From conscious experience to a conscious self

In his book The Opacity of Mind, Peter Carruthers (2011 Carruthers, P. (2011). The opacity of mind: An integrative theory of self-knowledge. Oxford: Oxford University Press.[Crossref] , [Google Scholar]) presents the Interpretive Sensory Awareness theory (“ISA”), which holds that while we have direct access to our own sensory states, our access to “self-knowledge” is almost always interpretive. In presenting his view, Carruthers also claims that his account is the first of its kind; after a cursory examination of major theories of mind, he concludes that “transparent access” accounts of self-knowledge—the alternative to ISA—have been endorsed throughout history. This paper challenges this latter claim. Contrary to Carruthers’ view, the paper argues that Buddhist theories of mind are not “transparent access” accounts. Instead, they not only have an analysis of sensory processing and conscious experience similar to that of ISA, but also share what Carruthers sees as ISA’s central tenet: individuals lack transparent, conscious access to most of their propositional attitudes. Given this fundamental alignment, the Buddhist perspective can offer us fresh responses to ISA’s critics, as well as approaches to ethics and free will that are aligned with ISA’s conclusions.     

The neural correlates of conscious experience: an experimental framework

Demonstrating that neural activity ‘represents’ physical properties of the world such as the orientation of a line in the receptive field of a nerve cell is a standard procedure in neuroscience. However, not all such neural activity will be associated with the mental representations that form the contents of consciousness. In some cases, such as when patients with blindsight correctly ‘guess’ the location of a stimulus, neural activity is associated with physical stimulation and with appropriate behaviour, but not with awareness. To identify the neural correlates of conscious experience we need to identify patterns of neural activity that are specifically associated with awareness. Experiments aimed at making such identifications require that subjects report some aspect of their conscious experience either verbally or through some pre-arranged non-verbal report while neural activity is measured. If there is some characteristic neural signature of consciousness, then this should be distinguishable from the kinds of neural activity associated with stimulation and/or behaviour in the absence of awareness. It remains to be seen whether the neural signature of consciousness relates to the location of the neural activity, the temporal properties of the neural activity or the form of the interaction between activity in different brain regions.     

Interval timing with gaps: gap ambiguity as an alternative to temporal decay

C. V. Buhusi, D. Perera, and W. H. Meck (2005) proposed a hypothesis of timing in rats to account for the results of experiments that have used the peak procedure with gaps. According to this hypothesis, the introduction of a gap causes the animal's memory for the pregap interval to passively decay (subjectively shorten) in direct proportion to the duration and salience of the gap. Thus, animals should pause with short, nonsalient gaps but should reset their clock with longer, salient gaps. The present authors suggest that the ambiguity of the gap (i.e., the similarity between the gap and the intertrial interval in both appearance and relative duration) causes the animal to actively reset the clock and prevents adequate assessments of the fate of timed intervals prior to the gap. Furthermore, when the intertrial interval is discriminable from the gap, the evidence suggests that timed intervals prior to the gap are not lost but are retained in memory.     

Accuracy of temporal coding: Auditory-visual comparisons

Three experiments were designed to decide whether temporal information is coded more accurately for intervals defined by auditory events or for those defined by visual events. In the first experiment, the irregular-list technique was used, in which a short list of items was presented, the items all separated by different interstimulus intervals. Following presentation, the subject was given three items from the list, in their correct serial order, and was asked to judge the relative interstimulus intervals. Performance was indistinguishable whether the items were presented auditorily or visually. In the second experiment, two unfilled intervals were defined by three nonverbal signals in either the auditory or the visual modality. After delays of 0, 9, or 18 sec (the latter two filled with distractor activity), the subjects were directed to make a verbal estimate of the length of one of the two intervals, which ranged from 1 to 4 sec and from 10 to 13 sec. Again, performance was not dependent on the modality of the time markers. The results of Experiment 3, which was procedurally similar to Experiment 2 but with filled rather than empty intervals, showed significant modality differences in one measure only. Within the range of intervals employed in the present study, our results provide, at best, only modest support for theories that predict more accurate temporal coding in memory for auditory, rather than visual, stimulus presentation.     

The illusion of conscious experience

Synthese - Illusionism about phenomenal consciousness is the thesis that phenomenal consciousness does not exist, even though it seems to exist. This thesis is widely judged to be uniquely...     

Acquaintance and the sublime: an alternative account of theistic sublime experience

In this paper I argue that when one has an epiphany of the form ‘God is F’ (e.g., ‘God is wise’) upon having a sublime experience one can be accurately described as being acquainted with the fact that God is F as opposed to inferring that God is F from the experience at hand. To argue for this, I will, first, outline what a sublime experience is, in general, before outlining what a theistic sublime experience is in particular. Second, I will outline two ways of understanding theistic sublime experiences. First, I will outline a model that I will call the ‘inference model’ which, put simply, says that when one has an epiphany of the form ‘God is F’, upon having a theistic sublime experience, one is drawing this conclusion via a process of ‘inference-to-the-best-explanation’ (Chignell and Halteman in: Costelloe (ed) The sublime: From antiquity to the present, Cambridge University Press, Cambridge, 2012, p. 426). Second, I will outline an alternative model that I call the ‘acquaintance model’ which, put simply, says that no inferential process occurs when one has an epiphany of the form ‘God is F’ upon having a theistic sublime experience, but one is made directly aware of the fact that God is F. Third, and finally, I will respond to some objections to the acquaintance model.     

