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Previous research on attention to fear-relevant stimuli has largely focused on static pictures or drawings, and thus did not consider the potential effect of natural motion. Here, we aimed to investigate the effect of motion on attentional capture in spider-fearful and non-fearful participants by using point-light stimuli and naturalistic videos. Point-light stimuli consist of moving dots representing joints and thereby visualizing biological motion (e.g. of a walking human or cat) without needing a visible body. Spider-fearful (n = 30) and non-spider-fearful (n = 31) participants completed a visual search task with moving targets (point-light/naturalistic videos) and static distractors (images), static targets and moving distractors, or static targets and static distractors. Participants searched for a specified animal type (snakes, spiders, cats, or doves) as quickly as possible. We replicated previous findings with static stimuli: snakes were detected faster and increased distraction, while spiders just increased distraction. However, contrary to our hypotheses, spider targets did not speed up responses, neither in the group of control nor in the group of spider-fearful participants. Interestingly, stimuli-specific effects were toned down, abolished, or even changed direction when motion was introduced. Also, we demonstrated that point-light stimuli were of similar efficiency as naturalistic videos, indicating that for testing effects of motion in visual search, "pure" motion stimuli might be sufficient. As we do show a substantial modulation of visual search phenomena by biological motion, we advocate for future studies to use moving stimuli, equivalent to our dynamic environment, to increase ecological validity.
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Atención , Miedo , Trastornos Fóbicos , Arañas , Arañas/fisiología , Humanos , Animales , Miedo/fisiología , Miedo/psicología , Femenino , Masculino , Adulto , Adulto Joven , Trastornos Fóbicos/psicología , Trastornos Fóbicos/fisiopatología , Atención/fisiología , Estimulación Luminosa/métodos , Percepción Visual/fisiología , Tiempo de Reacción/fisiologíaRESUMEN
The behavioral avoidance test (BAT) is a well-known diagnostic tool assessing fear by directly measuring avoidance behavior. For instance, in spider phobia, participants or patients gradually approach a live spider until they feel too uncomfortable to continue. However, the use of different BAT protocols in various studies hampers the comparability of results. Moreover, conducting the test requires considerable preparation by researchers and clinicians. Thus, we have developed an open-access online BAT (vBATon). We validated its efficacy in measuring avoidance behavior and eliciting feelings of anxiety and disgust by comparing it to a real-life BAT (rl-BAT). Spider-fearful (N = 31) and nonfearful (N = 31) individuals completed a rl-BAT and vBATon on two separate dates within a 1-week interval. As expected, both tests successfully distinguished between spider-fearful and nonfearful individuals. Crucially, equivalence tests confirmed that vBATon captures avoidance behavior, anxiety, and disgust equal to the rl-BAT. Assessing validity, we found moderate to high correlations between vBATon and (a) the rl-BAT and (b) self-report measurements of spider fear (Spider Phobia Questionnaire, Fear of Spiders Questionnaire). Overall, our study displayed initial evidence of validity of vBATon and suggests that it is a standardized, efficient, and user-friendly alternative to rl-BATs for measuring spider fear. It can be utilized in both research and clinical practice. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
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Reacción de Prevención , Miedo , Trastornos Fóbicos , Arañas , Humanos , Trastornos Fóbicos/psicología , Trastornos Fóbicos/diagnóstico , Femenino , Adulto , Masculino , Miedo/psicología , Adulto Joven , Animales , Reproducibilidad de los Resultados , Ansiedad/psicología , Ansiedad/diagnóstico , Asco , Psicometría , Internet , AdolescenteRESUMEN
OBJECTIVE: Exposure with response prevention (ERP) is the first-line treatment for obsessive-compulsive disorder (OCD). However, refusals, dropouts and the required high time and logistic effort constitute barriers to the use of ERP. In a non-inferiority randomized controlled trial, we compared metacognitive therapy (MCT) to exposure with response prevention (ERP) as treatments for OCD. METHOD: 74 outpatients received 12 weekly sessions of either manualized MCT or ERP, with primary outcomes assessed by blinded assessors using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) at pre-treatment, mid-treatment, post-treatment, and 6-month follow-up. Secondary outcomes included measures of depression and anxiety. Non-inferiority margin was specified at no less than d = 0.38 below the improvement reached by ERP, corresponding to a difference of about 3 points on the Y-BOCS. RESULTS: Drop-out rates were low (<14%) and similar in both groups. Linear models indicated non-inferiority of MCT to ERP at post-treatment, but not at 6-month follow-up. While both groups showed comparable Y-BOCS improvements, the MCT group demonstrated a significantly greater reduction in state anxiety scores at post-treatment and follow-up. CONCLUSIONS: Overall, MCT was not inferior to ERP, especially at post-treatment, suggesting it could be a treatment alternative. However, further research is needed to explore differential treatment indications.
