Arm-movement responses to Müller-Lyer stimuli

Similarities between eye- and arm-movement patterns during the Müller-Lyer illusion were investigated. The study was designed to find out if characteristics of a visual illusion would be reflected in tracings of an unseen ann. Six stimuli, three experimental and three control, were presented five times to each of seven Ss who were familiar with the illusion. Data were analyzed by measuring lengths of tracings and by making intraindividual comparisons using t tests for correlated means. Results for the arm were similar to those reported elsewhere for the eye. Arrows with outward-directed obliques were traced longer than arrows with inward-directed obliques, as well as longer than control stimuli. Agreement between eye- and arm-movement responses to the illusion lend support for using each technique to investigate stimuli that affect man’s distance metric.     

Big Five personality traits contribute to prosocial responses to others’ pain

ObjectivesTwo studies examined whether observers’ personality traits contribute to prosocial responses to others’ facial expression of pain. Experiment 1 examined the personality traits that could account for observers’ variability in estimating others’ pain intensity. Experiment 2 questioned to what extent the contribution of personality traits on inclination to help people in pain depend on observers’ beliefs about pain’ characteristics.Method59 (experiment 1) and 76 (experiment 2) participants observed to 3-D realistic synthetic face movements mobilizing action units of pain, in order to estimate others’ pain. In experiment 2, painful localizations (e.g., chest, hand) were also manipulated. In each experiment, Big Five personality traits were assessed.ResultsExperiment 1 revealed that agreeableness and conscientiousness contributed to observers’ pain estimates across the increase of facial expression intensity. Experiment 2 showed that conscientiousness contributed to observers’ judgments whatever pain’ characteristics. Neuroticism was only salient for pain referring to life-threatening pain.ConclusionProsocial response to others’ pain depends on agreeableness, conscientiousness and neuroticism. However, these links are modulated by the pain behavior elicited and observers’ belief about the characteristic of pain.     

Perceptual asymmetry and youths’ responses to stress: Understanding vulnerability to depression

This research examined the hypothesis that reduced posterior right hemisphere activity interferes with the regulation of emotions and behaviour in response to stress, creating vulnerability to depression. Consistent with a diathesis–stress model, we predicted that youths with a reduced posterior right hemisphere bias in emotional processing would engage in less adaptive responses to stress, which would be associated with depressive symptoms in those who reported the recent experience of high, but not low, levels of stress. Participants were 510 4th through 8th graders who completed the Chimeric Faces Task and measures of responses to stress and depressive symptoms. Results supported the idea that responses to stress account for the association between reduced posterior right hemisphere activity and depressive symptoms in youths who report high, but not low, levels of stress. This study provides insight into one process through which reduced posterior right hemisphere activity may confer vulnerability to depressive symptoms, and implicates responses to stress as a target for intervention.     

Electrodermal responses to movie stressors: Nicotine × extraversion interactions

Support was found for Eysenck's hypothesis that the effects of smoking sized doses of nicotine on cortical and electrodermal activity are functions of extraversion and the degree of externally-induced arousal. Responses to scenes that elicited moderate electrodermal and emotional responses followed the predicted extraversion ☆ nicotine interaction for electrodermal measures, but not for self-reported emotions, heart rate or electromyographic measures. The failure of the Ss to demonstrate an extraversion ☆ nicotine interaction when high-intensity stimuli were used (Gilbert and Hagen, 1980) is also interpreted as consistent with Eysenck's hypothesis.     

Substance use and mothers’ neural responses to infant cues

Substance use may influence mothers’ responsiveness to their infants and negatively impact the parent–infant relationship. Maternal substance use may co-opt neural circuitry involved in caregiving, thus reducing the salience of infant cues and diminishing the sense of reward experienced by caring for infants. Gaps in understanding exist with regard to the mechanisms by which substance use operates to influence mothers’ processing of infant cues and how this translates to caregiving. Therefore, we examined how substance use might relate to maternal neural responses to infant cues using event-related potentials (ERPs). Substance-using (n = 29) and nonsubstance-using (n = 29) mothers viewed photographs of infant faces and heard recordings of infant vocalizations while electroencephalography was recorded simultaneously. Three specific ERP components were used to examine initial processing of infant faces (N170) and cries (N100), and attentional allocation to infant faces and cries (P300). Substance-using mothers did not discriminate facial affect at early encoding stages (N170), were generally slower to orient to infant cries (N100), showed heightened responses to neutral faces (P300), and failed to adaptively differentiate between high-distress versus low-distress cries (P300). These differences may be important to caregiving behaviors associated with the formation of mother–child attachment. Implications are discussed, as are limitations and future directions.     

