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Rich TJ, Palmer J. Neglect dyslexia: whole-word and within-word errors with parafoveal and foveal viewing. Exp Brain Res 2023; 241:2655-2668. [PMID: 37773416 PMCID: PMC10635956 DOI: 10.1007/s00221-023-06708-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 09/13/2023] [Indexed: 10/01/2023]
Abstract
Patients with left-sided neglect dyslexia often omit whole words positioned on the left, termed whole-word errors, or commit errors on the left-sided letters of words, termed unilateral paralexias. In addition, the errors have been shown to be exacerbated by simultaneously presented distractors, which has been interpreted as a failure of selective attention. In two experiments, we examined the dependency of these error types on parafoveal versus foveal viewing. The first experiment used a paradigm with parafoveal targets and distractors; the second a paradigm with foveal targets and parafoveal distractors. This enabled a separate evaluation of the influences of stimulus position within an egocentric frame, a two-word allocentric frame, and a within-word allocentric frame. First, regarding whole-word errors, we found the expected spatial and distractor effects with parafoveal targets and distractors. With foveal targets and parafoveal distractors, however, the spatial effect was effectively eliminated. Surprisingly, intrusions from the distractor word were common in distractor conditions. This is consistent with an egocentric account and not a two-word allocentric account. Second, we found that unilateral paralexias remained largely consistent regardless of spatial position or the presence of a distractor. Thus, there is a contrast in spatial and distractor effects between whole-word errors and unilateral paralexias. These results are consistent with three distinct deficits: an egocentric deficit across space resulting in whole-word errors, a failure of selective attention that results in whole-word intrusion errors, and a within-word allocentric deficit resulting in unilateral paralexias.
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Affiliation(s)
- Timothy J Rich
- Center for Stroke Rehabilitation Research, Kessler Foundation, 1199 Pleasant Valley Way, West Orange, NJ, USA.
- Department of Physical Medicine and Rehabilitation, Rutgers University, New Brunswick, NJ, USA.
| | - John Palmer
- Department of Psychology, University of Washington, Seattle, WA, USA
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Luzzi S, Fiori C, Ranaldi V, Baldinelli S, Cherubini V, Morelli M, Silvestrini M, Snowden JS. Allochiria for spatial landmarks as the presenting feature of posterior cortical atrophy. Cortex 2022; 157:274-287. [PMID: 36370598 DOI: 10.1016/j.cortex.2022.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 08/22/2022] [Accepted: 09/19/2022] [Indexed: 12/15/2022]
Abstract
Allochiria refers to the mislocation of stimuli to the corresponding position on the opposite side of the body or hemispace. It is most often, although not exclusively, reported in the tactile modality and typically in association with unilateral neglect. We describe a patient presenting with a 2-year history of topographical disorientation without other cognitive complaints. We conducted a systematic exploration of his topographical problems to identify their cognitive substrate. Standard neuropsychological examination revealed no abnormalities. Notably, he performed well on perceptual, spatial, and constructional tasks. No signs of neglect were elicited. A tailored battery of tests was administered, involving road maps and landmarks, and designed to replicate the situations in which he experienced symptoms. The experimental tests showed no evidence of topographical agnosia or amnesia for landmarks and their spatial relationships and no hemispatial neglect. Nevertheless, the patient exhibited a systematic tendency to translocate topographical landmarks sited on the left to the right side. The phenomenon, consistent with representational allochiria, occurred exclusively for topographical landmarks, and was present along both personally familiar and new learned routes. Over the next two years more widespread visuoperceptual and spatial deficits emerged, with Balint and Gerstmann syndromes. Functional imaging revealed hypoperfusion of the occipito-parietal regions and amyloid PET the presence of amyloid plaques. A diagnosis was made of posterior cortical atrophy, the visual variant of Alzheimer's Disease. To our knowledge this is the first case of topographical disorientation presenting with selective representational allochiria and the first report of allochiria as an early sign of posterior cortical atrophy. The case sheds light on the cognitive basis of allochiria and on a puzzling clinical presentation of neurodegenerative brain disease.
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Affiliation(s)
- Simona Luzzi
- Department of Experimental and Clinical Medicine, Polytechnic University of Marche, Ancona, Italy.
| | - Chiara Fiori
- Department of Experimental and Clinical Medicine, Polytechnic University of Marche, Ancona, Italy
| | | | - Sara Baldinelli
- Department of Experimental and Clinical Medicine, Polytechnic University of Marche, Ancona, Italy
| | - Veronica Cherubini
- Department of Experimental and Clinical Medicine, Polytechnic University of Marche, Ancona, Italy
| | | | - Mauro Silvestrini
- Department of Experimental and Clinical Medicine, Polytechnic University of Marche, Ancona, Italy
| | - Julie S Snowden
- Division of Neuroscience and Experimental Psychology, University of Manchester, UK
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Trojano L, Papagno C, Vallar G. Dario GROSSI. Cortex 2021; 142:S0010-9452(21)00234-3. [PMID: 34366119 DOI: 10.1016/j.cortex.2021.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/01/2021] [Accepted: 07/07/2021] [Indexed: 11/26/2022]
Affiliation(s)
- Luigi Trojano
- Department of Psychology, University of Campania Luigi Vanvitelli, Caserta, Italy
| | - Costanza Papagno
- Department of Psychology, University of Milano-Bicocca, Milan, Italy; CIMeC & CeRiN, University of Trento, Rovereto, Italy
| | - Giuseppe Vallar
- Department of Psychology and NeuroMI - Milan Center for Neuroscience, University of Milano-Bicocca, Milan, Italy; Laboratory of Neuropsychology, IRCCS Istituto Auxologico Italiano, Milan, Italy.