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Terapia Cognitivo-Conductual , Terapia Implosiva , Metacognición , Trastorno Obsesivo Compulsivo , Humanos , Trastorno Obsesivo Compulsivo/terapia , Masculino , Femenino , Adulto , Terapia Implosiva/métodos , Terapia Cognitivo-Conductual/métodos , Metacognición/fisiología , Persona de Mediana Edad , Resultado del Tratamiento , Adulto JovenRESUMEN
Although psychological treatments are broadly recognized as evidence-based interventions for various mental disorders, challenges remain. For example, a substantial proportion of patients receiving such treatments do not fully recover, and many obstacles hinder the dissemination, implementation, and training of psychological treatments. These problems require those in our field to rethink some of our basic models of mental disorders and their treatments, and question how research and practice in clinical psychology should progress. To answer these questions, a group of experts of clinical psychology convened at a Think-Tank in Marburg, Germany, in August 2022 to review the evidence and analyze barriers for current and future developments. After this event, an overview of the current state-of-the-art was drafted and suggestions for improvements and specific recommendations for research and practice were integrated. Recommendations arising from our meeting cover further improving psychological interventions through translational approaches, improving clinical research methodology, bridging the gap between more nomothetic (group-oriented) studies and idiographic (person-centered) decisions, using network approaches in addition to selecting single mechanisms to embrace the complexity of clinical reality, making use of scalable digital options for assessments and interventions, improving the training and education of future psychotherapists, and accepting the societal responsibilities that clinical psychology has in improving national and global health care. The objective of the Marburg Declaration is to stimulate a significant change regarding our understanding of mental disorders and their treatments, with the aim to trigger a new era of evidence-based psychological interventions.
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Trastornos Mentales , Psicoterapia , Humanos , Trastornos Mentales/terapia , Psicoterapia/métodos , Psicoterapia/tendencias , Intervención Psicosocial/métodos , Psicología Clínica/tendenciasRESUMEN
Responding adequately to the behaviour of human and non-human animals in our environment has been crucial for our survival. This is also reflected in our exceptional capacity to detect and interpret biological motion signals. However, even though our emotions have specifically emerged as automatic adaptive responses to such vital stimuli, few studies investigated the influence of biological motion on emotional evaluations. Here, we test how the motion of animals affects emotional judgements by contrasting static animal images and videos. We investigated this question (1) in non-fearful observers across many different animals, and (2) in observers afraid of particular animals across four types of animals, including the feared ones. In line with previous studies, we find an idiosyncratic pattern of evoked emotions across different types of animals. These emotions can be explained to different extents by regression models based on relevant predictor variables (e.g. familiarity, dangerousness). Additionally, our findings show a boosting effect of motion on emotional evaluations across all animals, with an additional increase in (negative) emotions for moving feared animals (except snakes). We discuss implications of our results for experimental and clinical research and applications, highlighting the importance of experiments with dynamic and ecologically valid stimuli.
