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Hemisphere lateralization for cognitive processing of geometry
Abstract
A 54-item cross-modal visuo-tactile test involving geometrical discriminations in Euclidean, affine, projective and topological space (plane and 3-dimensional) was administered to 7 subjects with commissurotomy, 2 with hemispherectomy, 1 with agenesis of corpus callosum, and to 5 normal controls. Using blind manual stereognosis subjects selected one of a choice of three shapes, screened from sight, that best fitted a set of five different geometrical forms presented together on a panel in free vision. An intuitive apprehension of geometrical relations was involved that did not require formal training in geometry. Findings support a consistent minor hemisphere superiority and disclose orderly differences in left hemisphere capabilities correlated with the different types of geometry.
... Studies in brain-damaged patients provide compelling support for a right-hemisphere specialization for haptic processing (Fontenot and Benton, 1971;Milner and Taylor, 1972;Franco and Sperry, 1977;Kumar, 1977). Kumar (1977) had patients with hemispheric disconnection (i.e., split-brain) complete a tactile version of the Memory for Designs test (see Graham and Kendall, 1960). ...
... Participants made significantly fewer errors when using the left hand. The same result is found when patients actively encode geometrical shapes (Franco and Sperry, 1977). Franco and Sperry asked splitbrain patients to complete a geometrical shape-matching task. ...
... Studies involving psychophysics and neuroimaging have also demonstrated a right-hemisphere advantage for haptic processing in both humans (De Renzi et al., 1969;Milner and Taylor, 1972;Benton et al., 1973;Dodds, 1978;Riege et al., 1980;O'Boyle et al., 1987;Wilkinson and Carr, 1987;Fagot et al., 1993aFagot et al., ,b, 1994Butler et al., 2004;Harada et al., 2004;Loayza et al., 2011;Morange-Majoux, 2011;Tomlinson et al., 2011;Cormier and Tremblay, 2013;Stone and Gonzalez, 2014a,b) and non-human primates Fragaszy, 1996, 1999). For most of these studies, individuals have been asked to haptically explore, differentiate, or detect geometrical shapes (Franco and Sperry, 1977;Cormier and Tremblay, 2013;Stone and Gonzalez, 2014a,b), non-sense shapes (Dodds, 1978;Fagot et al., 1993aFagot et al., ,b, 1994, vibrations (Weinstein, 1978;Rhodes and Schwartz, 1981;Heller et al., 1990;Wiles et al., 1990), or object orientation (Cannon and Benton, 1969;Benton et al., 1973;Varney and Benton, 1975;Brizzolara et al., 1982). For instance, Fagot et al. (1993aFagot et al. ( ,b, 1994 had individuals haptically explore different cubes either unimanually or bimanually and measured accuracy during a recognition test. ...
This review aims to provide a comprehensive outlook on the sensory (visual and haptic) contributions to reaching and grasping. The focus is on studies in developing children, normal, and neuropsychological populations, and in sensory-deprived individuals. Studies have suggested a right-hand/left-hemisphere specialization for visually guided grasping and a left-hand/right-hemisphere specialization for haptically guided object recognition. This poses the interesting possibility that when vision is not available and grasping relies heavily on the haptic system, there is an advantage to use the left hand. We review the evidence for this possibility and dissect the unique contributions of the visual and haptic systems to grasping. We ultimately discuss how the integration of these two sensory modalities shape hand preference.
... Even for less complex operations that might be within the capacities of the higher nonhuman primates, it manifests superior abilities compared with the left hemisphere. It is capable of recognizing relations between solid geometric shapes and their depiction in opened-up two-dimensional drawings to a considerably better degree than the left hemisphere (Levy, 1970;Levy-Agresti & Sperry, 1968) and is superior to the left hemisphere in matching arcs of circles to whole circles of the same diameter (Nebes, 1971); in relating fragmented, exploded shapes to unified shapes (Nebes, 1972); in deciding whether tachistoscopically presented arrays of dots are aligned in rows or in columns, as denned by relative dot distances (Nebes, 1973); in classifying non-nameable objects according to various properties in a concept-formation task (Kumar, cited by Sperry, 1974); and in extracting set-defining characteristics for Euclidian, affine, projective, and topological sets (Franco & Sperry, 1977). ...
... The Franco and Sperry (1977) studies are definitive in showing the high level of geometric reasoning of which the human right hemisphere is capable. Patients saw in free vision a set of objects related by some geometric or topological invariant and were required to select by touch, from among three objects, the one belonging to the set. ...
