The Wisconsin card-sorting test (WCST) is a commonly used clinical tool for the detection of frontal lobe dysfunction, specifically executive dysfunction. Patients with lesions outside the frontal lobes sometimes show deficits on the WCST, however, and some researchers have implicated hippocampal dysfunction as the cause of the deficit. But a critical role for the hippocampus seems to be untenable because amnesic patients with bilateral medial temporal lobe (MTL) lesions perform the WCST normally. In the case of epileptic patients, (...) an alternative explanation of the card-sorting impairment is the propagation of abnormal discharges from MTL to frontal lobe structures, causing remote interference with executive circuits. (shrink)
Ruchkin et al. ascribe a pivotal role to long-term memory representations and binding within working memory. Here we focus on the interaction of working memory and long-term memory in supporting on-line representations of experience available to guide on-going processing, and we distinguish the role of frontal-lobe systems from what the hippocampus contributes to relational long-term memory binding.
The cognitive and behavioral functions of the frontal lobes have been of great interest to neuroscientists, neurologists, psychologists and psychiatrists. Recent technical advances have made it possible to trace their neuroanatomical connections more precisely and to conduct evoked potential and neuroimaging studies in patients. This book presents a broad and authoritative synthesis of research progress in this field. It encompasses neuroanatomical studies; experiments involving temporal organization and working memory tasks in non-human primates; clinical studies of patients following frontal lobe (...) excisions for intractable epilepsy; metabolic imaging in schizophrenia and affective disorder; neurobehavioral studies of patients with dementia, frontal lobe tumors, and head injuries; magnetic resonance imaging methods for studying human frontal lobe anatomy; theoretical approaches to describing frontal lobe functions; and rehabilitation of patients with frontal lobe damage including their core problem of diminished awareness. Written by a distinguished group of neuroscientists, psychologists and clinicians, Frontal Lobe Function and Dysfunction provides the best current source of information on this region of the brain and its role in cognition, behavior and clinical disorders. (shrink)
Reichle et al. show that saccades in reading are controlled by linguistic processing. The authors' Figure 13 shows the parietal and frontal eye fields as parts of a neural implementation. This commentary presents data from dyslexics performing nonreading saccade tasks. The dyslexics exhibit deficits in antisaccade control. Improvement of the deficits is achieved in 85% of the cases and results in advantages in learning how to read.
Green consumers are those who seek to fulfill economic responsibility with their choices of environment-friendly products. Previous research found that it is not easy to identify green consumers by using traditional demographic or psychographic measurements due to the instability of moral attitude and actual behavior. The frontal theta brain waves of 19 right-handed respondents were recorded and analyzed in a choice task between an environment-friendly (green) product and a conventional product. Product information, which was provided to the respondents, included written (...) descriptions as well as the price of each product without visual depiction. Based on the respondents’ choice, they were classified into two groups: green (GR) consumers who chose an environment-friendly product option and non-green (Non-GR) consumers who chose the option of a conventional product. While processing the green product message, we discovered that frontal theta activations were significantly higher among GR consumers than Non-GR consumers. On the contrary, the frontal theta waves of GR consumers were not differentiated from Non-GR consumers while processing the price information. Therefore, theta activations in the frontal area may potentially be a unique neural indicator of GR consumers’ cognitive engagement with environment-friendly product messages. (shrink)
Clinical cases of frontal lobe lesions have been significantly associated with acquired aggressive behaviour. Restoring neuronal and cognitive faculties of aggressive individuals through invasive brain intervention raises ethical questions in general. However, more questions have to be addressed in cases where individuals refuse surgical treatment. The ethical desirability and permissibility of using intrusive surgical brain interventions for involuntary or voluntary treatment of acquired aggressiveness is highly questionable. This article engages with the description of acquired aggressiveness in general, and presents (...) a rare clinical case to illustrate the difficulties of treating this population. To expand the debate further, this article explores the ethics related to invasive brain surgery in three parts: a) it examines coercive involuntary invasive brain surgery for the benefit of protecting others on individuals suffering from acquired aggressiveness who lack decision-making capacities to consent; b) it addresses voluntary psychosurgery on individuals suffering from acquired aggressiveness who are competent to consent; and, c) it questions whether acquired aggressive individuals, who are legally competent, have a duty to consent to invasive brain surgery, in order to maintain their autonomy by reducing or even eliminate their aggressive drives. Ensuring the safety and efficacy of surgical brain interventions could increase the ethical permissibility of voluntary treatment, but it would not necessarily entail ethical justification for proceeding with invasive brain surgery for treatment of intractable acquired aggressive behaviour. (shrink)
Recent theoretical and empirical work in cognitive science and neuroscience is brought into contact with the concept of the flow experience. After a brief exposition of brain function, the explicit–implicit distinction is applied to the effortless information processing that is so characteristic of the flow state. The explicit system is associated with the higher cognitive functions of the frontal lobe and medial temporal lobe structures and has evolved to increase cognitive flexibility. In contrast, the implicit system is associated (...) with the skill-based knowledge supported primarily by the basal ganglia and has the advantage of being more efficient. From the analysis of this flexibility/efficiency trade-off emerges a thesis that identifies the flow state as a period during which a highly practiced skill that is represented in the implicit system’s knowledge base is implemented without interference from the explicit system. It is proposed that a necessary prerequisite to the experience of flow is a state of transient hypofrontality that enables the temporary suppression of the analytical and meta-conscious capacities of the explicit system. Examining sensory-motor integration skills that seem to typify flow such as athletic performance, writing, and free-jazz improvisation, the new framework clarifies how this concept relates to creativity and opens new avenues of research. (shrink)
To investigate the possible dichotomy between the neurophysiological bases of perceptual transitions versus sustaining a particular percept over time, an fMRI study was conducted with subjects viewing fragmented pictures. Unlike most other perceptually unstable stimuli, fragmented pictures give rise to only one perceptual transition and a continuous period of sustained perception. Earlier research is inconclusive on the subject of which anatomical regions should be attributed to what temporal aspect of perception, and the aim of the present study was to shed (...) more light on the subject. In this study occipitotemporal and fronto-parietal regions were found to be activated for both aspects. However, regions in the medial-temporal lobe were activated specifically for transitions, whereas medial and dorsolateral prefrontal regions were activated specifically for sustained perception. These results provide further support for the theory that the initial creation of perceptual awareness and upholding perceptual awareness over time are separate processes involving different brain regions. (shrink)