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Emociones , Juicio , Animales , Humanos , Estimulación Luminosa/métodos , Emociones/fisiología , Reconocimiento en Psicología , Movimiento (Física)RESUMEN
OBJECTIVES: Individuals with obsessive-compulsive disorder (OCD) often suffer from impairments in social functioning. This study investigates differences in empathy, compassion, and Theory of Mind (ToM) in individuals with OCD as a possible cause for social functioning deficits. DESIGN: Sixty-four individuals diagnosed with OCD and 62 healthy individuals completed a naturalistic behavioural task (EmpaToM) and a self-report measure (Interpersonal Reactivity Index, IRI). METHODS: Three preregistered repeated measures analyses of variance (ANOVAs). RESULTS: People with OCD exhibited higher empathy levels - namely increased sharing of others' suffering - in the EmpaToM task and reported more distress (IRI) compared with healthy individuals. Furthermore, no differences in compassion (EmpaToM) between both groups emerged, although people with OCD reported more concern for others (IRI) compared with healthy individuals. Concerning the ToM, no group differences were detected, neither in the behavioural task, nor self-report. CONCLUSION: By investigating OCD with diverse scientific practices we shed light on the higher levels of empathy exhibited by individuals with OCD, which are relevant for clinical practice and our understanding of OCD symptomatology. PRACTITIONER POINTS: âPeople with obsessive-compulsive disorder show higher levels of empathy, that is the increased sharing of others' suffering, compared with healthy individuals in both a traditional self-report and a naturalistic task. âRegarding compassion, that is caring for others, their self-reported compassion was higher in people with OCD. âIn Theory of Mind, that is cognitively understanding the situation of another person, no differences have been found neither at self-report nor in a naturalistic task compared with healthy individuals. âIndependent of traditional interventions, it could prove useful to improve emotion regulation skills so people with OCD learn to cope with empathic distress. Furthermore, it might strengthen the treatment gains and lower dropout rates if the social mind and consequently social relationships become a topic in the treatment and prevention of OCD.
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Regulación Emocional , Trastorno Obsesivo Compulsivo , Teoría de la Mente , Empatía , Humanos , Trastorno Obsesivo Compulsivo/psicología , Teoría de la Mente/fisiologíaRESUMEN
Metacognitive therapy (MCT) has been shown to be a promising treatment approach for obsessive-compulsive disorder (OCD). The changeability of metacognitions by (metacognitive) treatment and its relevance to treatment outcome is, however, still unclear. The current study investigates, (1) if treatment with MCT or exposure and response prevention (ERP) in a randomized-controlled pilot trial (n = 24 patients with OCD) changes OCD-specific metacognitions of thought fusion beliefs, beliefs about rituals and stop signals, and (2) if these changes are relevant for the treatment outcome in terms of patient- and therapist-rated OCD symptoms. ANOVA with pretest, posttest and follow-up scores could show that all three metacognitions significantly decreased during both treatments. Regarding thought fusion beliefs, a significant interaction effect indicated a higher decrease after MCT than ERP treatment. In hierarchical regression analyses, changes in stop signals from pre- to post-treatment significantly predicted patient-rating OCD symptoms at post-treatment and follow-up at 3 months after treatment. These changes were even predictive of post-treatment outcome after controlling for general metacognitions and dysfunctional cognitive beliefs. These findings support the assumption that metacognitions can change during both treatments and that changes in stop signals might be relevant for the treatment outcome on the symptom level in OCD.
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The hypothesis of grounded procedures of separation predicts accentuated effects in individuals with psychiatric disorders, for example, obsessive-compulsive disorders with washing compulsion. This could provide a vantage point for understanding cognitive processes related to specific disorders. However, fully exploring it requires updated experimental designs, including extensive control conditions, exclusion of alternative explanations, internal replications, and parametric variation to strengthen internal validity.