Responds to M. S. Gazzaniga's review of right-hemisphere language in split-brain patients. The present author disagrees with (1) Gazzaniga's assumption that any capacity to extract meaning from spoken or written words is indicative of linguistic competence, and (2) Gazzaniga's claim that the right hemisphere is passive and nonresponsive. The present author provides evidence that, although the right hemisphere is nonlinguistic, it is active, highly intelligent, thinking, conscious, and fully human. (22 ref)
... For example, elbowmatching tasks have been shown to be more accurate in the left arm than in the right (Goble & Brown, 2007, 2008. Other research has also suggested a left hand (right hemisphere) specialization for haptic processing (Butler et al., 2004;Cormier & Tremblay, 2013;Fontenot & Benton, 1971;Franco & Sperry, 1977;Harada et al., 2004;Kumar, 1977;Loayza, Fernández-Seara, Aznárez-Sanado, & Pastor, 2011). For example, a study from our lab has found an increase in left-hand use for grasping when vision is occluded and an increase in right-hand use when haptic feedback is minimized (Stone & Gonzalez, 2014). ...
... It remains unclear why the Vision-only group did not show hand differences with respect to width. Perhaps, the right-hemisphere specialization for haptic processing (Butler et al., 2004;Cormier & Tremblay, 2013;Fontenot & Benton, 1971;Franco & Sperry, 1977;Harada et al., 2004;Kumar, 1977;Loayza et al., 2011) allowed more accurate estimates of left hand in the Vision?Haptics and the Haptics-only groups. ...
Previous research has found that the perception of our hands is distorted. The characteristics of this distortion are an overestimation of hand width and an underestimation of finger length. The present study examined the role that different sensory modalities (vision and/or haptics) play in the perception of our hands. Participants pointed to their concealed hand in one of three groups: Vision+Haptics, Vision-only, or Haptics-only. Participants in the Vision+Haptics group had vision (non-informative) of the experimental setup and of the pointing hand, but no vision of the hand being estimated. They also experienced haptic feedback as the palm of the hand was in contact with the undersurface of a tabletop, where the estimations were made. Participants in the Vision-only group, instead of placing the hand to be estimated underneath the tabletop, they placed it behind their backs. Participants in this group were asked to imagine as if the hand was under the table when making their estimations. In the Haptics-only group, participants completed the task with the hand underneath the tabletop (as in the Vision+Haptics group) but did so while wearing a blindfold (no vision). All participants estimated the position of ten landmarks on the hand: the fingertip and the metacarpophalangeal joint of each digit. Hand maps were constructed using a 3D motion capture system. Participants in the Haptics-only group produced the most accurate hand maps. We discuss the possibility that vision interferes with somatosensory processing.
... De même, certaines études utilisant les classiques méthodes d'analyse de la perception tactile par localisation de points et discrimination de deux points montrent soit aucun avantage de l'hémisphère droit ou de l'hémisphère gauche, soit une légère différence (Weinstein, 1968 ;Charron et al., 1996). Au contraire, les études de patients ayant subi une lésion cérébrale droite ou gauche impliquant des troubles somesthésiques ont mis en évidence certaines asymétries (Franco & Sperry, 1977). Il apparaît que les troubles de la perception tactile sont plus fréquents suite à une lésion de l'hémisphère droit que gauche. ...
... Toutefois, cette organisation est croisée car chaque hémisphère contrôle essentiellement les informations relatives à l'hémi-corps controlatéral (la main droite est contrôlée par l'hémisphère gauche par exemple). Néanmoins, les études de patients ayant subi des lésions cérébrales droite ou gauche impliquant des troubles somesthésiques ont mis en évidence certaines asymétries (Bottin et al, 1991 ;Franco & Sperry 1977). Il apparaît que les troubles de la perception tactile sont plus fréquents suite à une lésion de l'hémisphère droit que gauche. ...
The purpose of the work is to use the tactile modality to allow the surgeon to guide a needle until a target preserving the visual modality dedicated to the operative field observation. With this intention, the paradigm of sensory substitution using the lingual visuo-tactile device (Tongue Display Unit - TDU -) of Bach-y-Rita is exploited. This research relates to the guidance of puncture gesture with lingual electrotactile spatial information. The objective is to evaluate the performances of the lingual electrotactile system and the spatial tactile discriminative capacities of the tongue. For that, various experiments were carried out : two series of psychophysical fundamental experiments to analyze the lingual comfort and liminary electrotactile thresholds on various areas of the tongue surface and the capacity to discriminate electrotactile patterns of direction. The results are very heterogeneous according to the position of stimulation on the tongue and depend on the perceptive task carried out. Moreover, two experiments applied to the realization of trajectory of puncture using guidance TDU showed that a lingual electrotactile guidance allowed very precisely to direct a needle until a percutaneous target of a few millimeters.
... Particularly for visuomotor integration right hemisphere dominance has been well described (Callaert et al., 2011;Corballis, 2003). Symptoms resulting from lesions of the right hemisphere, particularly when the parietal cortex is involved, indeed include visuospatial disorientation and visuomotor deficit, but also contralateral neglect (Bogen and Gazzangia, 1965;Corbetta and Shulman, 2011;Franco and Sperry, 1977;Halligan et al., 2003;Perenin and Vighetto, 1988;Rossetti et al., 2003;Vallar and Perani, 1986). In this respect, the intact right hemisphere has been proposed to be more visually 'intelligent' than the left, equivalent to the superior capacities of the left hemisphere in other cognitive domains (Corballis, 2003). ...
