Motion Perception in Healthy Humans and Cognitive Disorders

2011 ◽  
pp. 156-161 ◽  
Author(s):  
Takao Yamasaki ◽  
Shozo Tobimatsu
Keyword(s):  
Motion Perception ◽  
Cognitive Disorders ◽  
Event Related Potentials ◽  
Coherent Motion ◽  
Motion Processing ◽  
Neural Basis ◽  
Healthy Humans ◽  
Dorsal Pathway ◽  
Close Relationship ◽  
Related Potentials

To elucidate how the dorsal visual pathway is functionally altered in mild cognitive impairment (MCI) and Alzheimer’s disease (AD) patients, first, the neural basis of motion perception in healthy young adults was examined by using visual event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI) with coherent motion stimuli such as radial optic flow (OF) and horizontal motion (HO). Nonspecific, motion-related N170 from V5/MT and OF-specific P200 with an inferior parietal lobule (IPL) origin were obtained in ERPs. fMRI revealed the close relationship between IPL activity and OF stimuli. Next, coherent motion perception was assessed by the psychophysical thresholds for patients with AD and MCI, as well as ERPs for MCI patients. MCI patients manifested a selective elevation of the OF threshold, while AD patients exhibited higher psychophysical thresholds for both OF and HO. In ERPs, the P200 latency for OF (but not the N170 latency for OF and HO) was significantly prolonged in MCI patients. These findings indicate that patients with AD and MCI have impaired coherent motion processing due to higher levels of the dorsal pathway. In particular, OF processing related to the IPL is selectively impaired in patients with MCI. Therefore, a combined approach with psychophysics and ERPs using coherent motion (particularly OF) can be useful to discriminate MCI and AD patients from older but healthy adults.

scholarly journals S-cone signals invisible to the motion system can improve motion extraction via grouping by color

2009 ◽  
Vol 26 (2) ◽  
pp. 237-248 ◽  
Author(s):  
JASNA MARTINOVIC ◽  
GEORG MEYER ◽  
MATTHIAS M. MÜLLER ◽  
SOPHIE M. WUERGER
Keyword(s):  
Event Related Potentials ◽  
Event Related Potential ◽  
Coherent Motion ◽  
Behavioral Experiment ◽  
Motion Processing ◽  
Global Motion ◽  
Local Motion ◽  
Motion System ◽  
Motion Extraction ◽  
Related Potentials

AbstractThe purpose of this study was to test whether color–motion correlations carried by a pure color difference (S-cone component only) can be used to improve global motion extraction. We also examined the neural markers of color–motion correlation processing in event-related potentials. Color and motion information was dissociated using a two-colored random dot kinematogram, wherein coherent motion and motion noise differed from each other only in their S-cone component, with spatial and temporal parameters set so that global motion processing relied solely on a constant L-M component. Hence, when color and the local motion direction are correlated, more efficient segregation of coherent motion can only be brought about by the S-cone difference, and crucially, this S-cone component does not provide any effective input to a global motion mechanism but only changes the color appearance of the moving dots. The color contrasts (vector length in the S vs. L-M plane) of both the dots carrying coherent motion and the dots moving randomly were fixed at motion discrimination threshold to ensure equal effectiveness for motion extraction. In the behavioral experiment, participants were asked to discriminate between coherent and random motion, and d′ was determined for three different conditions: uncorrelated, uncued correlated, and cued correlated. In the electroencephalographic experiment, participants discriminated direction of motion for uncued correlated and cued correlated conditions. Color–motion correlations were found to improve performance. Cueing a specific color also modulated the N1 component of the event-related potential, with sources in visual area middle temporal. We conclude that S-cone signals “invisible” to the motion system can influence the analysis by direction-selective motion mechanisms through grouping of local motion signals by color. This grouping mechanism must precede motion processing and is likely to be under attentional control.

