Insight without cortex: lessons from the avian brain

Insight is a cognitive feature that is usually regarded as being generated by the neocortex and being present only in humans and possibly some closely related primates. In this essay we show that especially corvids display behavioral skills within the domains of object permanence, episodic memory, theory of mind, and tool use/causal reasoning that are insightful. These similarities between humans and corvids at the behavioral level are probably the result of a convergent evolution. Similarly, the telencephalic structures involved in higher cognitive functions in both species show a high degree of similarity, although the forebrain of birds has no cortex-like lamination. The neural substrate for insight-related cognitive functions in mammals and birds is thus not necessarily based on a laminated cortical structure but can be generated by differently organized forebrains. Hence, neither is insight restricted to mammals, as predicted from a “scala naturae”, nor is the laminated cortex a prerequisite for the highest cognitive functions.     

Asymmetrical transfer of training between hands: implications for interhemispheric communication in normal brain

Two experiments are presented which investigated claims of asymmetrical transfer of training between the hands/hemispheres. In Experiment 1, 96 right- and left-handed male undergraduates practiced an inverted-reversed printing task with either the right or the left hand. Transfer to the opposite hand was then compared to same-hand transfer, in a between-subject design. In Experiment 2, 176 right-handed boys and girls were tested at ages 7, 9, and 11 years. For right-handed subjects in both experiments, the left hand benefited more from opposite-hand training than did the right. The reverse was true for left-handers in Experiment 1, although one group (who wrote with the "inverted" position) showed little transfer in either direction. Two current models of interhemispheric interaction do not satisfactorily explain these findings. A third model, based on cross-activation, may provide a more effective alternative.     

Language representation in the human brain: evidence from cortical mapping

The manner in which the human brain processes grammatical-syntactic and lexical-semantic functions has been extensively debated in neurolinguistics. The discreteness and selectivity of the representation of syntactic-morphological properties in the dominant frontal cortex and the representation of the lexical-semantics in the temporo-parietal cortex have been questioned. Three right-handed adult male neurosurgical patients undergoing left craniotomy for intractable seizures were evaluated using various grammatical and semantic tasks during cortical mapping. The sampling of language tasks consisted of trials with stimulation (experimental) and without stimulation (control) from sites in the dominant fronto-temporo-parietal cortex The sampling of language implicated a larger cortical area devoted to language (syntactic-morphological and lexical-semantic) tasks. Further, a large part of the fronto-parieto-temporal cortex was involved with syntactic-morphological functions. However, only the parieto-temporal sites were implicated with the ordering of lexicon in sentence construction. These observations suggest that the representation of language in the human brain may be columnar or multilayered.     

Asymmetrical switch costs in children

Switching between tasks produces decreases in performance as compared to repeating the same task. Asymmetrical switch costs occur when switching between two tasks of unequal difficulty. This asymmetry occurs because the cost is greater when switching to the less difficult task than when switching to the more difficult task. Various theories about the origins of these asymmetrical switch costs have emerged from numerous and detailed experiments with adults. There is no documented evidence of asymmetrical switch costs in children. We conducted a series of studies that examined age-related changes in asymmetrical switch costs, within the same paradigm. Similarities in the patterns of asymmetrical switch costs between children and adults suggested that theoretical explanations of the cognitive mechanisms driving asymmetrical switch costs in adults could be applied to children. Age-related differences indicate that these theoretical explanations need to incorporate the relative contributions and interactions of developmental processes and task mastery.     

Asymmetrical international attitudes

In general, attitudes towards nations have a fair amount of reciprocity: nations either like each other, are relatively indifferent to each other, or dislike each other. Sometimes, however, international attitudes are asymmetrical. In this study, we use social identity theory in order to explain asymmetrical attitudes. Parting from social identity theory, asymmetrical attitudes can be predicted to occur most likely between countries that are linguistically either similar or closely related, but differ in size. Europe, more than any other continent, offers a rich variety of nations which represent natural conditions for our study, such as size and degree of linguistic similarity. In order to test hypotheses derived from social identity theory, we asked respondents (N = 405) from (Dutch‐ and French‐speaking) Belgium, France, Germany, and The Netherlands to fill out a questionnaire on three large nations (Germany, Great Britain, France) and three smaller ones (The Netherlands, Belgium, and Denmark). Results strongly supported hypotheses and confirm that a social identity approach may help to better understand international attitudes. Copyright © 2002 John Wiley & Sons, Ltd.     