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Trastorno Obsesivo Compulsivo , Psicología Clínica , HumanosRESUMEN
Behavior therapy of obsessive-compulsive disorder (OCD) aims to reduce avoidance, rituals, and discomfort in OCD-relevant situations. The Behavioral Avoidance Test (BAT) measures these behavior-related outcomes in individually challenging OCD-related situations. The association of the BAT with OCD severity measures and its relevance for treatment outcome is, however, still unclear. The current study investigates with a retrospective analysis of a subsample of a pilot study, (1) if reactions on the BAT are related to OCD severity measures in an OCD sample (n = 28), (2) if treatment with two variants of cognitive-behavior therapy (exposure and response prevention vs. metacognitive therapy) changes the BAT scores and (3) if these changes as well as pretreatment BAT avoidance are relevant for OCD treatment outcome as measured by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS). Participants rated avoidance, ritual, and discomfort in three individually challenging OCD-related situations before and after therapy. For one of these situations, BAT dimensions were rated by the therapist and an independent rater in addition to the patients' ratings. Correlational analyses found significant correlations between BAT discomfort and OCD severity measures like the Y-BOCS. A repeated measures ANOVA with pre- and posttest scores showed that all three BAT dimensions significantly decreased during both treatments. Hierarchical regression analyses (controlling for Y-BOCS pretest scores) revealed that changes in BAT discomfort as well as pretreatment BAT avoidance scores predicted the Y-BOCS posttest score. These findings suggest that the BAT is a distinct measure of behavior-related outcomes partly being relevant for OCD treatment outcome.
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Mobile applications are increasingly part of mental health programs and various apps have been developed for treating anxiety disorders. Typically, they aim to improve anxiety symptoms via established CBT techniques, such as exposure principles, which are considered extremely unpleasant for fearful individuals. We combined in a mobile application exposure principles with gamification elements (e.g. narrative background, level progression, points, and feedback). These elements should increase the motivation for confronting spider images and decrease the experienced distress. To evaluate the application, two groups of spider-fearful individuals played either the Spider App (experimental group) or a non-spider associated app (control group) twice a day for approximately 12â¯min for 7 days. After this week, participants of the experimental group showed less avoidance behavior of spiders (BAT), as well as lower anxiety of spiders (SPQ, FAS). Groups were not different in measures of depression or psychological distress. Interestingly, participants playing the Spider App reported higher anxiety, disgust and arousal ratings shortly after playing the app. However, anxiety, disgust, and arousal ratings decreased from day to day. We discuss our findings with respect to implications for the clinical practice.
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Aplicaciones Móviles , Trastornos Fóbicos , Arañas , Animales , Ansiedad/terapia , Miedo , Humanos , Trastornos Fóbicos/terapiaRESUMEN
BACKGROUND AND OBJECTIVES: The fast detection of and response to threatening stimuli is an important task of the human visual and motor systems, and is especially challenging when stimuli are ambiguous. This study investigates the perception, evaluation and fast response to ambiguous natural spider stimuli in spider-fearful and non-anxious participants. METHODS: Stimuli were created by gradually morphing natural images of spiders and non-spiders (a crab, a starfish, a bunch of keys, and a flower). In Study 1, participants rated the images on perceptual and emotional dimensions and responded to them in a response priming task to measure rapid information processing. In Study 2, results were validated and extended in a different paradigm by using a go/no-go task. RESULTS: As expected, spider-fearful participants showed an interpretative bias for ambiguous stimuli (i.e., perceived them as more similar to spiders) and rated spider(-like) stimuli as more unpleasant, arousing, and disgusting. In Study 1, spider stimuli were preferentially processed in spider-fearful participants as observed in faster responses to spider targets-however, responses were not different to comparison participants for ambiguous stimuli. Study 2 suggests that this finding can be explained by differences in stimulus duration. LIMITATIONS: No participants with positive attitudes towards spiders or a second fearful comparison group were included. CONCLUSIONS: We suggest that these findings can be explained by the nature of the applied tasks that tap into early phases of visual processing, thereby relying on feedforward-mediated low-spatial-frequency information extracted via the fast, subcortical path to the amygdala.