... In this respect, the intact right hemisphere has been proposed to be more visually 'intelligent' than the left, equivalent to the superior capacities of the left hemisphere in other cognitive domains (Corballis, 2003). How such segregated hemisphere specializations are integrated in whole-brain neuronal networks, empowering one's sense of unity in perception and action (Bogen and Gazzangia, 1965;Franco and Sperry, 1977;Gazzaniga, 2005), remains an issue to be solved. In the present study, we are able to demonstrate differences between the left and right dorsal premotor cortex (PMd) regarding their patterns of connections in ipsilateral and contralateral hemispheres. ...
Lateralization of higher brain functions requires that a dominant hemisphere collects relevant information from both sides. The right dorsal premotor cortex (PMd), particularly implicated in visuomotor transformations, was hypothesized to be optimally located to converge visuospatial information from both hemispheres for goal-directed movement. This was assessed by probabilistic tractography and a novel analysis enabling group comparisons of whole-brain connectivity distributions of the left and right PMd in standard space (16 human subjects). The resulting dominance of contralateral PMd connections was characterized by right PMd connections with left visual and parietal areas, indeed supporting a dominant role in visuomotor transformations, while the left PMd showed dominant contralateral connections with the frontal lobe. Ipsilateral right PMd connections were also stronger with posterior parietal regions, relative to the left PMd connections, while ipsilateral connections of the left PMd were stronger with, particularly, the anterior cingulate, the ventral premotor and anterior parietal cortex. The pattern of dominant right PMd connections thus points to a specific role in guiding perceptual information into the motor system, while the left PMd connections are consistent with action dominance based on a lead in motor intention and fine precision skills.
... Based on the notion that the right hemisphere is specialized for visuospatial processing (e.g., Franco & Sperry, 1977;LeDoux, Wilson, & Gazzaniga, 1977) and that men are thought to excell in these tasks (e.g., Linn & Petersen, 1985), O'Boyle and Hoff (1987) conducted a study to explore the effects of sex and cerebral dominance (right vs left handedness) on mirrortracing performance. Contrary to one of their initial hypotheses, women outperformed men. ...
60 right-handed college students classified as preferring either a style of left or right hemisphericity mirror-traced a star pattern once with each hand. Speed of tracing and number of deviations outside the star pattern were the dependent measures. Analysis showed no statistically significant differences in performance between right- and left-style groups or between men and women. However, subjects classified as showing a right-hemisphericity style mirror-traced the star pattern significantly faster and more accurately with the left hand than with the right. The left-hemisphericity-scoring group displayed a nonsignificant tendency to perform better on the reverse pattern.
... The geometric stimuli were copied from Dehaene et al. (2006) and Franco & Sperry (1977) and created in the free software program Inkscape by tracing the stimuli from the images in the original papers. The images were all black and white. ...
Understanding geometry relies heavily on vision. In this work, we evaluate whether state-of-the-art vision language models (VLMs) can understand simple geometric concepts. We use a paradigm from cognitive science that isolates visual understanding of simple geometry from the many other capabilities it is often conflated with such as reasoning and world knowledge. We compare model performance with human adults from the USA, as well as with prior research on human adults without formal education from an Amazonian indigenous group. We find that VLMs consistently underperform both groups of human adults, although they succeed with some concepts more than others. We also find that VLM geometric understanding is more brittle than human understanding, and is not robust when tasks require mental rotation. This work highlights interesting differences in the origin of geometric understanding in humans and machines -- e.g. from printed materials used in formal education vs. interactions with the physical world or a combination of the two -- and a small step toward understanding these differences.
... Analysis of the training-related functional probe revealed for the 'novel' > 'trained' contrast greater activations in a right lateralized fronto-parietal network including the superior and inferior parietal lobule, the supramarginal gyrus, superior and inferior frontal gyri (frontal eye field (FEF)), the middle occipital cortex as well as the putamen. Even in comparatively early studies with split brain and neglect patients, specific involvement of the right hemisphere in visuo-spatial attention has been shown consistently (Franco & Sperry, 1977;Mesulam, 1981;Sperry, 1961 (Corbetta, Kincade, & Shulman, 2002;Corbetta, Patel, & Shulman, 2008). Indeed, the contrast 'novel sequence'>'trained sequence' shows considerable participation of dorsal-and ventral visuo-spatial attention systems. ...