Distressed yet empathically sensitive: Preschoolers’ responses to infant crying

Using a simulated long bout of progressively intense infant crying, this study demonstrated that preschoolers responded with infant-oriented empathic concern and helping actions despite evidence of self-focused distress. Preschoolers’ helping actions were predicted by the interaction between empathic concern and cognitive inquiry.     

Infant visual responses to pattern: Which metric perdicts best?

Visual fixations were recorded in newborn, 4-, and 8-week old human infants as they scanned displays that varied along several dimensions. These displays were designed to evaluate four metrics that have been theorized to control infant visual preference: Contour length, size, number, and a new metric, CVAL, based on Contour Variability, Amount, and Location. This latter metric reflects characteristics of the visual system that other metrics ignore. Both contour length and CVAL separately accounted for approximately 95% of looking-duration variance, a much larger portion than the other metrics considered; however, CVAL accounted for more looking variance than contour length when the number of lines and contour length were deconfounded, and uniquely accommodated a large orientation effect. Finally, several predictions were confirmed about characteristics of visual scanning. Retinal structure and natural scanning dispositions should be considered in accounts of infants' reactions to visual stimuli.     

Social comparison mediates chimpanzees’ responses to loss,not frustration

Why do chimpanzees react when their partner gets a better deal than them? Do they note the inequity or do their responses reflect frustration in response to unattainable rewards? To tease apart inequity and contrast, we tested chimpanzees in a series of conditions that created loss through individual contrast, through inequity, or by both. Chimpanzees were tested in four social and two individual conditions in which they received food rewards in return for exchanging tokens with an experimenter. In conditions designed to create individual contrast, after completing an exchange, the chimpanzees were given a relatively less-preferred reward than the one they were previously shown. The chimpanzees’ willingness to accept the less-preferred rewards was independent of previously offered foods in both the social and individual conditions. In conditions that created frustration through inequity, subjects were given a less-preferred reward than the one received by their partner, but not in relation to the reward they were previously offered. In a social context, females were more likely to refuse to participate when they received a less-preferred reward than their partner (disadvantageous inequity), than when they received a more-preferred reward (advantageous inequity). Specifically, the females’ refusals were typified by refusals to exchange tokens rather than refusals to accept food rewards. Males showed no difference in their responses to inequity or individual contrast. These results support previous evidence that some chimpanzees’ responses to inequity are mediated more strongly by what others receive than by frustration effects.     

Humans’ responses to novel stimulus compounds and the effects of training

Twenty-four college students participated in an experiment with stimulus compounds. Subjects learned to discriminate color stimuli that correlated with varying probabilities of reinforcement. Reinforcement consisted of points. For all subjects, two colors signaled a .80 reinforcement probability, and two others signaled a .20 probability. For compound-trained subjects, a fifth compound stimulus (composed of a high-probability color and a low-probability color) was correlated with a .10 reinforcement probability. During testing, interspersed probe trials required subjects to choose between two alternatives: a compound stimulus and either one of its constituent stimuli. Compound-untrained subjects preferred the compound over either individual stimulus, thus showing response summation. However, compound-trained subjects, having had experience with an exemplar compound, showed significantly lower choice proportions for a test compound, indicating that subjects’ responding to novel stimulus compounds is modifiable by experience with a single similar compound.     

