Thomas Nagel, in ‘Brain bisection and the unity of consciousness’ suggests that if persons are to be explained in terms of minds or consciousness, this might seem to cast doubt on the coherence of the concept of a person. In this sense, the brain bisection data + the psychological theory of personal identity might seem to lead to skepticism about persons.
1 Structure and Function
The brain has two cerebral hemispheres, which are connected via the corpus callosum, which can be thought of as an information pathway between the two hemispheres. The two hemispheres are connected differently to the rest of the body. In particular.
•Images on the left half of the retina (so from the right side of the visual field) only go to the left hemisphere, …show more content…
Sometimes their verbal reports seem to be mistaken interpretations of their facial/emotional responses — as when the man in the example above says, ‘Thats quite a machine that you’ve got there.’
2 Five interpretations of the data
As Nagel points out, there seem to be several different interpretations of the data. He distinguishes the following :
1.The patients have one mind associated with the left hemisphere; the responses associated with the right hemisphere are not the activities of a mind at all.
2.The patients have one mind associated with the left hemisphere but there also occurs isolated conscious mental phenomena by the right hemisphere which is not integrated into a mind at all.
3.The patients have two minds (one associated with each hemisphere), one of which can talk and one of which cannot.
4.The patients have one mind, involving both hemispheres, which is not as well integrated as normal …show more content…
(1 and 2) faces the problem that, if the patient’s left hemisphere were to stop functioning altogether, leaving the patient only able to perform the functions that are associated with the right hemisphere, we would not deny that he has a mind, or is conscious. (3) faces the problem that the two hemispheres are so well integrated in every day life. (4) faces the difficulty of making sense of the experimental data, which seem to to indicate that, if there is only mind present, that mind can simultaneously attend to two different tasks, which makes it hard to see what it could be like to be that mind; and such minds seem to violate our usual assumptions about the unity of consciousness, since it looks like there are two independent ‘streams of consciousness.’ (5) is independently implausible, since no changes in the physiology of the patient are introduced in the
1 Structure and Function
The brain has two cerebral hemispheres, which are connected via the corpus callosum, which can be thought of as an information pathway between the two hemispheres. The two hemispheres are connected differently to the rest of the body. In particular.
•Images on the left half of the retina (so from the right side of the visual field) only go to the left hemisphere, …show more content…
Sometimes their verbal reports seem to be mistaken interpretations of their facial/emotional responses — as when the man in the example above says, ‘Thats quite a machine that you’ve got there.’
2 Five interpretations of the data
As Nagel points out, there seem to be several different interpretations of the data. He distinguishes the following :
1.The patients have one mind associated with the left hemisphere; the responses associated with the right hemisphere are not the activities of a mind at all.
2.The patients have one mind associated with the left hemisphere but there also occurs isolated conscious mental phenomena by the right hemisphere which is not integrated into a mind at all.
3.The patients have two minds (one associated with each hemisphere), one of which can talk and one of which cannot.
4.The patients have one mind, involving both hemispheres, which is not as well integrated as normal …show more content…
(1 and 2) faces the problem that, if the patient’s left hemisphere were to stop functioning altogether, leaving the patient only able to perform the functions that are associated with the right hemisphere, we would not deny that he has a mind, or is conscious. (3) faces the problem that the two hemispheres are so well integrated in every day life. (4) faces the difficulty of making sense of the experimental data, which seem to to indicate that, if there is only mind present, that mind can simultaneously attend to two different tasks, which makes it hard to see what it could be like to be that mind; and such minds seem to violate our usual assumptions about the unity of consciousness, since it looks like there are two independent ‘streams of consciousness.’ (5) is independently implausible, since no changes in the physiology of the patient are introduced in the