Evaluation of P300 components for emotion-loaded visual event-related potential in elderly subjects, including those with dementia.

AIM: In the present study, the P300 component of the emotion-loaded visual event-related potential in response to photographs of babies crying or smiling was measured to evaluate cognitive function in elderly subjects, including those with dementia. METHODS: The subjects were 48 elderly people who consulted a memory disorder clinic. The visual event-related potential was measured using oddball tasks. Brain waves were recorded from four sites. We analyzed the P300 amplitude and latency. Subjects were divided into three groups (the dementia with Alzheimer's disease group [ADG]; the intermediate group [MG], and the healthy group [HG]) based on the Revised Hasegawa Dementia Scale, Mini-mental State Examination scores and the Clinical Dementia Rating. RESULTS: For all subjects, there was a significant positive correlation between P300 latency and Z-score of voxel-based specific regional analysis for Alzheimer's disease for crying or smiling faces. There was a negative correlation between P300 amplitude and Z-score for the crying face. MG subjects were divided into two groups (high risk: HRMG, low risk: LRMG) based on Z-scores (HRMG ≥ 2.0). The P300 amplitude of ADG was significantly smaller than that of HG, and the P300 latency of ADG was significantly longer than those of other groups for crying or smiling faces. The P300 latency of HRMG was significantly longer than that of LRMG for the smiling face. Furthermore, the P300 latency for the crying face was significantly shorter than that for the smiling face in HG and ADG. CONCLUSION: These findings suggest that analysis of P300 components of the emotion-loaded visual event-related potential may be a useful neuropsychological index for the diagnosis of Alzheimer's disease and high-risk subjects.

Effects of emotionally charged sounds in schizophrenia patients using exploratory eye movements: comparison with healthy subjects.

AIMS: Emotion-associated sounds have been suggested to exert important effects upon human personal relationships. The present study was aimed to characterize the effects of the sounds of crying or laughing on visual cognitive function in schizophrenia patients. METHODS: We recorded exploratory eye movements in 24 schizophrenia patients (mean age, 27.0 +/- 6.1 years; 14 male, 10 female) and age-matched controls. The total eye scanning length (TESL) and total number of gaze points in the left (left TNGP) and right (right TNGP) visual fields of the screen and the number of researching areas (NRA) were determined using eye-mark recording in the presence/absence of emotionally charged sounds. RESULTS: Controls' TESL for smiling pictures was longer than that for crying pictures irrespective of sounds. Patients' TESL for smiling pictures, however, was shorter than for crying pictures irrespective of the sounds. The left TNGP for smiling pictures was lower in patients than controls independent of sound. Importantly, the right TNGP was significantly larger with laughing sounds than in the absence of sound. In controls, the NRA for smiling pictures was significantly greater than for crying pictures irrespective of sound. Patient NRA did not significantly differ between smiling and crying pictures irrespective of sound. CONCLUSION: Eye movements in schizophrenia patients' left field for smiling pictures associated with laughing sounds particularly differed from those in controls, suggesting impaired visual cognitive function associated with positive emotion, also involving pleasure-related sounds, in schizophrenia.

Characteristics of exploratory eye movements in elderly people: possibility of early diagnosis of dementia.

BACKGROUND: Visual cognitive dysfunction is one of the most important signs indicating the early stage of dementia. Thus, visual testing could be used as an aid to the clinical diagnosis of dementia. In the present study, exploratory eye movement was measured to evaluate visual cognitive function in elderly subjects, including those with dementia. METHODS: We analyzed responsive search scores (RSS) from exploratory eye movements of 300 subjects who were examined with an eye mark recorder while viewing S shaped figures. Subjects were divided into three groups (dementia, intermediate, healthy) from the values of the Revised Hasegawa Dementia Scale (HDS-R), the Mini-Mental State Examination (MMSE) and the Clinical Dementia Rating. We further divided the intermediate groups into two subgroups, the high score and low score groups, based on RSS. In 202 subjects, Z-scores of voxel-based specific regional analysis system for Alzheimer's disease (VSRAD) were obtained from magnetic resonance imaging (MRI). RESULTS: RSS of the dementia group were significantly lower than those in the intermediate and healthy groups, in order: dementia < intermediate < healthy groups. RSS of the low score intermediate group was significantly lower than that of the high score intermediate group. There was no significant difference between the low score intermediate and dementia groups, or between the high score intermediate and healthy groups. No significant differences of either HSD-R or MMSE were observed between the low score and the high score intermediate groups. The Z-score of VSRAD using MRI in the low score intermediate group was significantly higher than that in the high score intermediate group. CONCLUSIONS: These findings suggest that RSS using an eye mark recorder is a useful psychophysiological marker to evaluate the early stage of dementia as well as at-risk elderly people.

A life span study of exploratory eye movements in healthy subjects: gender differences and affective influences.

To evaluate age and gender differences as well as effects of affection, we examined exploratory eye movements. Exploratory eye movements were recorded in healthy subjects (57 women and 57 men) ranging from 9 to 74 years. All subjects were divided into three groups as pre puberty, young, and older adults to study the influences of age and gonadal hormones. Exploratory eye movements were analyzed for total eye scanning length (TESL), and total numbers of gaze points (TNGP) as subjects viewed neutral or affectively charged pictures. TESL and TNGP in older adults were significantly larger than that in both pre puberty and young adults for crying babies. TESL and TNGP in pre puberty were significantly smaller than that in both young and older adults for circles. TESL and TNGP in pre puberty were significantly smaller than that in older adults for smiling babies. Pre puberty and young adult of both genders for crying babies showed significantly shorter TESL than for when smiling babies. When viewing circles, young adult women had shorter TESL than men. TNGP in young adult women was smaller than in men for circles or crying babies. TNGP of young adult women in the visual right field was significantly smaller than in men. TNGP for crying babies was significantly smaller than that for smiling babies in young adults of both genders for the left field. Exploratory eye movements thus are a useful marker of visual cognitive function. Gender differences were limited to younger adults, suggesting influences of gonadal hormones.