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Emociones/fisiología , Reconocimiento Visual de Modelos/fisiología , Trastornos Fóbicos/fisiopatología , Desempeño Psicomotor/fisiología , Adulto , Femenino , Humanos , Inhibición Psicológica , Masculino , Adulto JovenRESUMEN
The extent to which emotionally significant stimuli capture visual attention remains elusive because a preference for reporting or choosing emotionally significant stimuli could mimic attentional capture by these stimuli. We conducted two prior-entry experiments to disentangle whether phobic and fear-relevant stimuli capture attention or merely produce a response bias in spider-fearful participants. Prior entry denotes the effect that attended stimuli are perceived earlier than unattended stimuli as indicated by temporal order judgments. We presented phobic (spiders), fear-relevant (snakes) and neutral stimuli in pairs with varying temporal onset. The participants' task was to indicate which stimulus was presented first (Experiment 1) or second (Experiment 2). In the first experiment, spider-fearful but not control participants indicated that they had perceived spiders as occurring earlier in time, suggesting a prior-entry effect for spiders in this group. But surprisingly, in the second experiment, spider-fearful participants indicated more frequently that they had seen spiders as being presented second. This finding rules out a genuine prior-entry effect and instead suggests a strong preference for the response option associated with the feared animal. This response bias may result from a hypervigilance toward the feared stimulus and contribute to maintaining avoidance behavior in individuals with specific phobias.
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Ansiedad/psicología , Sesgo Atencional , Miedo/psicología , Trastornos Fóbicos/psicología , Arañas , Animales , Reacción de Prevención , Asco , Femenino , Humanos , Masculino , Serpientes , Percepción Visual , Adulto JovenRESUMEN
Selecting appropriate stimuli is a major challenge of affective research. Although several standardized databases for affective pictures exist, none of them focus on discrete emotions such as disgust. Validated pictures inducing discrete emotions are still limited, and this presents a problem for researchers interested in studying different facets of disgust. In this paper, we introduce the DIsgust-RelaTed-Images (DIRTI) picture set. The set consists of 240 disgust-inducing pictures divided into six categories (food, animals, body products, injuries/infections, death, and hygiene). Additionally, we included 60 matched neutral pictures (10 per category). All pictures were rated by 200 participants on nine-point rating scales measuring disgust, fear, valence, and arousal. The present validation study covered a wide age range (18-75 years) with a balanced number of participants in each decade of life. For each picture, we provide separate ratings on the four scales for men and women. In addition to the original pictures, we also provide a luminance-matched version for experiments that require control of the physical properties of the pictures. The standardized DIRTI picture set allows researchers to chose from a wide set of disgust-inducing pictures and may enhance researchers' ability to draw comparisons between studies on disgust. (Download DIRTI picture set: http://dx.doi.org/10.5281/zenodo.167037).
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Bases de Datos como Asunto/normas , Emociones , Percepción Visual , Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa , Caracteres Sexuales , Adulto JovenRESUMEN
Visual perception is not instantaneous; the perceptual representation of our environment builds up over time. This can strongly affect our responses to visual stimuli. Here, we study the temporal dynamics of visual processing by analyzing the time course of priming effects induced by the well-known Ebbinghaus illusion. In slower responses, Ebbinghaus primes produce effects in accordance with their perceptual appearance. However, in fast responses, these effects are reversed. We argue that this dissociation originates from the difference between early feedforward-mediated gist of the scene processing and later feedback-mediated more elaborate processing. Indeed, our findings are well explained by the differences between low-frequency representations mediated by the fast magnocellular pathway and high-frequency representations mediated by the slower parvocellular pathway. Our results demonstrate the potentially dramatic effect of response speed on the perception of visual illusions specifically and on our actions in response to objects in our visual environment generally.
