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1.
Psychol Res ; 84(8): 2248-2261, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31292736

RESUMO

Theories suggest that the perception of others' actions and social cues leads to selective processing of object features. Most recently, natural pedagogy theory postulated that ostensive cues lead to a selective processing of an object's features at the expense of processing of its location. This study examined this hypothesis in 10-year-old children with and without autism spectrum condition (ASC) to better understand social information processing in ASC and the relevance of observing others in human object processing in general. Participants saw an agent either ostensively pointing to an object or non-ostensively grasping an object. Thereafter, the cued or uncued object changed either its location or identity. We assessed not only behavioral responses, but also participants' gaze behavior by means of eye tracking. In contrast to natural pedagogy theory, we found that in the non-ostensive grasping context, participants rather noticed an identity change than a location change. Moreover, location changes were more readily identified in the ostensive pointing context. Importantly, there was no difference between children with and without ASC. Our study shows that the perception of ostensively vs. non-ostensively framed actions leads to different processing of object features, indicating a close link between action perception, object processing, and social cues. Moreover, the lacking group difference in our study suggests that these basic perception-action processes are not impaired in autism.


Assuntos
Atenção/fisiologia , Transtorno Autístico , Cognição/fisiologia , Fixação Ocular/fisiologia , Criança , Sinais (Psicologia) , Feminino , Movimentos da Cabeça/fisiologia , Humanos , Masculino , Estimulação Luminosa , Percepção Visual/fisiologia
2.
J Exp Child Psychol ; 156: 179-185, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28063604

RESUMO

Seeking proximity to another person immediately expresses affiliative intentions. These are highly relevant after experiencing social exclusion. Through a novel task, the current study investigated the relation between proximity and observed ostracism during early childhood. A sample of 64 children (Mage=58months) first watched priming videos either depicting ostracism or not. Subsequently, children saw four seats of varying distances from an interactant's seat and chose where to sit. Children who observed social exclusion selected seats with higher proximity. The results suggest that young preschoolers can immediately express the threatened need to belong by literally getting closer to even a stranger after witnessing ostracism. The task provides new opportunities to test reactions to social exclusion during early childhood.


Assuntos
Comportamento Infantil/psicologia , Relações Interpessoais , Distância Psicológica , Pré-Escolar , Feminino , Humanos , Lactente , Intenção , Masculino , Gravação de Videoteipe
3.
Psychopathology ; 49(4): 295-304, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27576511

RESUMO

BACKGROUND/AIMS: We investigated the links between maternal bonding, maternal anxiety disorders, and infant self-comforting behaviors. Furthermore, we looked at the moderating roles of infant gender and age. METHODS: Our sample (n = 69) comprised 28 mothers with an anxiety disorder (according to DSM-IV criteria) and 41 controls, each with their 2.5- to 8-month-old infant (41 females and 28 males). Infant behaviors were recorded during the Face-to-Face Still-Face paradigm. Maternal bonding was assessed by the Postpartum Bonding Questionnaire. RESULTS: Conditional process analyses revealed that lower maternal bonding partially mediated between maternal anxiety disorders and increased self-comforting behaviors but only in older female infants (over 5.5 months of age). However, considering maternal anxiety disorders without the influence of bonding, older female infants (over 5.5 months of age) showed decreased rates of self-comforting behaviors, while younger male infants (under 3 months of age) showed increased rates in the case of maternal anxiety disorder. CONCLUSIONS: The results suggest that older female infants (over 5.5 months of age) are more sensitive to lower maternal bonding in the context of maternal anxiety disorders. Furthermore, results suggest a different use of self-directed regulation strategies for male and female infants of mothers with anxiety disorders and low bonding, depending on infant age. The results are discussed in the light of gender-specific developmental trajectories.


