Localizing the human brain response to olfactory stimulation: A meta-analytic approach

Studies investigating human brain response to emotional stimuli—particularly high-arousing versus neutral stimuli—have obtained inconsistent results. The present study was the first to combine magnetoencephalography (MEG) with the bootstrapping method to examine the whole brain and identify the cortical regions involved in this differential response. Seventeen healthy participants (11 females, aged 19 to 33 years; mean age, 26.9 years) were presented with high-arousing emotional (pleasant and unpleasant) and neutral pictures, and their brain responses were measured using MEG. When random resampling bootstrapping was performed for each participant, the greatest differences between high-arousing emotional and neutral stimuli during M300 (270–320 ms) were found to occur in the right temporo-parietal region. This finding was observed in response to both pleasant and unpleasant stimuli. The results, which may be more robust than previous studies because of bootstrapping and examination of the whole brain, reinforce the essential role of the right hemisphere in emotion processing.

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Magnetic and electrical responses of the human brain to texture-defined form and to textons

Journal of Neurophysiology ◽

10.1152/jn.1995.74.3.1167 ◽

1995 ◽

Vol 74 (3) ◽

pp. 1167-1178 ◽

Cited By ~ 5

Author(s):

D. Regan ◽

P. He

Keyword(s):

Human Brain ◽

Neural Systems ◽

Magnetic Response ◽

Evoked Responses ◽

Local Orientation ◽

Brain Response ◽

Check Size ◽

Texture Discrimination ◽

Texture Pattern ◽

Brain Responses

1. We searched for a neurophysical correlate of preattentive texture discrimination by recording magnetic and electric evoked responses from the human brain during the first few hundred milliseconds following the presentation of texture-defined (TD) checkerboard form. The only two textons that changed when the TD checkerboard appeared or disappeared were the local orientation and line termination textons. (Textons are conspicuous local features within a texture pattern). 2. Our evidence that the magnetic response to TD form cannot be explained in terms of responses to the two associated textons is as follows: 1) by dissociating the two responses we showed that the magnetic response to TD form is almost entirely independent of the magnetic response to the local orientation texton; 2) a further distinction between the two responses is that their distributions over the head are different; and 3) the magnetic response to TD form differs from the magnetic response to the line termination texton in both distribution over the head and waveform. We conclude that this evidence identifies the existence of a brain response correlate of preattentive texture discrimination. 3. We also recorded brain responses to luminance-defined (LD) checkerboard form. Our grounds for concluding that magnetic brain responses to the onset of checkerboard form are generated by different and independent neural systems for TD and LD form are as follows: 1) magnetic responses to the onset of TD form and LD form had different distributions over the skull, had different waveforms, and depended differently on check size; and 2) the waveform of the response to superimposed TD and LD checks closely approximated the linear sum of responses to TD checks and LD checks alone. 4. One possible explanation for the observed differences between the magnetic and electric evoked responses is that responses to both onset and offset of TD form predominantly involve neurons aligned parallel to the skull, whereas that is not the case for responses to LD form.

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FRACTAL-BASED CLASSIFICATION OF HUMAN BRAIN RESPONSE TO LIVING AND NON-LIVING VISUAL STIMULI

Fractals ◽

10.1142/s0218348x1850069x ◽

2018 ◽

Vol 26 (05) ◽

pp. 1850069 ◽

Cited By ~ 30

Author(s):

MOHAMMAD ALI AHMADI-PAJOUH ◽

TIRDAD SEIFI ALA ◽

FATEMEH ZAMANIAN ◽

HAMIDREZA NAMAZI ◽

SAJAD JAFARI

Keyword(s):

Human Brain ◽

Human Behavior ◽

Fractal Structure ◽

Brain Activity ◽

Visual Stimuli ◽

Chaotic Signal ◽

Eeg Signal ◽

Brain Response ◽

Human Eeg ◽

Structure Complexity

Analysis of human behavior is one of the major research topics in neuroscience. It is known that human behavior is related to his brain activity. In this way, the analysis of human brain activity is the root for analysis of his behavior. Electroencephalography (EEG) as one of the most famous methods for measuring brain activity generates a chaotic signal, which has fractal characteristic. This study reveals the relation between the fractal structure (complexity) of human EEG signal and the applied visual stimuli. For this purpose, we chose two types of visual stimuli, namely, living and non-living visual stimuli. We demonstrate that the fractal structure of human EEG signal changes significantly between living versus non-living visual stimuli. The capability observed in this research can be applied to other kinds of stimuli in order to classify the brain response based on the types of stimuli.

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