Binary-Choice Decision Time Depends upon Cerebral Hemisphere and Nature of Task

Binary-choice paradigms are classificatory problems of basic importance to the understanding of elementary decision processes. Generally when subjects decide if two visual stimuli are identical or differ by as little as one element, the decision of “Different” takes longer. This finding is unexpected as decisions of “Different” should not require an exhaustive matching of elements. Using stimulus presentation to the right and left cerebral hemispheres, the right hemisphere initiated fast selections of “Same” for figural material and alone was responsible for the “Same”/ “Different” response differential. Exp. 1 ( n = 22) gave no differences for same-different, unilateral-bilateral stimulation, and left-right hemispheres. Exp. 2, using word meaning as the binary-choice task, also showed faster decisions for “Same” but a different left-hemisphere-dependent strategy. The nature of information processing in relation to binary-choice tasks is discussed and the utility of bihemispheric paradigms is demonstrated.

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Cooperative cortical network for categorical processing of Chinese lexical tone

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1710752114 ◽

2017 ◽

Vol 114 (46) ◽

pp. 12303-12308 ◽

Cited By ~ 10

Author(s):

Xiaopeng Si ◽

Wenjing Zhou ◽

Bo Hong

Keyword(s):

Speech Processing ◽

Right Hemisphere ◽

Categorical Perception ◽

Word Meaning ◽

Neural Mechanism ◽

Cortical Network ◽

Middle Temporal Gyrus ◽

Oddball Paradigm ◽

Lexical Tone ◽

The Right

In tonal languages such as Chinese, lexical tone with varying pitch contours serves as a key feature to provide contrast in word meaning. Similar to phoneme processing, behavioral studies have suggested that Chinese tone is categorically perceived. However, its underlying neural mechanism remains poorly understood. By conducting cortical surface recordings in surgical patients, we revealed a cooperative cortical network along with its dynamics responsible for this categorical perception. Based on an oddball paradigm, we found amplified neural dissimilarity between cross-category tone pairs, rather than between within-category tone pairs, over cortical sites covering both the ventral and dorsal streams of speech processing. The bilateral superior temporal gyrus (STG) and the middle temporal gyrus (MTG) exhibited increased response latencies and enlarged neural dissimilarity, suggesting a ventral hierarchy that gradually differentiates the acoustic features of lexical tones. In addition, the bilateral motor cortices were also found to be involved in categorical processing, interacting with both the STG and the MTG and exhibiting a response latency in between. Moreover, the motor cortex received enhanced Granger causal influence from the semantic hub, the anterior temporal lobe, in the right hemisphere. These unique data suggest that there exists a distributed cooperative cortical network supporting the categorical processing of lexical tone in tonal language speakers, not only encompassing a bilateral temporal hierarchy that is shared by categorical processing of phonemes but also involving intensive speech–motor interactions over the right hemisphere, which might be the unique machinery responsible for the reliable discrimination of tone identities.

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Does Brain Lateralization Affect the Performance in Binary Choice Tasks? A Study in the Animal Model Danio rerio

Symmetry ◽

10.3390/sym12081294 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1294

Author(s):

Maria Elena Miletto Petrazzini ◽

Alessandra Pecunioso ◽

Marco Dadda ◽

Christian Agrillo

Keyword(s):

Operant Conditioning ◽

Binary Choice ◽

Brain Lateralization ◽

Potential Predator ◽

Prolonged Training ◽

Low Performance ◽

Set Up ◽

The Right ◽

Choice Tasks ◽

Potential Confound

Researchers in behavioral neuroscience commonly observe the behavior of animal subjects in the presence of two alternative stimuli. However, this type of binary choice introduces a potential confound related to side biases. Understanding whether subjects exhibit this bias, and the origin of it (pre-existent or acquired throughout the experimental sessions), is particularly important to interpreting the results. Here, we tested the hypothesis according to which brain lateralization may influence the emergence of side biases in a well-known model of neuroscience, the zebrafish. As a measure of lateralization, individuals were observed in their spontaneous tendencies to monitor a potential predator with either the left or the right eye. Subjects also underwent an operant conditioning task requiring discrimination between two colors placed on the left–right axis. Although the low performance exhibited in the operant conditioning task prevents firm conclusions from being drawn, a positive correlation was found between the direction of lateralization and the tendency to select the stimulus presented on one specific side (e.g., right). The choice for this preferred side did not change throughout the experimental sessions, meaning that this side bias was not the result of the prolonged training. Overall, our study calls for a wider investigation of pre-existing lateralization biases in animal models to set up methodological counterstrategies to test individuals that do not properly work in a binary choice task with stimuli arranged on the left–right axis.

