Cluster analysis of depressed college students' social behaviors.

Measures of interpersonal behaviors exhibited by depressed college students toward their dormitory roommates were cluster analyzed, and this procedure produced 2 relatively distinct subgroups: a dependent, friendly, overgenerous type and an autocratic, competitive, aggressive, mistrustful type. These 2 groups were studied over a 9-month period; findings revealed that behaviors associated with each cluster were relatively stable and unrelated to gender or initial symptom severity. In longitudinal analyses, depressives in one group showed symptom abatement across time, whereas symptoms of the other group remained elevated. The roommates of depressives exhibited relatively high levels of hostility and a progressive decline in social contact and satisfaction with their depressed cohabitant. The results are discussed in relation to other typological approaches to unipolar depression.     

Localization of sound in the vertical plane with and without high-frequency spectral cues.

Binaural localization of 3.0-kHz high- and lowpass noise presented in the median vertical plane (MVP) and lateral vertical plane (LVP) was investigated. We anticipated superior performance when localizing the highpass noise by virtue of the availability of pinna cues. The viability of this supposition was strengthened by monaural localization tests in which performance proficiency for the highpass noise exceeded that for the lowpass noise (p less than .01). The main result showed that binaural localization of proficiency for highpass noise surpassed that for lowpass noise for all listening conditions (p less than .01). However, the importance of binaural temporal and level differences in vertical-plane localization was demonstrated by the highly respectable performances when the lowpass noise was presented in the LVP. Data from binaural localization in the MVP and monaural localization in the LVP suggested that the influence of pinna cues diminishes for source elevations above 45 degrees.     

Selective masking and processing strategy

A patterned masking stimulus was presented immediately following a 100-ms exposure of a centrally-fixated, eight-letter row. The bar-marker probe, indicating which letter to report, appeared either at onset (simultaneous cue), or at offset (delayed cue) of a letter row. A selective-masking effect--greater masking at the centre positions than at the ends of a row--was obtained with the delayed cue. With the simultaneous cue, all positions were masked and there was no selective-masking effect. These results indicate that the effects of a patterned masking stimulus are dependent upon the processing strategy, and they support previous interpretations of selective masking which state that it is produced by an ends-first processing strategy.     

The relative influence of pitch and timbre on the apparent location of sound in the median sagittal plane

Listeners were requested to locate sounds originating in the median sagittal plane (MSP). The stimuli, 75-Msec pulses, were repeated at a rate of 200 times/sec and were filtered to transmit narrow bands centered about 0.63, 1.6, 2.5, or 6.3 kHz. Despite the sameness of pitch generated by all stimuli, Os perceived the 0.63-, 1.6-, and 2.5-kHz-centered sounds as originating low, middle, and high, respectively, in the MSP, regardless of their actual positions. The stimuli centered about 6.3 kHz, on the other hand, were located accurately by most Os. These findings were interpreted to mean that under conditions of inadequate auditory cues, timbre, not pitch, influences perceived elevation. The implication is that timbre also served as the cue for the apparent elevation of those sounds which, due to their high-frequency components, can be located accurately.     

The BUS-ALL: An inexpensive set of interface for the SKED system

A cost-effective relay-transistor interface has been developed for connecting the minicomputer with the experimental environment. The interface contains a 10-msec clock, input (response) channels, and output (stimulus channels.     

Relationships between college performance and success as an Army officer

This study investigated the relationships between both academic and nonacademic indices of college success and four indices of occupational success of Army officers. Subjects were 103 U.S. Military Academy graduates from the Class of 1962. Criteria were gathered 6 and 10 years after graduation, and multiple regression results indicated that three of the four criteria were significantly predicted. Results also showed that a leadership rating received the most weight in the equations, and that academic grades can contribute significantly to the prediction of officer success. Grades in physical education and tactics received nonsignificant weights in all but one case.     

The influence of stimulus bandwidth on localization of sound in space

The ability of listeners, deprived of prominent interaural time and intensity cues, to locate noise bands differing in width was investigated. To minimize binaural cues, we placed the sound source at various positions in the median sagittal plane. To eliminate binaural cues, we occluded one ear. The stimuli consisted of broadband noise and bands of noise centered at 8.0 kHz. The width of the latter ranged from 1.0 to 6.0 kHz. The results from seven listeners showed that localization proficiency for sounds in the median sagittal plane decreased with decreases in bandwidth for both binaural and monaural listening conditions. This function was less orderly for monaural localization of horizontally positioned sounds. Another consequence of a reduction in bandwidth was an increasing tendency of listeners to select certain loudspeakers over others as the source of the sound. A previous finding showing that localization of sound in the median sagittal plane is more accurate when listening binaurally rather than monaurally was confirmed.     

Are monocular arrays discriminable from binocular arrays?

On each trial of this experiment, a subject was visually stimulated by one or two shadows on a translucent background in a Telebinocular. For each subject, there were 40 trials of monocular stimulation by one shadow, 40 trials of monocular stimulation by two shadows (one in each hemifield), and 40 trials of binocular stimulation by two shadows (one in the left hemifield of one eye and another in the right hemifield of the other eye). Across these randomly ordered trials, 52 subjects were unable to discriminate two right-eye shadows from two left-eye shadows and were unable to discriminate two monocularly perceived shadows from two binocularly perceived shadows. Generally, subjects tended to misidentify right-hemifield shadows as right-eye shadows and tended to misidentify two-hemifield shadows as two-eye shadows.