Correspondence should be addressed to David A. Leopold email@example.comDuring the viewing of certain patterns, widely known as ambiguous or puzzle figures, perception lapses into a sequence of spontaneous alternations, switching every few seconds between two or more visual interpretations of the stimulus. Although their nature and origin remain topics of debate, these stochastic switches are generally thought to be the automatic and inevitable consequence of viewing a pattern without a unique solution. We report here that in humans such perceptual alternations (...) can be slowed, and even brought to a standstill, if the visual stimulus is periodically removed from view. We also show, with a visual illusion, that this stabilizing effect hinges on perceptual disappearance rather than on actual removal of the stimulus. These findings indicate that uninterrupted subjective perception of an ambiguous pattern is required for the initiation of the brain-state changes underlying multistable vision.Visual perception involves coordination between sensory sampling of the world and active interpretation of the sensory data. Human perception of objects and scenes is normally stable and robust, but it falters when one is presented with patterns that are inherently ambiguous or contradictory. Under such conditions, vision lapses into a chain of continually alternating percepts, whereby a viable visual interpretation dominates for a few seconds and is then replaced by a rival interpretation. This multistable vision, or 'multistability', is thought to result from destabilization of fundamental visual mechanisms, and has offered valuable insights into how sensory patterns are actively organized and interpreted in the brain1, 2. Despite a great deal of recent research and interest in multistable perception, however, its neurophysiological underpinnings remain poorly understood. Physiological studies have suggested that disambiguation of ambiguous patterns. (shrink)
Background: Continuous viewing of ambiguous patterns is characterized by wavering perception that alternates between two or more equally valid visual solutions. However, when such patterns are viewed intermittently, either by repetitive presentation or by periodic closing of the eyes, perception can become locked or "frozen" in one configuration for several minutes at a time. One aspect of this stabilization is the possible existence of a perceptual memory that persists during periods in which the ambiguous stimulus is absent. Here, we use (...) a novel paradgim of temporally interleaved ambiguous stimuli to explore the nature of this memory, with particular regard to its potential impact on perceptual organization. Results: We found that the persistence of a perceptual configuration was robust to interposed visual patterns and, further, that at least three ambiguous patterns, when interleaved in time, could undergo parallel, stable time courses. Then, using an interleaved presentation paradigm, we established that the occasional reversal in one pattern could be coupled with that of its interleaved counterpart, and that this coupling was a function of the structural similarity between the patterns. Conclusions: We postulate that the stabilization observed with repetitive presentation of ambiguous patterns can be at least partially accounted for by processes that retain a recent perceptual interpretation, and we speculate that such memory may be important in natural vision. We further propose tha the interleaved paradigm introduced here may be of great value to gauge aspects of stimulus similarity that appeal to particular mechanisms of perceptual organization. (shrink)
The concept of the person, and the notion that the latter is an entity separate and distinct from other persons, has persisted as one of the more secure ‘givens’ of philosophical thought. We have very little difficulty, in observer language, in pointing to a person, describing his or her attributes, distinguishing him or her from other persons, etc. Likewise, it is ordinarily not much of a problem to subjectively experience, both sensorially and conceptually, the self – that is, to distinguish (...) in agent language ‘my person’ from the rest of the universe. The second of these two perspectives on the person defines the ‘I,’ ‘ego,’ or ‘identity.’ Several recent developments in experimental psychology and brain science – while not defeating the ordinary notion of the person on the merits of data per se – at least force a re-thinking of tacit assumptions basic to our sense of the concepts of both the person and personal identity. In this paper, I would like to show how the concept of the person needs revision, and at the same time to raise some objections to Shaffer's (1977) account of the consequences of brain bisection and brain transplant with respect to the fate of the person and his identity. CiteULike Connotea Del.icio.us What's this? (shrink)
One way of dealing with the proliferation of conjectures that accompany the diverse study of the evolution of language is to develop precise and testable models which reveal otherwise latent implications. We suggest how verbal theories of the role of individual development in language evolution can benefit from formal modeling, and vice versa.
Evolutionary psychologists should go beyond research on individual differences in attitudes and focus more on detailed models of psychological mechanisms. We argue for complementing attitude research with agent-based computational modeling of mate choice. Agent-based models require detailed specification of individual choice mechanisms that can be evaluated in terms of both their psychological plausibility and the population-level outcomes they produce.
