Left orbital frontal activation in pathological anxiety

Twelve patients with anxiety disorder were studied with respect to regional cerebral blood flow (rCBF) using a 32-detector system with the 133 Xe inhalation technique. Measurements were taken during a rest condition and during anxiety induction. Anxiety relevant to the patient's psychological disorder was induced with a projective test, the meta-contrast technique (MCT). Increased blood flow in the orbital frontal region of the left hemisphere was observed in each of the 11 subjects who showed evidence of experiencing anxiety during the procedure. In a second study four additional anxiety patients were studied with a high-resolution (254-detector)Xe rCBF system. In addition to the anxiety and resting conditions, a neutral verbalization condition was added to control for the verbal aspects of the anxiety induction procedure. The results again showed the experience of anxiety to be accompanied by increased blood flow in the left orbital frontal region, with the patients showing this flow increase to be greater in the posterior, paralimbic, areas of the region. These results are consistent with previous suggestions of left hemisphere involvement in anxiety. They also suggest that imaging methods may allow research into what appears to be exaggerated corticolimbic activity in this disorder.     

Validity and reliability of electroencephalographic frontal alpha asymmetry and frontal midline theta as biomarkers for depression

Electroencephalographic (EEG) frontal alpha asymmetry (FAA) and frontal midline (FM) theta have been suggested as biomarkers for depression and anxiety, but have mostly been assessed in small and non‐clinical studies. In a clinical sample of 79 adults with depression (ICD‐10: F32), resting EEG and scales of depression (MADRS) and anxiety (HADS‐A) were measured at intake and after 3 months. FAA and FM theta values were referenced to a normative population database. Internal consistency, test‐retest reliability, and correlations with psychiatric tests were examined. Reliability was sufficient. However, FAA and FM theta values were close to the general population, and correlations with psychiatric tests were mostly small and non‐significant, with the exception of FAA on F7–F8 z‐scores and HADS‐A. We conclude that the validity of FAA and FM theta and therefore their potential as biomarkers for depression and anxiety remain unclear.     

Left inferior frontal cortex can compensate the inhibitory functions of right inferior frontal cortex and pre-supplementary motor area

Right-IFG and pre-SMA are associated with inhibitory responses. We used functional Magnetic Resonance Imaging to explore whether the contralateral homotopic regions can functionally replace them. An adolescent, with an extensive traumatic lesion of the right cerebral hemisphere having occurred 5 years earlier, performed a motor response inhibition task (Go/Nogo), which was properly accomplished and associated to activations in the left-IFC, precuneus and occipital cortex. Such functional remodelling is in line with the theory of ‘near equipotentiality’ of the cerebral hemispheres.     

Left frontal cortical activation and spreading of alternatives: tests of the action-based model of dissonance

The action-based model of dissonance predicts that following decisional commitment, approach-oriented motivational processes occur to assist in translating the decision into effective and unconflicted behavior. Therefore, the modulation of these approach-oriented processes should affect the degree to which individuals change their attitudes to be more consistent with the decisional commitment (spreading of alternatives). Experiment 1 demonstrated that a neurofeedback-induced decrease in relative left frontal cortical activation, which has been implicated in approach motivational processes, caused a reduction in spreading of alternatives. Experiment 2 manipulated an action-oriented mindset following a decision and demonstrated that the action-oriented mindset caused increased activation in the left frontal cortical region as well as increased spreading of alternatives. Discussion focuses on how this integration of neuroscience and dissonance theory benefits both parent literatures.     

Developmental impact of frontal lobe injury in middle childhood.

Executive function of frontal lobe systems, like intelligent behavior, appears to demonstrate two major features: it is adaptive and goal-directed. Disruption of executive function following injury to the frontal lobes in childhood might be predicted to impact the trajectory of normal cognitive, behavioral, and social development. Case studies of two children injured at different ages showed the primary developmental impact to involve the behavioral and social realms. While cognitive development may be suspected to also be considerably influenced, assessment of changes in cognitive abilities by traditional psychometric means was found to be problematic. Psychometric changes were found to occur over a prolonged period of time, emphasizing the importance of documenting observations and chronicling postinjury events.     

