Science posts

See science posts on page 64 below.

    • 2007
    • Alexander Strobel et al
    • Genetic Variation of Serotonin Function and Cognitive Control
    • Although it is widely accepted that serotonin plays a pivotal role in the modulation of anxiety- and depression-related personality traits as well as in the pathogenesis of anxiety disorders and depression, the role of serotonin in cognition is less clear. In the present study, we investigated the involvement of serotonin in cognitive behaviors by examining the impact of genetic variation in key regulators of serotonergic neurotransmission on behavioral measures in a cognitive control task. Eighty-five healthy participants performed a cued continuous performance task (the AX Continuous Performance Task [AXCPT]) and were genotyped for polymorphisms in the transcriptional control regions of the tryptophan hydroxylase 2 gene (TPH2 G-703T; rs4570625) and the serotonin transporter gene (5-HTTLPR). The core result was that individuals lacking the rare TPH2 T allele were not faster than T allele carriers, but committed fewer errors and were less variable in responding. These findings parall..
    • 2014
    • Matthias J. Gruberemail , Bernard D. Gelman , Charan Ranganath
    • States of Curiosity Modulate Hippocampus-Dependent Learning via the Dopaminergic Circuit
    • People find it easier to learn about topics that interest them, but little is known about the mechanisms by which intrinsic motivational states affect learning. We used functional magnetic resonance imaging to investigate how curiosity (intrinsic motivation to learn) influences memory. In both immediate and one-day-delayed memory tests, participants showed improved memory for information that they were curious about and for incidental material learned during states of high curiosity. Functional magnetic resonance imaging results revealed that activity in the midbrain and the nucleus accumbens was enhanced during states of high curiosity. Importantly, individual variability in curiosity-driven memory benefits for incidental material was supported by anticipatory activity in the midbrain and hippocampus and by functional connectivity between these regions. These findings suggest a link between the mechanisms supporting extrinsic reward motivation and intrinsic curiosity and highlight t..
    • 2011
    • Valorie N Salimpoor, Mitchel Benovoy, Kevin Larcher, Alain Dagher & Robert J Zatorre
    • Anatomically distinct dopamine release during anticipation and experience of peak emotion to music
    • Music, an abstract stimulus, can arouse feelings of euphoria and craving, similar to tangible rewards that involve the striatal dopaminergic system. Using the neurochemical specificity of [11C]raclopride positron emission tomography scanning, combined with psychophysiological measures of autonomic nervous system activity, we found endogenous dopamine release in the striatum at peak emotional arousal during music listening. To examine the time course of dopamine release, we used functional magnetic resonance imaging with the same stimuli and listeners, and found a functional dissociation: the caudate was more involved during the anticipation and the nucleus accumbens was more involved during the experience of peak emotional responses to music. These results indicate that intense pleasure in response to music can lead to dopamine release in the striatal system. Notably, the anticipation of an abstract reward can result in dopamine release in an anatomical pathway distinct from that ass..
    • 2005
    • Annette Bolte, Thomas Goschke
    • On the speed of intuition: Intuitive judgments of semantic coherence under different response deadlines
    • Intuition is the ability to judge stimulus properties on the basis of information that is activated in memory but not consciously retrieved. We investigated one central feature of intuitive judgments— namely, their speed. Participants judged whether or not three clue words were coherent in the sense that they were weakly associated with a common fourth concept. To restrict the time available for conscious deliberation of possible solution words, participants had to synchronize their judgments with a response signal appearing at different lags after the clue words. In two experiments, participants discriminated coherent and incoherent triads reliably better than chance, even when they did not consciously retrieve the solution word and the lag between clue words and response signal was as short as 1.5 sec. Results indicate that intuitive judgments can indeed be made very fast and without extended conscious deliberation. Possible mechanisms underlying intuitive judgments are discussed.
    • 2005
    • Kimberly J. Saudino
    • Behavioral Genetics and Child Temperament
    • Most temperament theories presume a biological basis to those behavioral tendencies thought to be temperamental in origin. Behavioral genetic methods can be used to test this assumption. Twin and adoption studies suggest that individual differences in infant and child temperament are genetically influenced. However, behavioral genetics has much more to offer to the study of temperament than simple heritability estimates. The present paper describes some recent findings from behavioral genetics research in temperament that go well beyond the basic nature-nurture question. These findings include the importance of nonshared environmental influences on temperament, genetic continuity and environmental change during development, links between temperament and behavior problems, and harnessing the power of molecular genetics to identify specific genes responsible for genetic influence on early temperament.
