Splitbrain Monkeys: Cerebral Control of Ipsilateral and Contralateral Arm, Hand, and Finger Movements

Brinkman, J.; Kuypers, H.G.J.M.

doi:10.1126/science.176.4034.536

Cited by 196 publications

(68 citation statements)

References 18 publications

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“…Because the contralateral M1 is far more active than its ipsilateral counterpart, it can, under normal circumstances, be considered the main controller of hand and finger movements (Gazzaniga 1966;Brinkman and Kuypers 1972). However, our theoretical and empirical results suggest that both M1s are significantly event related in terms of phase locking or, in the case of rhythmic movements, by means of frequency locking.…”

Section: Discussionmentioning

confidence: 70%

“…While early studies on monkeys revealed activations of various cortical areas, including the contralateral primary motor cortex (M1), premotor cortex (PM1), supplementary motor area (SMA), sensorimotor cortex, as well as interhemispheric cross-talk via the corpus callosum (Gazzaniga 1966;Mark and Sperry 1968;Brinkman Correspondence to: A. and Kuypers 1972;Brinkman 1984;Tanji et al 1988), more recent brain-imaging studies identified further contributions of the bilateral secondary somatosensory areas, the basal ganglia, the ipsilateral cerebellum (Deiber et al 1991;Mima et al 1999), and the primary sensorimotor cortex (Kawashima et al 1994;Okuda et al 1995). In spite of this development, however, the derivation of theoretical models providing an encompassing functional interpretation of such data remains a formidable challenge that will occupy neuroscientists for years to come.…”

Section: Introductionmentioning

confidence: 99%

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Stabilization of bimanual coordination due to active interhemispheric inhibition: a dynamical account

2005

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Abstract. Based on recent brain-imaging data and congruent theoretical insights, a dynamical model is derived to account for the patterns of brain activity observed during stable performance of bimanual multifrequency patterns, as well as during behavioral instabilities in the form of phase transitions between such patterns. The model incorporates four dynamical processes, defined over both motor and premotor cortices, which are coupled through inhibitory and excitatory inter-and intrahemispheric connections. In particular, the model underscores the crucial role of interhemispheric inhibition in reducing the interference between disparate frequencies during stable performance, as well as the failure of this reduction during behavioral transitions. As an aside, the model also accounts for in-and antiphase preferences during isofrequency movements. The viability of the proposed model is illustrated by magnetoencephalographic signals that were recorded from an experienced subject performing a polyrhythmic tapping task that was designed to induce transitions between multifrequency patterns. Consistent with the model's dynamics, contra-and ipsilateral cortical areas of activation were frequency-and phase-locked, while their activation strength changed markedly in the vicinity of transitions in coordination.

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Section: Discussionmentioning

confidence: 70%

Section: Introductionmentioning

confidence: 99%

Stabilization of bimanual coordination due to active interhemispheric inhibition: a dynamical account

2005

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“…Nevertheless, the inferiority of the 2-fmger II-hand conditions relative to the l-flnger conditions and the similarity of the I-finger and 4-finger conditions (requiring only one-fourth the scanning distance) indicate that differences in the scanning distance for each finger were not important determinants of reading speed. The evidence for parallel processing of the inputs from the two hands is reminiscent of the suggestions, from studies of men and monkeys in whom the corpus callosum has been sectioned, that the two cerebral hemispheres can function independently as two separate centers for the conscious control of behavior (e.g., Brinkman & Kuypers, 1972;Gazzaniga, 1972). In contrast, the inferiority of the 2-finger / l-hand conditions might be taken to suggest that the middle and index fingers on the same hand compete for common neural pathways.…”