Assuntos
Transtornos de Ansiedade/psicologia , Comportamento do Lactente/psicologia , Relações Mãe-Filho/psicologia , Mães/psicologia , Apego ao Objeto , Fatores Etários , Transtornos de Ansiedade/diagnóstico , Manual Diagnóstico e Estatístico de Transtornos Mentais , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino , Distribuição Aleatória , Fatores Sexuais , Método Simples-Cego , Inquéritos e Questionários
4.
Psychopathology ; 49(5): 334-340, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27498091

RESUMO

BACKGROUND/AIMS: High maternal emotional availability (EA) positively affects various domains of child development. However, the question of which factors promote or hinder maternal EA has not been investigated systematically. The present study investigated several maternal characteristics, namely maternal psychopathology, maternal attachment style insecurity, and theory of mind (ToM) as possible factors that influence maternal EA. METHODS: The sample was comprised of 56 mothers and their preschool-aged children. Half of the mothers were diagnosed with postpartum depression and or anxiety disorders according to DSM-IV, and the other half were healthy controls. RESULTS: The results showed that both low maternal attachment style insecurity and high ToM skills significantly predicted maternal EA sensitivity, independently from maternal postpartum and concurrent psychopathology and education. Moreover, maternal attachment style insecurity fully mediated the link between maternal postpartum psychopathology and sensitivity. CONCLUSION: The findings suggest that maternal attachment style security can buffer negative effects of maternal psychopathology on maternal sensitivity in the mother-child interaction.


Assuntos
Depressão Pós-Parto/psicologia , Relações Mãe-Filho/psicologia , Mães/psicologia , Apego ao Objeto , Teoria da Mente , Adulto , Transtornos de Ansiedade/psicologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Psicopatologia , Autoimagem
5.
Arch Womens Ment Health ; 18(5): 707-16, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25833807

RESUMO

To enhance understanding of impaired socio-emotional development in children of postpartum depressed or anxious mothers, this longitudinal study addressed the question of whether maternal postpartum depression and anxiety disorders result in deficits in children's processing of facial emotional expressions (FEEs) at pre-school age. Thirty-two mothers who had fulfilled Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV) criteria for postpartum depression and/or anxiety disorder and their pre-school aged children were tested for FEE processing abilities and compared to a healthy control group (n = 29). Child assessments included separate tasks for emotion recognition and emotion labelling. Mothers completed an emotion recognition test as well as the Structured Clinical Interview for DSM-IV Axis I Disorders I (SCID-I). Children of postpartum depressed and/or anxious mothers performed significantly worse than control children at labelling, but not at recognizing facial expressions of basic emotions. Emotion labelling at pre-school age was predicted by child age and maternal postpartum mental health, but neither current maternal mental health nor current maternal emotion recognition was associated with child FEE processing. Results point to a specific importance of early social experiences for the development of FEE labelling skills. However, further studies involving sensitive measures of emotion recognition are needed to determine if there might also exist subtle effects on FEE recognition.


Assuntos
Transtornos de Ansiedade/complicações , Transtornos Cognitivos/etiologia , Depressão Pós-Parto/complicações , Emoções , Expressão Facial , Adulto , Transtornos de Ansiedade/psicologia , Criança , Filho de Pais com Deficiência , Pré-Escolar , Transtornos Cognitivos/psicologia , Depressão Pós-Parto/psicologia , Feminino , Alemanha , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Mães/psicologia , Período Pós-Parto , Gravidez , Reconhecimento Psicológico
6.
J Exp Child Psychol ; 124: 67-77, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24759211

RESUMO

Humans are specifically adapted to knowledge acquisition and transfer by social communication. According to natural pedagogy theory, infants are highly sensitive to signals that indicate a teacher's communicative intention and are biased to interpret communicative contexts as conveying relevant and generalizable knowledge that is also shared by other conspecifics. We investigated whether infants as young as 12 months interpret ostensively communicated object-directed emotion expressions as generalizable and shareable with others. Given that young infants pay particular attention to information about objects' functions, we were interested in whether the shareability assumption also holds for emotional attitudes toward functional features of unfamiliar objects. The results suggest that 12-month-olds (N=80) flexibly interpret another person's emotion displays toward unfamiliar artifacts either as object-centered and generalizable attitudes or as person-centered subjective attitudes, depending on the communicative characteristics of the learning context. Furthermore, the transfer of ostensively communicated information about the artifacts depended on their functional usability, which is consistent with infants' early sensitivity to function information in various areas of cognitive development.