Symptomatology of depression in adolescence.

The symptomatology and dimensions of depression in adolescence were studied using the MMPI protocols of 212 adolescent psychiatric patients. A Face Valid Depression Scale for Adolescents was judgmentally developed by five child psychiatrists and psychologists. It included symptoms common to depressive adults and adolescents as well as symptoms peculiar to adolescents, which was confirmed by comparison with adult depression scales. Factor analysis of the scale yielded the following six factors: lack of self-confidence, social abandonment, loss of interests, sadness, somatic symptoms, and acting-out. The second and sixth factors appeared to be particularly characteristic of adolescents.     

Proneness to hypomania/mania symptoms or depression symptoms and asymmetrical frontal cortical responses to an anger-evoking event

The behavioral approach system (BAS) reflects the propensity to respond to signals of reward, including stimuli associated with safety and goal-oriented attack (e.g., anger). Hypomania/mania has been posited to involve increased BAS activity. In contrast, depression has been posited to involve decreased BAS activity. Building on past research, which suggests that increased left frontal cortical activity is a neurophysiological index of BAS activity, the present research tested the hypotheses that proneness toward hypomania/mania symptoms would be related to increased relative left frontal activity and that proneness toward depression symptoms would be related to decreased relative left frontal activity in response to an anger-evoking event. Results from 67 individuals who had completed a measure of proneness toward these affective symptoms and were exposed to an anger-evoking event supported the hypotheses.     

Verbal indicators of depression.

Speech content, voice quality, and temporal pacing of speech were evaluated for 11 well and 11 depressed women. Sadness was the dominant mood of the depressed women's speech, whereas happiness and mood neutrality characterized the well women's speech. The well women's tone of voice changed with the content of their speech. The well women spoke with a wide range of fundamental frequency, and the average fundamental frequency of their voices changed according to speech content. In contrast, the depressed women spoke with a narrow range of fundamental frequency, and the average fundamental frequency of their speech was unaffected by speech content. The depressed women spoke with longer pauses than the well women did. The results of this study contribute to the understanding of measures for assessing depression.     

Long-term psychological consequences of childhood frontal lobe lesion in patient DT.

Patient DT was examined 26 years after she acquired focal frontal lobe damage at 7 years of age. This report focused on several aspects of psychological outcome, including the empirical study of social development into early adulthood. Standardized measures of empathy, psychosocial development, and personality were analyzed, along with a moral judgment interview and patterns of adult social behavior. Results indicated that DT has a very limited capacity for empathic understanding, inadequate identity development, difficulties in vocational adjustment, and a concrete level of moral reasoning. Her social behavior and profile of test scores suggest that social development and adaptation have been arrested at early adolescent levels. We conclude that early frontal lobe damage has profound effects on social development, and that the frontal lobes provide a crucial neural substrate for social maturation.     

Comorbidity of unipolar depression: I. Major depression with dysthymia

The degree of current and lifetime comorbidity between major depressive disorder (MDD) and dysthymia (DY) was examined in large community samples of older adolescents (n = 1,710) and adults (n = 2,060). DY was highly comorbid with MDD (lifetime odds ratio of 3.4 for adolescents and 1.6 for adults) and was more likely to precede than to follow MDD, especially in persons who became depressed early in life. MDD was by far the more frequent form of depression: Approximately 80% of the depressed persons experienced only MDD, 10% experienced only DY, and 10% experienced both MDD and DY. The large number of persons who had became depressed twice experienced MDD in the 2nd episode, regardless of the nature of the 1st depression. History of depression was associated with a greater probability for other mental disorders in both adolescents and adults; however, the rates of comorbidity for MDD did not differ from rates for DY or for both MDD and DY.     

Attention deficit hyperactivity disorder and the frontal lobe syndrome.