Section: Discussionmentioning

confidence: 90%

Expanding the tactual field of view

Lappin

Foulke

1973

Perception & Psychophysics

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Can tactual information be acquired simultaneously by several different fingers? Blind and sighted Ss were asked to scan vertical displays of braille (consisting of either one or two dots) with the index and middle fingers on each hand-using one, two, or four fingers at the same time. Stimuli were recognized most rapidly when the displays were scanned by two fingers on different hands and least rapidly when two fingers on the same hand were used; performance was similar with one finger and with four fingers. The results indicated some parallel perceptual processing of the inputs to the two hands and mutual interference in processing inputs from fingers on the same hand.Braille is read more slowly than print. The reading rates of skilled braille readers have typically been measured at about 60-80 words/min (see Nolan & Kederis, 1969); rates above 100 words/min are rare. Skilled sighted readers. however, commonly read 200-400 words/min, with rates in excess of 1,000 words/min occasionally attained after courses in speed reading.The principal reason for the difference in reading rates evidently derives from a difference in the number of visual and tactual characters that are simultaneously apprehended in a single "glance," rather than from a difference in the speed with which an individual character is processed. Braille readers generally utilize only one finger, usua lIy the index finger, to obtain information from braille text (Fertsch, 1946). The available evidence indicates that this information is processed serially, one character at a time (Foulke, 1964; Nolan & Kederis, 1969). In contrast, skilled sighted readers doubtlessly process printed text in units consisting of many simultaneously perceived letters (Kolers & Katzman, 1966;Reicher, 1969). When printed text is displayed one letter at a time, the reading rate for the visual mode falls to about the same level as for the tactual mode (Troxel, 1967).Braille is embossed in the same left-to-right sequential format as print. But this format might seem less appropriate for braille than for print, tending perhaps to limit the opportunity for sensing more than one character at a time. Although Fertsch (1946) found that many good braille readers employed both index fingers, the best readers usually read the first half of a line with *This report was supported in part by U.S. Office of Education Grant OEG-4-7l-0065 and by National Institute of Mental Health Grant MH-21105 to the first author and by USOE Grant OEG-D-S-0711S5-1S11(032) to the second author. A paper based on this work was presented at the Psychonomic Society convention, St. Louis, November 1971.t Requests for reprints may be sent to J. S. Lappin.Department of Psychology, Vanderbilt University. Nashville. Tennessee 37240. the left index finger and then read the remainder of the line with the right hand. Suppose, however, that braille was embossed with only one word on each line and that a sequence of words appeared in a vertical column down the page: Several fingers might then be used to perceive simul...

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“…This bilateral activity in SI is due to the fact that hands and fingers are controlled mainly by the contralateral hemisphere, whereas the arms can also be controlled to a significant degree by the ipsilateral hemisphere (Brinkman and Kuypers, 1972). The agouti usually sits on its HL, leaving the FL free for food manipulation while eating.…”

Section: Callosal Connections Of Agouti Si: Comparisons With Other Mamentioning

confidence: 99%

Callosal axon arbors in the limb representations of the somatosensory cortex (SI) in the agouti (Dasyprocta primnolopha)

Rocha

Santiago

Freire

et al. 2006

J of Comparative Neurology

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The present report compares the morphology of callosal axon arbors projecting from and to the hind- or forelimb representations in the primary somatosensory cortex (SI) of the agouti (Dasyprocta primnolopha), a large, lisencephlic Brazilian rodent that uses forelimb coordination for feeding. Callosal axons were labeled after single pressure (n = 6) or iontophoretic injections (n = 2) of the neuronal tracer biotinylated dextran amine (BDA, 10 kD), either into the hind- (n = 4) or forelimb (n = 4) representations of SI, as identified by electrophysiological recording. Sixty-nine labeled axon fragments located across all layers of contralateral SI representations of the hindlimb (n = 35) and forelimb (n = 34) were analyzed. Quantitative morphometric features such as densities of branching points and boutons, segments length, branching angles, and terminal field areas were measured. Cluster analysis of these values revealed the existence of two types of axon terminals: Type I (46.4%), less branched and more widespread, and Type II (53.6%), more branched and compact. Both axon types were asymmetrically distributed; Type I axonal fragments being more frequent in hindlimb (71.9%) vs. forelimb (28.13%) representation, while most of Type II axonal arbors were found in the forelimb representation (67.56%). We concluded that the sets of callosal axon connecting fore- and hindlimb regions in SI are morphometrically distinct from each other. As callosal projections in somatosensory and motor cortices seem to be essential for bimanual interaction, we suggest that the morphological specialization of callosal axons in SI of the agouti may be correlated with this particular function.

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Splitbrain Monkeys: Cerebral Control of Ipsilateral and Contralateral Arm, Hand, and Finger Movements

Cited by 196 publications

References 18 publications

Stabilization of bimanual coordination due to active interhemispheric inhibition: a dynamical account

Stabilization of bimanual coordination due to active interhemispheric inhibition: a dynamical account

Expanding the tactual field of view

Callosal axon arbors in the limb representations of the somatosensory cortex (SI) in the agouti (Dasyprocta primnolopha)

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