On the perception of shape from shading.

The extraction of three-dimensional shape from shading is one of the most perceptually compelling, yet poorly understood, aspects of visual perception. In this paper, we report several new experiments on the manner in which the perception of shape from shading interacts with other visual processes such as perceptual grouping, preattentive search ("pop-out"), and motion perception. Our specific findings are as follows: (1) The extraction of shape from shading information incorporates at least two "assumptions" or constraints--first, that there is a single light source illuminating the whole scene, and second, that the light is shining from "above" in relation to retinal coordinates. (2) Tokens defined by shading can serve as a basis for perceptual grouping and segregation. (3) Reaction time for detecting a single convex shape does not increase with the number of items in the display. This "pop-out" effect must be based on shading rather than on differences in luminance polarity, since neither left-right differences nor step changes in luminance resulted in pop-out. (4) When the subjects were experienced, there were no search asymmetries for convex as opposed to concave tokens, but when the subjects were naive, cavities were much easier to detect than convex shapes. (5) The extraction of shape from shading can also provide an input to motion perception. And finally, (6) the assumption of "overhead illumination" that leads to perceptual grouping depends primarily on retinal rather than on "phenomenal" or gravitational coordinates. Taken collectively, these findings imply that the extraction of shape from shading is an "early" visual process that occurs prior to perceptual grouping, motion perception, and vestibular (as well as "cognitive") correction for head tilt. Hence, there may be neural elements very early in visual processing that are specialized for the extraction of shape from shading.     

Misremembering a familiar object: Mnemonic illusion,not drawing bias

It was reported by Jones (1990) that the design of British coins is systematically misremembered. Although the Queen's head in fact faces right, most people draw it facing left. It is possible, however, that the origin of this phenomenon does not reside in memory but instead in a leftward drawing bias. Two experiments of the three reported here tested this hypothesis. In Experiment 1, British participants attempted to recall the direction of the Queen's head but responded verbally instead of pictorially. The results were similar to those of Jones and thus contradict the hypothesis that misremembering of the Queen's head is caused by a leftward drawing bias. In Experiment 2, Canadian participants attempted to draw a Canadian coin. Leftward misremembering was not observed in this case. Thus the hypothesized importance of a leftward drawing bias was again not supported. Instead, the results provided support for the schema explanation of the Queen's Head memory illusion proposed by Jones. The results of Experiment 3, which compared memory for British coins and stamps, further bolstered this conclusion.     

The usefulness of the Western Aphasia Battery for differential diagnosis of Alzheimer dementia and focal stroke syndromes: preliminary evidence.

We assessed the usefulness of the Western Aphasia Battery for distinguishing the language disturbances caused by Alzheimer dementia (AD) from those caused by stroke. Using discriminant function analyses, the multiple variable "aphasia quotient--reading quotient--writing quotient" classified 29 (72.5%) of the 40 patients correctly. These 29 patients included 8 of 10 patients with left hemisphere infarction and fluent aphasia; 6 of 10 with AD; 5 of 10 patients with right hemisphere infarction; and all 10 of the neurologically normal control subjects. The patients with AD and those with right hemisphere stroke were the most difficult to classify using the aphasia battery.     

Effects of chronic variable stress and antidepressant drugs on behavioral inactivity during an uncontrollable stress: interaction between both treatments.

Rats submitted to a chronic variable stress regime exhibited more inactivity during inescapable shock as compared with unstressed rats. Besides, chronic treatments with desipramine, imipramine, clomipramine, or phenelzine reduce the amount of inactivity exhibited during this aversive experience. Furthermore, the combination of both chronic treatments--stress and antidepressants--resulted in a potentiation of the antidepressant effect alone. This higher antidepressant efficacy may result from the interaction of the neural mechanisms triggered by chronic stress exposure and antidepressant drugs.     