Assuntos
Atenção , Comunicação , Psicologia da Criança , Feminino , Humanos , Lactente , Aprendizagem , Masculino , Percepção Social
7.
LGBT Health ; 11(2): 81-102, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37676973

RESUMO

Purpose: The purpose of this study was to provide a systematic review and, where possible, meta-analysis on the prevalence of physical health conditions in sexual minority men (SMM, i.e., gay- and bisexual-identified men) compared with heterosexual-identified men. Methods: A systematic literature search in the databases MEDLINE, Embase, CENTRAL, CINAHL, and Web of Science was conducted on epidemiological studies on physical health conditions, classified in the Global Burden of Disease project and published between 2000 and 2021. Meta-analyses comparing odds ratios were calculated. Results: In total, 23,649 abstracts were screened, and 32 studies were included in the systematic review. Main findings were that (1) Largest differences in prevalence by sexual identity were found for chronic respiratory diseases, particularly asthma: overall, SMM were significantly almost 50% more likely to suffer from asthma than heterosexual men. (2) Evidence of higher prevalence was also found for chronic kidney diseases and headache disorders in gay men and for hepatitis B/C in both gay and bisexual men. (3) We found an overall trend that bisexual men were more affected by some of the physical health conditions compared with gay men (e.g., cardiovascular diseases, asthma). However, regarding cancer, headache disorders, and hepatitis, gay men were more affected. Conclusion: We found evidence of physical health disparities by sexual identity, suggesting more health issues in SMM. Since some of these findings rely on few comparisons or small samples of SMM only, this review is intended to be a vehement plea for routinely including sexual identity assessment in health research and clinical practice.


Assuntos
Asma , Transtornos da Cefaleia , Minorias Sexuais e de Gênero , Humanos , Masculino , Asma/epidemiologia , Bissexualidade , Transtornos da Cefaleia/epidemiologia , Heterossexualidade , Homossexualidade , Fatores de Risco , Insuficiência Renal Crônica/enzimologia , Hepatite/epidemiologia , Neoplasias/epidemiologia
8.
Womens Health (Lond) ; 19: 17455057231219610, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38146632

RESUMO

BACKGROUND: Sexual minority individuals experience discrimination, leading to mental health disparities. Physical health disparities have not been examined to the same extent in systematic reviews so far. OBJECTIVES: To provide a systematic review and, where possible, meta-analyses on the prevalence of physical health conditions in sexual minority women (i.e. lesbian- and bisexual-identified women) compared to heterosexual-identified women. DESIGN: The study design is a systematic review with meta-analyses. DATA SOURCES AND METHODS: A systematic literature search in MEDLINE, EMBASE, CENTRAL, CINAHL, and Web of Science databases was conducted on epidemiologic studies on physical health conditions, classified in the Global Burden of Disease project, published between 2000 and 2021. Meta-analyses pooling odds ratios were calculated. RESULTS: In total, 23,649 abstracts were screened and 44 studies were included in the systematic review. Meta-analyses were run for arthritis, asthma, back pain, cancer, chronic kidney diseases, diabetes, headache disorders, heart attacks, hepatitis, hypertension, and stroke. Most significant differences in prevalence by sexual identity were found for chronic respiratory conditions, especially asthma. Overall, sexual minority women were significantly 1.5-2 times more likely to have asthma than heterosexual women. Furthermore, evidence of higher prevalence in sexual minority compared to heterosexual women was found for back pain, headaches/migraines, hepatitis B/C, periodontitis, urinary tract infections, and acne. In contrast, bisexual women had lower cancer rates. Overall, sexual minority women had lower odds of heart attacks, diabetes, and hypertension than heterosexual women (in terms of diabetes and hypertension possibly due to non-consideration of pregnancy-related conditions). CONCLUSION: We found evidence for physical health disparities by sexual identity. Since some of these findings rely on few comparisons only, this review emphasizes the need for routinely including sexual identity assessment in health research and clinical practice. Providing a more detailed picture of the prevalence of physical health conditions in sexual minority women may ultimately contribute to reducing health disparities.


