scholarly journals Glutamatergic facilitation of neural responses in MT enhances motion perception in humans

2018 ◽  
Author(s):  
Michael-Paul Schallmo ◽  
Rachel Millin ◽  
Alex M. Kale ◽  
Tamar Kolodny ◽  
Richard A.E. Edden ◽  
...  
Keyword(s):  
Individual Differences ◽  
Motion Perception ◽  
Neural Activity ◽  
Visual Motion ◽  
Large Individual ◽  
Resonance Spectroscopy ◽  
Neural Responses ◽  
Motion Direction ◽  
And Behavior ◽  
The Relationship

AbstractThere is large individual variability in human neural responses and perceptual abilities. The factors that give rise to these individual differences, however, remain largely unknown. To examine these factors, we separately measured fMRI responses to moving gratings in the motion-selective region MT, and perceptual duration thresholds for motion direction discrimination within the same group of male and female subjects. Further, we acquired MR spectroscopy data that allowed us to quantify an index of neurotransmitter levels in the region surrounding MT. We show that individual differences in the Glx (glutamate + glutamine) signal in the MT region are associated with both higher fMRI responses and improved psychophysical task performance. Our results suggest that individual differences in baseline levels of glutamate within MT contribute to motion perception by increasing neural responses in this region.SignificanceWhat factors govern the relationship between neural activity and behavior? Our results suggest that one such factor is the level of glutamate, an excitatory neurotransmitter, within a particular region of cortex. By measuring an index of glutamate in vivo using magnetic resonance spectroscopy, we show that human subjects with more glutamate in the visual motion area known as MT also have larger fMRI responses (an index of neural activity) in this region. Further, people with more glutamate in MT can accurately perceive moving images presented more briefly within a behavioral task. Our findings point to an important role for glutamate levels in determining the relationship between neural responses and behavior during visual motion perception.

scholarly journals Rapid Association Learning in the Primate Prefrontal Cortex in the Absence of Behavioral Reversals

2011 ◽  
Vol 23 (7) ◽  
pp. 1823-1828 ◽  
Author(s):  
Jason A. Cromer ◽  
Michelle Machon ◽  
Earl K. Miller
Keyword(s):  
Prefrontal Cortex ◽  
Neural Activity ◽  
Association Learning ◽  
Conditional Association ◽  
And Behavior ◽  
The Relationship ◽  
Behavioral Improvement ◽  
Previous Learning

The PFC plays a central role in our ability to learn arbitrary rules, such as “green means go.” Previous experiments from our laboratory have used conditional association learning to show that slow, gradual changes in PFC neural activity mirror monkeys' slow acquisition of associations. These previous experiments required monkeys to repeatedly reverse the cue–saccade associations, an ability known to be PFC-dependent. We aimed to test whether the relationship between PFC neural activity and behavior was due to the reversal requirement, so monkeys were trained to learn several new conditional cue–saccade associations without reversing them. Learning-related changes in PFC activity now appeared earlier and more suddenly in correspondence with similar changes in behavioral improvement. This suggests that learning of conditional associations is linked to PFC activity regardless of whether reversals are required. However, when previous learning does not need to be suppressed, PFC acquires associations more rapidly.

Perceptual Delays and Speed of Reading and Tapping

1964 ◽  
Vol 19 (3) ◽  
pp. 867-873 ◽  
Author(s):  
Albert J. Dinnerstein ◽  
Bernard Blitz
Keyword(s):  
Individual Differences ◽  
Simultaneous Presentation ◽  
Tactile Stimuli ◽  
Perceptual Latency ◽  
And Behavior ◽  
The Relationship

Simultaneous presentation of two stimuli from different modalities often produces an experience of apparent sequence. There are stable individual differences in the direction and degree of this temporal displacement. Comparing the relative latency of perception of visual and tactile stimuli by the above procedure, it was hypothesized that intermodal differences in perceptual latencies will produce a corresponding hierarchy in speeds of reading and tapping. The results were in accord with this hypothesis. The relationship between perceptual latency and behavior was most evident, however, only among the older and less educated Ss.

scholarly journals Suppression and facilitation of human neural responses

2017 ◽  
Author(s):  
M-P. Schallmo ◽  
A.M. Kale ◽  
R. Millin ◽  
A.V. Flevaris ◽  
Z. Brkanac ◽  
...  
Keyword(s):  
Visual Motion ◽  
Resonance Spectroscopy ◽  
Neural Responses ◽  
Strong Suppression ◽  
Selective Area ◽  
Neural Processes ◽  
Neural Inhibition ◽  
Divisive Normalization ◽  
Visual Areas ◽  
Insight Into

