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Functional neuroimaging studies have implicated the fusiform gyri (FG) in structural encoding of faces, while event-related potential (ERP) and magnetoencephalography studies have shown that such encoding occurs approximately 170 ms poststimulus. Behavioral and functional neuroimaging studies suggest that processes involved in face recognition may be strongly modulated by socially relevant information conveyed by faces. To test the hypothesis that affective information indeed modulates early stages of face processing, ERPs were recorded to individually assessed liked, neutral, and disliked faces and checkerboard-reversal stimuli. At the N170 latency, the cortical three-dimensional distribution of current density was computed in stereotactic space using a tomographic source localization technique. Mean activity was extracted from the FG, defined by structure-probability maps, and a meta-cluster delineated by the coordinates of the voxel with the strongest face-sensitive response from five published functional magnetic resonance imaging studies. In the FG, approximately 160 ms poststimulus, liked faces elicited stronger activation than disliked and neutral faces and checkerboard-reversal stimuli. Further, confirming recent results, affect-modulated brain electrical activity started very early in the human brain (approximately 112 ms). These findings suggest that affective features conveyed by faces modulate structural face encoding. Behavioral results from an independent study revealed that the stimuli were not biased toward particular facial expressions and confirmed that liked faces were rated as more attractive. Increased FG activation for liked faces may thus be interpreted as reflecting enhanced attention due to their saliency.
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<p>Twenty-six younger (ages 18–36 years) and 19 older (ages 60–88 years) healthy right-handed men and women were tested for interhemispheric transfer by using visual evoked potentials lo laterally presented checkerboards. Interhemispheric transfer time (IHTT) was estimated by subtracting latencies for both P100 and N160 peaks of the waveform contralateral to the stimulus from the waveform ipsilateral to the stimulus for homologous sites. The quality of interhemispheric transfer was estimated by comparing peak-to-peak amplitudes for homologous sites. IHTT did not change across age, but there was a suppression of the waveform over the indirectly stimulated hemisphere in the older participants. The significance of this finding for age-related changes in functions mediated by the corpus callosum is discussed.</p>
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<p>Publisher's description: Buddha Mind in Contemporary Art documents the growing presence of Buddhist perspectives in contemporary culture. This shift began in the nineteenth century and is now pervasive in many aspects of everyday experience. In the arts especially, the increasing importance of process over product has promoted a profound change in the relationship between artist and audience. But while artists have been among the most perceptive interpreters of Buddhism in the West, art historians and critics have been slow to develop the intellectual tools to analyze the impact of Buddhist concepts. This timely, multi-faceted volume explores the relationships between Buddhist practice and the contemporary arts in lively essays by writers from a range of disciplines and in revealing interviews with some of the most influential artists of our time. Elucidating the common ground between the creative mind, the perceiving mind, and the meditative mind, the contributors tackle essential questions about the relationship of art and life. Among the writers are curators, art critics, educators, and Buddhist commentators in psychology, literature, and cognitive science. They consider the many Western artists today who recognize the Buddhist notion of emptiness, achieved through focused meditation, as a place of great creative potential for the making and experiencing of art. The artists featured in the interviews, all internationally recognized, include Maya Lin, Bill Viola, and Ann Hamilton. Extending earlier twentieth-century aesthetic interests in blurring the boundaries of art and life, the artists view art as a way of life, a daily practice, in ways parallel to that of the Buddhist practitioner. Their works, woven throughout the book, richly convey how Buddhism has been both a source for and a lens through which we now perceive art.</p>

This article examines the lay meditation movement occurring in contemporary Buddhism in Sri Lanka. The lay meditation movement represents a different perspective from the nationalistic Sinhala Buddhism that has dominated the discourse in the wake of the intractable ethnic conflict in the country. The lay meditation movement reflects the contemporary ferment in Buddhist discourse among the laity. One of the key themes in this movement is the privileging of experience because it gives the lay groups authority to challenge contemporary orthodoxy and it has empowered a new class of spiritual leaders, the lay gurus. Paraphrasing Stirrat, we can say that these lay gurus are leading the lay meditation movement towards ‘a series of different interpretations of what it means’ to be a Buddhist today. In its overall effect the lay meditation movement not only reconstructs what it means to be a Buddhist today but also points in the direction of establishing new forms of sectarianism that could be considered to be ‘new religious movements’ under the umbrella of Buddhism.