Assuntos
Asma , Diabetes Mellitus , Hipertensão , Infarto do Miocárdio , Minorias Sexuais e de Gênero , Gravidez , Feminino , Humanos , Heterossexualidade/psicologia
9.
Br J Dev Psychol ; 29(Pt 3): 357-74, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21848735

RESUMO

This paper investigates the role of cause and effect relations for infants' learning about artifacts. Two experiments tested whether 12-month-olds categorized a given set of unfamiliar artifacts according to overall similarity and/or according to part similarity, depending on what kind of video demonstration was presented before the start of the categorization task. In both experiments, the actions performed with objects were accompanied by interesting effects but the causal relation between object-structure and effects was teased apart. In one video demonstration (Expt 1), the experimenter used the object part to produce some kind of effect in a causally plausible way. In another video demonstration (Expt 2), the experimenter performed similar actions with the same objects as in Expt 1, followed by the same effects as before. Importantly, however, no plausible cause-effect relation was provided this time. Only infants participating in Expt 1 categorized the set of unfamiliar objects according to part similarity. This finding suggests that 12-month-olds attend to the causal relation between specific object parts and their functional use when categorizing artifacts, rather than merely associating form-characteristics with an interesting effect.


Assuntos
Aprendizagem por Associação , Aprendizagem por Discriminação , Reconhecimento Visual de Modelos , Psicologia da Criança , Atenção , Formação de Conceito , Feminino , Humanos , Lactente , Masculino , Percepção de Movimento , Resolução de Problemas , Desempenho Psicomotor , Reconhecimento Psicológico
10.
PeerJ ; 9: e11771, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34316405

RESUMO

Additive and multiplicative regression models of habituation were compared regarding the fit to looking times from a habituation experiment with infants aged between 3 and 11 months. In contrast to earlier studies, the current study considered multiple probability distributions, namely Weibull, gamma, lognormal and normal distribution. In the habituation experiment the type of contrast between the habituation and the test trial was varied (luminance, color or orientation contrast), crossed with the number of habituation trials (1, 3, 5, or 7 habituation trials) and crossed with three age cohorts (4, 7, 10 months). The initial mean LT to dark stimuli (around 3.7 s) was considerably shorter than the mean LT to green and gray stimuli (around 5 s). Infants showed the strongest dishabituation to changes from dark to bright (luminance contrast) and weak-to-no dishabituation to a 90-degrees rotation of the gray stimuli (orientation contrast). The dishabituation was stronger after five and seven habituation trials, but the result was not statistically robust. The gamma distribution showed the best fit in terms of log-likelihood and mean absolute error and the best predictive performance. Furthermore, the gamma distribution showed small correlations between parameters relative to other models. The normal additive model showed an inferior fit and medium correlations between the parameters. In particular, the positive correlation between the initial looking time (LT) and the habituation rate was likely responsible for a different interpretation relative to the multiplicative models of the main effect of age on the habituation rate. Otherwise, the additive and multiplicative models provided similar statistical conclusions. The performance of the model versions without pooling and with partial pooling across participants (also called random-effects, multi-level or hierarchical models) were compared. The latter type of models showed worse data fit but more precise predictions and reduced correlations between the parameters. The performance of model variants with auto-regressive time structures were explored but showed considerably worse fit. The performance of quadratic models that allowed non-monotonic changes in LTs were investigated as well. However, when fitted with LT data, these models did not produce non-monotonic change in LTs. The study underscores the utility of partial-pooling models in terms of providing more accurate predictions. Further, it agrees with previous research in that a multiplicative LT model is preferable. Nevertheless, the current results suggest that the impact of the choice of an additive model on the statistical inference is less dramatic then previously assumed.