Abnormal Neural Basis of Emotional Conflict Control in Treatment-Resistant Depression

2016 ◽  
Vol 48 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Song Xue ◽  
Shanshan Wang ◽  
Xia Kong ◽  
Jiang Qiu
Keyword(s):  
Stroop Task ◽  
Event Related Potentials ◽  
Frontal Region ◽  
Healthy Controls ◽  
Treatment Resistant Depression ◽  
Treatment Resistant ◽  
Neural Basis ◽  
Emotional Conflict ◽  
Related Potentials ◽  
Resistant Depression

Emotional conflict has received increased attention as a research topic. The objective of this study is to confirm that the processing of emotional conflict is impaired in treatment-resistant depression (TRD). We compared the event-related potentials of 17 patients with TRD and 17 healthy controls during the face-word Stroop task, which is an effective way of assessing the effects of emotional conflict directly. Compared with healthy controls, the accuracy scores of the TRD patients were lower in both “congruent stimuli” and “incongruent stimuli” conditions, and their response times were longer. The TRD patients also had larger N2 amplitudes over the frontal region, regardless of stimulus condition, which might reflect that TRD patients pay more attention to emotional information. A larger P3 amplitude over the frontal region for “incongruent stimuli minus congruent stimuli” was also found among patients with TRD, which indicates interference effects in the Stroop task. The results of this study provide novel behavioral and neurophysiological evidence of anomalies in cognitive inhibition among patients with TRD using the word-face task. These findings not only improve our understanding of deficient inhibition in TRD, but also pave the way for a cognitive neuropsychiatric model of depression.

Neural Basis of Semantically Dependent and Independent Cross-Modal Boosts on the Attentional Blink

2020 ◽  
Author(s):  
Song Zhao ◽  
Chengzhi Feng ◽  
Xinyin Huang ◽  
Yijun Wang ◽  
Wenfeng Feng
Keyword(s):  
Object Recognition ◽  
Attentional Blink ◽  
Temporal Dynamics ◽  
Recognition Task ◽  
Event Related Potentials ◽  
Visual Object ◽  
Visual Object Recognition ◽  
Neural Basis ◽  
Related Potentials ◽  
The Cross

Abstract The present study recorded event-related potentials (ERPs) in a visual object-recognition task under the attentional blink paradigm to explore the temporal dynamics of the cross-modal boost on attentional blink and whether this auditory benefit would be modulated by semantic congruency between T2 and the simultaneous sound. Behaviorally, the present study showed that not only a semantically congruent but also a semantically incongruent sound improved T2 discrimination during the attentional blink interval, whereas the enhancement was larger for the congruent sound. The ERP results revealed that the behavioral improvements induced by both the semantically congruent and incongruent sounds were closely associated with an early cross-modal interaction on the occipital N195 (192–228 ms). In contrast, the lower T2 accuracy for the incongruent than congruent condition was accompanied by a larger late occurring cento-parietal N440 (424–448 ms). These findings suggest that the cross-modal boost on attentional blink is hierarchical: the task-irrelevant but simultaneous sound, irrespective of its semantic relevance, firstly enables T2 to escape the attentional blink via cross-modally strengthening the early stage of visual object-recognition processing, whereas the semantic conflict of the sound begins to interfere with visual awareness only at a later stage when the representation of visual object is extracted.

Reactivity and Event-Related Potentials in Attentional Tests: Effect of Training

2002 ◽  
Vol 94 (3) ◽  
pp. 817-833 ◽  
Author(s):  
Giuliano Fontani ◽  
Leda Lodi
Keyword(s):  
Reaction Time ◽  
Selective Attention ◽  
Event Related Potentials ◽  
Stimulus Onset ◽  
Negative Wave ◽  
Geometric Figure ◽  
Trained Subjects ◽  
Geometric Figures ◽  
Close Relationship ◽  
Related Potentials

To study the effects of training on reactivity and event-related potentials a complex attentional shifting test involving reaction time was administered (Test 1) to 24 healthy, young students. After five days, 12 subjects were tested with the same procedure (Test 2) without training (Untrained Subjects) while 12 repeated the test at the fifth day after four days of training (Trained Subjects). During Tests 1 and 2, event-related potentials were recorded by electroencephalogram. The task consisted of each subject responding to a stimulus of a letter appearing in the centre of a geometric figure on the screen of a computer monitor. In the prestimulus period black points were drawn and crowded randomly into a zone of the screen. The geometric figure and the letter were shown in the centre of the crowding. There were two letters and four geometric figures randomly combined in different ways. The subject had to press different keys of the computer keyboard when specific combinations appeared. The averaged event-related potentials were characterized by a negative wave with a close relationship to selective attention before the onset of the stimulus of a geometric figure followed by letters. After the stimulus onset, a P3 complex was recorded. Trained subjects were no different from untrained subjects in Test 1, while in Test 2 they had a shorter reaction time, an earlier peak of the selective attention related wave and P3, and a higher amplitude for the P3 complex. These measures and the correlations between them can be considered an index of the training effect. Thus, these tests could be used for evaluation of the attentional style and its modification with training.

