Excluded middle and bivalence

I consider two related objections to the claim that the law of excluded middle does not imply bivalence. One objection claims that the truth predicate captured by supervaluation semantics is not properly motivated. The second objection says that even if it is, LEM still implies bivalence. I show that LEM does not imply bivalence in a supervaluational language. I also argue that considering supertruth as truth can be reasonably motivated.     

Some cautionary notes regarding the use of aggregated scores as a measure of behavioral stability

The utility of the method of aggregation as a measure of behavioral consistency was examined in 26 studies involving computer-generated, repeated-measurement data. The first series of studies involved rectangular distributions in which score constant. A second series of studies used normally distributed z scores, and score consistency was manipulated by inducing a desired correlation between the scores in adjacent trials. In both sets of studies, the aggregate stability coefficient was a strictly increasing function of the number of aggregated trials, and even trivial amounts of score stability resulted in large stability coefficients. In a third series of studies, high stability coefficients occurred when computed on combined unstable subsamples which differed from each other only in central tendency. Terminal aggregate coefficients were compared with Spearman-Brown prophecy and Cronbach's alpha reliability coefficients computed on the experimental data. It was concluded that the method of aggregation produces spuriously high estimates of behavioral consistency. It was further shown that the Spearman-Brown prophecy formula and coefficient alpha accurately predict the results of the aggregation method, suggesting that aggregation is an internal consistency reliability procedure. The equating of stability with traditional notions of reliability was questioned.     

Irrelevance of mitigating circumstances in retaliatory behavior at high levels of excitation

Subjects were aggressively instigated by a provoker. They then performed either a nonstrenuous or a strenuous task in order to be placed in either a moderate or an extreme state of sympathetic arousal. Following the task, they either learned or did not learn about mitigating circumstances behind the provoker's behavior. This information was received prior to the provision of an opportunity to retaliate. Under conditions of moderate arousal, mitigating circumstances were found to reduce retaliation. In contrast, these circumstances failed to exert any appreciable effect on retaliation under conditions of extreme arousal. In addition, the induction of extreme arousal was observed to increase retaliatory behavior. The findings were considered to support a model of hostility and aggression that postulates a specific interdependency of cognitive and excitatory processes.     

A correction to “The retinal reference of the tilt aftereffect” by Coltheart and Cooper

Coltheart and Cooper (1972) reexamined the data of Day and Wade (1969) concerning the retinal or gravitational reference for normalization and the tilt aftereffect. Their analysis contained a factual error concerning the procedure employed in the latter investigation, which is here corrected. Day and Wade did not, however, distinguish between normalization and aftereffect. When this distinction is made, the data from the two studies taken together indicate that deviation of an inspection line from the vertical retinal meridian is not sufficient to produce normalization but does yield a visual tilt aftereffect.     

Induced subject-relative movement: Persistence of apparent movement of a stationary point after removal of inducing stimulus

It was observed by chance that perceived movement of a stationary spot of light in a dark featureless field persists after its induced movement by a moving frame. When the frame was suddenly occluded, apparent movement of the spot persisted in the same direction as prior induced movement. The effect which is compelling and readily reported and referred to as induced subject-relative movement (ISRM) was confirmed and further investigated in four experiments. In the first, the informal observations of ISRM were confirmed using manual tracking to index perceived movement, and in the second, it was shown to occur only very slightly and briefly when the frame merely stopped. In the third experiment, ISRM was shown to occur following two different paths of induced movement, and in the fourth, not to occur following real movement of the spot, which was almost indistinguishable from its induced movement. It is suggested that the effect arises from the absence of a signal for cessation of perceived movement when the frame disappears.     

Interpretations of sexual harassment: An attributional analysis

Two studies were conducted to examine an attributional model of judgments of sexual harassment. The key assumption of the model is that judgments of sexual harassment involve the attribution of negative intentions (e.g., hostility or callousness) to an actor with regard to a sexual behavior. The two studies effectively demonstrated that many factors known to influence the attribution of intentionality play an important role in judgments of sexual harassment. The findings are discussed with regard to understanding how people differ in their judgments of sexual harassment.The studies described in this article were reported in a presentation at the 1986 meeting of the Midwestern Psychological Association in Chicago.     

The representation of uniform motion in vision

For veridical detection of object motion any moving detecting system must allocate motion appropriately between itself and objects in space. A model for such allocation is developed for simplified situations (points of light in uniform motion in a frontoparallel plane). It is proposed that motion of objects is registered and represented successively at four levels within frames of reference that are defined by the detectors themselves or by their movements. The four levels are referred to as retinocentric, orbitocentric, egocentric, and geocentric. Thus the retinocentric signal is combined with that for eye rotation to give an orbitocentric signal, and the left and right orbitocentric signals are combined to give an egocentric representation. Up to the egocentric level, motion representation is angular rather than three-dimensional. The egocentric signal is combined with signals for head and body movement and for egocentric distance to give a geocentric representation. It is argued that although motion perception is always geocentric, relevant registrations also occur at the three earlier levels. The model is applied to various veridical and nonveridical motion phenomena.     

Provoked and unprovoked aggressiveness in athletes

In a factorial design, athletic involvement (no varsity sport, varsity noncontact sport, varsity contact sport) was varied with induced disposition (unprovoked, provoked). Under conditions of no provocation, no significant differences in aggressiveness were observed between nonathletes and athletes, nor between noncontact- and contact-sport athletes. In contrast, under conditions of provocation, nonathletes displayed more aggressiveness than athletes. Non-contact-sport athletes behaved significantly less aggressively than both nonathletes and contact-sport athletes. Contact-sport athletes failed to behave significantly less aggressively than nonathletes, however. The findings were explained as the result of an acquired superior ability in athletes to cope with provocation under competitive circumstances, which is partially counteracted in contact-sport athletes by their aggressiveness habits and disinhibition training.