Considerable research has disclosed how cognitive reappraisals and the modulation of emotional responses promote successful emotion regulation. Less research has examined how the early processing of emotion-relevant stimuli may create divergent emotional response consequences. Mindfulness—a receptive, non-evaluative form of attention—is theorized to foster emotion regulation, and the present study examined whether individual differences in mindfulness would modulate neural responses associated with the early processing of affective stimuli. Focus was on the late positive potential (LPP) of the event-related brain potential to visual stimuli varying in emotional valence and arousal. This study first found, replicating past research, that high arousal images, particularly of an unpleasant type, elicited larger LPP responses. Second, the study found that more mindful individuals showed lower LPP responses to high arousal unpleasant images, even after controlling for trait attentional control. Conversely, two traits contrasting with mindfulness—neuroticism and negative affectivity—were associated with higher LPP responses to high arousal unpleasant images. Finally, mindfulness was also associated with lower LPP responses to motivationally salient pleasant images (erotica). These findings suggest that mindfulness modulates neural responses in an early phase of affective processing, and contribute to understanding how this quality of attention may promote healthy emotional functioning.

Two groups of subjects classified as high vs. low in the need for power (n power) were assessed for augmenting versus reducing in the event-related potential (ERP) elicited by neutral and power-related words. Words at four different intensity levels in each of these two classes were randomly presented and ERPs in response to each word class at each of the four intensity levels were computed from EEG recorded at Fz. The results indicated that the two groups responded differentially to the power-related vs. neutral words. HIgh n power subjects showed reduction in response to both power-related and neutral words while low n power subjects showed augmentation in response to the power-related words.
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Two groups of subjects classified as high vs. low in the need for power (n power) were assessed for augmenting versus reducing in the event-related potential (ERP) elicited by neutral and power-related words. Words at four different intensity levels in each of these two classes were randomly presented and ERPs in response to each word class at each of the four intensity levels were computed from EEG recorded at Fz. The results indicated that the two groups responded differentially to the power-related vs. neutral words. HIgh n power subjects showed reduction in response to both power-related and neutral words while low n power subjects showed augmentation in response to the power-related words.

<p>In two prior studies, we investigated the neural mechanisms of spatial attention using a combined event-related potential (ERP) and positron emission tomography (PET) approach (Heinze et al. [1994]: Nature 392:543-546; Mangun et al. [1997]: Hum Brain Mapp 5:273-279). Neural activations in extrastriate cortex were observed in the PET measures for attended stimuli, and these effects were related to attentional modulations in the ERPs at specific latencies. The present study used functional magnetic resonance imaging (fMRI) and ERPs in single subjects to investigate the intersubject variability in extrastriate spatial attention effects, and to qualitatively compare this to variations in ERP attention effects. Activations in single subjects replicated our prior group-averaged PET findings, showing attention-related increases in blood flow in the posterior fusiform and middle occipital gyri in the hemisphere contralateral to attended visual stimuli. All subjects showed attentional modulations of the occipital P1 component of the ERPs. These findings in single subjects demonstrate the consistency of extrastriate attention effects, and provide information about the feasibility of this approach for integration of electrical and functional imaging data.</p>
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<p>Examined whether children with dyslexia (DYS) differ from matched controls on visual evoked potential measures of interhemispheric transfer time (IHTT). 20 right-handed boys (aged 9–12 yrs), 10 with DYS and 10 with normal reading ability, were selected to participate based on a battery of neuropsychological and reading tests. Checkerboard flashes were presented to Ss hemiretinally while evoked responses were recorded from right and left side occipital scalp locations. IHTT was computed separately in response to right and left visual field presentations. Ss with DYS were found to have faster IHTT from right-to-left hemisphere and slower IHTT from left-to-right hemisphere compared with controls. Evoked potential measures of IHTT accounted for significant variance in measures of reading and related cognitive skills.</p>
