Towards a true neural stance on consciousness

Consciousness is traditionally defined in mental or psychological terms. In trying to find its neural basis, introspective or behavioral observations are considered the gold standard, to which neural measures should be fitted. I argue that this poses serious problems for understanding the mind-brain relationship. To solve these problems, neural and behavioral measures should be put on an equal footing. I illustrate this by an example from visual neuroscience, in which both neural and behavioral arguments converge towards a coherent scientific definition of visual consciousness. However, to accept this definition, we need to let go of our intuitive or psychological notions of conscious experience and let the neuroscience arguments have their way. Only by moving our notion of mind towards that of brain can progress be made.     

The Simplest Axiom System for Plane Hyperbolic Geometry

We provide a quantifier-free axiom system for plane hyperbolic geometry in a language containing only absolute geometrically meaningful ternary operations (in the sense that they have the same interpretation in Euclidean geometry as well). Each axiom contains at most 4 variables. It is known that there is no axiom system for plane hyperbolic consisting of only prenex 3-variable axioms. Changing one of the axioms, one obtains an axiom system for plane Euclidean geometry, expressed in the same language, all of whose axioms are also at most 4-variable universal sentences. We also provide an axiom system for plane hyperbolic geometry in Tarski's language L _B which might be the simplest possible one in that language.     

The role of figure-ground segregation in change blindness

Partial report methods have shown that a large-capacity representation exists for a few hundred milliseconds after a picture has disappeared. However,change blindness studies indicate that very limited information remains available when a changed version of the image is presented subsequently. What happens to the large-capacity representation? New input after the first image may interfere, but this is likely to depend on the characteristics of the new input. In our first experiment, we show that a display containing homogeneous image elements between changing images does not render the largecapacity representation unavailable. Interference occurs when these new elements define objects. On that basis we introduce a new method to produce change blindness: The second experiment shows that change blindness can be induced by redefining figure and background, without an interval between the displays. The local features (line segments) that defined figures and background were swapped, while the contours of the figures remained where they were. Normally, changes are easily detected when there is no interval. However, our paradigm results in massive change blindness. We propose that in a change blindness experiment, there is a large-capacity representation of the original image when it is followed by a homogeneous interval display, but that change blindness occurs whenever the changed image forces resegregation of figures from the background.     

Improved mental rotation by near-sighted subjects

Several studies have shown significant correlations among factors such as sex, age, and hormone levels with performance on mental rotation tasks. To perform spatial rotation also seems to be related to cognitive abilities such as musical skills. The present experiment investigated a possible relationship for enhanced spatial abilities, as observed in near-sighted subjects, with mental rotation performance. 39 near-sighted and 21 normal-sighted subjects were tested on a mental rotation task using two-dimensional representations of three-dimensional objects. Near-sighted subjects displayed fewer errors in possible rotations than normal-sighted subjects. There was no difference in errors between groups in identification of mirror images ("impossible rotations"). Results were interpreted in terms of a relation between enhanced reliance on nonvisual information by near-sighted subjects and improved spatial representation.     

Luria in Uzbekistan: The Vicissitudes of Cross-Cultural Neuropsychology

If the material conditions of culture shape cognitive structures, as Luria and Vygotsky argued, the extraordinarily deep and rapid restructuring of historical forms (Luria, 1971, 265) in the Soviet Republics that followed the Bolshevik revolution of 1917 provided a natural laboratory to determine whether processes of modernization changed traditional ways of thinking. This was the purpose of Luria's 1931 expedition to the Soviet Republic of Uzbekistan in central Asia. Luria's initial reports attracted vitriolic criticism because he had allegedly belittled primitive Uzbeki culture. The lasting importance of the Uzbek expedition is its emphasis on culture as a determinant of cognitive processes that remains valid to the present: in 1984, Gilbert replicated Luria's field studies in South Africa with near-identical results. Yet current neuropsychology has been slow to recognize the need for culturally sensitive assessment.     

Intellectual differences among Mexican Americans, Papagos and Whites, independent of g

Patterns of intellectual abilities for Mexican American and Native American Papago children were contrasted with those of White children, independent of overall differences in ability. Large differences in highly verbal skills remained, with Whites consistently outscoring the other two groups. Native Americans showed higher performance than Whites on spatial-visualization tasks but Mexican Americans exceeded Whites on no tasks. These race-related patterns of ability are nearly opposite those found in Black–White comparisons.     