This thesis investigated fronto-striatal plasticity processes in the human brain via a multilevel (genes, brain, behavior) and multimodal neuroimaging (functional- and structural magnetic resonance imaging, magnetic resonance spectroscopy) approach. Neuroplasticity—an intrinsic property of our nervous system—can act in fronto-striatal circuits, specifically in the ‘motor-loop’. Within this circuitry, the striatum, as key structure, and glutamate, as important neurotransmitter, enable the acquisition and automatization of motor skills (e.g. playing an instrument). On a molecular level, brain-derived neurotrophic factor, a neurotrophin, is known to influence cellular plasticity processes, and a single-nucleotide polymorphism of the brain-derived neurotrophic factor gene (BDNF val66met), has been related to impairments in hippocampal learning and plasticity in humans. However, research and respective findings on the influences of this genetic variant in motor skill learning within the fronto-striatal motor-circuitry remain fragmented. 135 healthy right-handed subjects (mean age = 26.96 +/- 9.05 years, 80 females, 54 Met allele carriers) participated in this study. They received training on a sequential visual isometric pinch task in the laboratory and motor skill learning was measured via increases on a speed-accuracy trade-off function (skill measure). Subsequently, magnetic resonance imaging was performed. For functional magnetic resonance imaging, an adapted version of the pinch-force task was used, consisting of the trained, a novel and two control conditions. Furthermore, structural magnetic resonance imaging and magnetic resonance (glutamate) spectroscopy was conducted. Genomic DNA was extracted from whole blood according to standard procedures. Data were analyzed using classical toolboxes for brain imaging data (SPM8, VBM8), for spectroscopy data (LCModel) as well as Matlab-routines and statistics programs for behavioral data and further analysis. To validate the structural neuroimaging results, data of an independent replication sample of 286 healthy right-handed subjects (mean age = 33.39 +/- 9.8 years; 154 females, 101 Met allele carriers) were analyzed. The behavioral results indicated that skill measure constantly increased across the training period. Further analysis also revealed a significant difference in motor skill learning among carriers of the BDNF val66met polymorphism (i.e., impairment in motor skill learning in Met allele carriers). On a structural level, the same individuals also tended to have significantly greater gray matter volume in the striatum, a finding that was replicated in the validation sample. Neurochemically, Met allele carriers did not have altered resting state striatal glutamate concentration or deviations from Val allele carriers in any other of the measured metabolites. Functional neuroimaging data demonstrated strong task-effects within a cortico-striatal motor network and plausible training-related brain activations. However, no functional alterations in (training-related) activity within the fronto-striatal motor network for carriers of the Met variant were observed. The behavioral findings of this study complement previous findings on deficits of Met allele carriers of the BDNF val66met polymorphism in long term motor skill learning and reinforce our understanding of the molecular basis of this functional variant. The observed structural effects were interpreted as a compensatory mechanism for hippocampal deficits and are discussed in light of the limitations of the present study. The non-significant genotype results on glutamate concentration and (training-related) brain function are also consistent with the prior literature. Furthermore, this pattern of results points to the distinct qualities of the three neuroimaging methods used in this study and highlights the uniqueness of this multilevel and multimodal neuroimaging approach to study fronto-striatal learning and plasticity processes in humans. The scientific and possible clinical implications of these findings were discussed.
... These studies confirmed that in most individuals, certain language functions essential to produce speech were only present in the left hemisphere (Sperry, 1981). They also showed that the right hemisphere tended to be specialised for visuo-spatial tasks (Franco & Sperry, 1977;Levy, Trevarthen, & Sperry, 1972;Levy-Agresti & Sperry, 1968). Split-brain studies have, however, been biased towards emphasising differences between the cerebral hemispheres. ...
The performance of most tasks requires some interaction between the cerebral hemispheres. Despite this fact, research has focused on demonstrating that each hemisphere is specialised for certain processes and has largely neglected this interaction. ¶ Recent research has recognised the need for a better understanding of how resources are shared between the cerebral hemispheres. While these studies have shed light on factors external to the participants being tested, such as the type of task and stimuli used, presentation times, and different measurement methods, they have neglected variables that differ between individuals. The studies reported here focused on factors internal to the participants. They include sex, age, handedness, functional lateralisation, practice, attention, and hemispheric activation, which vary between individuals or within individuals across time, and have been shown to influence the structure and morphology of the corpus callosum which is the main pathway for hemispheric interactions. ¶ This thesis examines the relationship of these variables to the efficiency of hemispheric interactions. ¶ ...
... The perception of depth, shape, position, distance, orientation, route finding, and maze learning, as well as the localization of targets in space, and the detection of hidden figures, appear to be right cerebrum mediated. Investigation of right and left cerebral damaged subjects supports right-brain mediation of these visuospatial facets (Benton, 1979;Butters and Barton, 1970;Fontenot, 1973;Franco and Sperry, 1977;Fried et al., 1987;Hannay et al, 1987;Landis et al, 1986;Sperry, 1982). Important to environmental understanding, visuospatial perception is integral to our definition of self-awareness. ...