Asymmetrical brain activity induced by voluntary spatial attention depends on the visual hemifield: a functional near-infrared spectroscopy study

The effect of the visual hemifield to which spatial attention was oriented on the activities of the posterior parietal and occipital visual cortices was examined using functional near-infrared spectroscopy in order to investigate the neural substrates of voluntary visuospatial attention. Our brain imaging data support the theory put forth in a previous psychophysical study, namely, the attentional resources for the left and right visual hemifields are distinct. Increasing the attentional load asymmetrically increased the brain activity. Increase in attentional load produced a greater increase in brain activity in the case of the left visual hemifield than in the case of the right visual hemifield. This asymmetry was observed in all the examined brain areas, including the right and left occipital and parietal cortices. These results suggest the existence of asymmetrical inhibitory interactions between the hemispheres and the presence of an extensive inhibitory network.     

Asymmetrical cross-language priming effects

Three experiments were conducted to examine cross-language priming in bilinguals. The first was a cross-language primed lexical decision task experiment with Chinese-English bilinguals. Subjects made lexical decisions about primary associate targets in the two languages at the same rate, but priming occurred only when the prime was in their first language (L1), Chinese, and the target was in their second language (L2), English. Experiment 2 produced the same pattern of asymmetrical priming with two alphabetic languages, French and Dutch. In Experiment 3, the crucial stimuli were translation equivalents. In contrast to the results of Experiments 1 and 2, priming occurred across languages in both the L1-L2 and L2-L1 conditions. However, this priming was also asymmetrical, with more priming occurring in the L1-L2 condition. A tentative separate-interconnected model of bilingual memory is described. It suggests that the representations of words expressed in different languages are stored in separate memory systems, which may be interconnected via one-to-one links between same translation-equivalent representations as well as meaning-integration processes.     

Asymmetrical stimulus control and the mirror-image problem

An analysis of the mirror-image discrimination literature revealed a number of inconsistent and paradoxical results. A unifying conception was proposed and it was argued that lateral mirror-image stimuli constitute a special class of problems on which effective performance is related to the introduction of an asymmetrical event into the task. Some implications were derived and tested in two experiments. First, five different response modes were compared for children required to discriminate two lateral or up-down mirror-image stimulus pairs. Acquisition was significantly faster on the latter problems. On the former, it was shown that responding to just one side of the lateral mirror-image stimuli led to significantly faster learning. Subsequent generalization tests indicated control by one part of the stimulus display for those who responded to one side. Next, Ss unable to learn the problem in Experiment I were given further acquisition trials. Only those children given training designed to promote selective stimulus control learned the problem.     

Introspection and cognitive brain mapping: from stimulus-response to script-report

Cognitive science has wholeheartedly embraced functional brain imaging, but introspective data are still eschewed to the extent that it runs against standard practice to engage in the systematic collection of introspective reports. However, in the case of executive processes associated with prefrontal cortex, imaging has made limited progress, whereas introspective methods have considerable unfulfilled potential. We argue for a re-evaluation of the standard 'cognitive mapping' paradigm, emphasizing the use of retrospective reports alongside behavioural and brain imaging techniques. Using all three sources of evidence can compensate for their individual limitations, and so triangulate on higher cognitive processes.     

Asymmetrical perceptual load in lateralised word processing

We applied the Load Theory of attention (Lavie, 1995, 2005) to the case of distraction during processing of lateralised words presented in either the right or the left visual fields. Previous research (Brand-D'Abrescia & Lavie, 2007) showed that lexicality affects selective attention such that the number of letters in a search task only increases perceptual load and reduces irrelevant distractor effects for searches in nonwords but not in words. The present study examined the hypothesis that the effect of lexicality on distractor processing would be stronger for words presented to the left compared to the right hemisphere. The results supported this hypothesis and their implications for attention to words in the two cerebral hemispheres are discussed. We suggest that the efficiency of attentional selection differed because perceptual load in the visual fields taxed processing depending on hemispheric language expertise.     

