as alleged indices of more conscious maintained attention, a general food-related bias was observed, with no between-group differences. Further, in the obese group, significant positive correlations were observed between the food-related reaction time bias, food craving, and external eating, whereas in the normal-weight group, food craving scores correlated positively with P200/P300 amplitude biases. It can be concluded that obese individuals display an enhanced automatic, preconscious attentional processing of food-related stimuli, and this can be regarded as an initial expression of a greater responsiveness to food cues. In the current food-abundant environment, such a heightened food cue-responsiveness might contribute substantially to the tendency to overeat.

Neural Correlates of Developing and Adapting Behavioral Biases in Speeded Choice Reactions--An fMRI Study on Predictive Motor Coding

In reaction-time (RT) tasks with unequally probable stimuli, people respond faster and more accurately in high-probability trials than in low-probability trials. We used functional magnetic resonance imaging to investigate brain activity during the acquisition and adaptation of such biases. Participants responded to arrows pointing to either side with different and previously unknown probabilities across blocks, which were covertly reversed in the middle of some blocks. Changes in response bias were modeled using the development of the selective RT bias at the beginning of a block and after the reversal as parametric regressors. Both fresh development and reversal of an existing response bias were associated with bilateral activations in inferior parietal lobule, intraparietal sulcus, and supplementary motor cortex. Further activations were observed in right temporoparietal junction, dorsolateral prefrontal cortex, and dorsal premotor cortex. Only during initial development of biases at the beginning of a block, we observed additional activity in ventral premotor cortex and anterior insula, whereas the basal ganglia (bilaterally) were recruited when the bias was adapted to reversed probabilities. Taken together, these areas constitute a network that updates and applies implicit predictions to create an attention and motor bias according to environmental probabilities that transform into specific facilitation.

Food-related Stroop interference in obese and normal-weight individuals: Behavioral and electrophysiological indices

The primary objective of the present study was to investigate differences in the attentional processing of food-related words in a Stroop task, as assessed by means of behavioral (reaction times) and electrophysiological (P200 and P300 amplitudes) indices, between obese and normal-weight individuals. Results revealed a P200 bias to food-related words in obese participants, which was not seen in normal-weight participants. This indicates that, in an early, automatic stage of information processing, obese participants already tend to engage more attention towards food-related stimuli than to neutral stimuli. With respect to reaction times and P300 scores, as alleged indices of more conscious maintained attention, a general food-related bias was observed, with no between-group differences. Further, in the obese group, significant positive correlations were observed between the food-related reaction time bias, food craving, and external eating, whereas in the normal-weight group, food craving scores correlated positively with P200/P300 amplitude biases. It can be concluded that obese individuals display an enhanced automatic, preconscious attentional processing of food-related stimuli, and this can be regarded as an initial expression of a greater responsiveness to food cues. In the current food-abundant environment, such a heightened food cue-responsiveness might contribute substantially to the tendency to overeat.

Chimeric faces, visual field bias, and reaction time bias: Have we been missing a trick?

The chimeric faces test is a frequently used behavioural test of lateralisation for cognitive processing. Performance on this task is typically quantified in terms of bias towards selecting faces where positive facial emotion is expressed in the viewer's left visual field, indicating right hemisphere dominance for the task. This paper examines an alternative measure that may be extracted from responses to the chimeric faces test: reaction time bias. There was a strong positive correlation between the two asymmetry measures, which remained even after controlling for sex and handedness. The possible uses of reaction time bias in the measurement of cerebral lateralisation are discussed.