Extraversion, sensation seeking and electrodermal response: Probing a paradox

Extraversion and psychoticism are thought to relate inversely to electrodermal response amplitude. Paradoxically, sensation-seeking scales, which correlate positively with extraversion and psychoticism, have shown a positive relation to electrodermal response amplitude. In the present inquiry, inverse relationships were obeserved for extraversion and psychoticism with the electrodermal response to visual stimuli. Sensation seeking was also negatively related to the magnitude of the initial electrodermal response to pictures. A lowered response to words for low sensation seekers was observed that appeared to be influenced by skin conductance level.     

Fluency and eye contact as factors influencing observers' perceptions of stutterers

The purpose of this study was to determine the effects of different levels of eye contact and fluency on observers' perceptions of a speaker. One of four videotapes depicting an actor (playing the part of a supervisor) interviewing another actor (who played a subordinate) were shown to 127 college students. The four videotapes represented four different conditions comprising combinations of fluent vs nonfluent speech and normal vs low eye contact. Results indicated that these combinations of fluency and eye contact differentially influence listeners' perceptions of a speaker. Highest ratings were obtained for the fluent-normal eye-contact speaker, with lower ratings for all other conditions. In addition, it was determined that the frequency of eye contact rather than fluency was more strongly related to listeners' perceptions. The clinical implications of these findings are discussed.     

Building theories of reading ability: On the relation between individual differences in cognitive skills and reading comprehension

To date most theories of reading ability have emphasized a single factor as the major source of individual differences in performance. However there has been little agreement on what that factor is. However, candidates have included visual discrimination, phonological and semantic recoding, short-term memory, and utilization of linguistic knowledge and context. The single- factor theories are summarized. Literature is then reviewed to show that no single-factor theory is likely to be right, because a very wide range of component skills and abilities has in fact been shown to correlate with reading success. Among them are discrimination of letter location and letter order during perceptual recognition, use of orthographic regularity as an aid to visual code formation, use of spelling-to-sound regularity in phonological recoding, memory for word order, spontaneous identification of syntactic relations, flexibility in prediction from syntactic and semantic context, and context-specificity in semantic encoding. It is concluded that more complex, multifactor models of reading ability are required, and some recent attempts to collect data conducive to such a model are described. In the process, three different approaches to identifying factors relevant to reading success are delineated. These are general abilities assessment, learning potential assessment, and component skills analysis. Two methods of conducting component skills analysis are presented, and it is recommended that they be used as converging operations. Finally, the results of a component skills analysis are used to construct a tentative example of a class of hierarchical models of reading ability that can be pursued developmentally.     

Stimulus generalization of schedule-induced polydipsia

Five rats were exposed to an intradimensional discrimination by associating two tones of different frequency with the components of a multiple random-time 30-sec, extinction schedule of food presentation. After schedule-induced polydipsia developed and the intermittent schedule of food presentation established stable differential licking rates during the stimuli associated with the multiple schedule, a stimulus generalization test was conducted. When generalization testing was conducted by presenting stimuli that varied on the frequency dimension during the random-time 30-sec component of the multiple schedule, all five rats demonstrated moderately sloping symmetrical gradients. Thus, schedule-induced polydipsia can be brought under the control of stimuli other than the food pellet.     

Reinforcement by an imprinting stimulus versus water on simple schedules in ducklings

Ducklings (5 to 28 days old) were trained to peck a pole on fixed-ratio, fixed-interval, and multiple schedules using brief presentation of an imprinting stimulus as the response-contingent event. Other ducklings of the same age were trained similarly except that reinforcement consisted of access to water. With water reinforcement the typical fixed-ratio (“break-run”), fixed-interval (“scallop”), and multiple schedule response patterns were readily established and consistently maintained. With the imprinting stimulus these schedule effects were inconsistent in some subjects and virtually nonexistent in others, despite extended training. Schedule control with the imprinting stimulus was not improved by the use of a reinforcement signaling procedure which enhances responding reinforced by electrical brain stimulation on intermittent schedules. However, the overall rates of responding and the extinction functions generated after reinforcement with water versus the imprinting stimulus were comparable. These findings imply that control by temporal and discriminative stimuli may be relatively weak when a young organism's behavior is reinforced by presentation of an imprinting stimulus.     

The role of self-attribution differences in the utilization of social comparison information

A study is reported that investigated the effects of receiving social comparison information which implied individual's behavior was inconsistent with his/her self-ascribed trait. The effects of this information on subsequent self-labeling and behavior involving a similar task were found to be mediated by the attributional style of the subject. The social comparison information caused subjects to reevaluate their relevant self-labels regardless of their attributional style. However, only self-attributors also changed their behavior on a later task as a result of exposure to the comparison information. These findings and their implications were discussed with regard to self-attribution and the maintenance of traitbehavior consistency.     

Tests that discriminate between dyslexic and other learning-disabled boys

Dyslexic and nondyslexic boys within a single community's learning-disabled class were given a set of tests; performance on each of these tests has been reported to be significantly impaired in other dyslexic children compared to learning-disabled and normal groups. Linear discriminant function analysis revealed that error types rather than levels of performance best separated the carefully matched learning-disabled groups. Slow naming and high percentage of “dysphasic” errors characterized dyslexic boys. Visual temporal-spatial matching and “configuration-deficient” perceptual errors characterized the adequate readers who have other learning disabilities.     

Comprehension of gerundive constructions by Broca's aphasics

Eleven diagnosed Broca's aphasics were tested for comprehension of sentences containing gerundive constructions. Results showed that, as a group, these patients were sensitive to grammatical distinctions signaled by “function” words, contrary to the predictions of some current theories about the specific deficits exhibited in this syndrome. Further analysis showed that the patients fell into two subgroups, one which exhibited sensitivity to the distinctions in normal grammar, and another which exhibited no sensitivity to such distinctions. This suggests that the syndrome may have different manifestations in different populations—patient age is suggested as a possible means for distinguishing the two groups. Suggestions for further research into the nature of the comprehension deficits exhibited by Broca's aphasics are made.     

Depression in aphasic patients: Frequency, severity, and clinical-pathological correlations

Twenty-five hospitalized nonfluent, fluent, and global aphasic patients who were several months past the onset of their illness were compared for presence and severity of depression based on four psychopathological measures. The nonfluent aphasic patients had both greater frequency and severity of depression than the other two groups. CT scans showed that the global aphasic patients had the largest lesion size (volumetric) and showed a strong correlation between lesion size and degree of depression. In contrast, patients with fluent aphasias showed an inverse correlation between severity of depression and lesion size; among the nonfluent aphasic patients there was no significant correlation. Depression appears to be common in this population of hospitalized aphasic patients with chronic illness and nonfluent patients are the most depressed group within this population. The increased frequency and severity of depression in the nonfluent patients did not appear to be related to their overall physical or cognitive impairment; two possible mechanisms are discussed.