11.
Infancy ; 15(4): 434-444, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32693521

RESUMO

Recent studies suggest that even infants attend to others' beliefs in order to make sense of their behavior. To warrant the assumption of early belief understanding, corresponding competences need to be demonstrated in a variety of different belief-inducing situations. The present study provides corresponding evidence, using a completely nonverbal object-transfer task based on the general violation-of-expectation paradigm. A total of n = 36 infants (15-month-olds) participated in one of three conditions. Infants saw an actor who either observed an object's location change, did not observe it, or performed the location change manually without seeing it (i.e., variations in the actor's information access). Results are in accordance with the assumption that 15-month-old infants master different belief-inducing situations in a highly flexible way, accepting visual as well as manual information access as a proper basis for belief induction.

12.
Cogn Psychol ; 59(3): 275-95, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19596267

RESUMO

This paper investigates the role of static and dynamic attributes for the animate-inanimate distinction in category-based reasoning of 7-month-olds. Three experiments tested infants' responses to movement events involving an unfamiliar animal and a ball. When either the animal or the ball showed self-initiated irregular movements (Experiment 1), infants expected the previously active object to start moving again. When both objects were moving together in an ambiguous motion event (Experiment 2), infants expected only the animal to start moving again. Initial looking preferences for each object did not influence results. When either the facial features of the animal were removed, or its furry body was replaced by a plastic spiral in an ambiguous motion event (Experiment 3), infants formed no clear expectation regarding future movements. Based on this set of findings we conclude that 7-month-olds flexibly combine information about the static and dynamic properties of objects in order to reason about motion events.


Assuntos
Formação de Conceito/fisiologia , Aprendizagem por Discriminação/fisiologia , Comportamento do Lactente/fisiologia , Análise de Variância , Atenção/fisiologia , Desenvolvimento Infantil , Feminino , Humanos , Lactente , Masculino , Percepção de Movimento/fisiologia , Resolução de Problemas/fisiologia , Gravação em Vídeo
13.
PLoS One ; 14(8): e0220889, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31425561

RESUMO

GOALS AND METHODS: A simulation study investigated how ceiling and floor effect (CFE) affect the performance of Welch's t-test, F-test, Mann-Whitney test, Kruskal-Wallis test, Scheirer-Ray-Hare-test, trimmed t-test, Bayesian t-test, and the "two one-sided tests" equivalence testing procedure. The effect of CFE on the estimate of group difference and on its confidence interval, and on Cohen's d and on its confidence interval was also evaluated. In addition, the parametric methods were applied to data transformed with log or logit function and the performance was evaluated. The notion of essential maximum from abstract measurement theory is used to formally define CFE and the principle of maximum entropy was used to derive probability distributions with essential maximum/minimum. These distributions allow the manipulation of the magnitude of CFE through a parameter. Beta, Gamma, Beta prime and Beta-binomial distributions were obtained in this way with the CFE parameter corresponding to the logarithm of the geometric mean. Wald distribution and ordered logistic regression were also included in the study due to their measure-theoretic connection to CFE, even though these models lack essential minimum/maximum. Performance in two-group, three-group and 2 × 2 factor design scenarios was investigated by fixing the group differences in terms of CFE parameter and by adjusting the base level of CFE. RESULTS AND CONCLUSIONS: In general, bias and uncertainty increased with CFE. Most problematic were occasional instances of biased inference which became more certain and more biased as the magnitude of CFE increased. The bias affected the estimate of group difference, the estimate of Cohen's d and the decisions of the equivalence testing methods. Statistical methods worked best with transformed data, albeit this depended on the match between the choice of transformation and the type of CFE. Log transform worked well with Gamma and Beta prime distribution while logit transform worked well with Beta distribution. Rank-based tests showed best performance with discrete data, but it was demonstrated that even there a model derived with measurement-theoretic principles may show superior performance. Trimmed t-test showed poor performance. In the factor design, CFE prevented the detection of main effects as well as the detection of interaction. Irrespective of CFE, F-test misidentified main effects and interactions on multiple occasions. Five different constellations of main effect and interactions were investigated for each probability distribution, and weaknesses of each statistical method were identified and reported. As part of the discussion, the use of generalized linear models based on abstract measurement theory is recommended to counter CFE. Furthermore, the necessity of measure validation/calibration studies to obtain the necessary knowledge of CFE to design and select an appropriate statistical tool, is stressed.


