Anterior prefrontal cortex contributions to attention control

In a series of event-related functional magnetic resonance studies, we consistently found activation in anterior prefrontal cortex related to visual dimension changes in singleton search tasks. I review these data and discuss possible contributions of anterior prefrontal cortex to attention control in visual search. It is proposed that anterior prefrontal cortex may detect task-relevant stimulus changes when the target is ambiguously defined. This process may occur in the absence of awareness and may support visual dimension weighting by inhibition of the old relevant dimension in favor of the new dimension.     

Fish cognition: a primate's eye view

We provide selected examples from the fish literature of phenomena found in fish that are currently being examined in discussions of cognitive abilities and evolution of neocortex size in primates. In the context of social intelligence, we looked at living in individualised groups and corresponding social strategies, social learning and tradition, and co-operative hunting. Regarding environmental intelligence, we searched for examples concerning special foraging skills, tool use, cognitive maps, memory, anti-predator behaviour, and the manipulation of the environment. Most phenomena of interest for primatologists are found in fish as well. We therefore conclude that more detailed studies on decision rules and mechanisms are necessary to test for differences between the cognitive abilities of primates and other taxa. Cognitive research can benefit from future fish studies in three ways: first, as fish are highly variable in their ecology, they can be used to determine the specific ecological factors that select for the evolution of specific cognitive abilities. Second, for the same reason they can be used to investigate the link between cognitive abilities and the enlargement of specific brain areas. Third, decision rules used by fish could be used as 'null-hypotheses' for primatologists looking at how monkeys might make their decisions. Finally, we propose a variety of fish species that we think are most promising as study objects. Accepted after revision: 6 September 2001 Electronic Publication     

Age-related slowing in face and name recognition: evidence from event-related brain potentials

Age-related slowing in recognizing famous names and faces was investigated with event-related brain potentials (ERPs). In a group of young adults, item repetition induced early (220-340 ms) and late (400-700 ms) ERP modulations, apparently signaling the access to, respectively, domain-specific representations of faces and names and domain-general semantic knowledge about the persons. These repetition effects and other ERP components were then used as process-specific time markers in middle-aged and elderly participants. For both faces and names, the elderly participants' responses were slowed, but repetition priming in reaction times was not. The ERP latencies suggested that most of the age-related slowing occurred in the access to domain-specific representations and during response decision, whereas sensory and perceptual processing was largely spared.     

Division of labor between the hemispheres for complex but not simple tasks: an implemented connectionist model

When stimuli have to be matched in a complex task (such as whether 2 letters have the same name), then performance is better when stimuli are presented across the hemispheres of the brain, whereas for simpler tasks (such as whether 2 letters have the same shape), better performance is achieved when stimuli are presented unilaterally. The authors show that this bilateral distribution advantage effect emerged spontaneously in a neural network model learning to solve simple and complex tasks with separate input layers and separate, but interconnected, resources in a hidden layer. The authors show that relating computational models to behavioral and imaging data proves fruitful for understanding hemispheric processing and generating testable hypotheses.     

Pre-adjudicative and adjudicative competence in juveniles and young adults

There are several different types of legal competence, such as competence to waive Miranda rights, competence to confess, and competence to stand trial. Although it can be surmised that many of the underlying factors that influence the different legal competencies are similar, little research has been conducted to empirically test this hypothesis. In the present study, juveniles' and young adults' understanding and appreciation of their Miranda rights and their ability to stand trial were measured. Age, suggestibility, average grades in school, and frequency of previous police involvement were also examined as possible factors that influence both types of legal knowledge. Results indicated that Miranda competence and adjudicative competence are indeed strongly related, especially for juveniles. Also, age and suggestibility were found to predict Miranda competence, whereas suggestibility and average school grades predicted competence to stand trial. Patterns of findings often diverged for juveniles and young adults. Implications for legal policy are discussed.     

Respect for group members: intragroup determinants of collective identification and group-serving behavior

This experiment examined how (disrespectful vs. respectful) treatment and (negative vs. positive) performance evaluation, both received from the same fellow group members, affects collective identification and willingness to engage in group-serving behavior. It was predicted and found that respectful as opposed to disrespectful intragroup treatment increased collective identification and willingness to engage in group-serving behavior in the immediate group situation, irrespective of whether intragroup evaluation was positive or negative. There was also evidence of a mediating role of collective identification. Regression analyses based on the measurement of perceived intragroup treatment and perceived intragroup evaluation as continuous variables corroborated these findings but also pointed to limits of the positive effects of respectful intragroup treatment. Finally, the interrelation of treatment and evaluation by fellow group members as two possible components of intragroup respect are discussed as well as the political dimension of research on intragroup respect.     

Psychopharmacologic strategies for the treatment of aggression in juveniles

Maladaptive aggression in youth is one of the most common and troublesome reasons for referrals to child psychiatrists. It has a complex relationship with psychopathology. There are several syndromes, which are primary disturbances of clustered maladaptive aggression, most notably oppositional defiant disorder and conduct disorder. However, problems with aggression also appear in a wide range of other disturbances, such as bipolar disorder, posttraumatic stress disorder, and mood disorders. Additionally, aggression is normative, serves an adaptive purpose and can be situationally induced. These complexities need to be carefully addressed before targeting maladaptive aggression psychopharmacologically. We summarize the literature on the psychopharmacology of maladaptive aggression in youth, focusing on disorders without cognitive impairment. We delineate the subtypes of aggression which are most likely to respond to medication (reactive-affective-defensive-impulsive in their acute and chronic form) and conclude with a discussion of specific medication strategies which are supported by controlled clinical trials and clinical experience.     

Hindsight bias in gustatory judgments

Being in hindsight, people tend to overestimate what they had known in foresight. This phenomenon has been studied for a wide variety of knowledge domains (e.g., episodes with uncertain outcomes, or solutions to almanac questions). As a result of these studies, hindsight bias turned out to be a robust phenomenon. In this paper, we present two experiments that successfully extended the domain of hindsight bias to gustatory judgments. Participants tasted different food items and were asked to estimate the quantity of a certain ingredient, for example, the residual sugar in a white wine. Judgments in both experiments were systematically biased towards previously presented low or high values that were labeled as the true quantities. Thus, hindsight bias can be considered a phenomenon that extends well beyond the judgment domains studied so far.