Keynote speakersFriday June 20, 9:00AM-10:00AM at Alexander Hall
The Johannes Gutenberg-Universitat
The Phenomenal Self and the First-Person Perspective
How can a conscious self emerge from the physical dynamics unfolding within an embodied brain? And how exactly is the appearance of such a conscious self related to the subjectivity of our target phenomenon – to the fact that it seems to be tied to individual first-person perspectives? Self-consciousness is not just another form phenomenal content, and the conscious experience of selfhood is not just one detail problem among many others. If we aim at a comprehensive theory of consciousness which is conceptually coherent and firmly grounded in empirical data, then the phenomenal self will have to be right at the center of our efforts. Why?
Many anti-reductionist arguments take the epistemical asymmetry between first-person and third-person access to consciousness as their starting point. Philosophically, I will argue that it is a mistake to accept the vague metaphor of a “first-person perspective” as a conceptual primitive, and offer a naturalistic successor concept. I will also show that, metaphysically, no such things as selves actually exist and briefly sketch a theory of the phenomenal self. In support of this claim I will also present new empirical data from an interdisciplinary project in which we try to experimentally generate whole-body illusions and artificial out-of-body experiences in a virtual reality setting. Empirically, I will propose a scientific research program for “minimal phenomenal selfhood”, i.e., a strategy that attempts to isolate the neurofunctional correlates of the simplest form of self-awareness.
(2003). Being No One. The Self-Model Theory of Subjectivity. Cambridge, MA: MIT Press.
(2007). Self Models. Scholarpedia, p. 24066 http://www.scholarpedia.org/article/Self_Models
(2008). Empirical perspectives from the self-model theory of subjectivity: A brief summary with examples. In Rahul Banerjee and Bikas K. Chakrabarti (eds.), Progress in Brain Research, 168: 215-246. Amsterdam: Elsevier.
Friday June 20, 4:30PM-5:30PM at Alexander Hall
Barrow Neurological Institute
Microsaccades: Windows on the Mind
Our visual system contains a built-in contradiction: when we fixate our gaze on an object of interest, our eyes are never still. Instead we produce, several times each second, small eye movements of which we are unaware, called "microsaccades", "drifts" and "tremor". If we eliminate all these eye movements in the laboratory, our visual perception of stationary objects fades, due to neural adaptation. When our eyes move across the image once again, visual perception reappears. Due to their role in counteracting adaptation, fixational eye movements are an important tool to understand how the brain makes our environment visible. Moreover, because we are not aware of these eye movements, they can also help us understand the underpinnings of visual awareness. For the last decade, my laboratory and others have recorded the neural activity generated by microsaccades –the largest and fastest fixational eye movement- at different stages of the visual pathway. This presentation will review these discoveries and their implications for visual awareness. I will also discuss the contribution of microsaccades to bistable perception, and the role of microsaccades as indicators of the spatial location of covert attention.
Saturday June 21, 9:00AM-10:00AM at Alexander Hall
Primate Research Institute
Comparative Cognitive Science: Trade-off Theory of Memory and Symbolization in Humans and Chimpanzees
The present study is an effort to know the evolutionary basis of human mind. Human mind does not remain in the fossils. To know the evolution of intelligence, emotion, and consciousness, we have to compare those of humans and other living organisms. Three mother-offspring pairs learned the sequence of Arabic numerals from 1 to 9, using a touch-screen monitor connected to a computer. A memory task was then introduced at around the time when the young became 5 years old. In this test, after touching the first numeral, all other numerals were replaced by white squares. In general, the performance of the three young chimpanzees was better than that of the three mothers and human adults: Young chimpanzees were good at memorizing details at a glance. A symbolic matching task was then introduced at around the time when the young became 6 years old. In this test, the subjects learned to match a Color (red, yellow, or green) to the corresponding two visual symbols (Kanji and Lexigram). All of the six possible combinations of Color, Kanji, and Lexigram were simultaneously introduced. The results showed that the establishment of the stimulus equivalence or the symmetry rule was difficult in chimpanzees. Our data can be interpreted according to a “trade-off hypothesis of memory and symbolization” from both developmental and evolutionary perspectives. Developmental trade-off would mean that young individuals can perform better in immediate memory tasks but may not be as able at other cognitive tasks such as those involving symbolic relationships. This may be due to the difference in the speed of myelinaization of neurons in each part of the brain. Evolutionary trade-off suggests that the common ancestor of humans and chimpanzees may have possessed an extraordinary memory capability. At a certain point in evolution, because of limitations on brain capacity, the human brain may have acquired new functions of symbolization in parallel with losing immediate memory.
Sunday June 22, 9:00AM-10:00AM at Alexander Hall
Advanced Telecommunications Research Institute International
Computational Advantages of Internal Models as Self-Consciousness
Internal models are neural networks that can simulate dynamic behaviors of some processes inside or outside of the brain. 10 years ago, I postulated that self-consciousness could be an internal model that roughly approximates dynamic behavior of the brain. An internal model is doomed to be approximate, superficial and erroneous, as recently demonstrated by many experiments. In this talk, I discuss computational advantages of internal models as self-consciousness. They could involve fast computation, long-term planning, generating internal rewards and intrinsic motivations.