Assuntos
Projetos de Pesquisa , Análise de Variância , Teorema de Bayes , Entropia , Humanos , Modelos Lineares , Modelos Logísticos , Modelos Estatísticos , Probabilidade , Software
14.
Dev Cogn Neurosci ; 36: 100621, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30716584

RESUMO

We investigated young infants' object encoding and processing in response to isolated eye gaze cues on the neural and behavioral level. In two experiments, 4-month-old infants watched a pair of isolated eyes gazing towards or away from novel objects. Subsequently, the same objects were presented alone (i.e., without eyes). We measured event-related potentials (ERP) in response to object-directed and object-averted eye gaze as well as to the subsequently presented isolated objects. Using eye-tracking methods, we additionally measured infants' looking behavior in reaction to the subsequently presented isolated objects. The ERP data revealed an enhanced slow wave positivity for object-directed eye gaze, indicating increased encoding of observed gaze cues. Regarding the objects, we found an enhanced Nc amplitude and increased looking times in response to previously uncued objects, indicating a novelty response on the neural and behavioral level. The results suggest that isolated eye gaze stimuli are sufficient to trigger object encoding and facilitate further object processing.


Assuntos
Sinais (Psicologia) , Fixação Ocular/fisiologia , Comportamento do Lactente/fisiologia , Potenciais Evocados/fisiologia , Feminino , Humanos , Lactente , Masculino
15.
Dev Psychol ; 54(11): 2067-2076, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30265029

RESUMO

We investigated whether witnessing social exclusion influenced memory recall in preschool children. A sample of 81 children (Mage = 5 years, 4 months) first watched priming videos either depicting social exclusion or not. Subsequently, they participated in two memory tasks, one testing recall of numbers and the other testing recall of previously heard story events. These consisted of social (e.g., "brother") and nonsocial (e.g., "circus") items. In addition, a language-screening test was conducted to ensure that in both conditions (i.e., social exclusion and control), children's language levels were similar. In both conditions, children scored comparably on number recall and overall recall of story events. However, only children who observed social exclusion remembered more social than nonsocial items. The findings suggest that vicarious social exclusion triggers selective retention of social information in preschool age, in accord with findings of older children and adults who directly experienced social exclusion. Social exclusion affects the need to belong in young children, not only indicated by means of increased attempts to affiliate, but also by an increased memory for social events. (PsycINFO Database Record (c) 2018 APA, all rights reserved).


Assuntos
Comportamento Infantil/fisiologia , Rememoração Mental/fisiologia , Distância Psicológica , Retenção Psicológica/fisiologia , Percepção Social , Pré-Escolar , Feminino , Humanos , Masculino
16.
Cognition ; 105(2): 362-79, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17129581

RESUMO

This report examines whether knowledge about function influences the formation of artifact categories in 11-12- month old infants. Using an object-examination task, a set of artificial stimuli was presented that could either be grouped according to overall similarity or according to similarity in one functionally relevant part. Experiment 1 revealed that infants categorized the objects according to overall similarity but not part similarity under control conditions. Experiment 2 showed that after having seen the experimenter demonstrating the functional use of the critical part, infants later categorized the stimuli according to part similarity. When the same actions were performed without producing any effect, infants failed to categorize according to the critical part. This set of findings suggests that 11-12-month old infants use functional information as a cue to categorization.


