Hemispheric specialization of memory for visual hierarchical stimuli

Delis, Dean C.; Robertson, Lynn C.; Efron, Robert

doi:10.1016/0028-3932(86)90053-9

Cited by 369 publications

(213 citation statements)

References 20 publications

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“…Notably, a left-hemisphere advantage for processing fine spatial details (20) and shape discrimination (21) has been described in the visual system. Furthermore, patients with left but not right-hemisphere lesions have difficulties in perceiving local elements in a visual target stimulus (22). Thus, it is intriguing to find left-lateralized processing of fine spatial details in the somatosensory system as well.…”

Section: Discussionmentioning

confidence: 99%

Tactile form and location processing in the human brain

Boven

Ingeholm

Beauchamp

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

107

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To elucidate the neural basis of the recognition of tactile form and location, we used functional MRI while subjects discriminated gratings delivered to the fingertip of either the right or left hand. Subjects were required to selectively attend to either grating orientation or grating location under identical stimulus conditions. Independent of the hand that was stimulated, grating orientation discrimination selectively activated the left intraparietal sulcus, whereas grating location discrimination selectively activated the right temporoparietal junction. Hence, hemispheric dominance appears to be an organizing principle for cortical processing of tactile form and location.brain imaging ͉ functional MRI ͉ somatosensory T ouch provides a rich variety of information about both the world around us and the body itself. For example, we can dissociate information about features of objects touched from knowledge of the spatial location of bodily contact. Although much is known about the peripheral mechanisms of touch, central mechanisms beyond the primary somatosensory cortex (SI) are far less well understood. In this functional MRI (fMRI) study, we aimed to dissociate the higher, central neural correlates of tactile form vs. location processing by using a selective attention task under conditions of identical peripheral stimulation.For tactile form discrimination, we selected the grating orientation (GO) task (1), the performance of which is dependent on the spatial information conveyed by the population response of slow-adapting afferents of the peripheral nervous system (2). The information provided by this neuronal population is the basis of fine tactile form recognition used in Braille reading, texture discrimination, and other functions requiring fine spatial resolution. For grating location (GL) discrimination, we used a device to deliver small, discrete shifts in the stimulation site at which gratings were applied. By contrasting brain activations during the GO and GL tasks, we distinguished regions selectively associated with tactile form and location processing, respectively. Further, by comparing brain activations during stimulation of the right and left hands, we determined whether observed hemispheric lateralizations were a function of side of stimulation or hemispheric specialization for these perceptual attributes. We found that the regions mediating tactile form vs. location processing are distinct, lateralized, and independent of the side of the body stimulated. Materials and MethodsSubjects. Twenty healthy subjects (11 males; mean age, 25.6 years; range, 22-28 years; 18 right-handed and 2 left-handed, according to global self-assessment) participated in this study with informed consent according to a protocol approved by the institutional review board of the National Institute of Mental Health. Eight subjects were tested at the right hand, eight at the left hand, and four at both hands (the two left-handers were tested at the right hand only).The subjects had no history of neurological or psychiatri...

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Section: Discussionmentioning

confidence: 99%

Tactile form and location processing in the human brain

Boven

Ingeholm

Beauchamp

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

107

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“…When these interactions are disrupted (as when the global to local processor of the right hemisphere is no longer functioning) the local to global processor of the left may bias attention to such a degree that the global level is simply missed entirely. This result is evident in acute stages after right unilateral stroke (see Delis, Robertson & Efron, 1986). It is as if the preferred level for the undamaged hemisphere captures so many attentional resources that access to other representations that may still exist are compromised.…”

Section: Implicit Integration and Integrative Agnosiamentioning

confidence: 94%

Implicit integration in a case of integrative visual agnosia

Aviezer¹,

Landau²,

Robertson³

et al. 2007

Neuropsychologia

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We present a case (SE) with integrative visual agnosia following ischemic stroke affecting the right dorsal and the left ventral pathways of the visual system. Despite his inability to identify global hierarchical letters (Navon, 1977), and his dense object agnosia, SE showed normal global-to-local interference when responding to local letters in Navon hierarchical stimuli and significant pictureword identity priming in a semantic decision task for words. Since priming was absent if these features were scrambled, it stands to reason that these effects were not due to priming by distinctive features. The contrast between priming effects induced by coherent and scrambled stimuli is consistent with implicit but not explicit integration of features into a unified whole. We went on to show that possible/ impossible object decisions were facilitated by words in a word-picture priming task, suggesting that prompts could activate perceptually integrated images in a backward fashion. We conclude that the absence of SE's ability to identify visual objects except through tedious serial construction reflects a deficit in accessing an integrated visual representation through bottom-up visual processing alone. However, top-down generated images can help activate these visual representations through semantic links.

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“…The stimuli have also been used in neuropsychological research to examine how the brain implements localglobal processing in an asymmetric manner, with the left and right hemispheres more attuned to local and global levels, respectively (e.g. Delis, Robertson, & Efron, 1986;Lamb, Robertson, & Knight, 1989;Robertson, Lamb, & Knight, 1988). Finally, the stimuli have been used in developmental work to investigate the emergence of local-global processing in normally developing children (e.g.…”

Section: Attention To Local-global Structure and Spatial Frequencies mentioning

confidence: 99%

Auditory attention to frequency and time: an analogy to visual local–global stimuli

Justus

List

2005

Cognition

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Two priming experiments demonstrated exogenous attentional persistence to the fundamental auditory dimensions of frequency (Experiment 1) and time (Experiment 2). In a divided-attention task, participants responded to an independent dimension, the identification of three-tone sequence patterns, for both prime and probe stimuli. The stimuli were specifically designed to parallel the local-global hierarchical letter stimuli of [Navon D. (1977). Forest before trees: The precedence of global features in visual perception. Cognitive Psychology, 9, 353-383] and the task was designed to parallel subsequent work in visual attention using Navon stimuli [Robertson, L. C. (1996). Attentional persistence for features of hierarchical patterns. Journal of Experimental Psychology: General, 125, 227-249; Ward, L. M. (1982). Determinants of attention to local and global features of visual forms. Journal of Experimental Psychology: Human Perception and Performance, 8,[562][563][564][565][566][567][568][569][570][571][572][573][574][575][576][577][578][579][580][581]. The results are discussed in terms of previous work in auditory attention and previous approaches to auditory local-global processing.

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Hemispheric specialization of memory for visual hierarchical stimuli

Cited by 369 publications

References 20 publications

Tactile form and location processing in the human brain

Tactile form and location processing in the human brain

Implicit integration in a case of integrative visual agnosia

Auditory attention to frequency and time: an analogy to visual local–global stimuli

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