Reflex modification in the rat: the inhibitory effects of intensity and frequency changes in steady tones

In laboratory rats (as in humans) a low-intensity tone that precedes a high-intensity burst of noise by approximately 100 ms can reduce the amplitude of the startle reaction elicited by the burst of noise. A series of four experiments with rats investigated the relation between the inhibitory effects of tonal frequency change and the length of the silent period (gap) preceding it. The major findings were the following: (a) A gap in an otherwise continuous pure tone inhibited startle when the gap occurred approximately 100 ms prior to the noise burst. (b) Although an increase in gap duration increased the inhibition afforded by the gap, the maximum inhibition was yielded by gaps of 100 ms and greater; this maximum was equivalent to the inhibition yielded by the presentation of a postgap tone alone. (c) A shift in tonal frequency across a 10-ms gap yielded more inhibition than did the same gap with no frequency shift; again the shift yielded equivalent inhibition to the presentation of the postgap tone alone. (d) An increase in the frequency shift increased inhibition when the shift occurred across a 10-ms gap, but not when the shift occurred across a 100-ms gap.     

The word-superiority effect under conditions that approximate reading

Observers detected a briefly flashed target letter embedded in word, pronounceable nonword, and unpronounceable nonword contexts. The word context facilitated perception under both holistic and analytical processing strategies; the facilitative effect was enhanced when processing was analytical.     

On the role of differential sample behaviors in matching-to-sample

Pigeons were trained on matching-to-sample (MTS) with differential sample-response requirements that were identical with respect to two pairs of sample stimuli but were either correlated or uncorrelated with correct choice. Experiment 1A showed that birds in the uncorrelated condition were slower to reach criterion levels of accuracy than birds in the correlated condition in spite of their equivalent sample discriminations. However, correlated birds were more disrupted in their matching performances than the uncorrelated birds when subsequently switched to nondifferential sample-response requirements (Experiment 1B). Experiment 2 showed that differential sample behaviors also generated higher levels of accuracy on delayed MTS when correlated with choice, and that accuracy in this condition did not differ as a function of whether the samples were hues or lines. Sample dimension did affect memory performance, on the other hand, in the uncorrelated condition. In Experiment 3, reversing differential sample-response requirements for one pair of samples substantially reduced matching accuracy in the correlated group but had almost no effect in the uncorrelated group. These findings demonstrate that differential sample behaviors directly control pigeons' matching performances and also overshadow conditional stimulus control by the samples when these behaviors are predictive of correct choice. The facilitation in matching produced by differential sample behaviors apparently arises from the additional cue these behaviors provide, not because they enhance sample discriminability.     

Vowel duration in stutterers participating in precision fluency shaping

The purpose of this study was to determine the extent to which stutters manipulate vowel duration to achieve fluency after participating in Precision Fluency Shaping. Nine stutterers who read an all-voiced sentence fluently before and after therapy were selected for study. Wide-band spectrograms were made of the initial phrase of the sentences, and vowel durations were computed. Results indicated that extended vowel durations were characteristic of the fluency of stutterers posttherapy. The subject that had the highest rate of disfluency after therapy also had the shortest vowel durations. Clinical implications concerning the importance of speech rate during carryover practice are made.     

Validity and reliability of the EOM-EIS for early adolescents

The Extended Objective Measure of Ego Identity Status (EOM-EIS) was examined for reliability and validity among early/middle adolescent subjects. The EOM-EIS represents a combination of the Objective Measure of Ego Identity Status and a structured interview of identity status. The instrument was designed to measure ego identity with regard to occupational, religious, political, philosophical, and social contexts along ideological and interpersonal dimensions. A total of 467 students aged 12 to 18 (median = 15.73) responded to the instrument. In general the results from the analyses of reliability, validity, demographic characteristics, and psychosocial maturity yielded results which parallel the theoretical framework and the results from college-aged subjects.     

Patterns of discipline enforcement and the perception of justice in two educational frameworks in Israel

The purpose of the present study was to examine the types of discipline enforcement measures employed in the Israeli elementary and junior high schools, and their fairness as viewed by students. The central hypothesis was that patterns of discipline enforcement vary considerably depending on school characteristics. These patterns, in turn, together with students' sex, socioeconomic and ethnic background, and academic status within the school, determine students' perceptions of justice concerning misbehavior management. It was found that junior high school teachers rely more on problem-centered, and elementary school teachers rely more on relationship-centered techniques of discipline enforcement. However, in spite of these differences and the report of about half of the students that they personally had been unfairly treated, the majority of the respondents reported that the punishments employed in their school were generally fair, and that the severity of punishments was in the right proportion to the severity of the misconduct. Students' traits have accounted for only a small percentage of the variance of the various dimensions of justice that were examined. It has been suggested that students' perceptions of justice are related to an overall tendency to perceive schools' authority as legitimate rather than to schools' structural characteristics, misbehavior management techniques, and students' traits. Several possible bases of schools' legitimation are discussed.     

Visual information processing speed in hypnotized and nonhypnotized subjects

Using a backward-masking paradigm with a bias-free and ceiling-free psychophysical task, we tested hypnotized and control subjects for speed of visual information processing. Approximately half of each group received visual imagery suggestions in an attempt to influence attention. Imagery produced no significant differential effect. Although an absence of a hypnotizability-performance relationship was in keeping with findings of a previous study, those subjects in the present study who performed under hypnosis were, as a group, significantly superior to the other subjects in speed of information processing.     

Effects of head restraint on signal detectability in simultaneous and successive vigilance tasks

Dittmar, Warm, and Dember (1985) suggested that visual parallax may lead to declines in perceptual sensitivity over time in spatial vigilance tasks involving comparative judgments. The present study tested this possibility by restraining subjects' head movements during a 1-hr vigil in which comparative (simultaneous task) or absolute (successive task) judgments of line length were necessary for signal detection. Under free-viewing conditions, perceptual sensitivity declined over time with both types of tasks. Head restraint eliminated the sensitivity decrement in both cases. The results highlight signal quality as a crucial determinant of perceptual decrements in sustained attention.