AbstractEfficient neural processing depends on regulating responses through suppression and facilitation of neural activity. Utilizing a well-known visual motion paradigm that evokes behavioral suppression and facilitation, and combining 5 different methodologies (behavioral psychophysics, computational modeling, functional MRI, pharmacology, and magnetic resonance spectroscopy), we provide evidence that challenges commonly held assumptions about the neural processes underlying suppression and facilitation. We show that: 1) both suppression and facilitation can emerge from a single, computational principle – divisive normalization; there is no need to invoke separate neural mechanisms, 2) neural suppression and facilitation in the motion-selective area MT mirror perception, but strong suppression also occurs in earlier visual areas, and 3) suppression is not driven by GABA-mediated inhibition. Thus, while commonly used spatial suppression paradigms may provide insight into neural response magnitudes in visual areas, they cannot be used to infer neural inhibition.

scholarly journals Motion Perception in the Common Marmoset

2019 ◽  
Vol 30 (4) ◽  
pp. 2659-2673
Author(s):  
Shaun L Cloherty ◽  
Jacob L Yates ◽  
Dina Graf ◽  
Gregory C DeAngelis ◽  
Jude F Mitchell
Keyword(s):  
Motion Perception ◽  
Visual Motion ◽  
Common Marmoset ◽  
Neural Population ◽  
Motion Processing ◽  
Motion Direction ◽  
Visual Motion Processing ◽  
Trade Offs ◽  
Population Codes ◽  
The Common

Abstract Visual motion processing is a well-established model system for studying neural population codes in primates. The common marmoset, a small new world primate, offers unparalleled opportunities to probe these population codes in key motion processing areas, such as cortical areas MT and MST, because these areas are accessible for imaging and recording at the cortical surface. However, little is currently known about the perceptual abilities of the marmoset. Here, we introduce a paradigm for studying motion perception in the marmoset and compare their psychophysical performance with human observers. We trained two marmosets to perform a motion estimation task in which they provided an analog report of their perceived direction of motion with an eye movement to a ring that surrounded the motion stimulus. Marmosets and humans exhibited similar trade-offs in speed versus accuracy: errors were larger and reaction times were longer as the strength of the motion signal was reduced. Reverse correlation on the temporal fluctuations in motion direction revealed that both species exhibited short integration windows; however, marmosets had substantially less nondecision time than humans. Our results provide the first quantification of motion perception in the marmoset and demonstrate several advantages to using analog estimation tasks.

scholarly journals Understanding heterosexual women’s erotic flexibility: the role of attention in sexual evaluations and neural responses to sexual stimuli

2020 ◽  
Vol 15 (4) ◽  
pp. 447-465
Author(s):  
Janna A Dickenson ◽  
Lisa Diamond ◽  
Jace B King ◽  
Kay Jenson ◽  
Jeffrey S Anderson
Keyword(s):  
Sexual Orientation ◽  
Neural Activity ◽  
Visual Processing ◽  
Neural Responses ◽  
Attentional Processing ◽  
Sexual Stimuli ◽  
Mindful Attention ◽  
Heterosexual Women ◽  
And Behavior

Abstract Many women experience desires, arousal and behavior that run counter to their sexual orientation (orientation inconsistent, ‘OI’). Are such OI sexual experiences cognitively and neurobiologically distinct from those that are consistent with one’s sexual orientation (orientation consistent, ‘OC’)? To address this question, we employed a mindful attention intervention—aimed at reducing judgment and enhancing somatosensory attention—to examine the underlying attentional and neurobiological processes of OC and OI sexual stimuli among predominantly heterosexual women. Women exhibited greater neural activity in response to OC, compared to OI, sexual stimuli in regions associated with implicit visual processing, volitional appraisal and attention. In contrast, women exhibited greater neural activity to OI, relative to OC, sexual stimuli in regions associated with complex visual processing and attentional shifting. Mindfully attending to OC sexual stimuli reduced distraction, amplified women’s evaluations of OC stimuli as sexually arousing and deactivated the superior cerebellum. In contrast, mindfully attending to OI sexual stimuli amplified distraction, decreased women’s evaluations of OI stimuli as sexually arousing and augmented parietal and temporo-occipital activity. Results of the current study constrain hypotheses of female erotic flexibility, suggesting that sexual orientation may be maintained by differences in attentional processing that cannot be voluntarily altered.