The usefulness of frontal lobe (FL) dysfunction as a conceptual model for Attention Deficit Hyperactivity Disorder (ADHD) was investigated. Twenty-four ADHD and 24 normal control (NC) children were tested using two batteries of tasks. The first was sensitive to FL deficits in motor control and problem solving skills. The second consisted of memory tasks sensitive to temporal lobe dysfunction. ADHD children differed significantly from NCs on measures of FL function, but not on tests of temporal lobe functions. Where norms were available for normal children on the same FL tests, ADHDs performed like 6- to 7-year-olds, despite their mean age of 10 years and minimum age of 8 years. The differential performance of ADHDs on tasks sensitive to FL and temporal lobe dysfunction supports the hypothesis that ADHD deficits are analogous to FL dysfunction and demonstrates that the children's deficits do not reflect generalized cognitive impairment.     

Recollective experience, normal aging, and frontal dysfunction.

This study examined the nature of verbal recognition memory in young and old subjects. Following presentation of a word list, subjects undertook a yes-no recognition test and indicated whether their decision was based on explicit recollection or assessment of familiarity. Explicit recollection declined with age, and familiarity-based recognition increased. Furthermore, the extent to which older subjects relied on familiarity-based recognition correlated with neuropsychological indices of frontal lobe dysfunction. A further experiment indicated that the change from explicit recollection to familiarity-based responding was unrelated to changes in older subjects' confidence about their memory. The data indicate the central role of frontal dysfunction in understanding age-related memory loss.     

Analyzing distances in a frontal plane

In an exploration of the process whereby horizontal and vertical components are extracted from distances between pairs of points, participants made speeded absolute distance judgments—deciding whether horizontal distances between pairs of points in a frontal plane exceeded a criterion distance. Judgments reflected the horizontal and vertical distances between the points. Three accounts of the results were considered. (1) Only the overall distance between two points was directly available to judgment processes; the horizontal or vertical distance between the points was available only to the extent that the horizontal and vertical positions of the points were differentially weighted prior to the assessment of overall distance. (2) The perceptual effects of positions on the horizontal and vertical dimensions were collapsed onto a composite dimension. (3) The decision criterion for the distance judgment considered both the horizontal and vertical distances between the points. In support of the overall distance account, (1) performance in the distance judgment task was facilitated by repetition of the same overall distance from trial to trial, but not by repetition of the distance on the composite dimension or by repetition of horizontal or vertical distance; (2) differential weighting that the overall distance account predicted for the absolute distance judgments was reflected in concurrent relative distance judgments pitting horizontal against vertical distance, counter to the composite dimension account, which sees the horizontal and vertical dimensions as collapsing onto the composite dimension in balanced, symmetrical fashion, and counter the decisional account, given that no criterion is required for the relative judgment.     

The role of the frontal lobes in the regulation of cognitive development.

Between the ages of 1.5 and 5 years, and again between the ages of 5 and 10 years, a sequence of changes takes place in children's behavior which indicates a fundamental reorganization of their attentional, executive, and self-reflexive processes. In the present article, these changes are summarized, and evidence is adduced to support the claims (1) that these changes are frontally mediated and (2) that the underlying mechanism that generates them is similar to the one that generates the changes in EEG coherence during the same time period. The psychological model that has been hypothesized to explain the cycles of cognitive development (Case, 1992) is then compared to the physiological model that has been proposed to explain cycles of EEG development (Thatcher, 1992). It is shown that the two models are complementary, both in the underlying developmental sequence that they postulate and in the recursive dynamic they propose for producing movement through this sequence. A number of implications and predictions are derived, which follow from the proposition that the two sets of changes are different manifestations of a common underlying process.     

Inhibitory control in children with frontal infarcts related to sickle cell disease.

Evidence from past studies indicates that children with traumatic brain injury experience difficulties with inhibitory control. Less is known about inhibitory control in children with frontal brain injury related to cerebral infarction. We compared the inhibitory performance of children with frontal infarcts related to sickle cell disease with that of a control group of children with sickle cell disease but no history of cerebral infarction. On a stimulus-response reversal task, children with frontal infarcts made significantly more accuracy errors in the inhibitory condition than controls. Findings from this study and from previous research suggest that impairments in inhibitory control are common following frontal injury in a range of pediatric populations.