scholarly journals Neural Basis of Intrinsic Motivation: Evidence from Event-Related Potentials

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Jia Jin ◽  
Liping Yu ◽  
Qingguo Ma
Keyword(s):  
Intrinsic Motivation ◽  
Social Factor ◽  
Event Related Potentials ◽  
P300 Amplitude ◽  
Neural Basis ◽  
Outcome Feedback ◽  
Quantitative Measurements ◽  
Machine Learning Model ◽  
Stop Watch ◽  
Related Potentials

Human intrinsic motivation is of great importance in human behavior. However, although researchers have focused on this topic for decades, its neural basis was still unclear. The current study employed event-related potentials to investigate the neural disparity between an interesting stop-watch (SW) task and a boring watch-stop task (WS) to understand the neural mechanisms of intrinsic motivation. Our data showed that, in the cue priming stage, the cue of the SW task elicited smaller N2 amplitude than that of the WS task. Furthermore, in the outcome feedback stage, the outcome of the SW task induced smaller FRN amplitude and larger P300 amplitude than that of the WS task. These results suggested that human intrinsic motivation did exist and that it can be detected at the neural level. Furthermore, intrinsic motivation could be quantitatively indexed by the amplitude of ERP components, such as N2, FRN, and P300, in the cue priming stage or feedback stage. Quantitative measurements would also be convenient for intrinsic motivation to be added as a candidate social factor in the construction of a machine learning model.

scholarly journals Selective Attention to Specific Features within Objects: Behavioral and Electrophysiological Evidence

2006 ◽  
Vol 18 (4) ◽  
pp. 539-561 ◽  
Author(s):  
Anna Christina Nobre ◽  
Anling Rao ◽  
Leonardo Chelazzi
Keyword(s):  
Selective Attention ◽  
Negative Priming ◽  
Brain Activity ◽  
Event Related Potentials ◽  
Motion Processing ◽  
Neural Modulation ◽  
Priming Paradigm ◽  
Related Potentials ◽  
Physical Stimuli ◽  
Feature Dimension

Evidence regarding the ability of attention to bias neural processing at the level of single features has been gathering steadily, but most of the experiments to date used arrays with multiple objects and locations, making it difficult to rule out indirect influences from object or spatial attention. To investigate feature-specific selective attention, we have assessed the ability to select and ignore individual features within the same object. We used a negative-priming paradigm in which the color or the direction of internal motion of the object could determine the relevant response. Bidimensional (colored and moving) and unidimensional (colored and stationary, or gray and moving) stimuli appeared in unpredictable order. In successive blocks, participants were instructed that one feature dimension was dominant. During that block, participants responded according to the dominant dimension for bidimensional stimuli. For unidimensional stimuli, participants responded to the only dimension of the stimulus that afforded a response, regardless of the instruction for the block. The ability to inhibit irrelevant task information at the level of specific features (negative priming for features) was indexed by a decrease in performance to detect one particular feature value (e.g., red) if the same feature value (red) but not another color value (green) had been ignored in the previous bidimensional stimulus. Behavioral results confirmed the existence of inhibitory, negative-priming mechanisms at the singlefeature level for both color and motion dimensions of stimuli. Event-related potentials recorded during task performance revealed the dynamics of neural modulation by feature attention. Comparisons were made using the identical physical stimuli under different conditions of attention to isolate purely attentional effects. Processing of identical bidimensional stimuli was compared as a function of the dimension of attention (color, motion). Processing of identical unidimensional stimuli that followed bidimensional stimuli was also compared to identify possible effects of feature-specific negative priming. The electrophysiological effects revealed that inhibition of irrelevant features leads to modulation of brain activity during early stages of perceptual analysis.

Combining CDP-choline and galantamine: Effects of a selective α7 nicotinic acetylcholine receptor agonist strategy on P50 sensory gating of speech sounds in healthy volunteers

2019 ◽  
Vol 33 (6) ◽  
pp. 688-699 ◽  
Author(s):  
Joelle Choueiry ◽  
Crystal M Blais ◽  
Dhrasti Shah ◽  
Dylan Smith ◽  
Derek Fisher ◽  
...  
Keyword(s):  
Pilot Study ◽  
Acetylcholine Receptor ◽  
Nicotinic Acetylcholine Receptor ◽  
Event Related Potentials ◽  
Sensory Gating ◽  
Nicotinic Acetylcholine ◽  
Healthy Humans ◽  
Α7 Nachr ◽  
Related Potentials ◽  
Sensory Processes