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BACKGROUND: Two core characteristics of pathologic fear are its rapid onset and resistance to cognitive regulation. We hypothesized that activation of the amygdala early in the presentation of fear-relevant visual stimuli would distinguish phobics from nonphobics. METHODS: Chronometry of amygdala activation to phobia-relevant pictures was assessed in 13 spider phobics and 14 nonphobics using functional magnetic resonance imaging (fMRI). RESULTS: Blood oxygen level-dependent (BOLD) responses in the amygdala early in picture processing consistently differentiated between phobic and nonphobic subjects, as well as between phobogenic and nonphobogenic stimuli among phobics. Furthermore, amygdalar BOLD responses associated with timing but not magnitude of activation predicted affective responses to phobogenic stimuli. Computational modeling procedures were used to identify patterns of neural activation in the amygdala that could yield the observed BOLD data. These data suggest that phobic responses were characterized by strong but brief amygdala responses, whereas nonphobic responses were weaker and more sustained. CONCLUSIONS: Results are discussed in the context of the amygdala's role in rapid threat detection and the vigilance-avoidance hypothesis of anxiety. These data highlight the importance of examining the neural substrates of the immediate impact of phobogenic stimuli for understanding pathological fear.
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High vs. low scorers on the Beck Depression Inventory (BDI) were compared on measures of resting EEG activation asymmetry from frontal and parietal brain regions. Depressed subjects showed greater relative right frontal activation compared with nondepressed subjects. Parietal asymmetry did not distinguish between the groups. These data support the hypothesis of right hemisphere hyperactivation in the frontal region of depressed individuals and are consistent with the growing body of literature which suggests that the left and right frontal regions may be differentially specialized for particular positive and negative affects.
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Individuals differ dramatically in the quality and intensity of their response to affectively evocative stimuli. On the basis of prior theory and research, we hypothesized that these individual differences are related to variation in activation of the left and right frontal brain regions. We recorded baseline brain electrical activity from subjects on two occasions 3 weeks apart. Immediately following the second recording, subjects were exposed to brief positive and negative emotional film clips. For subjects whose frontal asymmetry was stable across the 3-week period, greater left frontal activation was associated with reports of more intense positive affect in response to the positive films, whereas greater right frontal activation was associated with more intense reports of negative affect in response to the negative film clips. The methodological and theoretical implications of these data are discussed.
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Developments in technologic and analytical procedures applied to the study of brain electrical activity have intensified interest in this modality as a means of examining brain function. The impact of these new developments on traditional methods of acquiring and analyzing electroencephalographic activity requires evaluation. Ultimately, the integration of the old with the new must result in an accepted standardized methodology to be used in these investigations. In this paper, basic procedures and recent developments involved in the recording and analysis of brain electrical activity are discussed and recommendations are made, with emphasis on psychophysiological applications of these procedures.
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Research on the anatomical bases of interhemispheric interaction, including individual differences in corpus callosum (CC) anatomy, is reviewed. These anatomical findings form the basis for the discussion of two major themes. The first considers interhemispheric transfer time (IHTT) and related issues. These include varieties of IHTT and possible directional asymmetries of IHTT. Evidence suggests that pathological variations in IHTT may have cognitive consequences. The second involves conditions under which interhemispheric interaction is necessary and beneficial. The data suggest that when both hemispheres have some competence at a difficult task, there is a benefit to interhemispheric interaction. The role of the CC in the dynamic distribution of attention may be particularly relevant to this advantage. Throughout the article reference is made to individual differences and developmental changes associated with interhemispheric interaction.
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Neurosurgical treatment of psychiatric disorders has been influenced by evolving neurobiological models of symptom generation. The advent of functional neuroimaging and advances in the neurosciences have revolutionized understanding of the functional neuroanatomy of psychiatric disorders. This article reviews neuroimaging studies of depression from the last 3 decades and describes an emerging neurocircuitry model of mood disorders, focusing on critical circuits of cognition and emotion, particularly those networks involved in the regulation of evaluative, expressive and experiential aspects of emotion. The relevance of this model for neurotherapeutics is discussed, as well as the role of functional neuroimaging of psychiatric disorders.
