Auditory evoked potentials and sex-related differences in brain development

Auditory evoked potentials (AEPs) were obtained to probe tones which were delivered during the presentation of complex verbal and nonverbal auditory stimulation to 3-month-old infants. Significant sex-dependent AEP amplitude asymmetries were found. Females produced higher-amplitude responses from the left hemisphere and males produced higher-amplitude responses from the right hemisphere during both the verbal and nonverbal presentations. No significant AEP asymmetries were obtained in an independent group of infants that received only the probe tones. These findings are consistent with theories and behavioral data suggesting differences between males and females in the development of language and spatial functions.     

EMDR and early psychological intervention following trauma

IntroductionThis article evaluates developments in the field of early psychological intervention (EPI) after trauma in general and the place of early eye movement desensitization and reprocessing (EMDR) intervention (EEI) in particular. The issues and dilemmas involved with EPI and EEI will be outlined; related research presented and the current status evaluated.Literature and clinical findingsReviewing the literature and drawing on findings from initial research and case studies, the rationale and contribution that EMDR therapy has to offer is discussed relative to current evidence and theory regarding post-traumatic stress syndromes and trauma memories. The relative advantages of EEI will be elaborated.Discussion and conclusionIt is proposed that EEI, while trauma memories have not yet been integrated, may be used not only to treat acute distress but may also provide a window of opportunity in which a brief intervention, possibly on successive days, could prevent complications and strengthen resilience. Through the rapid reduction of intrusive symptoms and de-arousal response as well as by identifying potential obstructions to adaptive information processing (AIP), EMDR therapy may reduce the sensitisation and accumulation of trauma memories.     

Cortical potentials evoked by confirming and disconfirming feedback following an auditory discrimination

Vertex potentials elicited by visual feedback (signals following an auditory intensity discrimination have been studied with eight Ss. Feedback signals which confirmed the prior sensory decision elicited small P3s, while disconfirming, feedback elicited P3s that were larger. On the average, the latency of P3 was also found to increase with increasing disparity between the judgment and. the feedback information. These effects were part bf an overall dichotomy in waveshape following confirming vs disconforming feedback. These findings are incorporated in a general model of the role of P3 in perceptual decision making.     

Moving targets: A developmental framework for understanding children's changes following disasters

This paper proposes a developmental framework for disaster studies with children that allows researchers to explore the interaction between developmental change (defined as change that is extended, self-regulated, qualitative, and progressive) and cataclysmic change. It outlines three levels of analysis related to disasters: 1) observing the harm of disasters in the context of age-related changes in children, 2) demonstrating how children are restored to age-typical developmental trajectories following disasters, and 3) investigating how specific disaster experiences are integrated over time with children's ongoing developmental processes, such as their understanding of self and their views of the world. The paper identifies existing studies at each level of the framework, outlines how these levels of analysis can be used in constructing developmental models of disaster response, and offers suggestions for expanding disaster research into additional developmental areas.     

Psychometric intelligence and visual evoked potentials: a replication

Previously we have reported significant correlations between EEG visual evoked potential (EP) parameters and scores on the Raven's Advanced Progressive Matrices (RAPM) test. This study is an attempt to replicate those findings in a new sample of 27 S s. The results provide further evidence that EP amplitude is related to intelligence-test performance. There is also confirmation that stimulus luminance levels influence the magnitude of EP amplitude/intelligence correlations. In addition, the results indicate that age may be a confounding variable.     

Significance of latency and amplitude values of the visual evoked potential in children with early childhood brain damage

The latency and amplitude data of optically evoked potentials (unipolar from the vertex) were measured during the 50-200 ms interval in a group of normal boys (n = 26) and a group of boys with brain damage sustained during early childhood (n = 38). The latency periods were sometimes significantly longer and the amplitudes larger (flash stimulus) and smaller (pattern stimulus) respectively in the brain damaged than in the normal subjects. In view of the results of clinical, neurological and psychological examinations, these phenomena must be attributed to delayed maturation of the central nervous functional system.     

Graded changes in evoked response (P300) amplitude as a function of cognitive activity

Using a stepwise discriminant analysis, we demonstrate that the amplitude of P300 is a graded function of the complexity of information processing required of a S following a stimulus. This relationship between cognitive complexity and P300 is apparent only when the S is not pressed to generate fast and accurate discriminant responses to the stimuli. Under a reaction-time regime, a large P300 is elicited independently of stimulus predictability or cognitive complexity. It seems that P300 is a measure of the amount of activity of a general-purpose cortical processor.     

Kinematics of aiming in direction and amplitude: a developmental study.

The patterns of aimed movements to visual targets were analyzed in children aged 6, 8 and 10. Tasks with direction and/or amplitude requirements were used. The tasks were performed both with and without vision. Peak velocity, acceleration and deceleration and their relative temporal occurrence were evaluated. Overall, the 6- and 10-year-olds exhibited higher peak velocity and acceleration when performing the pure directional task than when performing tasks with an amplitude or stopping requirement. On the contrary, 8-year-olds showed similar peak acceleration and velocity across all three tasks. Similarly, when performing the pure directional task, the 6- and 10-year-olds reached their peak velocity and acceleration relatively later in time than the 8-year-olds. Vision of movement increased the peak velocity in all experimental tasks and peak acceleration was increased only in the pure directional task. Thus, movement kinematics varied according to the task requirements and age. Eight-year-olds showed greater propensity to feedback control in all tasks, suggesting an over-inhibition in their approach patterns, whereas 10-year-olds tended to use feedforward processes, with a shortened deceleration phase.     

Sexual trauma and personality: developmental vulnerability and additive effects.

Two types of sexual trauma, sexual abuse in childhood and rape in adulthood, were investigated in terms of possible effects on personality. Four groups of participants were studied: women who had experienced sexual abuse in childhood, women who had experienced rape as adults, women who had experienced both of these sexual traumas, and a control group of women who had experienced no sexual trauma. Personality functioning was assessed using the Dimensional Assessment of Personality Pathology. Groups who had experienced childhood sexual abuse displayed the highest degree of personality disturbance; however, the additive effects of repeated sexual trauma were limited. These findings may reflect the outcome of specific adversity in childhood on the psychobiological constructs underlying personality.