Intended responses to romantic partners’ annoying behaviours vary with willpower beliefs

When a romantic partner behaves in an annoying way – for example, by leaving a mess – we might respond with frustration or understanding. Responses may vary with contextual factors, including whether the partner could be mentally fatigued or depleted. We hypothesized that limited willpower theorists – who believe self-control diminishes with use – might be especially likely to consider their partner’s preceding mental exertion. Two preregistered studies (combined N = 428) examined participants’ responses to four hypothetical scenarios. Limited theorists responded more compassionately to infractions performed after fatiguing days than to those performed after relaxing days; non-limited theorists responded more consistently, regardless of context. Beliefs about one’s own willpower, rather than beliefs about one’s partner’s willpower, can affect how people respond to their partner’s undesirable behaviours.     

Congruence or coherence? Emotional and physiological responses to colours in synaesthesia

Lexical–chromatic synaesthesia is a condition in which letters and/or words elicit percepts of synaesthetic colours, termed photisms. Anecdotal data suggest that synaesthetes are particularly sensitive to inconsistencies between their synaesthetic percepts and the real world, e.g., it can be annoying and unpleasant for them to see a letter printed in a colour different than the respective photism colour. For R, a synaesthete subject who participated in the present study, the photisms possess specific emotional values (a red photism is pleasing and attractive, green is repulsive and unpleasant, etc.). In contrast to the anecdotal data, R does not always find the colour–photism incongruence to be disturbing. More importantly, he states that it is the emotional coherence between the stimulus and the corresponding photism that matters. In a series of experiments, we studied this new concept of emotional coherence on three levels—subjective (self-report), behavioural, and physiological, corroborating R's introspective statements. Besides the implications of the concept of coherence itself, the results presented here suggest that even highly subjective cognitive constructs can be approached and measured experimentally, uncovering the workings of the underlying psychophysiological mechanisms.     

Too good to be true? Psychological responses to uncommon options in risk–reward environments

Risks and rewards, or payoffs and probabilities, are inversely related in many choice environments. We investigated people's psychological responses to uncommon combinations of risk and reward that deviate from learned regularities (e.g., options that offer a high payoff with an unusually high probability) as they evaluated risky options. In two experiments (N = 183), participants first priced monetary gambles drawn from environments in which risks and rewards were negatively correlated, positively correlated, or uncorrelated. In later trials, they evaluated gambles with uncommon combinations of risk and reward—that is, options that deviated from the respective environment's risk–reward structure. Pricing, response times, and (in Experiment 2) pupil dilation were recorded. In both experiments, participants took more time when responding to uncommon compared to foreseeable options or when the same options were presented in an uncorrelated risk–reward environment. This result was most pronounced when the uncommon gambles offered higher expected values compared to the other gambles in the set. Moreover, these uncommon, high‐value options were associated with an increase in pupil size. These results suggest that people's evaluations of risky options are based not only on the options' payoffs and probabilities but also on the extent to which they fit the risk–reward structure of the environment.     

Bicyclists’ behavioral and physiological responses to varying roadway conditions and bicycle infrastructure

Population growth increase of vehicle ownership, and development patterns have resulted in greater levels of congestion, pollution, and crash frequency. A proposed solution to lessen current transportation system demands is to increase the share of bicycle trips. Furthermore, as cycling is perceived by some as both a dangerous and stressful mode of transportation, understanding the factors that lead to less comfortable and stressful riding, can help drive bicycle infrastructure development. To establish a more robust understanding of the behaviors of bicyclists and how infrastructure design and operations influence them, a bicycle simulator was used to evaluate bicyclist performance measures of velocity, horizontal displacement, and physiological responses (i.e., galvanic skin response) while riding in varying roadway conditions. Results showed that bicyclists in the bike lane condition, had a GSR reading 1.77 peaks per min less than when cycling in the no bike lane condition. When bicyclists were in no bike lane condition, the GSR reading was not affected by vehicle speed but it was affected by the vehicular volume. Additionally, females felt less comfortable when riding in either bike condition, even though they reported that they were “Strong and Fearless” riders. The methodology used for this study sets forth the foundation for future research that could evaluate varying facility designs and a wider range of individuals.     

