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Biomedical subjects

Helen Fisher

Publications and source records attributed to Helen Fisher.

9 recordsLinked to original sources
PubMed2006

Environment and schizophrenia: environmental factors in schizophrenia: childhood trauma--a critical review.

There is renewed interest in the relationship between early childhood trauma and risk of psychosis in adulthood. There are a large number of studies of psychiatric inpatients, and of outpatients in which a majority have a psychotic disorder, that suggest the prevalence of childhood trauma in these populations is high. However, these are generally small studies of diagnostically heterogeneous and chronic samples and, as such, can tell us very little about whether childhood trauma is of etiological importance in psychosis. A small number of recent population-based studies provide more robust evidence of an association, and there are now plausible biological mechanisms linking childhood trauma and psychosis. However, there remain a number of conceptual and methodological issues, which mean much more research is needed before firm conclusions can be drawn about whether childhood trauma is a cause of psychosis.

Adolescent↗
PubMed2006

Diagnostic omission errors in acute paediatric practice: impact of a reminder system on decision-making.

BACKGROUND: Diagnostic error is a significant problem in specialities characterised by diagnostic uncertainty such as primary care, emergency medicine and paediatrics. Despite wide-spread availability, computerised aids have not been shown to significantly improve diagnostic decision-making in a real world environment, mainly due to the need for prolonged system consultation. In this study performed in the clinical environment, we used a Web-based diagnostic reminder system that provided rapid advice with free text data entry to examine its impact on clinicians' decisions in an acute paediatric setting during assessments characterised by diagnostic uncertainty. METHODS: Junior doctors working over a 5-month period at four paediatric ambulatory units consulted the Web-based diagnostic aid when they felt the need for diagnostic assistance. Subjects recorded their clinical decisions for patients (differential diagnosis, test-ordering and treatment) before and after system consultation. An expert panel of four paediatric consultants independently suggested clinically significant decisions indicating an appropriate and 'safe' assessment. The primary outcome measure was change in the proportion of 'unsafe' workups by subjects during patient assessment. A more sensitive evaluation of impact was performed using specific validated quality scores. Adverse effects of consultation on decision-making, as well as the additional time spent on system use were examined. RESULTS: Subjects attempted to access the diagnostic aid on 595 occasions during the study period (8.6% of all medical assessments); subjects examined diagnostic advice only in 177 episodes (30%). Senior House Officers at hospitals with greater number of available computer workstations in the clinical area were most likely to consult the system, especially out of working hours. Diagnostic workups construed as 'unsafe' occurred in 47/104 cases (45.2%); this reduced to 32.7% following system consultation (McNemar test, p < 0.001). Subjects' mean 'unsafe' workups per case decreased from 0.49 to 0.32 (p < 0.001). System advice prompted the clinician to consider the 'correct' diagnosis (established at discharge) during initial assessment in 3/104 patients. Median usage time was 1 min 38 sec (IQR 50 sec-3 min 21 sec). Despite a modest increase in the number of diagnostic possibilities entertained by the clinician, no adverse effects were demonstrable on patient management following system use. Numerous technical barriers prevented subjects from accessing the diagnostic aid in the majority of eligible patients in whom they sought diagnostic assistance. CONCLUSION: We have shown that junior doctors used a Web-based diagnostic reminder system during acute paediatric assessments to significantly improve the quality of their diagnostic workup and reduce diagnostic omission errors. These benefits were achieved without any adverse effects on patient management following a quick consultation.

Adolescent↗
PubMed2006

Genetic diversity analyses of grapevine Rupestris stem pitting-associated virus reveal distinct population structures in scion versus rootstock varieties.

Grapevine Rupestris stem pitting-associated virus (GRSPaV) is a member of the genus Foveavirus within the family Flexiviridae. GRSPaV is closely associated with the disease Rupestris stem pitting and is frequently detected in grapevines worldwide. Previous research in several laboratories suggests that GRSPaV consists of a family of sequence variants. However, the genetic composition of GRSPaV variants in viral isolates from scion and rootstock varieties has not been studied extensively. In this report, the genetic diversity and population structure of GRSPaV isolates from scion and rootstock varieties were analysed using two pairs of primers targeting two different genomic regions encoding the helicase domain of the replicase and the capsid protein. In total, 190 cDNA clones derived from 24 isolates were sequenced and analysed. At least four major groups of GRSPaV variants were found to exist in grapevines. Interestingly, the majority of the scion varieties (9/10) that were analysed, regardless of their genetic background and geographical origin, harboured complex viral populations composed of two to four distinct viral variants. In contrast, the viral populations in isolates from rootstock varieties were homogeneous and comprised a single variant. The practice of grafting between scion and rootstock varieties commonly used in modern viticulture, coupled with the frequent regional and international exchange of propagating materials, may have played a major role in the ubiquitous distribution and mixed infections of distinct GRSPaV variants among scion varieties. The possible origin and evolution of GRSPaV are also discussed.

Cloning, Molecular↗
PubMed2005

Romantic love: an fMRI study of a neural mechanism for mate choice.