For many years, self-awareness was beyond scientific inquiry and lost in language that defied investigation using the scientific method. This included very diffuse language like conscious or unconscious thought, which was largely the language of the Freudian and Neo-Freudian era, historically. These diffuse attributions might be replaced with evidence of inaccessibility of one or of another brain region to the language-processing systems in the left cerebral hemisphere, for example. But, with the development of neuropsychological methods, scientific language evolved with relevance to the role of differing cerebral regions in the awareness of self. Heath Demaree initially discussed this in a model of self-awareness of deficits underlying the emotional disorders. Each brain contributes a somewhat different understanding of our self, and evidence for this is fundamental to several of our theories of spatial analysis. One example might be the differential specialization of each brain for the processing of space, with superiority of left cerebral systems in personal spatial analysis (e.g., body parts and gestures) and with superiority of right cerebral systems in extrapersonal space (e.g., the role of others in my attributions of causality). Paul Foster extended this model of spatial analysis to emotional valence.
... De Spinnler, 1966, 1967;De Renzi et al., 1969;Zaidel and Sperry, 1973;Gainotti et al., 1994), tactual (e.g. Carmon and Benton, 1969;De Renzi et al., 1970;Franco and Sperry, 1977;Harada et al., 2004) and auditory (e.g. Kimura, 1964;Faglioni et al., 1969;Tervaniemi and Hugdahl, 2003) stimuli. ...
The present review aimed to check two proposals alternative to the original version of the 'semantic hub' hypothesis, based on Semantic Dementia (SD) data, which assumed that left and right anterior temporal lobes (ATLs) store in a unitary, amodal format all kinds of semantic representations. The first alternative proposal is that the right ATL might subsume non-verbal representations and the left ATL lexical-semantic representations and that only in the advanced stages of SD, when atrophy affects the ATLs bilaterally, the semantic impairment becomes 'multi-modal'. The second alternative suggestion is that right and left ATLs might underlie two different domains of knowledge, because general conceptual knowledge might be supported by the left ATL, and social cognition by the right ATL. Results of the review substantially support the first proposal, showing that the right ATL subsumes non-verbal representations and the left ATL lexical-semantic representations. They are less conclusive about the second suggestion, because the right ATL seems to play a more important role in behavioural and emotional functions than in higher level social cognition.
Copyright © 2015. Published by Elsevier Ltd.
... The left hand performs better when matching wooden blocks to 2-dimensional drawings of the block in "opened up" form (Levy-Agresti & Sperry, 1968), and when assembling coloured blocks to match a design (Gazzaniga, 1970). This superiority of the right hemisphere appears to increase as shapes become less geometric and more free form (Franco & Sperry, 1977). Likewise, Nebes (1971) has shown that the "left hand system" is superior in establishing the relationship between an arc and the circle from which it came. ...
... We also conjectured that in attempting to solve this task learners might also have followed a sequential and hierarchical order, starting from a visual perspective then complementing that with an analytical approach. Franco and Sperry (1977) posited that nonverbal visuospatial apprehension commonly seemed to precede and support the sequential deductive analysis involved in the solution of geometry problems. Even the well-known and widely applied van Hiele model of geometric thought also specifies visual reasoning as an initial level of geometric understanding (Bansilal & Naidoo, 2012). ...
This article reports on regularities observed in learners' preconceptions of reflective symmetry. Literature suggests that the very existence of such regularities indicates a gap between what learners know and what they need to know. Such a gap inhibits further understanding and application, and hence needed to be investigated. A total of 235 Grade 11 learners, from 13 high schools that participate in the First Rand Foundation-funded Mathematics Education project in the Eastern Cape, responded to a task on reflective symmetry. Our framework for analysing the responses was based on the taxonomy of structure of the observed learning outcome. The results indicated that 85% of learner responses reflect a motion understanding of reflections, where learners considered geometric figures as physical motions on top of the plane. While this understanding is useful in some cases, it is not an essential aspect of mapping understanding, which is critical for application in function notations and other analytical geometry contexts. We suggest that if this gap is to be closed, learners need to construct these reflections physically so that they may think of reflections beyond motion.
The literature on giftedness gives the impression that most authors conceive of talent (talent, giftedness and prodigious performance will be used interchangeably) as a stable trait that belongs to a person. Although some writers have warned us not “to view giftedness as an absolute concept—something that exists in and of itself, without relation to anything else” (Renzulli 1980, p. 4), most people consider giftedness as an objective fact, something you either have or don’t have, like green eyes or a mole on the nose.
Traditional Japanese typewriting is basically a hunt-and-peck method using approximately 3,000 base characters. Because of its cumbersome operation and slow speed, typewriting has not been as common in Japan as in the United States or Europe.
During the period in which Lashley was promoting the view that cortical functions in the rat defied localization, clinical observations of humans with focal brain lesions were painting quite a different picture of cerebral organization. Localized damage to specific cortical regions was found to result in specific behavioral disturbances. Moreover, the behavioral disorders that emerged seemed to be dependent on the hemisphere damaged as well as on the intrahemispheric location of the pathology. This approach to brain and behavior caught on, and the field of neuropsychology was the result.