Self-rated adjustment and sex-typing on the Bem Sex-Role Inventory: Is masculinity the primary predictor of adjustment?

Questions concerning the relationship between self-rated adjustment and the Bem Sex-Role Inventory (BSRI) were examined in two studies. In Study I, whether sex-typing was defined by Bem's original t-test criterion or the newer median-split criterion, superior adjustment was associated with androgynous vs. traditional typing only among women, not men. Also in conflict with the androgyny position, adjustment differences among sex-types were accounted for by differences in masculinity, not in femininity or androgyny per se. The greater contribution of masculinity vs. femininity to self-rated adjustment may be exaggerated because BSRI femininity includes items which do not load on a unidimensional femininity factor. In Study II, inspection of these unrelated items suggested that they reduce the desirability of BSRI femininity, thereby reducing its relationship to adjustment. Comparisons between standard BSRI scoring and an alternative based on unidimensional subscales revealed that the alternative femininity subscale was judged to be more desirable, and it reduced the degree of difference between masculinity and femininity in their relationships to adjustment. Superior adjustment, however, was again associated with androgynous vs. traditional sex-typing only among women, and adjustment differences among sex-types were again accounted for by differences in masculinity.The authors acknowledge the assistance of the following persons who helped in the administration, scoring, or preparation of questionnaire materials: Jill Jamison, Eric Isberg, Kay Peter, Steve Zalinger, Walter Davis, James Ball, Mark Jensen, and Heidi Sanft. Correspondence should addressed to Dr. Louise Silvern, Psychology Department, University of Colorado, Boulder, Colorado 80309.     

Self-serving bias in the attribution of responsibility: Cognitive versus motivational explanations

The purpose of this study is to compare the cognitive and motivational explanations of differences in the responsibility assigned to the victim of a crime. It has generally been found that the victim of a crime is assigned more responsibility for that crime by similar others if its consequences are severe. The motivational explanation for this finding is that subjects are threatened by the idea that a serious crime can happen by chance. The cognitive explanation is that serious crimes are rarer and subjects attribute more of the responsibility for rarer events to those who experience them. This study tested these two explanations by independently varying the severity and the likelihood of a crime and examining attributions of responsibility to its victim. The results of the study support the cognitive explanation. Similar others were found to attribute more responsibility for a crime to the victim when that crime was presented as rare, irrespective of whether its consequences were mild or severe. In addition, when likelihood was controlled experimentally no effect of severity upon attributions of responsibility was found. These results suggest that, within the context of attributions of responsibility to victims, patterns of attribution consistent with those predicted by theories suggesting motivational influences upon attribution may actually represent the operation of cognitive processes.     

Analogue drinking assessment: Sensation seeking and gender

This study assessed the relationship between sensation seeking measured as a trait variable and drinking behaviors observed unobtrusively in the laboratory. It was hypothesized that high-sensation-seeking subjects would consume more alcohol than low sensation seekers and experience greater enhancement of positive moods and body sensations associated with intoxication. Thirty female and 31 male subjects divided into high- and low-sensation-seeking subgroups participated in an ad libitum drinking situation with the manifest task of taste rating three types of vodka (actually 95% alcohol) or tonic. Dependent variables included beverage consumption, positive/negative mood states, body sensations, breath estimates of blood alcohol levels, and self-rated level of intoxication. All subjects reported feeling the effects of alcohol. Contrary to predictions, high-sensation-seeking subjects neither consumed more alcohol than their low-sensation-seeking counterparts nor drank more alcohol than tonic, Paradoxically, low-sensation-seeking women displayed significantly greater alcohol intake and intoxication than all other groups. Possible explanations for findings were considered as well as the necessity for multimethod assessments of both predictor (i.e., sensation seeking) and criterion (i.e., alcohol consumption) variables across time and situations.This research was supported by Grant Award AA04042-03 from the National Institute on Alcohol Abuse and Alcoholism to the first and third authors. Special Appreciation is expressed to Anne T. Patsiokas, Susan W. Altman, Victoria Molony-Sinnott, and Pamela J. Thompson for their invaluable assistance in collecting and analyzing the data.