Overhabituation and dishabituation: Effects of extraversion and amount of training

The Eysenck (1967) hypothesis that introverts have higher levels of cortical activation than extraverts has received support in a number of psychophysiological studies, though there is not complete consistency. The present study extended the habituation paradigm used in some previous work to include an examination of differences between extraverts and introverts during and following long-term overhabituation. Electrodermal activity was recorded while 72 extraverts and 72 introverts were subjected to criterion auditory habituation to a 1000-Hz, 90-db tone, followed by 60, 100, or 140 trials of overhabituation. The overhabituation run was followed by a test stimulus of 7000 Hz and a final repetition of the standard stimulus. Results showed that introverts increased in response frequency with increasing overhabituation exposure, while extraverts showed an increase only from 100 to 140 trials. In addition, the hypothesis that differences in test response amplitude favoring introverts would be eliminated by extended overhabituation training was supported. Specifically, extraverts showed increased responses at 100 and 140 trials, while introverts remained approximately constant across the three conditions. Finally, results supported the Sokolov hypothesis that overhabituation training produces test responses of larger amplitude.     

Dishabituation and spontaneous recovery of the electrodermal orienting response: Effects of extraversion,impulsivity, sociability,and caffeine

The relationship between extraversion and psychophysiological indices of arousal is not yet fully understood. The present study attempted to further clarify this relationship by using caffeine to systematically manipulate arousal. Subjects pretested on the Eysenck Personality Inventory were given caffeine or a placebo, then underwent habituation, dishabituation, and spontaneous recovery of the electrodermal OR. Separate analyses examined the main and interactive effects of extraversion, impulsivity, and sociability with caffeine. Several tonic and phasic measures showed group reversal effects, with introverts having higher tonic levels and larger phasic responses under placebo conditions and extraverts having larger phasic responses and higher tonic levels under caffeine. Although both tonic and phasic responses were differentially affected, the group reversal effects occurred at different points in time on tonic than they did on phasic measures relative to the theoretical buildup of inhibition. The findings for impulsivity were quite consistent with those for extraversion, and both sets of results were generally supportive of the Eysenck hypothesis.     

Reaction time for voiced and whispered /a/ in stutterers and nonstutterers

Recent research reviewed in this article suggests that stutterers' inability to initiate phonation promptly could be a significant factor in the occurence of stuttering. Since stuttering is either completely absent or markedly reduced in frequency during whisper, the present study tested the hypothesis that stutterers do not significantly differ from nonstutterers in reaction time (RT) for the initiation of whispered/a/, whereas the two groups differ significantly in RT for the initiation of voiced /a/. Ten adult stutterers and an equal number of comparable nonstutterers produced prolonged versions of the vowel /a/ using voice and whisper in response to tone stimuli. The results showed that stutteres and nonstutterers did not differ in RT for either voiced or whispered /a/. The stutterers, however, exhibited significantly longer RT to produce voiced /a/ than whispered /a/.     

Teacher attitudes toward stuttering

Attitudes of 100 elementary school teachers toward stuttering were studied using the Teacher Attitudes Toward Stuttering (TATS) Inventory. Teacher attitudes, as indicated by TATS Inventory scores, were compared with teacher knowledge of stuttering, age of teacher, number of years teaching experience, educational level, and whether the teacher had personal experience with a stutterer. Results indicated that significant positive correlations existed between teacher attitudes toward and knowledge of stuttering. Significant negative correlations were demonstrated between teacher attitudes/knowledge of stuttering and the presence of a stuttering child in the classroom. The applicability of the TATS Inventory as a clinical instrument in its current form and the research needed to enhance its flexibility are discussed.     

A shortened version of the Southern Illinois university speech situation checklist for the identification of speech-related anxiety

This study investigated the ability of the 51-item Southern Illinois University Speech Situation Checklist (SSC) to differentiate stutterers known to have high levels of speech-related anxiety from nonstutterers with normal levels of speech- related anxiety. Checklist responses of 65 randomly selected subjects (33 stutterers and 32 nonstutterers) were subjected to a stepwise discriminant analysis. The analysis identified a combination of 21 SSC items that had significant discriminative power. Subsequently, the derived discriminant equation achieved 93% accuracy in correctly classifying a hold-out sample of 29 subjects (14 stutterers and 15 nonstutterers). These results strongly suggest that the 21 items of the SSC identified by discriminant analysis may provide an effective screening device for identifying disfluent speakers who experience an abnormal amount of speech-related anxiety.     

Alexia and agraphia with spared spelling and letter recognition abilities

A patient with alexia and agraphia had intact spelling and comprehension of spelled words and used a letter-naming strategy to read and write. We propose that there is a graphemic area important for distinguishing graphemic features and for programming movements used in writing. In this patient this area was not functioning or did not have access to the area of visual word imagés. Therefore, he used an ideographic letter-naming strategy to verbally circumvent his disability and gain access to the area of visual word images.     

Effects of positive and negative adult-child interactions on children's task performance and task preferences

In individual sessions, an adult directed three boys to work on each of three different tasks. Within a given session the on-task behavior for one task was praised, the off-task behavior for another task was verbally reprimanded, and all behavior was ignored with the third task. Using a multielement baseline design, the manner in which the adult interacted with the children on a given task varied from day to day. Across 18 sessions, verbal reprimands produced the highest task rates, with praise producing only a slightly higher rate of responding than noninteraction. After each session the children were given the choice of which of the three tasks they wished to work on when the adult left the room for a few minutes. Tasks associated with verbal reprimands of off-task behavior were never chosen. The first and second choices were always the task associated with praise for on-task behavior or the task where the children were ignored. These preferences generalized to similar tasks.     

Developmental differences in subjects' associative-learning strategies and performance: Assessing a hypothesis

Fifth-, seventh-, and ninth-grade (11-, 13-, and 15-year-old) subjects were presented with a list of paired associates to learn and were interviewed about the strategies used to learn them. Although a majority of fifth graders reported simply rehearsing the pairs in order to remember them, very few ninth graders relied exclusively on rehearsal. Consistent with a hypothesis advanced by Rohwer (1973), the number of subjects who elaborated some or all of the pairs increased with age. Paired-associate performance increased with age, but the level of paired-associate learning was much more related to the type of strategy reported by the subject than to the age of the subject per se.     

Ear asymmetries on a selective attentional task

To ascertain whether there are ear-hemisphere asymmetries of selective attention, signal stimuli (tonal sequences) were presented monaurally with and without complex maskers (music and speech). The right ear-left hemisphere was more disrupted by language maskers; the left ear-right hemisphere was more disrupted by music maskers. These results suggest that there are hemispheric asymmetries of selective attention and that the ear hemisphere that usually processes a class of stimuli has greater difficulty filtering out those stimuli than does the nonspecialized hemisphere.