Response-contingent stimulation as a treatment for developmental failure in infancy

An 8-month-old infant with a developmental quotient of $\text{1}\text{1}\text{2}$ months was given response-contingent stimulation using a pressure-sensitive pillow which turned an overhead mobile. The subject learned to control the mobile by kicking the pillow, and concurrently began smiling at both the mobile and her mother for the first time. After mastering three contingencies on arm, head, and leg movement, she displayed what appeared to be a Piagetian coordinated secondary circular reaction, in which one response provided 4 seconds of access to another contingency. Although the subject remains severely retarded, the results suggest that some forms of developmental delay may be treated at least in part as a failure to develop contingency awareness.     

Discriminative infant smiling to orientations of talking faces of mother and stranger.

Thirty-two infants aged 14 and 20 weeks were presented with a live face in each of eight conditions, which consisted of all combinations of (a) a 0° or 90° orientation; (b) familiar face (the infant's mother) or distinctively unfamiliar face; and (c) talking or silent context. The previous findings that younger infants smile longer at 0° than at 90° faces and that this differential responsiveness to orientation wanes with increasing age were replicated; the hypothesis that older infants would smile longest at their mothers' talking faces in the 0° orientation was confirmed. In addition, infants of both ages smiled more at their mothers than at the stranger, although this effect interacted with orientation and sex of the infant.     

Manipulating the word frequency effect in free recall

A recall advantage for common words was not evidenced when subjects generated or rated the list words on the basis of commonness and on a semantic, phonological, or orthographic basis prior to recall. Recall of the same set of words following only structural judgments of the words resulted in the usual recall advantage for common words. Results were not consistent with interpretations based only on the associative strengths of the recalled items. A process based on categorization of the words to be recalled was suggested as an alternative explanation.     

Ratio scaling of taste intensity by a matching procedure

Given the assumptions that the taste sense is analytic and that the total perceived intensity of a complex taste equals the sum of the perceived intensities of the components, a new procedure was devised to scale taste intensity. Subjects matched the intensity of test substances either to the total intensity or to the intensity of one component of two-component mixtures tin which the two components appeared equally intense. Given the above-stated assumptions, such a pair of matches should define a psychological ratio of 2∶1. Scales erected by this procedure agreed well with scales determined by magnitude estimation.     

Electromyography: A review of the current status of subvocal speech research

Electromyographic studies of subvocal speech are evaluated with two different aims: (1)a methodological review of controls for nonspeech artifact and of data analysis techniques, and (2) a review of substantive findings and suggestions for future research. A highly effective procedure, involving manipulation of phoneme content in certain trials, has been developed to control nonspeech artifact generated by the speech musculature. The commonly used data analysis technique of amplitude measurement of the single highest polygraph pen deflection is inadequate. Techniques which take frequency into account, such as analog computer integration of voltage values, are more sensitive. Even greater sensitivity is needed to isolate individual words so that rehearsal strategies can be investigated. It has been clearly established that preschool children as young as age 4 engage in spontaneous subvocalization that is related to recall in boys but not in girls.     

A device for presenting attack opportunity as a reinforcer for operant behavior

A device is described which automatically measures barpresses reinforced by short opportunities to attack male mice. Data on barpress rates indicate rapid and reliable acquisition of preferences for reinforcer bars and rapid abolition of this preference when the reinforcement contingency is subsequently eliminated. The data are less reliable for reversal learning.