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Lesions to right posterior parietal cortex impair visual depth perception from disparity but not motion cues

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2015.0263 ◽

2016 ◽

Vol 371 (1697) ◽

pp. 20150263 ◽

Cited By ~ 4

Author(s):

Aidan P. Murphy ◽

David A. Leopold ◽

Glyn W. Humphreys ◽

Andrew E. Welchman

Keyword(s):

Parietal Cortex ◽

Depth Perception ◽

Posterior Parietal Cortex ◽

Right Hemisphere ◽

3D Structure ◽

Three Dimensional ◽

Stimulus Presentation ◽

Visual Depth ◽

Posterior Parietal ◽

The Right

The posterior parietal cortex (PPC) is understood to be active when observers perceive three-dimensional (3D) structure. However, it is not clear how central this activity is in the construction of 3D spatial representations. Here, we examine whether PPC is essential for two aspects of visual depth perception by testing patients with lesions affecting this region. First, we measured subjects' ability to discriminate depth structure in various 3D surfaces and objects using binocular disparity. Patients with lesions to right PPC ( N = 3) exhibited marked perceptual deficits on these tasks, whereas those with left hemisphere lesions ( N = 2) were able to reliably discriminate depth as accurately as control subjects. Second, we presented an ambiguous 3D stimulus defined by structure from motion to determine whether PPC lesions influence the rate of bistable perceptual alternations. Patients' percept durations for the 3D stimulus were generally within a normal range, although the two patients with bilateral PPC lesions showed the fastest perceptual alternation rates in our sample. Intermittent stimulus presentation reduced the reversal rate similarly across subjects. Together, the results suggest that PPC plays a causal role in both inferring and maintaining the perception of 3D structure with stereopsis supported primarily by the right hemisphere, but do not lend support to the view that PPC is a critical contributor to bistable perceptual alternations. This article is part of the themed issue ‘Vision in our three-dimensional world’.

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Investigation of the Effect of Mode and Tempo on Emotional Responses to Music Using EEG Power Asymmetry

Journal of Psychophysiology ◽

10.1027/0269-8803/a000099 ◽

2013 ◽

Vol 27 (3) ◽

pp. 142-148 ◽

Cited By ~ 11

Author(s):

Konstantinos Trochidis ◽

Emmanuel Bigand

Keyword(s):

Left Hemisphere ◽

Right Hemisphere ◽

Emotional Responses ◽

Interactive Effects ◽

Eeg Activity ◽

Musical Excerpt ◽

Major Mode ◽

Musical Modes ◽

Slow Tempo ◽

The Right

The combined interactions of mode and tempo on emotional responses to music were investigated using both self-reports and electroencephalogram (EEG) activity. A musical excerpt was performed in three different modes and tempi. Participants rated the emotional content of the resulting nine stimuli and their EEG activity was recorded. Musical modes influence the valence of emotion with major mode being evaluated happier and more serene, than minor and locrian modes. In EEG frontal activity, major mode was associated with an increased alpha activation in the left hemisphere compared to minor and locrian modes, which, in turn, induced increased activation in the right hemisphere. The tempo modulates the arousal value of emotion with faster tempi associated with stronger feeling of happiness and anger and this effect is associated in EEG with an increase of frontal activation in the left hemisphere. By contrast, slow tempo induced decreased frontal activation in the left hemisphere. Some interactive effects were found between mode and tempo: An increase of tempo modulated the emotion differently depending on the mode of the piece.

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Right-Hemisphere Specialization for Contour Grouping

Experimental Psychology (formerly Zeitschrift für Experimentelle Psychologie) ◽

10.1027/1618-3169/a000252 ◽

2014 ◽

Vol 61 (5) ◽

pp. 331-339 ◽

Cited By ~ 1

Author(s):

Gregor Volberg

Keyword(s):

Right Hemisphere ◽

Contour Detection ◽

Global Processing ◽

Detection Accuracy ◽

Frequency Spectra ◽

Visual Hemifield ◽

Spatial Frequencies ◽

A Chain ◽

The Right ◽

Hemisphere Specialization

Previous studies often revealed a right-hemisphere specialization for processing the global level of compound visual stimuli. Here we explore whether a similar specialization exists for the detection of intersected contours defined by a chain of local elements. Subjects were presented with arrays of randomly oriented Gabor patches that could contain a global path of collinearly arranged elements in the left or in the right visual hemifield. As expected, the detection accuracy was higher for contours presented to the left visual field/right hemisphere. This difference was absent in two control conditions where the smoothness of the contour was decreased. The results demonstrate that the contour detection, often considered to be driven by lateral coactivation in primary visual cortex, relies on higher-level visual representations that differ between the hemispheres. Furthermore, because contour and non-contour stimuli had the same spatial frequency spectra, the results challenge the view that the right-hemisphere advantage in global processing depends on a specialization for processing low spatial frequencies.

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