Scholars have noted the need to examine the psychometric properties of measures that can be used in evaluating moral education programs. The present study was designed to examine the best?fitting factor model of a commonly?used measure of prosocial moral reasoning (PROM) across samples from Brazil and the USA, gender and adolescent age groups. The samples consisted of 619 college students (M age = 20.59 years, SD = 4.08; 41% men, 59% women) and 239 middle and high school students (M age (...) = 14.02 years, SD = 3.04; 45% boys, 55% girls) from the USA. There were 114 college students (M age = 21.81, SD = 4.33; 35% men, 65% women) and 136 middle and high school students (M age = 14.93 years, SD = 1.55; 42% boys, 58% girls) from Brazil. A series of (multigroup) confirmatory factor analyses were conducted to test the best fitting factor structure of the PROM and the invariance of this factor structure across culture, gender and age groups. Evidence for measurement invariance was found such that a four?factor model was a slightly better fitting model than the five?factor model across all groups. Discussion focuses on theoretical and methodological implications of the findings. (shrink)
This study examined relations between parenting dimensions (involvement, autonomy support and structure) and adolescents' moral values internalisation. A sample of 101 adolescents (71% female; 76% white; M age = 16.10, SD = 1.17) reported on the parenting behaviour of one of their parents and on their own moral values. Four forms of values regulation were assessed (external, introjected, identified and integrated), as well as overall internalisation. Structure was positively linked to external and introjected regulation, involvement was positively associated with identified (...) and integrated regulation and structure was negatively linked to overall internalisation. Additionally, positive interactions were found for autonomy support and involvement predicting identified and integrated regulation. Implications for parenting and moral education are discussed. (shrink)
This study examined the hypothesis that religiosity would be differentially related to six types of adolescent prosocial behaviour, and that these relations would be mediated by the prosocial value of kindness. Self?report data were collected from 142 high school students (63 per cent female; 91 per cent White; M age?=?16.8, S?=?.80). Religiosity was a significant positive predictor of kindness, as well as compliant, anonymous and altruistic prosocial behaviour, but not public, dire and emotional prosocial behaviour. Associations between religiosity and both (...) compliant and altruistic prosocial behaviours were mediated by kindness. Direct and indirect paths were found between religiosity and anonymous prosocial behaviour. Thus, partial support was found for the mediational hypothesis. Discussion focused on the utility of distinguishing among different types of prosocial behaviours and on the role of religion and values in promoting moral education. (shrink)
We agree that much of language evolution is likely to be adaptation of languages to properties of the brain. However, the attempt to rule out the existence of language-specific adaptations a priori is misguided. In particular, the claim that adaptation to cannot occur is false. Instead, the details of gene-culture coevolution in language are an empirical matter.
There are three concerns regarding Rachlin's altruism model. First, proximal causal mechanisms such as those identified by cognitive neuroscientists and behavioral neuropharmacologists are not emphasized. Second, there is a lack of clear testable hypotheses. And third, extreme forms of altruism are emphasized rather than common forms. We focus on an overarching theme – proximal mechanisms of individual differences in altruism.
This joint article reflects the authors’ personal views regarding noteworthy advances in the neuroscience of consciousness in the last ten years, and suggests what we feel may be promising future directions. It is based on a small conference at the Samoset Resort in Rockport, Maine, USA, in July of 2012, organized by the Mind Science Foundation of San Antonio, Texas. Here, we summarize recent advances in our understanding of subjectivity in humans and other animals, including empirical, applied, technical and conceptual (...) insights. These include the evidence for the importance of fronto-parietal connectivity and of feedback processes, both of which enable information to travel across distant cortical areas effectively, as well as numerous dissociations between consciousness and cognitive functions, such as attention, in humans. In addition, we describe the development of mental imagery paradigms, which made it possible to identify covert awareness in non-responsive subjects. Non-human animal consciousness research has also witnessed substantial advances on the specific role of cortical areas and higher order thalamus for consciousness, thanks to important technological advances. In addition, much progress has been made in the understanding of non-vertebrate cognition relevant to possible conscious states. Finally, major advances have been made in theories of consciousness, and also in their comparison with the available evidence. Along with reviewing these findings, each author suggests future avenues for research in their field of investigation. (shrink)
The necessary starting point in an analysis of Yugoslavia is the level of development of self-management. The 1973 law on collective work, the goal of which was to contain growing technocratic tendencies in the enterprises, has disciplined the powers of the “work units,” the democratic cells which are directed from below (in practice, they are something similar to department assemblies) and which were supposed to provide the most authentic foundation for self-management. These productive units can be compared to Western capitalist (...) firms whose goal, as we know, it to strengthen control over production costs, increase economic efficiency, facilitate management and create a more congenial atmosphere for work. (shrink)
Today there is a great interest in reconstructing Lenin's thought concerning the relation between vangard and masses. Lenin's definitive theses on the problem are seen to have been outlined in his famous and much discussed work, What Is to Be Done? which, for some, remains the only scientific answer to the problem (not fully developed by Marx and Engels) of the passage from “class-in-itself” to “class-for-itself.” For others, this work, impregnated by intellectualism and idealism, is seen as a classic of (...) the Stalinist era and is held to be the root of all the bureaucratic deviations of the Soviet experience. (shrink)
In this paper I present an argument against the feasibility of the Imitation Game as a test for thinking or language understanding. The argument is different from the five objections presented by Turing in his original paper, although it tries to maintain his original intention. I therefore call it “the Sixth Argument” or “the Argument from Context”. I show that – although the argument works against the original version of the imitation game – it may suggest a new version of (...) the Turing Test, still coherent with the idea of thinking and understanding as symbol manipulation. In a new form, the main idea which lies behind the original Imitation Game remains untouched by the criticism of Searle’s Chinese room argument and suggest a possible implementation which avoids some of the shortcomings of the original Turing Test. (shrink)
Dieter Senghaas' recent volume on the problem of underdevelopment represents one of the few actual efforts in Western European culture of the last twenty years toward understanding the problem of underdevelopment from a progressive perspective. This exception is all the more relevant since it comes from a German scholar, i.e., an exponent of a scientific climate which is definitely conservative and often openly reactionary. Starting from the empirical discovery of the existence of an unbalanced social division of labor in the (...) world market (pp. 15 and 25), Senghaas is led to the repudiation of the Ricardian law of comparative costs and benefits (p. 27ff). (shrink)