Tags

Type your tag names separated by a space and hit enter

Allocentric to Egocentric Spatial Switching: Impairment in aMCI and Alzheimer's Disease Patients?
Curr Alzheimer Res. 2018; 15(3):229-236.CA

Abstract

OBJECTIVE

Deficits in egocentric (subject-to-object) and allocentric (object-to-object) spatial representations, with a mainly allocentric impairment, characterize the first stages of the Alzheimer's disease (AD).

METHODS

To identify early cognitive signs of AD conversion, some studies focused on amnestic-Mild Cognitive Impairment (aMCI) by reporting alterations in both reference frames, especially the allocentric ones. However, spatial environments in which we move need the cooperation of both reference frames. Such cooperating processes imply that we constantly switch from allocentric to egocentric frames and vice versa. This raises the question of whether alterations of switching abilities might also characterize an early cognitive marker of AD, potentially suitable to detect the conversion from aMCI to dementia. Here, we compared AD and aMCI patients with Normal Controls (NC) on the Ego-Allo- Switching spatial memory task. The task assessed the capacity to use switching (Ego-Allo, Allo-Ego) and non-switching (Ego-Ego, Allo-Allo) verbal judgments about relative distances between memorized stimuli.

RESULTS

The novel finding of this study is the neat impairment shown by aMCI and AD in switching from allocentric to egocentric reference frames. Interestingly, in aMCI when the first reference frame was egocentric, the allocentric deficit appeared attenuated.

CONCLUSION

This led us to conclude that allocentric deficits are not always clinically detectable in aMCI since the impairments could be masked when the first reference frame was body-centred. Alongside, AD and aMCI also revealed allocentric deficits in the non-switching condition. These findings suggest that switching alterations would emerge from impairments in hippocampal and posteromedial areas and from concurrent dysregulations in the locus coeruleus-noradrenaline system or pre-frontal cortex.

Authors+Show Affiliations

Department of Psychology, Laboratory of Cognitive Science and Immersive Virtual Reality, CS-IVR, University of Campania L. Vanvitelli, Caserta, Italy.Laboratory of Clinical Neuropsychology, Neurological Unit of "Ospedali dei Colli", Naples, Italy.Department of Psychology, Laboratory of Cognitive Science and Immersive Virtual Reality, CS-IVR, University of Campania L. Vanvitelli, Caserta, Italy.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

29086696

Citation

Ruggiero, Gennaro, et al. "Allocentric to Egocentric Spatial Switching: Impairment in aMCI and Alzheimer's Disease Patients?" Current Alzheimer Research, vol. 15, no. 3, 2018, pp. 229-236.
Ruggiero G, Iavarone A, Iachini T. Allocentric to Egocentric Spatial Switching: Impairment in aMCI and Alzheimer's Disease Patients? Curr Alzheimer Res. 2018;15(3):229-236.
Ruggiero, G., Iavarone, A., & Iachini, T. (2018). Allocentric to Egocentric Spatial Switching: Impairment in aMCI and Alzheimer's Disease Patients? Current Alzheimer Research, 15(3), 229-236. https://doi.org/10.2174/1567205014666171030114821
Ruggiero G, Iavarone A, Iachini T. Allocentric to Egocentric Spatial Switching: Impairment in aMCI and Alzheimer's Disease Patients. Curr Alzheimer Res. 2018;15(3):229-236. PubMed PMID: 29086696.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Allocentric to Egocentric Spatial Switching: Impairment in aMCI and Alzheimer's Disease Patients? AU - Ruggiero,Gennaro, AU - Iavarone,Alessandro, AU - Iachini,Tina, PY - 2017/03/08/received PY - 2017/07/11/revised PY - 2017/07/30/accepted PY - 2017/11/1/pubmed PY - 2019/3/5/medline PY - 2017/11/1/entrez KW - AD KW - Egocentric-allocentric representations KW - aMCI KW - heading disorientation KW - switching/non-switching abilities KW - visuospatial memory disorders. SP - 229 EP - 236 JF - Current Alzheimer research JO - Curr Alzheimer Res VL - 15 IS - 3 N2 - OBJECTIVE: Deficits in egocentric (subject-to-object) and allocentric (object-to-object) spatial representations, with a mainly allocentric impairment, characterize the first stages of the Alzheimer's disease (AD). METHODS: To identify early cognitive signs of AD conversion, some studies focused on amnestic-Mild Cognitive Impairment (aMCI) by reporting alterations in both reference frames, especially the allocentric ones. However, spatial environments in which we move need the cooperation of both reference frames. Such cooperating processes imply that we constantly switch from allocentric to egocentric frames and vice versa. This raises the question of whether alterations of switching abilities might also characterize an early cognitive marker of AD, potentially suitable to detect the conversion from aMCI to dementia. Here, we compared AD and aMCI patients with Normal Controls (NC) on the Ego-Allo- Switching spatial memory task. The task assessed the capacity to use switching (Ego-Allo, Allo-Ego) and non-switching (Ego-Ego, Allo-Allo) verbal judgments about relative distances between memorized stimuli. RESULTS: The novel finding of this study is the neat impairment shown by aMCI and AD in switching from allocentric to egocentric reference frames. Interestingly, in aMCI when the first reference frame was egocentric, the allocentric deficit appeared attenuated. CONCLUSION: This led us to conclude that allocentric deficits are not always clinically detectable in aMCI since the impairments could be masked when the first reference frame was body-centred. Alongside, AD and aMCI also revealed allocentric deficits in the non-switching condition. These findings suggest that switching alterations would emerge from impairments in hippocampal and posteromedial areas and from concurrent dysregulations in the locus coeruleus-noradrenaline system or pre-frontal cortex. SN - 1875-5828 UR - https://www.unboundmedicine.com/medline/citation/29086696/Allocentric_to_Egocentric_Spatial_Switching:_Impairment_in_aMCI_and_Alzheimer's_Disease_Patients L2 - http://www.eurekaselect.com/156652/article DB - PRIME DP - Unbound Medicine ER -