scholarly journals The BioLuminescent-OptoGenetic in vivo Response to Coelenterazine is Proportional, Sensitive and Specific in Neocortex

2019 ◽  
Author(s):  
Manuel Gomez-Ramirez ◽  
Alexander I. More ◽  
Nina G. Friedman ◽  
Ute Hochgeschwender ◽  
Christopher I. Moore
Keyword(s):  
Neural Activity ◽  
Bioluminescence Imaging ◽  
Photon Emission ◽  
Gaussia Luciferase ◽  
Light Production ◽  
Electrophysiological Recordings ◽  
Dynamic Concentration ◽  
And Behavior ◽  
The Relationship

ABSTRACTBioLuminescent (BL) light production can modulate neural activity and behavior through coexpressed OptoGenetic (OG) elements, an approach termed ‘BL-OG’. Yet, the relationship between BL-OG effects and bioluminescent photon emission has not been characterized in vivo. Further, the degree to which BL-OG effects strictly depend on optogenetic mechanisms driven by bioluminescent photons is unknown. Crucial to every neuromodulation method is whether the activator shows a dynamic concentration range driving robust, selective, and non-toxic effects. We systematically tested the effects of four key components of the BL-OG mechanism (luciferin, oxidized luciferin, luciferin vehicle, and bioluminescence), and compared these against effects induced by the Luminopsin-3 (LMO3) BL-OG molecule, a fusion of slow burn Gaussia luciferase (sbGLuc) and Volvox ChannelRhodopsin-1 (VChR1). We performed combined bioluminescence imaging and electrophysiological recordings while injecting specific doses of Coelenterazine (substrate for sbGluc), Coelenteramide (CTM, the oxidized product of CTZ), or CTZ vehicle. CTZ robustly drove activity in mice expressing LMO3, with photon production proportional to firing rate. In contrast, low and moderate doses of CTZ, CTM, or vehicle did not modulate activity in mice that did not express LMO3. We also failed to find bioluminescence effects on neural activity in mice expressing an optogenetically non-sensitive LMO3 variant. We observed weak responses to the highest dose of CTZ in control mice, but these effects were significantly smaller than those observed in the LMO3 group. These results show that in neocortex in vivo, there is a large CTZ range wherein BL-OG effects are specific to its active chemogenetic mechanism.

scholarly journals White matter deficits correlate with visual motion perception impairments in dyslexic carriers of the DCDC2 genetic risk variant

2021 ◽  
Author(s):  
Daniela Perani ◽  
Paola Scifo ◽  
Guido M. Cicchini ◽  
Pasquale Della Rosa ◽  
Chiara Banfi ◽  
...  
Keyword(s):  
White Matter ◽  
Motion Perception ◽  
Visual Motion ◽  
Visual Analysis ◽  
Temporal Cortex ◽  
Inferior Temporal Cortex ◽  
Motion Processing ◽  
Motion Direction ◽  
Risk Variant ◽  
Visual Motion Processing

AbstractMotion perception deficits in dyslexia show a large intersubjective variability, partly reflecting genetic factors influencing brain architecture development. In previous work, we have demonstrated that dyslexic carriers of a mutation of the DCDC2 gene have a very strong impairment in motion perception. In the present study, we investigated structural white matter alterations associated with the poor motion perception in a cohort of twenty dyslexics with a subgroup carrying the DCDC2 gene deletion (DCDC2d+) and a subgroup without the risk variant (DCDC2d–). We observed significant deficits in motion contrast sensitivity and in motion direction discrimination accuracy at high contrast, stronger in the DCDC2d+ group. Both motion perception impairments correlated significantly with the fractional anisotropy in posterior ventral and dorsal tracts, including early visual pathways both along the optic radiation and in proximity of occipital cortex, MT and VWFA. However, the DCDC2d+ group showed stronger correlations between FA and motion perception impairments than the DCDC2d– group in early visual white matter bundles, including the optic radiations, and in ventral pathways located in the left inferior temporal cortex. Our results suggest that the DCDC2d+ group experiences higher vulnerability in visual motion processing even at early stages of visual analysis, which might represent a specific feature associated with the genotype and provide further neurobiological support to the visual-motion deficit account of dyslexia in a specific subpopulation.

