Two notions of epistemic validity

How to accept a conditional? F. P. Ramsey proposed the following test in (Ramsey 1990). (RT) ‘If A, then B’ must be accepted with respect to the current epistemic state iff the minimal hypothetical change of it needed to accept A also requires accepting B. In this article we propose a formulation of (RT), which unlike some of its predecessors, is compatible with our best theory of belief revision, the so-called AGM theory (see (Gärdenfors 1988), chapters 1–5 for a survey). The new test, which, we claim, encodes some of the crucial insights defended by F. P. Ramsey in (Ramsey 1990), is used to study the conditionals epistemically validated by the AGM postulates. Our notion of validity (PV) is compared with the notion of negative validity (NV) used by Gärdenfors in (Gärdenfors 1988). It is observed that the notions of PV and NV will in general differ and that when these differences arise it is the notion of PV that is preferable. Finally we compare our formulation of the Ramsey test with a previous formulation offered by Gärdenfors (GRT). We show that any attempt to interpret (GRT) as delivering acceptance conditions for Ramsey's conditionals is doomed to failure.     

Temporal aspects of female musk shrew (Suncus murinus) sexual behavior

The effects of testing condition on sexual behavior were examined in female musk shrews (Suncus murinus). Females were tested in 2 conditions, a pair test and a paced test. The pair test was similar to traditional sex test conditions in which the female and male are placed into the same chamber together until mating occurs. The paced condition allowed the female to leave the male's chamber and revisit him at will, thus "pacing" the interaction. Females displayed receptivity continuously for 14 days in both conditions. In the paced condition, females were less likely to become receptive within 30 min and mate to ejaculation. However, few additional differences were found between test conditions. Because this is the 1st experiment to use a pacing test paradigm in a species with induced ovulation, the authors speculate that the absence of pacing behavior during mating may be shown by other species that have induced ovulation.     

A solid-state device for eliminating electrical noise and biopotentials in electromyographic (EMG) recordings

A small, low-cost, integrated circuit device is described. This circuit reduces electrical noise, such as that produced from a poor electrode-skin interface and power-line interference (60 Hz). Advantages of this device, with regard to use in electrically noisy environments and with long cables, are discussed.     

Perceptual-motor development of first graders as related to class,race, intelligence,visual discrimination,and motivation

The Bender Motor Gestalt Test was administered to 60 white advantaged, 60 white disadvantaged, and 60 black disadvantaged first graders. Contrary to expectation, there was no significant difference between the perceptual-motor performance of the white advantaged and disadvantaged children despite meaningful group differences in verbal IQ. The disadvantaged black children, however, performed significantly more poorly than either of the white groups. Perceptual-motor proficiency was also examined in relation to sex, intelligence, accuracy of visual discrimination, level of motivation, and familiarity with test content. While no single factor investigated was clearly related to level of perceptual-motor functioning, the perceptual-motor performance of girls regardless of race or class, was found to improve following familiarization with the test figures and heightening of motivation. The educational implications of a group-specific perceptual-motor “lag” are discussed.     

The Personality of R’ Nahman of Bratslav: Comparing Dream Content Analysis and Biography

The technique of dream content analysis as a source for gaining a clear personality picture of the dreamer was first formalized by Calvin S. Hall. It has been used in this paper to gain a better understanding of a historical, renowned personage—R Nahman of Bratslav, who established a distinct sect within the Jewish-Hasidic circles in Eastern Europe about two hundred years ago. He was a very controversial figure, and remains so to this day. Following a detailed analysis of 17 of his dreams, a personality picture of R Nahman has been derived. A comparison of this picture with what is known from his biography, showed many correspondences, as well as some non correspondences. The dream analysis discloses basic, psychological motivation, while the biography points to relatively more specific behavioral traits, even though both relate to the highly complex personality of R Nahman.