Dreading the pain of others? Altruistic responses to others' pain underestimate dread

A dislike of waiting for pain, aptly termed ‘dread’, is so great that people will increase pain to avoid delaying it. However, despite many accounts of altruistic responses to pain in others, no previous studies have tested whether people take delay into account when attempting to ameliorate others' pain. We examined the impact of delay in 2 experiments where participants (total N = 130) specified the intensity and delay of pain either for themselves or another person. Participants were willing to increase the experimental pain of another participant to avoid delaying it, indicative of dread, though did so to a lesser extent than was the case for their own pain. We observed a similar attenuation in dread when participants chose the timing of a hypothetical painful medical treatment for a close friend or relative, but no such attenuation when participants chose for a more distant acquaintance. A model in which altruism is biased to privilege pain intensity over the dread of pain parsimoniously accounts for these findings. We refer to this underestimation of others' dread as a ‘Dread Empathy Gap’.     

The effect of age and reminders on witnesses’ responses to cross-examination-style questioning

Witnesses of all ages struggle with cross-examination questions, often changing their testimony as a result. In the laboratory, cross-examination-style questioning decreases both children's and adults’ accuracy. We examined the extent to which this effect varies with age. We interviewed children, adolescents, and adults (N = 128) about a film clip after a short delay. Eight months later we cross-examined participants on their original responses to some questions, and simply repeated other questions. Participants of all ages were more likely to change their answers when cross-examined than when asked the same question again. Cross-examination negatively affected accuracy, although this effect decreased as age increased. Listening to an audio-recording of their original responses before the second interview reduced the number of changes participants made in response to repeated questions, but not cross-examination questions. These data give cause for concern about the effect cross-examination has on the accuracy of child and adolescent witnesses.     

What else could I have done? Patients' responses to failed treatment decisions

Successful and failed renal transplant patients were compared concerning their perceptions of the initial decision to undergo transplantation. Results suggest that, relative to successful transplant patients, failed transplant patients recalled the circumstances of the initial decision in a manner that lessened personal responsibility for that decision. In essence, they indicated that they had had little choice but to make the decision they had made. There was slight evidence that failed transplant patients diffused responsibility for the decision or its outcome onto others. Implications for patient involvement in medical decision making and for the informed consent procedure are discussed. It is concluded that cognitive factors may play a role in undermining possible self-recrimination following failed treatment decisions in which a patient has been involved.     

Individual differences in the responses of naïve rhesus monkeys to snakes

The authors demonstrated individual differences in inhibited behavior and withdrawal responses of laboratory-born rhesus monkeys when initially exposed to a snake. Most monkeys displayed a small significant increase in their behavioral inhibition in the presence of a snake. A few monkeys had marked responses, and some actively withdrew. Although the responses of the most extreme laboratory-born monkeys were comparable to feral-born monkeys, the responses of the laboratory-born monkeys rapidly habituated. The individual differences in the responses of na?ve monkeys likely reflect a continuum from orienting to wariness to fear. A neurobiological model is presented that addresses potential mechanisms underlying these individual differences, their relation to fear, and how they may predispose to phobia development.     

What does it mean to be human? How salience of the human category affects responses to intergroup harm

Two studies explore how salience of the human category influences responses to intergroup harm and how different images of humanity modify these effects. In Study 1, British participants (n = 86) contemplated acts of terrorism against their group. When the human category (versus intergroup distinctions) was salient and when the prevailing image of humanity was malevolent (versus benevolent), participants were not only more understanding of terrorism, blamed this less on religious group memberships, but also more strongly endorsed the use of extreme force by countries to defend their boarders, preserve the peace and prevent future attacks. In Study 2, British participants (n = 83) contemplated the torture of Iraqi prisoners by British soldiers. When the human category was salient and the prevailing image of humanity was malevolent, participants experienced less guilt and justified torture more. We conclude that the effects of human category salience on interpretations of intergroup harm depend on what it means to be human. When human nature is perceived negatively, thinking in terms of the human category can normalise intergroup harm regardless of whether the outgroup or the ingroup is the perpetrator. Implications for re‐categorisation approaches to conflict reduction are discussed. Copyright © 2011 John Wiley & Sons, Ltd.