scholarly journals Suppression and facilitation of human neural responses

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Michael-Paul Schallmo ◽  
Alexander M Kale ◽  
Rachel Millin ◽  
Anastasia V Flevaris ◽  
Zoran Brkanac ◽  
...  
Keyword(s):  
Visual Motion ◽  
Resonance Spectroscopy ◽  
Neural Responses ◽  
Strong Suppression ◽  
Selective Area ◽  
Neural Processes ◽  
Neural Inhibition ◽  
Divisive Normalization ◽  
Visual Areas ◽  
Insight Into

Efficient neural processing depends on regulating responses through suppression and facilitation of neural activity. Utilizing a well-known visual motion paradigm that evokes behavioral suppression and facilitation, and combining five different methodologies (behavioral psychophysics, computational modeling, functional MRI, pharmacology, and magnetic resonance spectroscopy), we provide evidence that challenges commonly held assumptions about the neural processes underlying suppression and facilitation. We show that: (1) both suppression and facilitation can emerge from a single, computational principle – divisive normalization; there is no need to invoke separate neural mechanisms, (2) neural suppression and facilitation in the motion-selective area MT mirror perception, but strong suppression also occurs in earlier visual areas, and (3) suppression is not primarily driven by GABA-mediated inhibition. Thus, while commonly used spatial suppression paradigms may provide insight into neural response magnitudes in visual areas, they should not be used to infer neural inhibition.

scholarly journals An objective and reliable electrophysiological marker for implicit trustworthiness perception

2020 ◽  
Vol 15 (3) ◽  
pp. 337-346
Author(s):  
Derek C Swe ◽  
Romina Palermo ◽  
O Scott Gwinn ◽  
Gillian Rhodes ◽  
Markus Neumann ◽  
...  
Keyword(s):  
Individual Differences ◽  
Face Processing ◽  
Neural Activity ◽  
Visual Stimulation ◽  
Neural Responses ◽  
Individual Level ◽  
Face Images ◽  
Neural Signature ◽  
The Individual ◽  
Facial Trustworthiness

Abstract Trustworthiness is assumed to be processed implicitly from faces, despite the fact that the overwhelming majority of research has only involved explicit trustworthiness judgements. To answer the question whether or not trustworthiness processing can be implicit, we apply an electroencephalography fast periodic visual stimulation (FPVS) paradigm, where electrophysiological cortical activity is triggered in synchrony with facial trustworthiness cues, without explicit judgements. Face images were presented at 6 Hz, with facial trustworthiness varying at 1 Hz. Significant responses at 1 Hz were observed, indicating that differences in the trustworthiness of the faces were reflected in the neural signature. These responses were significantly reduced for inverted faces, suggesting that the results are associated with higher order face processing. The neural responses were reliable, and correlated with explicit trustworthiness judgements, suggesting that the technique is capable of picking up on stable individual differences in trustworthiness processing. By demonstrating neural activity associated with implicit trustworthiness judgements, our results contribute to resolving a key theoretical debate. Moreover, our data show that FPVS is a valuable tool to examine face processing at the individual level, with potential application in pre-verbal and clinical populations who struggle with verbalization, understanding or memory.

Effect of Viewing Distance on Looking Behavior in Neonates

1979 ◽  
Vol 2 (2) ◽  
pp. 121-131 ◽  
Author(s):  
Angela Schoetzau
Keyword(s):  
Individual Differences ◽  
Major Influence ◽  
Large Individual ◽  
Visual Orientation ◽  
Viewing Distance ◽  
Median Distance ◽  
Behavior Study ◽  
Human Newborn ◽  
Eyes Open ◽  
The Relationship

Two studies were conducted to investigate the relationship between the distance of an adult's face from a human newborn and the infant's looking behavior. Study 1 was concerned with how mothers regulate distance while interacting with their babies. 20 mother-infant pairs were filmed in profile and the eye-to-eye distance measured every six sec. The median distance was 22.5 cm, with 80% of the values lying between 16.0 and 27.3 cm. No significant differences in distance were found related to whether the babies had their eyes open or closed or whether they were on their mother's lap or on a diaper-changing table. There were large individual differences in the range of distances the mothers maintained and the frequency of alteration of distance. In Study 2, the visual orientation of 44 newborns was observed under two conditions: (A) 20 cm between faces of experimenter and baby; (B) 40 cm distance. The experimenter was talking to the baby under both conditions. Distance, at least in the range tested, does not appear to have any major influence on the baby's looking behavior, probably because of the immaturity of the newborn's visual system.

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