    • 2003
    • Reif A
    • Toward a molecular architecture of personality.
    • Epidemiological studies provided a large body of evidence that personality dimensions are influenced by genetic factors and that the genetic component is highly complex, polygenic, and epistatic. However, consistent findings on the genetic basis of personality have yet remained sparse. In recent years, molecular genetics has begun to identify specific genes coding in particular for components of the serotonergic and dopaminergic neurotransmitter systems representing quantitative trait loci (QTLs) for behavioral traits. The QTL concept suggests that complex traits are not attributable to single genes. According to this polygenic model, the genetic basis of personality and behavior and its pathological variations thus results from additive or nonadditive interactions of various genes. As the number of suitable candidate genes constantly increases, the QTL model provides a reasonable explanation for the genetic basis of personality and its disorders. In this review, the current knowledg..
    • 1997
    • Phillips K
    • Evidence for genetic influence on both cross-situation and situation-specific components of behavior.
    • An assumption often made in the study of personality and in social psychology is that methods variance and situation-specific effects, as key components of measured behavioral variance, are environmental effects. The results of the present research refute that assumption. Nine measures-3 aspects of temperament measured in each of 3 ways-were obtained at age 24 months for twin sibships participating in the Louisville Twin Study. This report describes a new model that captures the unique information potentially available in such data, by combining multitrait-multimethod and twin-family analytic designs. The results indicated significant genetic influence on methods-situations components of variance along with genetic influence on traits. The findings support heuristics that include both situation-specific patterns of behavior and cross-situational consistencies.
    • 2009
    • Kevin N. Ochsner
    • Bottom-Up and Top-Down Processes in Emotion Generation
    • Emotions are generally thought to arise through the interaction of bottom-up and top-down processes. However, prior work has not delineated their relative contributions. In a sample of 20 females, we used functional magnetic resonance imaging to compare the neural correlates of negative emotions generated by the bottom-up perception of aversive images and by the top-down interpretation of neutral images as aversive. We found that (a) both types of responses activated the amygdala, although bottom-up responses did so more strongly; (b) bottom-up responses activated systems for attending to and encoding perceptual and affective stimulus properties, whereas top-down responses activated prefrontal regions that represent high-level cognitive interpretations; and (c) self-reported affect correlated with activity in the amygdala during bottom-up responding and with activity in the medial prefrontal cortex during top-down responding. These findings provide a neural foundation for emotion the..
    • 2014
    • Brian G Dias, Kerry J Ressler
    • Parental olfactory experience influences behavior and neural structure in subsequent generations
    • Using olfactory molecular specificity, we examined the inheritance of parental traumatic exposure, a phenomenon that has been frequently observed, but not understood. We subjected F0 mice to odor fear conditioning before conception and found that subsequently conceived F1 and F2 generations had an increased behavioral sensitivity to the F0-conditioned odor, but not to other odors. When an odor (acetophenone) that activates a known odorant receptor (Olfr151) was used to condition F0 mice, the behavioral sensitivity of the F1 and F2 generations to acetophenone was complemented by an enhanced neuroanatomical representation of the Olfr151 pathway. Bisulfite sequencing of sperm DNA from conditioned F0 males and F1 naive offspring revealed CpG hypomethylation in the Olfr151 gene. In addition, in vitro fertilization, F2 inheritance and cross-fostering revealed that these transgenerational effects are inherited via parental gametes. Our findings provide a framework for addressing how environ..
    • 2000
    • Tony W Buchanan
    • Recognition of emotional prosody and verbal components of spoken language: an fMRI study
    • This study examined the neural areas involved in the recognition of both emotional prosody and phonemic components of words expressed in spoken language using echo-planar, functional magnetic resonance imaging (fMRI). Ten right-handed males were asked to discriminate words based on either expressed emotional tone (angry, happy, sad, or neutral) or phonemic characteristics, specifically, initial consonant sound (bower, dower, power, or tower). Significant bilateral activity was observed in the detection of both emotional and verbal aspects of language when compared to baseline activity. We found that the detection of emotion compared with verbal detection resulted in significant activity in the right inferior frontal lobe. Conversely, the detection of verbal stimuli compared with the detection of emotion activated left inferior frontal lobe regions most significantly. Specific analysis of the anterior auditory cortex revealed increased right hemisphere activity during the detection of..

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