§ 7. Reproduction in Perceptual Process. — In purely perceptual process, the only forms of reproduction are (1) Acquirement of meaning, (2) Complication, and (3) The revival of general states of nervous excitement and their concomita?it organic sensations.

(1)    Acquirement of meaning is the most primary and essential. It is grounded in the very nature of perceptual process considered as appetitive activity. The whole process, in so far as it is one and continuous, leaves behind it a cumulative disposition. Hence, when it is repeated, it is modified as a whole from the outset.

(2)    Complication is a process for which there are probably special prearrangements in the original constitution of the nervous system. It consists in modification of the quality and increase of the complexity of certain sensations by association with other kinds of sensation in past experience. It mainly takes place between sensations belonging to different senses such as sight and touch. In looking at a hard object, our visual experience is different from that which we have in looking at a soft object, and the difference is due to the corresponding tactile experiences.

*Psychological Review, vol. v., No. 5, pp. 552553. I am greatly impressed by the coincidence between the conclusion which Mr. Thorndike draws from his experiments, and that which I had previously formed on more general grounds.

(3) The revival of general states of nervous excitement and their concomitant organic sensations is of especial importance in connexion with emotion. A dog which has been whipped will whine and display signs of fear and distress at the sight of the lash. The original pain-sensations produced a diffused nervous excitement, which gave rise to a general disturbance of organic functions, and to organic sensations. The sight of the whip revives an analogous nervous and bodily excitement and with it analogous experiences.