Intentional action: conscious experience and neural prediction

Intentional action involves both a series of neural events in the motor areas of the brain, and also a distinctive conscious experience that "I" am the author of the action. This paper investigates some possible ways in which these neural and phenomenal events may be related. Recent models of motor prediction are relevant to the conscious experience of action as well as to its neural control. Such models depend critically on matching the actual consequences of a movement against its internally predicted effects. However, it remains unclear whether our conscious experience of action depends on a precise matching process, or a retrospective inference that "I" must have been responsible for a particular event. We report an experiment in which normal subjects judged the perceived time of either intentional actions, involuntary movements, or subsequent effects (auditory tones) of these. We found that the subject's intention to produce the auditory tone produced an intentional binding between the perceived times of the subject's action and the tone. However, if the intention was interrupted by an imposed involuntary movement, followed by the identical tone, no such binding occurred. The phenomenology of intentional action requires an appropriate predictive link between intentions and effects, rather than a retrospective inference that "I" caused the effect.     

Art and architecture as experience: an alternative approach to bridging art history and the neurosciences

In 1972, Michael Baxandal characterizes the processes responsible for the cultural relativism of art experience as highly complex and unknown in their physiological detail. While art history still shows considerable interest in the brain sciences forty years later, most cross-disciplinary studies today are referring to the neurosciences in an attempt to seek scientific legitimization of variations of a generalized and largely deterministic model of perception, reducing interaction between a work of art and its observers to a set of biological automatisms. I will challenge such an approach and take up art theory's interest in the historico-cultural and situational dimensions of art experience. Looking at two examples of large-scale installation and sculptural post-war American art, I will explore instable perceptions of depth and changing experiences of space that indicate complex interactions between perceptual and higher cognitive processes. The argument will draw on recent theories describing neuronal processes underlying multistable phenomena, eye movement, visual attention and decision-making. As I will show a large number of neuroscientific studies provide theoretical models that help us analyse not the anthropological constants but the influence of cultural, individual and situational variables on aesthetic experience.     

Color coding information: assessing alternative coding systems using independent brightness and hue dimensions

Can independent dimensions of brightness and hue be used in a combined digital information code? This issue was addressed by developing 2 color-coding systems and testing them on informed and naive participants in signal beam detection and classification experiments for simulated sonar displays. Each coding system's results showed both groups efficiently used encoded information that varied simultaneously along the 2 dimensions of brightness and hue. Findings support the proposed procedures for developing color information codes and the validity of such information codes across different populations. Applied significance of these results is provided by the test of principled methods of color-code construction and the demonstration that extending the information content of user interfaces beyond 1 dimension is feasible in practice.     

Effects of item concreteness on temporal coding

Recently several authors have suggested that coding of serial position in a word list is an automatic process. This contention is questioned in the present paper: two experiments explore the concrete-abstract distinction and show that temporal order retention is higher with concrete than with abstract lists. An alternative view that temporal coding is influenced by either selective attention and/or the selective strategies used by the subjects to meet the requirements set by the memory task is put forward.     

Problems in the timing of conscious experience

Libet's (2000) arguments in defense of his interpretation of his experimental results are insufficient. The claims of my critical review (Gomes, 1998) do not suffer with his new statements.     

The mind's best trick: how we experience conscious will

We often consciously will our own actions. This experience is so profound that it tempts us to believe that our actions are caused by consciousness. It could also be a trick, however - the mind's way of estimating its own apparent authorship by drawing causal inferences about relationships between thoughts and actions. Cognitive, social, and neuropsychological studies of apparent mental causation suggest that experiences of conscious will frequently depart from actual causal processes and so might not reflect direct perceptions of conscious thought causing action.     

Anterior medial temporal lobe activation during encoding of words: FMRI methods to optimize sensitivity

The existence of a rostrocaudal gradient of medial temporal lobe (MTL) activation during memory encoding has historically received support from positron emission tomography studies, but less so from functional MRI (FMRI) studies. More recently, FMRI studies have demonstrated that characteristics of the stimuli can affect the location of activation seen in the MTL when those stimuli are encoded. The current study tested the hypothesis that MTL activation during memory encoding is related to the modality of stimulus presentation. Subjects encoded auditorily or visually presented words in an FMRI novelty paradigm. Imaging and analysis parameters were optimized to minimize susceptibility artifact in the anterior MTL. Greater activation was observed in the anterior than posterior MTL for both modalities of stimulus presentation. The results indicate that anterior MTL activation occurred during encoding, independent of stimulus modality and provide support for the hypothesis that verbal-semantic memory processing occurs in anterior MTL. The authors suggest that technical factors are critical for observing the rostrocaudal gradient in MTL memory activation.     

The thalamic dynamic core theory of conscious experience

I propose that primary conscious awareness arises from synchronized activity in dendrites of neurons in dorsal thalamic nuclei, mediated particularly by inhibitory interactions with thalamic reticular neurons. In support, I offer four evidential pillars: (1) consciousness is restricted to the results of cortical computations; (2) thalamus is the common locus of action of brain injury in vegetative state and of general anesthetics; (3) the anatomy and physiology of the thalamus imply a central role in consciousness; (4) neural synchronization is a neural correlate of consciousness.