The perennial puzzle of a child who reads poorly despite normal intellect and absence of diseases beyond chicken pox and the common cold still defies solution. Dyslexic children have been described, diagnosed, characterized, labeled, classified, and reclassified by educators, pediatricians, neurologists, social scientists, psychologists, educational psychologists, social psychologists, school psychologists, testing psychologists, clinical psychologists, psychiatric psychologists, and finally, neuropsychologists. The unique ways in which these individuals perform are well-documented, yet the problem persists. The most serious consequence of this diversity is the multitude of treatments, remedial training, behavior modification, and medications that are developed to deal with these individuals. Successes have been claimed for all, yet newer techniques are continually being developed and marketed as the process is perpetuated. One gets the impression that virtually every method effects an improvement, yet none works well (or well enough). Thus, more research is deemed necessary, producing even more techniques in a seemingly unending and costly spiral.
Early in this century, an Australian psychologist by the name of Stanley D. Porteus designed what he hoped would be a new test of intelligence: printed labyrinths, or mazes, that were age-graded, being simple for young children and becoming progressively more complex for older children. The task was to trace through the correct path with a pencil. The score depended on speed and the number of entrances into a cul-de-sac, or dead end.
This chapter focuses on man and the aspects of the human nervous system that make man unique among all living creatures. In man the cerebral cortex is much more developed and complex than in other animals such as chimpanzees, rats, and tree shrews. Man, in particular, has large areas of cortex that are uncommitted at birth which with development become programmed for serving the subjective self and speech. The large areas of the cerebral cortex that man possesses above and beyond other animals are concentrated in the parietal lobe, temporal lobe, and frontal lobe. The somesthetic cortex analyzes and combines sensations from the skin and deeper regions of the body, including its joints, where angles bespeak position and movement. Other regions of the parietal lobe blend all these sensations with others, the sights and sounds evaluated by the nearby occipital and temporal lobes. In the parietal lobe, afferent input from many systems, particularly the somatosensory, visual, and vestibular, is integrated. The result is a bigger, more meaningful picture in which a person's self begins to take form amidst its environment.
The human brain seems mysteriously unique in phylogeny. In addition to being unpredictably large, man’s brain differs from its anthropoid legacy in that the two halves are functionally asymmetric, with the left performing better on verbal tasks and the right excelling in some situations demanding nonverbal skills. These observations have led to the view that each half-brain has evolved its own specialized neural substrate to sustain a unique cognitive style and mode of information processing.
Studies of patients with unilateral cerebral lesions or with commissurotomy and of normal individuals show that the two sides of the brain are functionally asymmetric. Although the right hemisphere manifests profound deficiencies in language, it is superior to the left hemisphere in tasks requiring a good understanding of spatial relationships or memory for experiences resistant to verbal description. However, in recent years, some have suggested that only the left hemisphere is conscious, and others have proposed that the right hemisphere only surpasses the left for tasks involving spatial/manipulative skills of the hands. Evidence bearing on these issues is reviewed, and its relevance for understanding the animal mind is discussed.
Over the course of evolution, each half of the brain has developed its own unique strategy for perceiving, processing, and expressing information as well as specialized neuroanatomical interconnections that assist in mediating these functions. Indeed, the human brain is organized such that two potentially independent mental systems coexist, literally side by side. (cf. Gazzaniga & LeDoux, 1978; Joseph, 1982, 1988a,b; Levy, 1983; Sperry, 1966, 1982).
This article begins with reviews of parallel processing models in the areas of visual perception and memory, pointing out kinds of information purported to be processed in each, and the overlap in the physiological substrates involved. Next, some pertinent literature having to do with the linkage between perception and memory is reviewed (e.g., visual memory for what or where), concluding that there exists a serious lack of research and knowledge of how different perceptual processes may lead to facilitated, distorted or impaired memory in different forms of storage. Some possible scenarios are presented concerning how perceptual information might be interfaced with memorial mechanisms, and some working hypotheses are considered. Finally, a new paradigm is outlined that examines the linkage between local and global perceptual processing and explicit and implicit learning. This paradigm combines the global precedence paradigm of Navon (1977; 1981) and the sequence learning paradigm of Nissen and Bullemer (1987). Convincing arguments indicate that global stimuli are mediated more quickly via one perceptual stream (the M-cell pathway), but can be processed more slowly by another (the P-cell system). Local aspects of the stimuli are exclusively mediated by the P-cell system. The results of two experiments employing iterations of stimulus sequence, in which sequence teaming is possible and measurable in terms of reaction time changes over trials are presented. The second experiment indicates that information thought to be mediated by the M-cell pathway results in incidental sequential learning, while other information thought to be mediated by the P-cell pathway does not. Spatial filtering of the visual stimuli reveals that low spatial frequencies are necessary for sequence learning to occur. The issue of whether this learning is implicit or explicit is also discussed. Ideas for future research, exploring this new area of interest, are proposed. Current knowledge of perceptual and memorial deficits in special populations are considered in an attempt to identify new areas of investigation.
