Distance perception and the ambiguity of visual stimulation: A theoretical note

Certain current views postulate that visual perception, especially of distance, is a function of optical stimulation alone. It is shown here that the optical array does not, in fact, specify absolute distance unambiguously, for either a stationary or a moving O. In view of this ambiguity of optical information, a more complex theory, comprising both visual and nonvisual information, as needed to explain, veridical perception.     

FACTORS INFLUENCING TWO-DIMENSIONAL FORM PERCEPTION

The perceived shape of a circle and ellipse has been studied as influenced by the size of the figure, size of the reference frame, contrast and intensity. It was found that these factors have a systematic influence upon form perception. The data are considered within the context of the shape slant invariance hypothesis and are interpreted as providing evidence against this hypothesis as applied to the proximal form.     

BEHAVIOUR OF RATS UNDER THE INFLUENCE OF ETHYL ALCOHOL IN AN OPEN-FIELD SITUATION

In a standardized open-field test, ambulation, defecation, time of non-locomotor activity, time spent motionless, preening, and rearing were recorded. Inter-observer differences were small. Test repetition caused significant behavioural changes. Different rats were used for each of five doses of alcohol (0.5–2 mg/g). The lowest dose (0.75 mg/g) affecting behaviour significantly increased time motionless, decreased non-locomotor activity, and depressed preening. Ambulation was the last sensitive measure of behaviour. The results suggest that arousal mechanisms are particularly sensitive to alcohol. The procedure seems useful for studies of effects of small doses of alcohol.     

Sex differences in episodic memory: minimal influence of estradiol

Sex differences exist for several cognitive tasks and estrogen has been suggested to influence these differences. Eighteen men and 18 women were matched on age and estradiol level. Potential sex differences were assessed in episodic memory, semantic memory, verbal fluency, problem solving, and visuospatial ability. Significant sex differences, favoring women, were found for tasks assessing episodic memory. Correlations between estradiol level and cognitive performance were significant for face recognition in females. Since sex differences remained in verbal episodic memory tasks and face recognition despite matched levels of estradiol, circulating estradiol does not appear to be of paramount consequence for observed sex differences in episodic memory.     

Effects of training on age estimation

This study examined the possibility to improve accuracy of age estimates through training. Thirty‐four participants were divided into an experimental and a control group. The sessions included a pre‐test before training, six feedback or no‐feedback training tests and a post‐test after training. The experimental group performed the feedback tests and the control group the no‐feedback tests. Training was found to improve age estimation accuracy, particularly estimations of old stimuli, and training with feedback seemed to be superior to training without feedback. No difference was found between the groups at pre‐test, but at post‐test the experimental group exhibited greater accuracy in age estimation. Moreover, the experimental group increased its accuracy between the pre‐ and post‐tests. Copyright © 2006 John Wiley & Sons, Ltd.     

Elaborating Expressivism: Moral judgments,Desires and Motivation

According to expressivism, moral judgments are desire-like states of mind. It is often argued that this view is made implausible because it isn’t consistent with the conceivability of amoralists, i.e., agents who make moral judgments yet lack motivation. In response, expressivists can invoke the distinction between dispositional and occurrent desires. Strandberg (Am Philos Quart 49:81–91, 2012) has recently argued that this distinction does not save expressivism. Indeed, it can be used to argue that expressivism is false. In this paper I argue that expressivism is a much more complex thesis than Strandberg assumes. Once these complexities are acknowledged, Strandberg’s arguments are rendered ineffective and expressivism rendered more plausible.