Communicator credibility and persuasian

Prior research has usually found a positive relationship between a communicator’s perceived credibility and his persuasiveness. An experiment was designed to test the hypothesis that the perceived vested interest of a speaker, the position the speaker advocated, and the social similarity between audience and speaker would influence attributions of credibility and affect the speaker’s persuasiveness. Three variables were manipulated in a 2 by 2 by 2 factorial design. Ss read a speech that either favored (pro) or opposed (con) student voting rights; the speech was attributed to a speaker who was either similar (student) or dissimilar (townie) to the stndent audience and who either had a vested interest (running for elective office) or had no vested interest (merely giving his opinion) :in the position he advocated. As predicted, the similarity of the speaker to the audience, the vested interest of the speaker, and the position advocated in the speech strongly influenced attributions of credibility. However, in contrast to much previous research, persuasion was found to be relatively independent of the variation in the speaker’s perceived credibility. It was suggested that the failure of attributions of credibility to relate to persuasion may have been due to the high degree of ego involvement for the Ss in the topic of student voting rights.     

Some factors involved in the comparison of response systems: acquisition, extinction, and transfer of head-poke and lever-press Sidman avoidance

Head poking, a suggested natural escape reaction to shock for the rat, was compared to lever pressing in a Sidman avoidance study. Both responses could be emitted at any time, but only one was effective in a given session. Acquisition and extinction of the two responses were compared under both signalled and unsignalled avoidance. Then, a test for transfer was conducted in which acquisition conditions were re-instated, but the effectiveness of the responses was reversed. Three differences between responses were noted: (a) head poking was superior in reducing shock rates under signalled conditions; (b) head poking was more resistant to extinction, especially under signalled conditions; (c) under unsignalled conditions, animals were unable to learn to head poke if they had previously learned to lever press. Findings a and c were pursued in later experiments. Finding a depended on the location of the warning signal with respect to the response system. When the lever press required approach to the warning signal, the head poke was superior. But when the head poke required approach to the warning signal, the two responses were equally effective. Finding c depended on the absence of feedback for head poke during transfer. Two conclusions are offered: first, the two responses appear to obey the same laws when their topographical differences are taken into account. Second, response feedback appears to be more critical in transfer than in original acquisition.     

The role of posture in sound localization

Studies of auditory localization revealed that where a subject hears a sound is dependent on both his perceived head position and the auditory cues at his ears. If an error is induced between his true and registered head posture, then errors in his auditory localizations of corresponding size and time course result. The presence of visual information prevents the development of postural errors and, consequently, prevents the development of errors in auditory localization, too. These observations are related to the oculogravic illusion and are interpreted as one aspect of the functioning of a spatial reference system involved in the maintenance of the constancies of auditory and visual detection.     

Sequential constraint impairment in aphasia: A case study

Our aphasic subject appeared to demonstrate disorders related to phonological sequential constraint rules. In particular, he seemed to have difficulty in distinguishing between accidental and systematic gaps. Although he had little trouble repeating actual English lexical items, he was unable in the majority of cases to repeat possible but non-existent ones (as well as impossible ones). A reading test was administered in o der to control for errors related to the modality of the repetition test.In order for us to insure that his disorder was related to his aphasia, three normal subjects performed both the repetition test and the reading test. The aphasic's results were significantly different from theirs.We conclude that the aphasic's lexical redundancy system was impaired and that the phonological lexical redundancy rules of generative phonology form a functional neuropsychological unit the proper function of which can be selectively disrupted by brain damage.     

Acute and chronic peripheral nerve stimulation: Surgical preparation and electrode design

An electrode for peripheral nerve stimulation and surgical procedures for implantation are described. Results indicating its effectiveness are provided with discussion of durability and applicability.     

Instrumental and contingent saccharin licking in rats: Response deprivation and reinforcement

Instrumental licking of .4% saccharin solution was increased by the contingent opportunity to lick a less-preferred saccharin solution when the contingency schedule deprived the subject of the contingent response, but not otherwise. Schedules that imposed comparable amounts of response deprivation produced comparable increases in instrumental responding. The results support the hypothesis that instrumental responding will increase if and only if the contingency schedule deprives the subject of the contingent response. They also support the implication that the predicted increase will occur even if the contingent response has a lower operant level than the instrumental response.     

Natural law and politics

The Journal of Value Inquiry -     

The transfer of information across sensory modalities

Previous research has shown that Ss can recognize, classify, or identify the same nominal stimuli when presented via different sensory modalities. Two hypotheses, the mediational and invariant features, have been forwarded in an attempt to account for this ability. The present study was designed so that the reliable transfer of either specific or conceptual sources of information across sensory modalities would provide support for the invariant-feature hypothesis. Evidence was obtained for the transfer of both sources of information when the stimulus modality was not changed. However, neither source of transfer was evident when the stimulus modality was changed; thus, no support for the invariant features hypothesis was obtained in the present study.