An fMRI investigation of a novel analogue to the Trail-Making Test

The Trail-Making Test (TMT) is a widely used neuropsychological measure that assesses visuomotor abilities and cognitive flexibility. For the TMT-A condition participants are required to locate and connect numbers (i.e. 1-2-3…) while in the TMT-B condition participants perform the set-shifting task of locating and connecting numbers and letters (i.e. 1-A-2-B…). The TMT-B condition has shown impairments in many clinical populations, particularly schizophrenia patients, but the neurobiological underpinning of the task can be difficult to discern given pragmatic obstacles in adapting the task for neuroimaging. In a behavioural testing experiment we demonstrated a close correspondence between performance on the standard TMT and a novel, computer programmed adaptation of the TMT (pcTMT). The pcTMT was designed for functional magnetic resonance imaging (fMRI) administration and neuroimaging data for this task were obtained in. A whole brain analysis revealed significantly greater activation during the pcTMT-B relative to the pcTMT-A in right inferior/middle frontal cortices, right precentral gyrus, left angular gyrus/left middle temporal gyrus. These results identify the regions that most likely underlie cognitive flexibility during the TMT and are candidate regions underlying the impairment of groups with poor set-shifting abilities.     

Skin-transmitted pathogens and the heebie jeebies: evidence for a subclass of disgust stimuli that evoke a qualitatively unique emotional response

Skin-transmitted pathogens have threatened humans since ancient times. We investigated whether skin-transmitted pathogens were a subclass of disgust stimuli that evoked an emotional response that was related to, but distinct from, disgust and fear. We labelled this response “the heebie jeebies”. In Study 1, coding of 76 participants’ experiences of disgust, fear, and the heebie jeebies showed that the heebie jeebies was elicited by unique stimuli which produced skin-crawling sensations and an urge to protect the skin. In Experiment 2,350 participants’ responses to skin-transmitted pathogen, fear-inducing, and disgust-inducing vignettes showed that the vignettes elicited sensations and urges which loaded onto heebie jeebies, fear, and disgust factors, respectively. Experiment 3 largely replicated findings from Experiment 2 using video stimuli (178 participants). Results are consistent with the notion that skin-transmitted pathogens are a subclass of disgust stimuli which motivate behaviours that are functionally consistent with disgust yet qualitatively distinct.     

United we stand: Intergroup conflict moderates the intergroup sensitivity effect

Ingroup members who criticize their group face much less resistance than outgroup members who say the same thing (the intergroup sensitivity effect). In the context of intergroup conflict, however, it was predicted that treatment of ingroup critics would not be so generous. Muslim Indonesians read an extract from an interview in which the speaker criticized Muslims. The comments were attributed to either another Muslim or to a Christian. Before reading the criticism, half of the participants had read an article describing intense conflict between Muslims and Christians in Indonesia, whereas the other half read a neutral article. As predicted, negativity toward the ingroup critic and the ingroup critic's comments increased in the conflict salience condition, to the point that the intergroup sensitivity effect disappeared. However, conflict salience did not have an effect on attributions of motive or on agreement with the message. Implications for our understanding of “patriotic criticism” are discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Preservation of mouth region processing in two cases of prosopagnosia

Although most adults are considered experts in face recognition, brain trauma can produce a selective loss in this ability, a condition referred to as prosopagnosia. This study examined the processing strategies of prosopagnosic patients LR and HH using the Face Dimensions Test. In this test, featural and configural information in the upper and lower halves of the face was parametrically varied and sensitivity to these changes measured. We found that relative to age‐matched control participants, LR and HH exhibited an impaired ability to discriminate differences in the eye region, but a preserved ability to detect featural and configural differences in the mouth region. This pattern of impairment and sparing was demonstrated in tests of direct perception and immediate memory. The obtained findings demonstrate that prosopagnosia does not necessarily cause a global impairment to face perception, but a selective impairment to the perception of information in the upper half of the face.     

Action‐Based Model of Dissonance: A Review of Behavioral,Anterior Cingulate,and Prefrontal Cortical Mechanisms

Research and theoretical developments on the theory of cognitive dissonance are reviewed. After this critical review, we present the action‐based model of dissonance, which accepts the original theory's proposal that a sufficient cognitive inconsistency causes dissonance and extends the original theory by proposing why cognitive inconsistency prompts dissonance. Finally, we present results from behavioral and physiological experiments examining predictions derived from the action‐based model. In particular, this evidence converges with recent neuroscience evidence in suggesting that the anterior cingulate cortex and left prefrontal cortical region are involved in conflict detection and resolution, respectively.     

Exploring cognitive effects of self reported mild stroke in older adults: selective but robust effects on story memory

Relatively little systematic information is available regarding patterns of cognitive effects of mild stroke in older adults. We explored this problem with a series of two independent samples from the Victoria Longitudinal Study data archives. In Study 1, self-reported mild stroke and neurologically intact matched controls were (a) confirmed as similar on a set of neurocognitive speed, basic cognition, and awareness indicators, and (b) compared for differences on a set of episodic, semantic, and working memory tasks. The mild stroke group was selectively worse on the language intensive story memory task. This effect was partially attributable to a deficit in remembering the most thematic information. Study 2 closely replicated these procedures and results. In addition, Study 2 follow-up analyses, comparing provisional right-hemisphere damaged and left-hemisphere damaged (LHD) participants, revealed that the thematic story memory deficit for mild stroke participants could be due to the selective impairment of LHD participants.     

The Effects of Adult Suggestion and Child Consistency on Young Children's Reports1

The purpose of the present study was to contrast the effects of children's response consistency and adult leading questions in a structured memory interview. Children (N = 70) who viewed a 2‐min video clip were asked 3 questions (leading, misleading, and neutral) related to the video. Children's responses (assent vs. deny) were predicted by the type of question asked by the adult (neutral, leading, and misleading), but not by the previous response given by the child or the child's age in months. Specifically, children assented the least often to misleading questions. Accuracy was predicted by both question type and in the last question–answer pair, children's previous response accuracy. These findings are discussed with relation to interview dynamics.     

Comparing expert and novice understanding of a complex system from the perspective of structures, behaviors, and functions

Complex systems are pervasive in the world around us. Making sense of a complex system should require that a person construct a network of concepts and principles about some domain that represents key (often dynamic) phenomena and their interrelationships. This raises the question of how expert understanding of complex systems differs from novice understanding. In this study we examined individuals’ representations of an aquatic system from the perspective of structural (elements of a system), behavioral (mechanisms), and functional aspects of a system. Structure-Behavior-Function (SBF) theory was used as a framework for analysis. The study included participants from middle school children to preservice teachers to aquarium experts. Individual interviews were conducted to elicit participants’ mental models of aquaria. Their verbal responses and pictorial representations were analyzed using an SBF-based coding scheme. The results indicated that representations ranged from focusing on structures with minimal understanding of behaviors and functions to representations that included behaviors and functions. Novices’ representations focused on perceptually available, static components of the system, whereas experts integrated structural, functional, and behavioral elements. This study suggests that the SBF framework can be one useful formalism for understanding complex systems.