Hair cell and neural contributions to the cochlear summating potential.

The cochlear summating potential (SP) to a tone is a baseline shift that persists for the duration of the burst. It is often considered the most enigmatic of cochlear potentials because its magnitude and polarity vary across frequency and level and its origins are uncertain. In this study, we used pharmacology to isolate sources of the SP originating from the gerbil cochlea. Animals either had the full complement of outer and inner hair cells (OHCs and IHCs) and an intact auditory nerve or had systemic treatment with furosemide and kanamycin (FK) to remove the outer hair cells. Responses to tone bursts were recorded from the round window before and after the neurotoxin kainic acid (KA) was applied. IHC responses were then isolated from the post-KA responses in FK animals, neural responses were isolated from the subtraction of post-KA from pre-KA responses in NH animals, and OHC responses were isolated by subtraction of post-KA responses in FK animals from post-KA responses in normal hearing (NH) animals. All three sources contributed to the SP; OHCs with a negative polarity and IHCs and the auditory nerve with positive polarity. Thus the recorded SP in NH animals is a sum of contributions from different sources, contributing to the variety of magnitudes and polarities seen across frequency and intensity. When this information was applied to observations of the SP recorded from the round window in human cochlear implant subjects, a strong neural contribution to the SP was confirmed in humans as well as gerbils. NEW & NOTEWORTHY Of the various potentials produced by the cochlea, the summating potential (SP) is typically described as the most enigmatic. Using combinations of ototoxins and neurotoxins, we show contributions to the SP from the auditory nerve and from inner and outer hair cells, which differ in polarity and vary in size across frequency and level. This complexity of sources helps to explain the enigmatic nature of the SP.

Development and validation of a self-report measure of emotional intelligence as a multidimensional trait domain.

Psychometric review of 33 peer-reviewed studies of six self-report emotional intelligence (EI) measures supports a multidimensional conceptualization of EI. The nature and number of EI facets, however, and their distinctiveness from more established trait domains is unclear. Building on earlier efforts, three studies were undertaken (Ns = 138, 163, 152) to develop self-report measures of 10 facets of EI proposed by Salovey and Mayer (1990). Results support the reliability (internal consistency, test-retest) and validity (content, criterion, construct, structural) of the proposed scales and their distinctiveness among themselves and with respect to more established trait domains (e.g., personality). Specifically, three satisfaction and four cross-cultural adaptability facets were predicted uniquely by 9 of the 10 proposed subscales, controlling for social desirability, the Big Five, positive and negative affect, and self-monitoring. All told, results confirm that trait-EI can be measured using self-report and conceptualized as a distinct multidimensional domain.

Supervisor referrals to work-family programs.

Supervisors play an important role in determining whether employees use work-family programs. Yet little research has examined the factors that relate to supervisor perceptions of and behaviors surrounding work-family programs. This study builds on past research, the theory of reasoned action, and expectancy theory to explore factors that contribute to supervisors' decisions to refer subordinates to work-family programs. Usable surveys assessing perceptions of work-family programs were completed and returned by 1972 managers in a large government agency. Results revealed that program awareness and instrumentality perceptions both contributed uniquely to predicting the frequency of supervisors' referrals to work-family programs. Supportive attitudes also predicted referrals, but only through their shared relationship with instrumentality perceptions.