Background: Schizophrenia (SCZ) patients and relatives have deficits in early cortical sensory gating (SG) typically measured by suppression of electroencephalography-derived P50 event-related potentials (ERPs) in a conditioning-testing (S1–S2) paradigm. Associated with alpha 7 nicotinic acetylcholine receptor (α7 nAChR) dysfunction and shown to be improved with nicotine and α7 nAChR agonists, SG has recently been shown to be improved in low P50 suppressing SCZ patients following acute CDP-choline treatment. Aims: This pilot study in healthy humans assessed the SG effects of an α7 nAChR strategy combining CDP-choline with galantamine, a positive allosteric modulator (PAM) of nAChRs, aimed at increasing and prolonging nicotinic receptor activity. Methods: The combined effect of CDP-choline (500 mg) and galantamine (16 mg) on speech P50 gating indices rP50 (S2/S1) and dP50 (S1–S2) was examined in 30 healthy participants stratified into low and high baseline P50 suppressors in a randomized, double-blind, placebo-controlled and counterbalanced design. Results: In low suppressors, CDP-choline/galantamine (vs. placebo) improved rP50 and dP50 gating, and reduced S2P50 amplitudes. No P50 gating effects were observed in high suppressors; however, CDP-choline/galantamine (vs. placebo) increased their S2P50 amplitudes. Conclusion: Findings from this pilot study with CDP-choline/galantamine in a healthy, SCZ-like surrogate deficient gating sample are consistent with the association of α7 nAChR mechanisms in SG impairment in SCZ and support further research trials with CDP-choline and galantamine targeting sensory processes.

scholarly journals Cortico-Cortical Interactions in Spatial Attention: A Combined ERP/TMS Study

2006 ◽  
Vol 95 (5) ◽  
pp. 3277-3280 ◽  
Author(s):  
Giorgio Fuggetta ◽  
Enea F. Pavone ◽  
Vincent Walsh ◽  
Monika Kiss ◽  
Martin Eimer
Keyword(s):  
Posterior Parietal Cortex ◽  
Right Hemisphere ◽  
Response Times ◽  
Event Related Potentials ◽  
Single Pulse ◽  
Behavioral Effect ◽  
Search Display ◽  
Delayed Response ◽  
Neural Basis ◽  
Related Potentials

To gain insight into the neural basis of visual attention, we combined transcranial magnetic stimulation (TMS) and event-related potentials (ERPs) during a visual search task. Single-pulse TMS over right posterior parietal cortex (rPPC) delayed response times to targets during conjunction search, and this behavioral effect had a direct ERP correlate. The early phase of the N2pc component that reflects the focusing of attention onto target locations in a search display was eliminated over the right hemisphere when TMS was applied there but was present when TMS was delivered to a control site (vertex). This finding demonstrates that rPPC TMS interferes with attentional selectivity in remote visual areas.

Effects of Feature-selective and Spatial Attention at Different Stages of Visual Processing

2011 ◽  
Vol 23 (1) ◽  
pp. 238-246 ◽  
Author(s):  
Søren K. Andersen ◽  
Sandra Fuchs ◽  
Matthias M. Müller
Keyword(s):  
Spatial Attention ◽  
Visual Processing ◽  
Human Subjects ◽  
Event Related Potentials ◽  
Attentional Selection ◽  
Coherent Motion ◽  
False Alarms ◽  
Related Potentials ◽  
Trial Participants ◽  
Selection Of

We investigated mechanisms of concurrent attentional selection of location and color using electrophysiological measures in human subjects. Two completely overlapping random dot kinematograms (RDKs) of two different colors were presented on either side of a central fixation cross. On each trial, participants attended one of these four RDKs, defined by its specific combination of color and location, in order to detect coherent motion targets. Sustained attentional selection while monitoring for targets was measured by means of steady-state visual evoked potentials (SSVEPs) elicited by the frequency-tagged RDKs. Attentional selection of transient targets and distractors was assessed by behavioral responses and by recording event-related potentials to these stimuli. Spatial attention and attention to color had independent and largely additive effects on the amplitudes of SSVEPs elicited in early visual areas. In contrast, behavioral false alarms and feature-selective modulation of P3 amplitudes to targets and distractors were limited to the attended location. These results suggest that feature-selective attention produces an early, global facilitation of stimuli having the attended feature throughout the visual field, whereas the discrimination of target events takes place at a later stage of processing that is only applied to stimuli at the attended position.

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