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Venneri A, Pentore R, Cobelli M, Nichelli P, Shanks MF. Translocation of the embodied self without visuospatial neglect. Neuropsychologia 2012; 50:973-8. [PMID: 22349442 DOI: 10.1016/j.neuropsychologia.2012.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 01/27/2012] [Accepted: 02/03/2012] [Indexed: 10/28/2022]
Abstract
This is the case report of RB, a 68-year-old retired woman who, following an extensive right sided ischaemic stroke, showed hemiplegia, anosognosia and allochiria, but no somato-sensory deficits and no visuospatial neglect. A high resolution 3D MRI structural scan of her brain was acquired to define the structural damage in detail. Morphometric analyses of grey and white matter data revealed a large lesion which involved most of her right parietal, temporal, and mesial frontal cortex, with partial sparing of the right dorsolateral prefrontal cortex and part of the posterior corpus callosum. Detailed examination showed that RB attributed sensory stimuli, both on the left and on the right, to the opposite side of her body. This mirror reversed representation of her body caused misattribution of items even in the absence of stimulation, as for instance when the patient spontaneously reported pain in her right knee while pointing to her left knee. RB's neuropsychological profile showed normal or borderline performance on most cognitive tasks. Language comprehension was intact and she could tell left from right without difficulty in all instances except for those referable to her soma. To our knowledge this is the first description of severe allochiria for body representation in the absence of neglect. The evidence from this case supports the developing concept that the body representation is not simply a systematic registration of proprioceptive inputs, but that the brain has a more sophisticated high level representation of one's body map which is updated on the basis of multimodal information.
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Affiliation(s)
- Annalena Venneri
- Department of Neuroscience, University of Sheffield and Sheffield Teaching Hospital NHS Foundation Trust, Sheffield, UK.
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Heath M, Maraj A, Maddigan M, Binsted G. The antipointing task: vector inversion is supported by a perceptual estimate of visual space. J Mot Behav 2009; 41:383-92. [PMID: 19460747 DOI: 10.3200/35-08-016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The authors examined whether the visual field-specific endpoint bias of mirror-symmetrical reaching movements (i.e., antipointing) is related to top-down decoupling of the normal spatial relations between target and response (i.e., visuomotor inhibition) or the inversion of target coordinates to a mirror-symmetrical location (i.e., vector inversion). Participants completed pro- and antipointing movements in left and right visual space under conditions in which movement type was performed in separate blocks (i.e., blocked condition) and when randomly interleaved on a trial-by-trial basis (i.e., random condition). Most important, the random condition entailed equivalent premovement inhibition across pro- and antipointing. Propointing produced comparable endpoint accuracy in left and right visual space whereas antipointing under- and overshot target position: a finding characterizing blocked and random conditions. The authors attribute the visual field-specific bias of antipointing to the obligatory nature of the task and the integration of visuoperceptual networks to support vector inversion.
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Affiliation(s)
- Matthew Heath
- School of Kinesiology, The University of Western Ontario, London, Ontario, Canada.
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Conson M, Salzano S, Manzo V, Grossi D, Trojano L. Closing-in without severe drawing disorders: The “fatal” consequences of pathological attraction. Cortex 2009; 45:285-92. [DOI: 10.1016/j.cortex.2007.11.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 10/23/2007] [Accepted: 11/08/2007] [Indexed: 11/29/2022]
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Trojano L, Grossi D, Flash T. Cognitive neuroscience of drawing: Contributions of neuropsychological, experimental and neurofunctional studies. Cortex 2009; 45:269-77. [DOI: 10.1016/j.cortex.2008.11.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Revised: 11/21/2008] [Accepted: 11/21/2008] [Indexed: 10/21/2022]
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Heath M, Maraj A, Gradkowski A, Binsted G. Anti-pointing is mediated by a perceptual bias of target location in left and right visual space. Exp Brain Res 2008; 192:275-86. [PMID: 18982320 DOI: 10.1007/s00221-008-1612-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Accepted: 10/06/2008] [Indexed: 11/30/2022]
Abstract
We sought to determine whether mirror-symmetrical limb movements (so-called anti-pointing) elicit a pattern of endpoint bias commensurate with perceptual judgments. In particular, we examined whether asymmetries related to the perceptual over- and under-estimation of target extent in respective left and right visual space impacts the trajectories of anti-pointing. In Experiment 1, participants completed direct (i.e. pro-pointing) and mirror-symmetrical (i.e. anti-pointing) responses to targets in left and right visual space with their right hand. In line with the anti-saccade literature, anti-pointing yielded longer reaction times than pro-pointing: a result suggesting increased top-down processing for the sensorimotor transformations underlying a mirror-symmetrical response. Most interestingly, pro-pointing yielded comparable endpoint accuracy in left and right visual space; however, anti-pointing produced an under- and overshooting bias in respective left and right visual space. In Experiment 2, we replicated the findings from Experiment 1 and further demonstrate that the endpoint bias of anti-pointing is independent of the reaching limb (i.e. left vs. right hand) and between-task differences in saccadic drive. We thus propose that the visual field-specific endpoint bias observed here is related to the cognitive (i.e. top-down) nature of anti-pointing and the corollary use of visuo-perceptual networks to support the sensorimotor transformations underlying such actions.
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Affiliation(s)
- Matthew Heath
- School of Kinesiology, The University of Western Ontario, London, ON, N6A 3K7, Canada.
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Chapter 19 Visuospatial and visuoconstructive deficits. HANDBOOK OF CLINICAL NEUROLOGY 2008; 88:373-91. [DOI: 10.1016/s0072-9752(07)88019-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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