Online research in philosophy

In "Consciousness Explained," Dennett (1991) denies that split-brain humans have double consciousness: he describes the experiments as "anecdotal." In attempting to replace the Cartesian Theatre of the Mind" with his own "Multiple Drafts" view of consciousness, Dennett rejects the notion of the mind as a countable thing in favour of its being a mere "abstraction." His criticisms of the standard interpretation of the split-brain data are analyzed here and each is found to be open to objections. There exist people who have survived left ["dominant"] cerebral hemispherectomy; by Dennett's criteria, they would not have minds.

The issue of hemispheric processing of art works, either alone or in relation to a certain aspect of language, was investigated in normal subjects. Three experiments were performed. In the first, memory for surrealistic versus realistic pictures was investigated. In the second, memory for metaphoric versus literal titles of these pictures was measured. In the third, memory for the paintings was determined as a function of the same titles. The results of the first experiment showed a right visual field (RVF) advantage for the surrealistic pictures. No field difference emerged for the realistic pictures. The results of the second experiment indicated a RVF advantage in memory for metaphoric titles. Moreover, in the RVF, there was an advantage for titles from surrealistic-metaphoric pairs over all other pairings. Results of experiment three showed a RVF advantage in remembering pictures from surrealistic-metaphoric pairs and in the left visual field (LVF) there was advantage for pictures with literal titles. Taken together, the results suggest left hemisphere advantage in processing meaningful, yet incongruous arrays, both pictorial and linguistic. The results are discussed in terms of hemispheric memory for art works, metaphors, and the relationship between the two in the brain.

INTRODUCTION Beyond Dissociations Reassembling the mind-brain after all? Yves Rossetti Antti Revonsuo "Comme des banes de poissons de meme espece, ...

Gamma rhythms are associated with external and internal sensory processing. Within the conceptual framework of “top-down” and “bottom-up” processing, this suggests that gamma represents a format common to both camps. As these oscillations facilitate communication in the temporal domain, they may represent a mechanism by which top-down and bottom-up processing can interact. A breakdown in this interaction may lead to hallucinations.

Despite considerable evidence that neural activity in monkeys reflects various aspects of face perception, relatively little is known about monkeys’ face processing abilities. Two characteristics of face processing observed in humans are a subordinate-level entry point, here, the default recognition of faces at the subordinate, rather than basic, level of categorization, and holistic effects, i.e. perception of facial displays as an integrated whole. The present study used an adaptation paradigm to test whether untrained rhesus macaques (Macaca mulatta) display these hallmarks of face processing. In experiments 1 and 2, macaques showed greater rebound from adaptation to conspecific faces than to other animals at the individual or subordinate level. In experiment 3, exchanging only the bottom half of a monkey face produced greater rebound in aligned than in misaligned composites, indicating that for normal, aligned faces, the new bottom half may have influenced the perception of the whole face. Scan path analysis supported this assertion: during rebound, fixation to the unchanged eye region was renewed, but only for aligned stimuli. These experiments show that macaques naturally display the distinguishing characteristics of face processing seen in humans and provide the first clear demonstration that holistic information guides scan paths for conspecific faces.

According to conventional wisdom, the split-brain syndrome puts paid to the thesis that consciousness is necessarily unified. The aim of this paper is to challenge that view. I argue both that disunity models of the split-brain are highly problematic, and that there is much to recommend a model of the split-brain—the switch model—according to which split-brain patients retain a fully unified consciousness at all times. Although the task of examining the unity of consciousness through the lens of the split-brain syndrome is not a new one—such projects date back to Nagel’s seminal paper on the topic—the time is ripe for a re-evaluation of the issues.