Low-dimensional chaos maps learning in a model neuropil (olfactory bulb)

Quantification of a chaotic system can be made by calculating the correlation dimension (D2) of the data that the system generates (Packard et al., 1980). The D2 algorithm, however, requires stationarity of the generator, a feature that biological data rarely reflect (Mayer-Kress et al., 1988). So we developed the “point correlation dimension” (PD2), an algorithm that accurately tracks D2 in linked data of different dimensions (Carpeggiani et al., 1991). We now present a mathematical argument that, for stationary data, individual PD2s converge to D2 and we demonstrate that the algorithm rejects contributions made by bursts of noise. Data were obtained from the surface of the olfactory bulb of the conscious rabbit (64 electrodes, 640 Hz each, 1.3 sec epochs) before and after presentation of a novel or habituated odor. D2 could be calculated in only 1 of 10 novel-odor trials, whereas PD2 could be calculated in all. Both algorithms indicated that a novel odor evokes a spatially uniform dimensional increase. The PD2 uniquely exhibited the dimensional decreases that occur during inspiration and the gradients of mean dimension present during the nonstimulated control state. These control gradients remained unchanged without odor experience, but showed spatially specific PD2 increases following odor habituation. It is interpreted that, 1) the PD2 issensitive, accurate, and appropriate for dimensional assessment of biological data, 2) that during analysis of unfamiliar information a singleglobal process is transiently evoked in the neuropil, and 3) after experience multiplespatially specific processes tonically map the sites of learning. Grant Support: National Institutes of Health, HL 31164 and NS27745     

Subliminal processes,dissociation and the 'I'

The study of unconscious processes leads to the hypothesis of the limit of consciousness, which involves two main kinds of psychic activity. The first represents psychic contents which are subliminal for their low energy, the second subliminal contents which are inaccessible to consciousness because they are dissociated in the subliminal region. Dissociation is a concept introduced by Pierre Janet for splitting consciousness due to traumatic events or during hypnosis. It takes a more general form in Hilgard's neo-dissociation theory of hypnotic phenomena and also in Jung's theory of the collective unconscious. Further generalization links it to the modern findings of explicit and implicit perception, leading to a shift in dissociation from hypothesis to clinical, experimental and theoretical reality. Studies in hypnosis also point to the existence of an integrative psychic entity, that comprises the conscious 'I'. Hilgard called this the hidden observer, and his findings represent empirical confirmation of Jung's term for the Self as mirror 'I', which leads to many important consequences for self-discovery and the meaning of life.     

A Note on (K)Nots: Response to Robert W. Kentridge''s Commentary

GY, an extensively studied human hemianope, is aware of salient visual events in his cortically blind field but does not call this "vision." To learn whether he has low-level conscious visual sensations or whether instead he has gained conscious knowledge about, or access to, visual information that does not produce a conscious phenomenal sensation, we attempted to image process a stimulus s presented to the impaired field so that when the transformed stimulus T(s) was presented to the normal hemifield it would cause a sensation similar to that caused by s in the impaired field. While degradation of contrast, spatio-temporal filtering, contrast reversal, and addition of smear and random blobs all failed to match the response to a flashed bar s(f), moving textures of low contrast were accepted to match the response to a moving contrast-defined bar, s(m). Orientation and motion direction discrimination of the perceptually matched stimuli [s(m) and T(s(m))] was closely similar. We suggest that the existence of a satisfactory match indicates that GY has phenomenal vision.     

Enactive or inactive? Cranially envatted dream experience and the extended conscious mind

When we dream, it is often assumed, we are isolated from the external environment. It is also commonly believed that dreams can be, at times, accurate, convincing replicas of waking experience. Here I analyse some of the implications of this view for an enactive theory of conscious experience. If dreams are, as described by the received view, “inactive”, or “cranially envatted” whilst replicating the experience of being awake, this would be problematic for certain extended conscious mind theories. Focusing specifically on Alva Noë’s enactive view, according to which the vehicles of perceptual experience extend beyond the brain, I argue that dreams are a quandary. Noë’s view is that dreaming is consistent with enactivism because even if dreams are inactive and shut off from the external environment, they are not “full-blown” perceptual consciousness, and also, there is some reason to reject the inactive claim. However, this view rests on an unjustified and reductive account of dreams which is not supported by empirical evidence. Dreams can indeed replicate waking phenomenal experience during inactive periods of sleep, and we have no reason to suspect that dreams which are more inactive are less “full-blown”. Taken together, this shows that dreams are indeed relevant to extended conscious mind theories and need to be taken into account by enactivists.     

Occurrent states

The distinction between occurrent and non-occurrent mental states is frequently appealed to by contemporary philosophers, but it has never been explicated in any significant detail. In the literature, two accounts of the distinction are commonly presupposed (and occasionally stated explicitly). One is that occurrent states are conscious states. The other is that non-occurrent states are dispositional states, and thus that occurrent states are manifestations of dispositions. I argue that neither of these accounts is adequate, and therefore that another account is needed. I propose that occurrent states are active states.     

死亡心理:外部防御还是内在成长?

对西方主要的死亡心理研究进行了回顾和比较分析,不同的死亡心理研究在研究传统、研究对象和研究方法方面存在差异。但是根据研究的侧重点,可以总结出死亡心理的核心内涵:外部防御和内在成长。对死亡的抽象认知产生死亡焦虑,死亡焦虑产生死亡恐惧、自我保护、外在价值导向等外部防御反应;对死亡的具体认知产生死亡反省,死亡反省产生死亡接受、亲社会动机和行为、内在价值导向等内在成长反应。作者以死亡心理的两类反应为框架,综述了近5年来新的研究证据,并对该领域当前研究的局限和未来研究方向进行了分析。     

单独持续输注瑞芬太尼用于纤维支气管镜检术清醒镇静的临床探讨

观察单独输注瑞芬太尼用于支气管纤维镜检术的临床效果和安全性.120例患者随机分为瑞芬太尼单用组（A组）和瑞芬太尼、异丙酚联用组（B组）.记录不同时间点的血流动力学指标与脑电双频指数数值以及不良反应.B组患者诱导时间较A组明显缩短、呼吸抑制几率较高、T1~T4各时间点平均动脉压、心率和脑电双频指数较T0时均明显下降（P＜0.05）,而A组各指标则均无明显变化（P＞0.05）;两组操作满意度均较高（P＞0.05）.单独瑞芬太尼0.1μg/（kg min）持续输注用于支气管镜清醒插管,临床效果良好.     

FREE YOUR MIND: BUDDHISM,CAUSALITY, AND THE FREE WILL PROBLEM

The problem of free will is associated with a specific and significant kind of control over our actions, which is understood primarily in the sense that we have the freedom to do otherwise or the capacity for self-determination. Is Buddhism compatible with such a conception of free will? The aim of this article is to address three critical issues concerning the free will problem: (1) what role should accounts of physical and neurobiological processes play in discussions of free will? (2) Is a conception of mental autonomy grounded in practices of meditative cultivation compatible with the three cardinal Buddhist doctrines of momentariness, dependent arising, and no-self? (3) Are there enough resources in Buddhism, given its antisubstantialist metaphysics, to account for personal agency, self-control, and moral responsibility?