Asymmetrical drawing patterns on the temples by left-handers

Twenty-three Japanese genuine left-handers were selected by a Laterality Quotient scale and asked to draw the letter S on their own temples and foreheads. The way they drew on the temples showed an asymmetry that was the mirror reversal of that of right-handers, as found in a previous study. Left-handers drew a reversed letter S on their right temple much more often than on the left temple, whereas right-handers drew them in reverse more often on the left temple. They also drew it in reverse on the forehead irrespective of their handedness.     

History and future directions of human brain mapping and functional neuroimaging

It has long been known that there is some degree of localisation of function in the human brain, as indicated by the effects of traumatic head injury. Work in the middle of the 20th century, notably the direct cortical stimulation of patients during neurosurgery, suggested that the degree and specificity of such localisation of function were far greater than had earlier been imagined. One problem with the data based on lesions and direct stimulation was that the work depended on the study of what were, by definition, damaged brains. During the second half of the 20th century, a collection of relatively non-invasive tools for assessing and localising human brain function in healthy volunteers has led to an explosion of research in what is often termed "Brain Mapping". The present article reviews some of the history associated with these tools, but emphasises the current state of development with speculation about the future.     

A space for measuring mind and brain: interdisciplinarity and digital tools in the development of brain mapping and functional imaging, 1980-1990

Brain mapping is said to have opened up the possibility of a new collaboration between the sciences of mind and the sciences of the brain, potentially leading to a new kind of scientist, sometimes called "cognitive neuroscientist." This article traces the recent history of brain mapping and analyzes the processes that have led to a new "close working relationship" between the sciences of mind and brain. A key part of the working relationship is shown to be constituted through the development of the Talairach system, a digital space in which to measure structure and function. The development of meaningful brain mapping data involves the creation of measurement spaces that allow interdisciplinary collaboration and is not the result solely of theoretical developments or of the application of a technology.     

Functional brain mapping of extraversion and neuroticism: learning from individual differences in emotion processing

This review outlines how functional brain imaging, using an individual-differences approach in the processing of emotional stimuli, has begun to reveal the neural basis of extraversion (E) and neuroticism (N), two traits that are linked to both emotion and health. Studies using functional magnetic resonance imaging have shown that individual differences in participants' E and N scores are correlated with individual differences in brain activation in specific brain regions that are engaged during cognitive-affective tasks. Imaging studies using genotyped participants have begun to address the molecular mechanisms that may underlie these individual differences. The multidisciplinary integration of brain imaging and molecular genetic methods offers an exciting and novel approach for investigators who seek to uncover the biological mechanisms by which personality and health are interrelated.     

Asymmetrical interactions between thirst and hunger in pavlovian-instrumental transfer

Pavlovian-instrumental transfer experiments have demonstrated that a stimulus paired with a sucrose solution under hunger will increase instrumental performance under thirst relative to a stimulus previously paired with food pellets. In Experiment 1 it was demonstrated that this difference is, in part, produced by suppression induced by the pellet stimulus, which, it was found, acted to reduce instrumental performance under thirst. In Experiment 2, the reverse shift was examined, comparing the effects of stimuli paired with either a saline solution or a sucrose solution under thirst on instrumental performance under hunger. Although the sucrose stimulus was found to elevate performance when hungry, the saline stimulus was found to be without effect. This asymmetry in the interaction between hunger and thirst is discussed in terms of the way motivational states control the interaction between sensory and affective components of the reinforcer.     

Asymmetrical hand usage in infancy: An ethological approach

Observations of the motor behavior of 22 infants were made by 8-hour daily video recording of nursery school activity over 11 days. Recorded object-oriented manipulating or holding actions were scored as the number of movements made by each hand separately and together, by each child, each day, and the average duration of hand activity. For the group, the right hand made significantly more movements than the left, and the duration of right-hand use was longer than the left. Although individual differences in frequency of hand use were reliably consistent, they were not for movement duration. The results show that data from spontaneous object manipulation can be a highly reliable and valid means of assessing differences in hand usage.