Outlines of physiological psychology : A text-book of mental science for academies and colleges / by George Trumbull Ladd.

  • George Trumbull Ladd
Date:
1891 [©1890]
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of physiological psychology : A text-book of mental science for academies and colleges / by George Trumbull Ladd. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    that the end-organs of pressure, temperature, and ppinful sensation, are not the same (see p. 237 f.). It is probable also that impulses resulting in pain travel by more or less dis- tinct paths in the spinal cord (see p. 71 f.). In certain cases of disease the sensibility of the skin to pain is lost, while its sensibility to touch is not weakened. The reverse con- dition also sometimes occurs. In some diseased conditions a difference of as much as one or two seconds occurs in the time at which the sensations of contact and the feelings of pain (caused—for example — by the prick of a needle) arise in the mind. The ]3ainful feeling of being blinded, when the stimulus of light is too intense, seems to arise from simultaneous irritation of the trigeminus, rather than from the same irritation of the optic nerve which results in sensations of light. The tendency of recent evidence seems to be, then, toward a somewhat complete separation of the nervous mechanism, whose excitement produces feelings of sen- suous pain or pleasure, from that whose excitement results in the production of the sensations themselves. This evi- dence favors, so far as physiological theory can, the view of those psychologists who regard feeling as a primitive and underived form of conscious life. As to the peculiar nature of the physiological action — whether in the end-organs, the nerve-tracts, or the nerve- centres— which results in conscious states of feeling, we have no information. Indeed, the facts just referred to are very difficult to reconcile with the rule which certainly covers a large number of cases, — namely, that increased intensity of stimulus, beyond a certain point, results in the production of painful sensations. This rule itself is un- doubtedly due to inter-cerebral relations whose physical and physiological description science cannot give at present. Classification of the Feelings. — It may be doubted whether the feelings, as such and strictly spealcing, admit of classi-