The field of developmental neuropsychology has reached adolescence resting on its collective diagnostic laurels. Percent-correct classification has represented the staple of neuropsychological sophistication, and professional one-upmanship has focused on surpassing hit rates reported for earlier measures (Wedding, 1983). Despite the pleas of some experts that neuropsychology must address the implications of neurologic conditions, especially in view of such tools as the computed axial tomography (CAT) and positron emission tomography (PET) scans (Dean, 1982, 1985), in general neuropsychology remains arrested at the diagnostic level. Some of the major sources in the field published during the past five years make only passing reference to rehabilitation—presumably the end purpose for which clinicians engage in the rites of diagnosis. Those sources that at least acknowledge the issue of rehabilitation (Rourke, Bakker, Fisk, & Strang, 1983; Rutter, 1983) are fairly consistent in their conclusion that much of what is prescribed in the name of intervention is speculative (Gittelman, 1983; Hynd & Cohen, 1983; Rourke et al., 1983).
The world is shadowed plays of light,
Modelled, stripped, reformed, and lined,
Bounded, bordered by the mind,
Redone into an inner sight,
Created worlds of shape and hue,
Music, meaning, rhythm, time,
Configurations made sublime,
Constructions of an inner view.
Background: The purpose of the present study was to investigate the effect of stimulation with low-frequency magnetic waves on the behavior of alpha, beta, SMR, theta and delta waves in patients after ischemic or hemorrhagic stroke in the left hemisphere. Material and methods: The research involved 68 right-handed patients between 57 and 66 years of age. EEG recordings were made in real time at F3-C3 and F4-C4 using a ProComp +/BioGraph V2.1 integrator (Thought Technology Ltd.). Measurements were taken at baseline, again after exposure to a placebo, and again after ten expositions to low-frequency magnetic fields generated with a Viofor JPS device (Med & Life Polska), using the M1P2 program. Neuropsychological evaluation was performed using selected parameters from the Trail-Making Test, the Stroop Color-Word Test, and the Wisconsin Card Sorting Test. Results: Regardless of the etiology of stroke, no statistically significant differences were found between the two hemispheres in respect to the degree of sensitivity to magnetic fields. Nevertheless, shortly after administration the emission amplitudes became symmetrical and synchronous in both hemispheres, the effect being significantly larger (p < 0.05) in the left hemisphere. No such differences were noted after the application of the placebo. The improvement on the selected neuropsychological parameters was statistically significant. Conclusions: The possible therapeutic effect of low frequency magnetic waves on recovery from stroke deserves further attention and will be the subject of future reports.
Although considerably less extensive and obvious than functional cerebral asymmetries in the human brain (see Bradshaw & Nettleton, 1983), recent research has demonstrated beyond question that the two cerebral hemispheres are laterally specialized in species as widely separated as passerine birds, rodents, and monkeys (see Glick, 1985, for reviews). The presence of cerebral asymmetry in such diverse groups can be explained by a parallel evolution in response to common selective pressures for an efficient use of neural space, in which different neural programs that serve different functions are organized in opposite sides of the brain. A neural organization that is optimally designed to serve one set of functions cannot normally be optimally designed to serve a different set of functions, and lateral differentiation allows the development of two different operational programs that serve different and equally important processes.
The purpose of this study was to explore the role of spatial orientation skill in the solution of mathematics problems. Fifty-seven tenth-grade students who scored high or low on a spatial orientation test were asked to solve mathematics problems in individual interviews. A group of specific behaviors was identified in geometric settings, which appeared to be manifestations of spatial orientation skill. Spatial orientation skill also appeared to be involved in understanding the problem and linking new problems to previous work in nongeometric settings.
Resumen. Se discute el desarrollo psicogenético de un niño hemisferectomizado derecho a los 3 años de edad por epilepsia intratable, que concurre en la actualidad (6 años) a primer grado y se desempeña brillantemente en la escuela. La teoría epigenética y contructivista de Piaget parece explicar mejor esta excepcional rehabilitación cognitiva con sólo medio cerebro que el cognitivismo genético e innato de Chomsky. Summary. The case of a right hemispherectomized child (at 3 for intractable epilepsy) is discussed. He is in his first grade at school where he performs brightly. The epigenetic and contructivist theory of Jean Piaget seems to explain better this exceptional cognitive rehabilitation with only half a brain than Chomsky's genetic and innate cognitivism. A los 100 años del nacimiento de Jean Piaget, que ahora conmemoramos sus discípulos de todo el mundo, las neurociencias cognitivas han venido a ampliar nuestra visión del hombre. Lo que sigue es un intento de indagar en la neurobiología de las operaciones mentales, tales como fueran descriptas por Piaget.
