Logical Self-Reference as a Model for Conscious Experience

The structure of autoreferential statements that describe (or serve as a logical model for) the human conscious experience is analyzed. Autoreferential statements are introduced by autoreferential definitions, such as a=F(a, x), where F is a Boolean function and x is some atomic statement describing the content of the experience, or by analogous systems of inter-related definitions, such as a=F(b, x, y) and b=G(a, x, z). It is argued that only "noncreative" (systems of) definitions introduce statements that describe conscious experience, the noncreativeness meaning that no statement with non-tautological content can be derived from these definitions. The structure of such (systems of) definitions is comprehensively characterized in a series of theorems. A potential of the model in addressing empirical data is illustrated by applying it to the choice between two alternatives in the absence of a preference criterion. Copyright 2001 Academic Press.     

Computational Theories of Conscious Experience: Between a Rock and a Hard Place

Very plausibly, nothing can be a genuine computing system unless it meets an input-sensitivity requirement. Otherwise all sorts of objects, such as rocks or pails of water, can count as performing computations, even such as might suffice for mentality—thus threatening computationalism about the mind with panpsychism. Maudlin in J Philos 86:407–432, (1989) and Bishop (2002a, b) have argued, however, that such a requirement creates difficulties for computationalism about conscious experience, putting it in conflict with the very intuitive thesis that conscious experience supervenes on physical activity. Klein in Synthese 165:141–153, (2008) proposes a way for computationalists about experience to avoid panpsychism while still respecting the supervenience of experience on activity. I argue that his attempt to save computational theories of experience from Maudlin’s and Bishop’s critique fails.     

Conscious, preconscious, and subliminal processing: a testable taxonomy

Of the many brain events evoked by a visual stimulus, which are specifically associated with conscious perception, and which merely reflect non-conscious processing? Several recent neuroimaging studies have contrasted conscious and non-conscious visual processing, but their results appear inconsistent. Some support a correlation of conscious perception with early occipital events, others with late parieto-frontal activity. Here we attempt to make sense of these dissenting results. On the basis of the global neuronal workspace hypothesis, we propose a taxonomy that distinguishes between vigilance and access to conscious report, as well as between subliminal, preconscious and conscious processing. We suggest that these distinctions map onto different neural mechanisms, and that conscious perception is systematically associated with surges of parieto-frontal activity causing top-down amplification.     

The Timing of Conscious Experience: A Critical Review and Reinterpretation of Libet''s Research

An extended examination of Libet's works led to a comprehensive reinterpretation of his results. According to this reinterpretation, the Minimum Train Duration of electrical brain stimulation should be considered as the time needed to create a brain stimulus efficient for producing conscious sensation and not as a basis for inferring the latency for conscious sensation of peripheral origin. Latency for conscious sensation with brain stimulation may occurafterthe Minimum Train Duration. Backward masking with cortical stimuli suggests a 125–300 ms minimum value for the latency for conscious sensation of threshold skin stimuli. Backward enhancement is not suitable for inferring this latency. For determining temporal relations between stimuli that correspond to subjects' reports, theendof cerebral Minimum Train Duration should be used as reference, rather than its onset. Results of coupling peripheral and cortical stimuli are explained by a latency after the cortical Minimum Train Duration, having roughly the same duration as the latency for supraliminal skin stimuli. Results of coupling peripheral stimuli and stimuli to medial lemniscus (LM) are explained by a shorter LM latency and/or a longer peripheral latency. This interpretation suggests a 230 ms minimum value for the latency for conscious sensation of somatosensory near-threshold stimuli. The backward referral hypothesis, as formulated by Libet, should not be retained. Long readiness potentials preceding spontaneous conscious or nonconscious movements suggest that both kinds of movement are nonconsciously initiated. The validity of Libet's measures of W and M moments (Libet et al., 1983a) is questionable due to problems involving latencies, training, and introspective distinction of W and M. Veto of intended actions may be initially nonconscious but dependent on conscious awareness.     