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Ilusiones/fisiología , Desempeño Psicomotor/fisiología , Tiempo de Reacción/fisiología , Percepción Visual/fisiología , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
Many visual illusions result from assumptions of our visual system that are based on its long-term adaptation to our visual environment. Thus, visual illusions provide the opportunity to identify and learn about these fundamental assumptions. In this paper, we investigate the Ponzo illusion. Although many previous studies researched visual processing of the Ponzo illusion, only very few considered temporal processing aspects. However, it is well known that our visual percept is modulated by temporal factors. First, we used the Ponzo illusion as prime in a response priming task to test whether it modulates subsequent responses to the longer (or shorter) of two target bars. Second, we used the same stimuli in a perceptual task to test whether the Ponzo illusion is effective for very short presentation times (12 ms). We observed considerable priming effects that were of similar magnitude as those of a control condition. Moreover, the variations in the priming effects as a function of prime-target stimulus-onset asynchrony were very similar to that of the control condition. However, when analyzing priming effects as a function of participants' response speed, effects for the Ponzo illusion increased in slower responses. We conclude that although the illusion is established rapidly within the visual system, the full integration of context information is based on more time-consuming and later visual processing.
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Ilusiones Ópticas/fisiología , Tiempo de Reacción/fisiología , Percepción Visual/fisiología , Adulto , Femenino , Humanos , Masculino , Estimulación Luminosa , Adulto JovenRESUMEN
This study investigates the interpretative bias in spider phobia with respect to rapid visuomotor processing. We compared perception, evaluation, and visuomotor processing of ambiguous schematic stimuli between spider-fearful and control participants. Stimuli were produced by gradually morphing schematic flowers into spiders. Participants rated these stimuli related to their perceptual appearance and to their feelings of valence, disgust, and arousal. Also, they responded to the same stimuli within a response priming paradigm that measures rapid motor activation. Spider-fearful individuals showed an interpretative bias (i.e., ambiguous stimuli were perceived as more similar to spiders) and rated spider-like stimuli as more unpleasant, disgusting, and arousing. However, we observed no differences between spider-fearful and control participants in priming effects for ambiguous stimuli. For non-ambiguous stimuli, we observed a similar enhancement for phobic pictures as has been reported previously for natural images. We discuss our findings with respect to the visual representation of morphed stimuli and to perceptual learning processes.
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Miedo/psicología , Trastornos Fóbicos/diagnóstico , Trastornos Fóbicos/psicología , Estimulación Luminosa/métodos , Arañas , Percepción Visual/fisiología , Adulto , Animales , Nivel de Alerta/fisiología , Emociones/fisiología , Miedo/fisiología , Femenino , Humanos , Aprendizaje/fisiología , Masculino , Adulto JovenRESUMEN
Numerous studies have identified attentional biases and processing enhancements for fear-relevant stimuli in individuals with specific phobias. However, this has not been conclusively shown in blood-injury-injection (BII) phobia, which has rarely been investigated even though it has features distinct from all other specific phobias. The present study aims to fill that gap and compares the time-course of visuomotor processing of phobic stimuli (i.e., pictures of small injuries) in BII-fearful (n=19) and non-anxious control participants (n=23) by using a response priming paradigm. In BII-fearful participants, phobic stimuli produced larger priming effects and lower response times compared to neutral stimuli, whereas non-anxious control participants showed no such differences. Because these effects are fully present in the fastest responses, they indicate an enhancement in early visuomotor processing of injury pictures in BII-fearful participants. These results are comparable to the enhanced processing of phobic stimuli in other specific phobias (i.e., spider phobia).
