2011年6月26日星期日

Could Raichle's default mode state be Freud's ego?

Robin Carhart-Harris and Karl Friston of Rosetta stone software
Imperial College London explored that question in a recent article in Brain,[ii] where they proposed that the Freudian ideas of primary and secondary cognitive processes (corresponding to the id and the ego, respectively) fit comfortably with modern notions of functional brain architecture, at both a computational and neurophysiological level. Acknowledging the ambitious nature of that thesis, the authors reviewed a large body of evidence to support it. Freud's theory that ego represses id is consistent, they argued, both with the default mode's characteristic ebb and flow of neuronal activity in opposition to neuronal firing in other brain areas and with theories about the hierarchy of brain systems (e.g., the cortical thinking brain is higher-order and therefore regulates the subcortical primitive brain).The Disordered SelfClues about the neurobiological underpinnings of self can also be seen in psychopathology. There are a whole range of disorders in which self-identity is affected, in the sense of 'who am I?' and 'how am I distinguished from those around me and things occurring around me?, says Coyle.The delusions of schizophrenia, for example, have been described as a loss of ego boundaries. Patients may interpret neutral events as being self-referential or may be unable to distinguish what's happening in here from out there, as in the case of Rosetta Stone Indian Levev 1-3
auditory hallucinations. These disruptions are thought to be linked to structural changes seen in the brains of people with schizophrenia, including smaller cortical neurons that have fewer connections than normal.[iii]In frontotemporal dementia (FTD), a key feature is loss of self-awareness or self-identity, sometimes to the point of a complete shift in personality.[iv] Imaging studies have revealed severe abnormalities in frontal regions among FTD patients with the most dramatic changes, further supporting the frontal lobe's role in mediating self.[v]Narcissistic Personality Disorder is characterized by grandiose self-importance and such extreme preoccupation with self that you lose the capacity to see things through other people's eyes, says Oldham. In contrast, people with Borderline Personality Disorder characteristically lack a strong sense of identity and sometimes get intrusively close to other people, as if they're putting on the costume of somebody else's personality, he says. In autism, the representation of self may appear to be wholly absent or greatly exaggerated, to the extent that others are under-recognized.[vi]The manic Rosetta Stone Greek Levev 1-3
phase of bipolar disorder is often marked by grandiosity, which represents the extreme of what we would call egocentricity, a logarithmic multiplication of extreme narcissism. says Oldham. Depression, conversely, often goes hand in hand with extremely low self-esteem.All personality traits exist on a continuum, Oldham points out, with extremes at either end that sometimes cross the line into psychopathological behavior. The key determinants of whether that line has been crossed are the degree of disruption on interpersonal relations and daily activities. Who goes over the line and who doesn't involves a complex interplay of genetic factors -- comprising up to 50 percent of the risk -- and environmental triggers, mostly related to stress. Beyond that, there are many more questions than answers.We're just beginning to understand this, says Kagan. There are no firm facts yet. We have some hints, but at this point everything is up for grabs.

0 评论:

发表评论

Twitter Delicious Facebook Digg Stumbleupon Favorites More