The Delay Hypothesis: The Manifestation of Media ..
ARTICLE The Delay Hypothesis: The Manifestation of Media ..
The present findings also demonstrate how research with human and non-human animals can be mutually informative and, as such, are consistent with the view that species comparisons can increase our understanding of human decision making (Hackenberg, ; Shettleworth, ). Although the results of Experiment 1 suggested striking differences between humans and pigeons with respect to their choice between delayed rewards, consideration of recently proposed models of human discounting (Green et al., ) suggested critical procedural changes that were made in Experiment 2. The results observed with this modified procedure, in turn, revealed fundamental similarities between pigeons’ and humans’ choice behavior. More specifically, the present findings extend the generality of the hyperboloid discounting model and provide interspecies support for the hypothesis that choice between delayed outcomes is based on comparison of their hyperbolically discounted present values.
A formalization of the comparator hypothesis.
On this view, the end product of adaptation to an ORD is arecalibration of proprioceptive position sense at one or more pointsof articulation in the body (see the entry on ). Asyou practice reaching for a target while wearing laterally displacingprisms, for example, the muscle spindles, joint receptors, and Golgitendon organs in your shoulder and arm continue to generate the samepatterns of action potentials as before, but the proprioceptive andkinaesthetic meaning assigned to them by their“consumers” in the brain undergoes change: whereas beforethey signified that your arm was moving along one path through theseven-dimensional space of possible arm configurations (the human armhas seven degrees of freedom: three at the wrist, one at the elbow,and three at the shoulder), they gradually come to signify that it ismoving along a different path in that kinematic space, namely, the oneconsistent with the prismatically distorted visual feedback you arereceiving. Similar recalibrations are possible with respect to sourcesof information for head and eye position. After adapting to laterallydisplacing prisms, signals from receptors in your neck that previouslysignified the alignment of your head and torso, for example, may cometo signify that your head is turned slightly to the side. Fordiscussion, see Harris 1965, 1980 and Welch 1978: chap. 3.