Conscious machines: Memory,melody and muscular imagination

A great deal of effort has been, and continues to be, devoted to developing consciousness artificially (A small selection of the many authors writing in this area includes: Cotterill (J Conscious Stud 2:290–311, 1995, 1998), Haikonen (2003), Aleksander and Dunmall (J Conscious Stud 10:7–18, 2003), Sloman (2004, 2005), Aleksander (2005), Holland and Knight (2006), and Chella and Manzotti (2007)), and yet a similar amount of effort has gone in to demonstrating the infeasibility of the whole enterprise (Most notably: Dreyfus (1972/1979, 1992, 1998), Searle (1980), Harnad (J Conscious Stud 10:67–75, 2003), and Sternberg (2007), but there are a great many others). My concern in this paper is to steer some navigable channel between the two positions, laying out the necessary pre-conditions for consciousness in an artificial system, and concentrating on what needs to hold for the system to perform as a human being or other phenomenally conscious agent in an intersubjectively-demanding social and moral environment. By adopting a thick notion of embodiment—one that is bound up with the concepts of the lived body and autopoiesis (Maturana and Varela 1980; Varela et al. 2003; and Ziemke 2003, 2007a, J Conscious Stud 14(7):167–179, 2007b)—I will argue that machine phenomenology is only possible within an embodied distributed system that possesses a richly affective musculature and a nervous system such that it can, through action and repetition, develop its tactile-kinaesthetic memory, individual kinaesthetic melodies pertaining to habitual practices, and an anticipatory enactive kinaesthetic imagination. Without these capacities the system would remain unconscious, unaware of itself embodied within a world. Finally, and following on from Damasio’s (1991, 1994, 1999, 2003) claims for the necessity of pre-reflective conscious, emotional, bodily responses for the development of an organism’s core and extended consciousness, I will argue that without these capacities any agent would be incapable of developing the sorts of somatic markers or saliency tags that enable affective reactions, and which are indispensable for effective decision-making and subsequent survival. My position, as presented here, remains agnostic about whether or not the creation of artificial consciousness is an attainable goal.     

社会印象:意识,还是无意识控制

通过两个实验分别考察了在自然判断和社会判断条件下社会印象受意识控制情况的不同特点.实验-采用2×2×2×2的混合设计,给被试提供不同声望、不同性别的人名(组内设计),考察了在再认判断和频度判断条件下(组内设计)被试性别特征(组间设计)对社会记忆的影响;实验二采用2×2×2×2的混合设计,给被试呈现不同性别的人名(组内设计),考察了新、旧人名(呈现与否,组内设计)在声望判断和影响力判断条件下(组内设计),被试性别特征(组间设计)对社会印象影响;同时,还探讨了信号检测论(SDT)方法对测量内隐社会印象的有效性.结果表明,在自然判断的任务条件下,被试的记忆出现了"名人优势效应";在社会判断的任务条件下,被试的辨别力非参数指标A'没有表现出显著的差异,而其判断标准B则在被试性别、判断类型上表现出了差异.     

逻辑论证与主体体验:中西哲学 "形上本体"之比较

哲学从某种意义上就是关于“形上本体”之学。哲学如海德格尔所言,总是表达着人的某种天性,也可以把这种天性叫“形而上学”。哲学关注于“形上之在”(人),凭借着“形上之思”(与计算性思维)相区别,构建着“形而上学”,表达着“形上之追求”。可以说,康德的观点是正确的,即形而     

Explaining 'The Hardness of the Logical Must': Wittgenstein on Grammar, Arbitrariness and Logical Necessity

This paper explains (in Part A) Wittegnstein's understanding of the 'grammar' of our (or any) language, tracing its origins in the Tractatus's concept of logical syntax, and then examining the senses in which Wittegnstein, in his later work, viewed grammar as being 'arbitrary'. Then, armed with this understanding, it moves on (in Part B) to the task of examining how, within the framework of a Wittegnsteinian view of language, we should understand the inescapable 'compellingness' of logical necessity – what Wittegnstein calls the "hardness of the logical must". Whereas it is often thought that Wittegnstein's views on the nature of the 'grammar' of our concpets leads him towards a vitiatingly conventionalist or anti-realist understanding of necessity, in which its logical 'superhardness' becomes problematic, this paper will argue that there is actually no such tension in Wittegnstein's thought. In fact, it will be argued, an understanding of the ways in which our conceptual grammar is arbitrary casts a great deal of light on how it is that our concepts can nevertheless support a logically superhard, and normatively commanding, notion of necessity. In support of this view, I distinguish Wittegnstein's views on necessity from the 'classical' conventionalism of the Vienna Circle, and from the radical conventionalism of Michael Dummett, and defend Wittegnstein's view from a powerful recent attack from Quassim Cassam.