Event-related potentials elicited by automatic targets: A dual-task analysis.

Investigated the role of limited capacity processes in the detection of automatic targets in a dual-task paradigm using both behavioral and event-related potential (ERP) measures. Six right-handed undergraduates served as Ss. An automatic detection task was paired with another concurrent discrimination while the relative importance of each task was systematically varied. The resulting performance operating characteristic showed that both the speed and accuracy of automatic detection responses were affected by the allocation of attention. Reductions in the accuracy of each task were accompanied by reductions in the amplitude of a late-positive component of the ERP (P300). The latency of the P300 component elicited by automatic targets was increased in dual-task conditions. A comparison of behavioral and ERP measures suggested the involvement of 2 separate limited-capacity processes in automatic detection: one concerned with the formation of an episodic representation of target occurrence and the other with the execution of rapid motor responses. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The interpretation of detection data through direct multivariate frequency analysis.

Many psychological experiments generate data that form multidimensional tables of frequencies. Although these tables are conventionally analyzed by such theoretical models as signal-detection theory, a direct and atheoretical analysis of the associations present in the data gives additional valuable information about the underlying detection processes. The present article demonstrates an application of these models to psychophysiological data, which provides an attractive compliment to the more usual signal-detection theory analysis. It is suggested that direct frequency analysis can investigate quite complicated patterns of association; furthermore, it allows approximate statistical test of specific hypotheses to be run. Thus, it provides a valuable adjunct to theoretical models. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral consequences of crowding in the deermouse (Peromyscus maniculatus).

Hypothesized that, when the degree of crowding is manipulated by varying group size in cages of equal size, it is probable that crowded animals will engage in more contact than uncrowded animals. Home-cage observation of 24 male and 24 female deer mice indicates that crowded Ss do, in fact, engage in more contact behavior. Both home-cage observation and testing in pairs for pain-elicited aggression reveal that (a) crowded Ss display more agonistic behavior than uncrowded Ss, and (b) agonistic behavior increases with prolonged crowding. Support is obtained for the theory that the effect of crowding derives from contact with conspecifics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-Monitoring, Activity Levels, and Mood in the Development and Maintenance of Depression.

The reactive effect on mood of self-monitoring pleasant and unpleasant events was assessed. Forty-five females spent 28 days monitoring in one of four conditions: (a) pleasant events, (b) unpleasant events, (c) both, and (d) no monitoring. Motor activity level (pedometer recordings) and mood were also assessed daily. Class of event monitored was not found to influence mood. Correlations between mood and both pleasant and unpleasant events were found even with activity level partialed out. Implications for self-monitoring assessment in depression therapy programs and for models of depression are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Angiotensin II stimulates cAMP production and protein tyrosine phosphorylation in mouse spermatozoa

Angiotensin II (AII), found in seminal plasma, has been shown to stimulate capacitation in uncapacitated mammalian spermatozoa. The present study investigated the location of AII receptors on spermatozoa and AII's mechanism of action. AT1 type receptors for AII are present on the acrosomal cap region and along the whole of the flagellum of both mouse and human spermatozoa. Because combinations of low concentrations of AII and either calcitonin or fertilization-promoting peptide (FPP), both known to regulate the adenylyl cyclase (AC)/cAMP signal transduction pathway, elicited a significant response, this study investigated the hypothesis that these peptides act on the same pathway. AII was shown to significantly stimulate cAMP production in both uncapacitated and capacitated mouse spermatozoa and this was associated with increases in protein tyrosine phosphorylation. Using an anti-phosphotyrosine antibody to visualize the location of tyrosine phosphoproteins within individual cells, AII significantly stimulated phosphorylation within 20 min in both the head, especially in the acrosomal cap region, and the flagellum, especially in the principal piece, of uncapacitated mouse spermatozoa; combined AII + FPP was stimulatory within 5 min. In addition, Western blotting revealed that AII stimulation increased phosphorylation in a number of tyrosine phosphoproteins in both uncapacitated and capacitated mouse spermatozoa, with some being altered only in the latter category of cells. These results support the hypothesis that AII stimulates AC/cAMP in mammalian spermatozoa.     

Man-Made Electromagnetic Noise in Southern California and Southern Nevada

A brief history of man-made noise interference is provided. A series of examples of this type of radio interference points out the generally insidious?or in a few instances the somewhat ridiculous?nature and effects of man-made noise. It is demonstrated how the Pacific Missile Range and the Western Area Frequency Coordinator mitigate man-made noise by the use of area controls, engineering, testing, monitoring, training, and frequency management.