Assuntos
Aprendizagem por Associação , Formação de Conceito , Aprendizagem por Discriminação , Reconhecimento Visual de Modelos , Psicologia da Criança , Feminino , Humanos , Lactente , Masculino , Orientação
17.
PeerJ ; 3: e1243, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26401454

RESUMO

We explore the role of eye movements in a chase detection task. Unlike the previous studies, which focused on overall performance as indicated by response speed and chase detection accuracy, we decompose the search process into gaze events such as smooth eye movements and use a data-driven approach to separately describe these gaze events. We measured eye movements of four human subjects engaged in a chase detection task displayed on a computer screen. The subjects were asked to detect two chasing rings among twelve other randomly moving rings. Using principal component analysis and support vector machines, we looked at the template and classification images that describe various stages of the detection process. We showed that the subjects mostly search for pairs of rings that move one after another in the same direction with a distance of 3.5-3.8 degrees. To find such pairs, the subjects first looked for regions with a high ring density and then pursued the rings in this region. Most of these groups consisted of two rings. Three subjects preferred to pursue the pair as a single object, while the remaining subject pursued the group by alternating the gaze between the two individual rings. In the discussion, we argue that subjects do not compare the movement of the pursued pair to a singular preformed template that describes a chasing motion. Rather, subjects bring certain hypotheses about what motion may qualify as chase and then, through feedback, they learn to look for a motion pattern that maximizes their performance.

18.
Front Psychol ; 5: 1423, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25566114

RESUMO

We investigate the influence of perceived displacement of moving agent-like stimuli on the performance in dynamic interactive tasks. In order to reliably measure perceived displacement we utilize multiple tasks with different task demands. The perceived center of an agent's body is displaced in the direction in which the agent is facing and this perceived displacement is larger than the theoretical position of the center of mass would predict. Furthermore, the displacement in the explicit judgment is dissociated from the displacement obtained by the implicit measures. By manipulating the location of the pivot point, we show that it is not necessary to postulate orientation as an additional cue utilized by perception, as has been suggested by earlier studies. These studies showed that the agent's orientation influences the detection of chasing motion and the detection-related performance in interactive tasks. This influence has been labeled wolfpack effect. In one of the demonstrations of the wolfpack effect participants control a green circle on a display with a computer mouse. It has been shown that participants avoid display areas with agents pointing toward the green circle. Participants do so in favor of areas where the agents point in the direction perpendicular to the circle. We show that this avoidance behavior arises because the agent's pivot point selected by the earlier studies is different from where people locate the center of agent's body. As a consequence, the nominal rotation confounds rotation and translation. We show that the avoidance behavior disappears once the pivot point is set to the center of agent's body.

19.
Front Psychol ; 5: 1141, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25346712

RESUMO

A large body of research has documented infants' ability to classify animate and inanimate objects based on static or dynamic information. It has been shown that infants less than 1 year of age transfer animacy-specific expectations from dynamic point-light displays to static images. The present study examined whether basic motion cues that typically trigger judgments of perceptual animacy in older children and adults lead 7-month-olds to infer an ambiguous object's identity from dynamic information. Infants were tested with a novel paradigm that required inferring the animacy status of an ambiguous moving shape. An ambiguous shape emerged from behind a screen and its identity could only be inferred from its motion. Its motion pattern varied distinctively between scenes: it either changed speed and direction in an animate way, or it moved along a straight path at a constant speed (i.e., in an inanimate way). At test, the identity of the shape was revealed and it was either consistent or inconsistent with its motion pattern. Infants looked longer on trials with the inconsistent outcome. We conclude that 7-month-olds' representations of animates and inanimates include category-specific associations between static and dynamic attributes. Moreover, these associations seem to hold for simple dynamic cues that are considered minimal conditions for animacy perception.

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