[Introduction] Until a few years ago, prevailing views regarding the syndrome of the corpus callosum in man were based very largely on the studies of Akelaitis and his co-workers (Akelaitis et al. 1942; Akelaitis 1944). Using a wide variety of tests Akelaitis examined a series of more than two dozen patients with partial and complete surgical sections of the corpus callosum and anterior commissure and was unable to find any consistent neurological or psychological dysfunctions that could be reliably attributed to the commissural sections. Symptoms such as unilateral astereognosis, alexia, agraphia, ideo-motor apraxia (Sweet 1941), as well as apathy, amnesia, personality changes and related effects, that earlier had been ascribed to callosal lesions (Alpers and Grant 1931) seemed accordingly to be more properly explained in terms of the extracallosal cerebral damage that commonly accompanies lesions in the commissures. These Akelaitis reports in combination with confirmatory observations on absence of symptoms after callosum section in animals established the general doctrine of the 1940's and 1950's in which it was believed that behavioral deficits seen in connection with callosal lesions are best ascribed to associated brain damage (Bremer et al. 1956). Meanwhile, the discrepancy between the enormous size and strategic position of the corpus callosum on the one hand and the observed lack of any important functional disturbance following its complete surgical section on the other remained during this period one of the more puzzling enigmas of neurology.
Commissurotomy patients with surgical disconnection of the cerebral hemispheres offer special advantages for studies involving quantitative and qualitative comparisons between the mental capacities of the 2 hemispheres in that the 2 can be compared directly on the same task in a single individual. In the present study the Raven's Colored Progressive Matrices (RCPM) was modified for lateralized testing in a group of commissurotomy patients. It was administered to a group of patients with surgical section of the cerebral hemispheres in order to compare the independent capacity of left and right hemispheres for spatial apprehension and reasoning. The patterns with missing parts were presented in free vision but the answer had to be sought among a choice of 3 metal-etched patterns in blind tactual exploration using the left and right hands separately. Scores for the 2 hands and speed of performance showed a consistent left hand-right hemisphere superiority, even though the order of presentation was biased in favor of the left hemisphere. Scores for the left hemisphere, however, were well above chance. Results indicate that the test can be performed by either the right or left hemisphere but that the 2 use different strategies of approach and different modes of central processing. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Ten commissurotomy patients (8 with complete and 2 with partial section of the forebrain commissures) obtained subnormal scores on a battery of 6 standardized tests for assessment of memory. Although the observed memory impairment is presumed to have been amplified by extracommissural brain damage in most of the cases, it is concluded that the loss of the cerebral commissures is mainly responsible and that these commissures serve selective mnestic functions. In particular the data suggest that processes mediating the initial encoding of engrams and the retrieval and read out of contralateral engram elements involve hemispheric cooperation and depend upon the function of the interhemispheric commissures.
Cognitive abilities were investigated in three patients with hemispherectomy for noninfantile disease. Two had the right and one had the left hemisphere removed. Results indicate that after right hemispherectomy in the mature brain the left hemisphere remains decidedly more proficient in verbal than nonverbal functions. In the developing younger brain, however, regardless of which hemisphere was removed, less difference exists between abilities in verbal and nonverbal functions, and level of performance is in general lower than in the adult case. Memory functions were impaired after hemispherectomy with removal of the left hemisphere producing the greater deficit.
Seven patients with presumed complete midline section of the inter-hemispheric commissures were tested for delayed matching of tactile patterns. In six of these patients, left-hand performance was unequivocally superior to right, thus demonstrating right-hemisphere specialization for the perception and recall of spatial patterns. The fact that the non-speaking right hemisphere could bridge intratrial intervals of at least 2 minutes, whereas the left hemisphere could not, shows that verbal coding is neither necessary nor sufficient for the retention of complex perceptual material. The further finding that subjects with cortical lesions but intact commissures were more proficient than the commissurotomized patients (even with the left hand) suggests that both cerebral hemispheres normally participate in such tasks, but with the right playing a preponderant role.
Information processing and higher cognitive functions in the disconnected hemispheres of human commissurotomy patients. Unpublished doctoral dissertation. California Institute of Technology The other side of the brain-I. Disgraphia and discopia following cerebral commissurotomy
- J 7 Levy
- J E Bo~en
LEVY, J. Information processing and higher cognitive functions in the disconnected hemispheres of human commissurotomy patients. Unpublished doctoral dissertation. California Institute of Technology, 1969. 7, BO~EN, J. E. The other side of the brain-I. Disgraphia and discopia following cerebral commissurotomy. Bull. Los Angeles Neurol. Soc. Vol. 34, No. 2, April, 1969.
La Reprdsentation de l'Espace chez l'Enfant
- J I~aget
- B Inhelder
I~AGET, J. and INHELDER, B. La Reprdsentation de l'Espace chez l'Enfant. Delachaux et Niestl6. Neuchatel, 1948.