The relationship between research and design of AIDS prevention program

The global threat of AIDS requires massive public educational campaigns that employ social and behavioral sciences such as psychology, sociology, and anthropology because sexual behavior possesses a social dimension. Research is concerned with what stimulates behavioral change, what are the prerequisites of learned behavior, and what enables personal control over the environment and future. Educational programs designing strategies for AIDS prevention require social and behavioral science content and input. Interdisciplinary provides general principles with psychological, social, and cultural aspects of human behavior. Without knowledge about psychological processes (thinking, perception, speech, aspects of personality, and interactive behavior) and social processes (economic conditions, social networks, and resources) which are implicated in health problems and also in AIDS, these educational programs cannot produce credible results. These programs and their subsequent implementation require their application in practice in a systemic and consistent fashion. Evaluations are also needed to make sure that the applied processes for behavioral change conform to methodological criteria that ensure their effectiveness. These types of studies are more complex than pure AIDS research which is aimed at finding a cure.     

Representation by counsel: Right or obligation?

Since the Supreme Court's decision in Faretta v. California (1975), courts have generally permitted defendants to represent themselves, as long as they are competent to do so. The problem lies in the definition of competency to waive counsel, which has been vaguely defined by the courts. Little is known about the frequency of, or reasons for, attempts to waive counsel, about the process of forensic evaluation of such competency, and about the success of such attempts. The authors briefly review the case law on competency to waive representation, report on a longitudinal prospective study of these issues in a population of defendants referred to an inpatient forensic facility for evaluation of all types of competency related to their criminal prosecutions, and discuss the significance of the issue for forensic clinicians. A key question for courts, lawyers, and clinicians is whether a competency evaluation can be invoked to overcome a defendant's constitutional rights to self-representation and bail.     

Spatial cognition and neighborhood use: the relationship in older adults.

Measures of spatial cognition, neighborhood knowledge, and neighborhood use from the research described by Walsh, Krauss, and Regnier (1981) were examined to determine if laboratory tests of spatial cognition were significant predictors of older adults' use of their neighborhoods. The overall results show that laboratory-based measures of spatial cognition and subjects' knowledge of their neighborhoods are both significant predictors of their use of neighborhood goods and services. The ability to learn and remember the location and orientation of objects, when contextual cues were not provided at test, was more predictive of the participants' neighborhood use than either the participants' number of years in the neighborhood or their mobility. Spatial memory as measured by the Educational Testing Service Building Memory task predicted neighborhood knowledge, which was predictive of neighborhood use.     

Adult age differences in the rate of learning serial patterns: evidence from direct and indirect tests.

Subjects performed a serial reaction time task (adopted from Nissen & Bullemer, 1987) that contained a repeating pattern of spatial locations. In Experiment 1, following 20 repetitions of a 10- or 16-element pattern, reaction time was equally disrupted for both younger and older people when the sequence became random. In Experiment 2, the response times for subjects encountering the 10-element pattern were compared with those of subjects encountering a random sequence. These response time functions diverged at the same point in training for the 2 age groups. Thus, on this indirect measure of response time facilitation, both experiments revealed age similarity in the rate of pattern learning. In contrast, on a subsequent direct test of pattern learning that required prediction, the younger people earned a higher percentage correct score than the older in both experiments. Age-related dissociations between direct and indirect measures of learning and comparisons with memory-impaired populations are discussed.     

Respect for cultures,beliefs and attitudes: A way to better relationships and understanding

Beliefs and attitudes play a very important role in human behaviour. Particularly when strategies in psychological, social counselling and therpay are being forumulated, attitudes and beliefs, and beliefs about beliefs, play a crucial role. Personal, political and social considerations become more relevant and unavoidable (Lokare, 1975). When the counsellor or the therapist translates their theoretical and so-called scientific training and knowledge into gudance and advice things get tinted with the therapist's personal attudes and beliefs and mingle with those of the client (Loakare, 1974).     

On axiomatization of many-valued logics associated with formalization of plausible reasonings

This paper studies a class of infinite-valued predicate logics. A sufficient condition for axiomatizability of logics from that class is given.To the memory of Jerzy Supecki