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This research assessed whether individual differences in anterior brain asymmetry are linked to differences in basic dimensions of emotion. In each of 2 experimental sessions, separated by 3 weeks, resting electroencephalogram (EEG) activity was recorded from female adults during 8 60-s baselines. Mean alpha power asymmetry across both sessions was extracted in mid-frontal and anterior temporal sites. Across both regions, groups demonstrating stable and extreme relative left anterior activation reported increased generalized positive affect (PA) and decreased generalized negative affect (NA) compared with groups demonstrating stable and extreme relative right anterior activation. Additional correlational analyses revealed robust relations between anterior asymmetry and PA and NA, particularly among subjects who demonstrated stable patterns of EEG activation over time. Anterior asymmetry was unrelated to individual differences in generalized reactivity.
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Baseline resting electroencephalogram activity was recorded with 3 different reference montages from 15 clinically depressed and 13 control subjects. Power in all frequency bands was extracted by fast Fourier transformation. There was a significant Group X Hemisphere interaction in the mid-frontal region, for the alpha band power only. Depressed subjects had less left-sided activation (i.e., more alpha activity) than did normal control subjects. This pattern of diminished left-sided frontal activation is interpreted as indicating a deficit in approach mechanisms in depressed subjects.
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The capacity to stabilize the content of attention over time varies among individuals, and its impairment is a hallmark of several mental illnesses. Impairments in sustained attention in patients with attention disorders have been associated with increased trial-to-trial variability in reaction time and event-related potential deficits during attention tasks. At present, it is unclear whether the ability to sustain attention and its underlying brain circuitry are transformable through training. Here, we show, with dichotic listening task performance and electroencephalography, that training attention, as cultivated by meditation, can improve the ability to sustain attention. Three months of intensive meditation training reduced variability in attentional processing of target tones, as indicated by both enhanced theta-band phase consistency of oscillatory neural responses over anterior brain areas and reduced reaction time variability. Furthermore, those individuals who showed the greatest increase in neural response consistency showed the largest decrease in behavioral response variability. Notably, we also observed reduced variability in neural processing, in particular in low-frequency bands, regardless of whether the deviant tone was attended or unattended. Focused attention meditation may thus affect both distracter and target processing, perhaps by enhancing entrainment of neuronal oscillations to sensory input rhythms, a mechanism important for controlling the content of attention. These novel findings highlight the mechanisms underlying focused attention meditation and support the notion that mental training can significantly affect attention and brain function.
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<p>Subregional analyses of the hippocampus have suggested a selective role for the CA1 subregion in intermediate/long-term spatial memory and consolidation, but not short-term acquisition or encoding processes. It remains unclear how the direct cortical projection to CA1 via the perforant path (pp) contributes to these CA1-dependent processes. It has been suggested that dopamine selectively modulates the pp projection to CA1 while having little to no effect on the Schaffer collateral (SC) projection to CA1. This series of behavioral and electrophysiological experiments takes advantage of this pharmacological dissociation to demonstrate that the direct pp inputs to CA1 are critical in CA1-dependent intermediate-term retention and retrieval function. Here we demonstrate that local infusion of the nonselective dopamine agonist, apomorphine (10, 15 microg), into the CA1 subregion of awake animals produces impairments in between-day retention and retrieval, sparing within-day encoding of a modified Hebb-Williams maze and contextual conditioning of fear. In contrast, apomorphine produces no deficits when infused into the CA3 subregion. To complement the behavioral analyses, electrophysiological data was collected. In anesthetized animals, local infusion of the same doses of apomorphine significantly modifies evoked responses in the distal dendrites of CA1 following angular bundle stimulation, but produces no significant effects in the more proximal dendritic layer following stimulation of the SC. These results support a modulatory role for dopamine in the EC-CA1, but not CA3-CA1 circuitry, and suggest the possibility of a more fundamental role for EC-CA1 synaptic transmission in terms of intermediate-term, but not short-term spatial memory.</p>
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