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Sangre , Inyecciones/psicología , Trastornos Fóbicos/psicología , Tiempo de Reacción/fisiología , Encuestas y Cuestionarios , Heridas y Lesiones/psicología , Atención , Estudios de Casos y Controles , Miedo/fisiología , Humanos , Trastornos Fóbicos/fisiopatología , Estimulación LuminosaRESUMEN
Healthy aging is accompanied by working memory-related functional cerebral changes. Depending on performance accuracy and the level of working memory demands, older adults show task-related patterns of either increased or decreased activation compared to younger adults. Controversies remain concerning the interpretation of these changes and whether they already manifest in earlier decades of life. To address these issues, functional magnetic resonance imaging (fMRI) was used to examine brain activation during spatial working memory retrieval in 45 healthy individuals between 20 and 68 years of age. Participants performed a modified version of the Corsi Block-Tapping test (CBT). The CBT requires the storage and subsequent reproduction of spatial target sequences and allows modulating working memory load by a variation of sequence length. Results revealed that activation intensity at the lowest CBT load level increased with increasing age and positively correlated with the number of errors. At higher CBT load levels, activation intensity decreased with increasing age together with a disproportional accuracy decline on the behavioral level. Moreover, results suggests that younger individuals showed higher activation intensity at high CBT load than at low CBT load switching to the opposite pattern at an age of about 40 years. Consistent with the assumptions of the Compensation-Related Utilization of Neural Circuits Hypothesis (CRUNCH), the present results reveal specific age-related alterations in left dorsolateral prefrontal cortex activation in response to increasing task load. Specifically, the results point toward increasing neural inefficiency with age at low task load and a progressive limitation of resources with age at higher task load. The present findings argue for an increasing functional cerebral dysfunction over a time span of 50 years that may partly be compensated on the behavioral level until a resource ceiling is approached.
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This study investigates enhanced visuomotor processing of phobic compared to fear-relevant and neutral stimuli. We used a response priming design to measure rapid, automatic motor activation by natural images (spiders, snakes, mushrooms, and flowers) in spider-fearful, snake-fearful, and control participants. We found strong priming effects in all tasks and conditions; however, results showed marked differences between groups. Most importantly, in the group of spider-fearful individuals, spider pictures had a strong and specific influence on even the fastest motor responses: Phobic primes entailed the largest priming effects, and phobic targets accelerated responses, both effects indicating speeded response activation by phobic images. In snake-fearful participants, this processing enhancement for phobic material was less pronounced and extended to both snake and spider images. We conclude that spider phobia leads to enhanced processing capacity for phobic images. We argue that this is enabled by long-term perceptual learning processes.
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Miedo/fisiología , Trastornos Fóbicos/fisiopatología , Desempeño Psicomotor , Serpientes , Arañas , Percepción Visual , Adulto , Animales , Femenino , Humanos , Aprendizaje , Masculino , Estimulación Luminosa , Adulto JovenRESUMEN
Visual stimuli can be classified so rapidly that their analysis may be based on a single sweep of feedforward processing through the visuomotor system. Behavioral criteria for feedforward processing can be evaluated in response priming tasks where speeded pointing or keypress responses are performed toward target stimuli which are preceded by prime stimuli. We apply this method to several classes of complex stimuli. (1) When participants classify natural images into animals or non-animals, the time course of their pointing responses indicates that prime and target signals remain strictly sequential throughout all processing stages, meeting stringent behavioral criteria for feedforward processing (rapid-chase criteria). (2) Such priming effects are boosted by selective visual attention for positions, shapes, and colors, in a way consistent with bottom-up enhancement of visuomotor processing, even when primes cannot be consciously identified. (3) Speeded processing of phobic images is observed in participants specifically fearful of spiders or snakes, suggesting enhancement of feedforward processing by long-term perceptual learning. (4) When the perceived brightness of primes in complex displays is altered by means of illumination or transparency illusions, priming effects in speeded keypress responses can systematically contradict subjective brightness judgments, such that one prime appears brighter than the other but activates motor responses as if it was darker. We propose that response priming captures the output of the first feedforward pass of visual signals through the visuomotor system, and that this output lacks some characteristic features of more elaborate, recurrent processing. This way, visuomotor measures may become dissociated from several aspects of conscious vision. We argue that "fast" visuomotor measures predominantly driven by feedforward processing should supplement "slow" psychophysical measures predominantly based on visual awareness.