Neuroimaging Evidence (neuroimaging + evidence)

Distribution by Scientific Domains

Selected Abstracts

Attention to Spoken Word Planning: Chronometric and Neuroimaging Evidence

Ardi Roelofs
This article reviews chronometric and neuroimaging evidence on attention to spoken word planning, using the WEAVER++ model as theoretical framework. First, chronometric studies on the time to initiate vocal responding and gaze shifting suggest that spoken word planning may require some attention, even though it is one of our most highly practiced psychomotor skills. Second, neuroimaging studies that localized brain activity during word planning suggest that attention enhances activity in perisylvian cortical areas. What word to enhance and for how long is determined by an executive control system located in anterior cingulate and lateral prefrontal cortex. Commonalities of anterior cingulate function across verbal vocalizations (speech) and nonverbal vocalizations (e.g. human crying, laughter, and monkey calls) are outlined. [source]

Flickering admissibility: neuroimaging evidence in the U.S. courts,

Jane Campbell Moriarty J.D.
This article explores the admissibility of neuroimaging evidence in U.S. courts, recognizing various trends in decisions about such evidence. While courts have routinely admitted some neuroimages, such as CT scans and MRI, as proof of trauma and disease, they have been more circumspect about admitting the PET and SPECT scans and fMRI evidence. With the latter technologies, courts have often expressed reservations about what can be inferred from the images. Moreover, courts seem unwilling to find neuroimaging sufficient to prove either insanity or incompetency, but are relatively lenient about admitting neuroimages in death penalty hearings. Some claim that fMRI and "brain fingerprinting" are able to detect deception. Other scholars argue that brain fingerprinting is a dubious concept and that fMRI is not yet sufficiently reliable. Moreover, there are substantial concerns about privacy and the perils of mind reading implicit in such technology. Yet, there is a movement to try to make these new technologies "courtroom ready" in the near future, raising a host of legal, policy, and ethical questions to be answered. Copyright 2008 John Wiley & Sons, Ltd. [source]


BIOETHICS, Issue 6 2009
ABSTRACT According to many researchers, it is inevitable and obvious that psychiatric illnesses are biological in nature, and that this is the rationale behind the numerous neuroimaging studies of individuals diagnosed with mental disorders. Scholars looking at the history of psychiatry have pointed out that in the past, the origins and motivations behind the search for biological causes, correlates, and cures for mental disorders are thoroughly social and historically rooted, particularly when the diagnostic category in question is the subject of controversy within psychiatry. This is obscured by neuroimaging studies that drive researchers to proclaim ,revolutions' in psychiatry, namely in the DSM. Providing neuroimaging evidence to support the contention that a condition is ,real' is likely to be extremely influential, as has been extensively discussed in the neuroethics literature. This type of evidence will also reinforce the pre-existing beliefs of those researchers or clinicians who are already expecting a biological description. The uncritical credence given to neuroimaging research is an ethical issue, not in its potential for contributing to misdiagnosis per se but because of the motivations that often drive this research. My claim is that this research should proceed with an awareness of presumptions and motivations underlying the field as a whole, in addition to an explicit focus on the past and potential future consequences of classification and diagnosis on the groups of individuals under study. [source]

The neuropsychology and neuroanatomy of bipolar affective disorder: a critical review

Carrie E Bearden
Objectives: To present a comprehensive review of the existing neuropsychological and neuroimaging literature on bipolar affective disorder. This review critically evaluates two common conceptions regarding the neuropsychology of bipolar disorder: 1) that, in contrast to schizophrenia, bipolar affective disorder is not associated with general cognitive impairment independent of illness episodes, and 2) relative right hemisphere (RH) dysfunction is implicated in bipolar illness patients, supported by reports of relatively greater impairment in visuospatial functioning, lateralization abnormalities, and mania secondary to RH lesions. Methods: The major computerized databases (Medline and PSYCInfo) were consulted in order to conduct a comprehensive, integrated review of the literature on the neuropsychology and neuroanatomy of bipolar disorder. Articles meeting specified criteria were included in this review. Results: In a critical evaluation of the above notions, this paper determines that: 1) while there is little evidence for selective RH dysfunction, significant cognitive impairment may be present in bipolar illness, particularly in a subgroup of chronic, elderly or multiple-episode patients, suggesting a possible toxic disease process, and 2) the underlying functional correlate of these cognitive deficits may be white matter lesions (,signal hyperintensities') in the frontal lobes and basal ganglia, regions critical for executive function, attention, speeded information processing, learning and memory, and affect regulation. While this hypothesized neural correlate of cognitive impairment in bipolar disorder is speculative, preliminary functional neuroimaging evidence supports the notion of frontal and subcortical hypometabolism in bipolar illness. Conclusions: The etiology of the structural brain abnormalities commonly seen in bipolar illness, and their corresponding functional deficits, remains unknown. It is possible that neurodevelopmental anomalies may play a role, and it remains to be determined whether there is also some pathophysiological progression that occurs with repeated illness episodes. More research is needed on first-episode patients, relatives of bipolar probands, and within prospective longitudinal paradigms in order to isolate disease-specific impairments and genetic markers of neurocognitive function in bipolar disorder. [source]

Progressive stroke in pontine infarction

V. Saia
Objective,,, The pathogenesis of isolated pontine infarctions is still unclear, being attributed both to small or large vessel disease. The extension of infarcted tissue to the pons surface has been indicated as a possible marker of basilar branch atheromatous disease and some neuroimaging evidence confirms this finding. Methods,,, On the basis of Kim's et al., study, we performed a revision of the literature addressing this topic. Results,,, Several authors confirm an association between basilar artery branch disease and isolated pontine infarction; moreover, the enlargement of pontine lesion seems to be associated with neurological worsening. We therefore performed a brief analysis of possible mechanisms of progression. Conclusions,,, Prospective studies could be useful to evaluate predictors of neurological worsening in pontine stroke. Improvement of neuroimaging techniques is needed for a deeper comprehension of the etiopathogenesis of isolated pontine infarction. [source]

Prognostic factors in the surgical treatment of medically intractable epilepsy associated with mesial temporal sclerosis

M. J. Hennessy
Objectives, To assess the prognostic factors determining seizure remission after temporal lobectomy for intractable epilepsy associated with mesial temporal sclerosis (MTS) at pathology. Methods, The clinical and investigative features of 116 consecutive patients who had temporal lobe surgery for drug-resistant epilepsy and MTS at pathology were assessed using actuarial statistics and logistic regression analysis. Results, At a median follow-up of 63 months the probability of achieving at least a 1-year period of continuous seizure freedom was 67%. Factors contributing to a favourable outcome were interictal EEG localization to the operated lobe and the absence of secondarily generalized seizures. These were also selected in the multivariate analysis, although at lower statistical significance (P=0.08 and 0.09, respectively). Perinatal complications were associated with a significantly worse outcome but overall, complicated febrile convulsions and congruent neuropsychological deficits were not significantly predictive variables. Conclusions, The present findings may aid in the non-invasive presurgical assessment of patients with intractable TLE and clinical and neuroimaging evidence of MTS. [source]