Scientists have described myriad traits in mammalian and avian species that evolved to attract mates. But the brain mechanisms by which conspecifics become attracted to these traits is largely unknown. Yet mammals and birds express mate preferences and make mate choices, and data suggest that this "attraction system" is associated with the dopaminergic reward system. It has been proposed that intense romantic love, a cross-cultural universal, is a developed form of this attraction system. To determine the neural mechanisms associated with romantic love we used functional magnetic resonance imaging (fMRI) and studied 17 people who were intensely "in love" (Aron et al. [2005] J Neurophysiol 94:327-337). Activation specific to the beloved occurred in the right ventral tegmental area and right caudate nucleus, dopamine-rich areas associated with mammalian reward and motivation. These and other results suggest that dopaminergic reward pathways contribute to the "general arousal" component of romantic love; romantic love is primarily a motivation system, rather than an emotion; this drive is distinct from the sex drive; romantic love changes across time; and romantic love shares biobehavioral similarities with mammalian attraction. We propose that this attraction mechanism evolved to enable individuals to focus their mating energy on specific others, thereby conserving energy and facilitating mate choice-a primary aspect of reproduction. Last, the corticostriate system, with its potential for combining diverse cortical information with reward signals, is an excellent anatomical substrate for the complex factors contributing to romantic love and mate choice.

Adolescent↗
PubMed2005

Moving up from the segment: a comment on Aichert and Ziegler's syllable frequency and syllable structure in apraxia of speech, Brain and Language, 88, 148-159, 2004.

In a recent article, explore whether apraxia of speech (AOS) can be explained by disruption of the phonetic plans for high frequency syllables. This approach is a hybrid one, combining the notion of a mental syllabary with an explanation that the impairment in AOS results from reduced access to supra-segmental phonetic plans. In this commentary, we explore Aichert and Ziegler's approach and suggest that in testing a hybrid model it is important to be cautious in identifying implications for the two source models.

Aphasia↗
PubMed2005

Reward, motivation, and emotion systems associated with early-stage intense romantic love.

Early-stage romantic love can induce euphoria, is a cross-cultural phenomenon, and is possibly a developed form of a mammalian drive to pursue preferred mates. It has an important influence on social behaviors that have reproductive and genetic consequences. To determine which reward and motivation systems may be involved, we used functional magnetic resonance imaging and studied 10 women and 7 men who were intensely "in love" from 1 to 17 mo. Participants alternately viewed a photograph of their beloved and a photograph of a familiar individual, interspersed with a distraction-attention task. Group activation specific to the beloved under the two control conditions occurred in dopamine-rich areas associated with mammalian reward and motivation, namely the right ventral tegmental area and the right postero-dorsal body and medial caudate nucleus. Activation in the left ventral tegmental area was correlated with facial attractiveness scores. Activation in the right anteromedial caudate was correlated with questionnaire scores that quantified intensity of romantic passion. In the left insula-putamen-globus pallidus, activation correlated with trait affect intensity. The results suggest that romantic love uses subcortical reward and motivation systems to focus on a specific individual, that limbic cortical regions process individual emotion factors, and that there is localization heterogeneity for reward functions in the human brain.

Adolescent↗
PubMed2005

Some thoughts on the neurobiology of stalking.

The authors examine the crime of stalking, including the cognitive traits, emotional reactions, attachment pathology, violence patterns and sex differences of samples of stalking offenders. They focus on two common types of stalkers: 1) those who sustain pursuit of a former sexual intimate who has rejected them; and 2) those who pursue a stranger or acquaintance who has failed to return the stalker's romantic overtures. The authors discuss data from neuroimaging (fMRI) studies of romantic love which suggest that these forms of stalking may be associated with heightened activity of subcortical dopaminergic pathways of the "Reward System" of the brain, perhaps in combination with low activity of central serotonin. The authors propose that this set of neural correlates may contribute to the stalker's focused attention, increased energy, following behaviors, obsessive thinking about and impulsivity directed toward the victim. To further explore the neural systems associated with stalking behavior, they also discuss several biopsychological phenomena associated with romantic rejection, including the "protest response," "frustration attraction," "abandonment rage" and "mate guarding." They illustrate the parallels between stalking and addiction. They conclude that stalking may be associated with a specific set of biological components and they offer suggestions for further research into this pathological emotional/motivational state.

Brain↗
PubMed2002

The neural mechanisms of mate choice: a hypothesis.

Scientists have described many physical and behavioral traits in avian and mammalian species that evolved to attract mates. But the brain mechanisms by which conspecifics become attracted to these traits is unknown. This paper maintains that two aspects of mate choice evolved in tandem: 1) traits that evolved in the "display producer" to attract mates and, 2) corresponding neural mechanisms in the "display chooser" that enable them to become attracted to these display traits. Then it discusses our (in-progress) fMRI brain scanning project on human romantic attraction, what we believe is a developed form of "courtship attraction" common to avian and mammalian species as well as the primary neural mechanism underlying avian and mammalian mate choice. The paper hypothesizes that courtship attraction is associated with elevated levels of central dopamine and norepinephrine and decreased levels of central serotonin in reward pathways of the brain. It also proposes that courtship attraction is part of a triune brain system for mating, reproduction and parenting. 1)The sex drive evolved to motivate birds and mammals to court any conspecifics. 2) The attraction system evolved to enable individuals to discriminate among potential mating partners and focus courtship activities on particular individuals, thereby conserving mating time and energy. 3) The neural circuitry for attachment evolved to enable individuals to complete species-specific parental duties.

Brain Mapping↗