Attention Disorders After Right Brain Damage (eBook)

Dr. Paolo Bartolomeo, MD, PhD trained as a clinical neurologist and as a neuroscientist. He is head scientist of the research team investigating the Cognitive Neurosciences of Attention at the Brain and Spine Institute in the Salpêtrière Hospital, Paris, France, and full professor of Neuropsychology and Cognitive Neuroscience at the Catholic University, Milan, Italy. By using advanced behavioural, neuroimaging and neurostimulation methods, Dr. Bartolomeo has developed high impact work revealing the structural and functional neuroanatomy of attentional functions in normal individuals and in brain-damaged patients.

Foreword 6
Preface and Acknowledgments 10
References 13
Abbreviations 14
Contents 16
Chapter 1: The Attention Systems of the Human Brain 20
1.1 Spatial Selective Attention 21
1.1.1 Manual Response Time Paradigms 22
1.1.2 Anatomical Brain Structures and Networks of Spatial Attention 23
1.1.3 Spatial Attention and Visual Awareness 27
1.1.4 Attention and Visual Perception 29
1.1.4.1 Cortical Streams of Visual Processing 29
1.1.4.2 Attentional Modulations of Visual Perception 30
1.2 Sustained Attention, Vigilance, Alertness, Arousal 31
1.3 Executive Control 33
References 34
Further Reading 38
Chapter 2: Sensorimotor Deficits After Right Brain Damage 39
2.1 Hemiplegia, Hemianopia, and Hemianesthesia 39
2.2 Perceptual Extinction 42
2.2.1 Allesthesia 43
2.2.2 Mechanisms of Extinction 43
2.2.3 Attention and Extinction 44
2.3 Motor Neglect 45
2.4 Conjugate Gaze Paresis 46
2.5 “Magnetic” Gaze Attraction 47
2.6 Conclusion: Apparent Sensorimotor Deficits After Right Hemisphere Damage 47
References 48
Further Reading 51
Chapter 3: Consequences of Right Hemisphere Lesions on Bodily Awareness and Control 52
3.1 Body-Related Cognition in the Right Hemisphere 52
3.2 Anosognosia and Anosodiaphoria 54
3.3 Misoplegia and Left Hemiconcern 56
3.4 Asomatognosia and Somatoparaphrenia 58
3.5 Supernumerary Phantom Limbs, Xenomelia, and Autoscopic Phenomena 59
3.6 Motor Impersistence 62
References 62
Further Reading 64
Chapter 4: Unilateral Spatial Neglect: Clinical Aspects 65
4.1 Definition and Causes 65
4.2 Clinical Presentation 66
4.3 Diagnostic Tests: General Considerations 69
4.4 Visuo-perceptual Tests 70
4.4.1 Wundt–Jastrow Illusion 70
4.4.2 Overlapping Figures 71
4.4.3 Search for Images 71
4.4.4 Reading in Neglect 72
4.5 Visuo-graphic Tests 73
4.5.1 Drawing Tasks 73
4.5.1.1 Allochiria 75
4.5.1.2 Copy of Multielement Drawings: Scene-Based and Object-Based Neglect 76
4.5.2 Cancellation Tasks 77
4.5.3 Line Bisection 81
4.5.3.1 Visual Field Defects 81
4.5.3.2 Severity of Neglect 82
4.5.3.3 Position of the Line 82
4.5.3.4 Patterns of Line Exploration 83
4.5.3.5 Mechanisms of Subjective Center Shift in Line Bisection 84
4.6 Representational (or Imaginal) Tasks 84
4.6.1 Relation with Visual Tasks 87
4.7 Other Spatial Sectors: “Near” and “Far” Neglect, Personal Neglect 89
4.7.1 Near vs. Far Space 89
4.7.2 Personal Neglect 90
4.8 Ecological Assessment of Neglect 92
References 93
Further Reading 99
Chapter 5: Experimental Variants of Neglect Tests 100
5.1 Variants of Drawing Tasks: Blind Drawing 100
5.2 Variants of Cancellation Tasks 103
5.2.1 Erasing Targets 103
5.2.2 “Invisible” Cancellation Marks 103
5.2.3 Left–Right Asymmetric Targets 104
5.3 Variants of Line Bisection 104
5.3.1 The Landmark Task 104
5.3.2 Pseudoneglect and the Attentional Repulsion Effect 105
5.3.3 Bisecting Imagined Lines: The Endpoint Task 106
5.3.4 Length Reproduction and Estimation 109
5.4 Variants of Representational Tasks 111
5.4.1 Problems with Place Descriptions 111
5.4.2 Mental Line Bisection 112
5.4.3 Imaginal Response Times 112
5.4.4 REMs in Neglect 114
5.5 Dissociations in Performance Within and Between Patients 115
References 116
Further Reading 119
Chapter 6: Component Deficits of Neglect 120
6.1 Spatial Attention 121
6.1.1 Early Ipsilesional Capture and the Disengagement Deficit 121
6.1.2 Ineffective Exploration and Implicit Knowledge 124
6.1.3 Neglect of Spatial Locations or of Objects in Space? 125
6.1.4 Object-Based Neglect 127
6.1.5 Neglect and Inhibition of Return 129
6.1.6 Neglect and Spontaneous Brain Activity 131
6.1.7 The Paradox of the Left Hemisphere 132
6.2 Nonspatial Attention Deficits: Impaired Alertness and Sustained Attention 133
6.3 Lateralized Premotor Deficits 134
6.3.1 Spatial Response Bias 134
6.3.2 Directional Hypokinesia 135
6.4 Spatially Nonlateralized Deficits 138
6.4.1 Impaired Spatial Working Memory 138
6.4.2 Constructional Apraxia 139
6.5 Imaginal Deficits 140
6.6 Impaired Processing of Time 140
References 141
Further Reading 148
Chapter 7: The Anatomy of Neglect 149
7.1 Methodological Issues 149
7.2 Voxel-Based Lesion–Symptom Mapping (VLSM) 152
7.3 Frontoparietal Networks 152
7.4 Callosal Neglect 157
7.5 More Ventral Networks 158
7.6 Lesional Correlates of Specific Forms of Neglect 159
References 160
Further Reading 163
Chapter 8: Attention Disorders in Neurodegenerative Conditions 164
8.1 Clinical and Neuroscientific Relevance 164
8.2 Occipitotemporal and Frontoparietal Systems in Degenerative Diseases 165
8.3 Spatial Attention in Degenerative Diseases 166
8.4 Control and Monitoring Deficits 169
References 170
Further Reading 171
Chapter 9: Treatment of Attention Disorders 172
9.1 Top-Down Techniques 172
9.2 Bottom-Up Techniques 173
9.2.1 Vestibular Stimulation 173
9.2.2 Trunk Rotation 175
9.2.3 Mechanical and Electrical Transcutaneous Stimulations 175
9.2.4 Stimulation of the Left Hand 176
9.2.5 Alertness Training 177
9.2.6 Prism Adaptation 178
9.3 Noninvasive Brain Stimulation 179
9.4 Pharmacological Treatments 180
9.4.1 Dopaminergic Agents 180
9.4.2 Noradrenergic Agents 181
9.4.3 Cholinergic Agents 181
References 182
Further Reading 185
Conclusion and Perspectives 186
References 187
Subject Index 188
Author Index 192