scholarly journals Ocular exposure to blue-enriched light has an asymmetric influence on neural activity and spatial attention

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Daniel P. Newman ◽  
Steven W. Lockley ◽  
Gerard M. Loughnane ◽  
Ana Carina P. Martins ◽  
Rafael Abe ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Spatial Attention ◽  
Neural Activity ◽  
Right Hemisphere ◽  
Response Times ◽  
Visual Stimuli ◽  
Asymmetric Effect ◽  
Attention Orienting ◽  
Ocular Exposure ◽  
First Time

AbstractBrain networks subserving alertness in humans interact with those for spatial attention orienting. We employed blue-enriched light to directly manipulate alertness in healthy volunteers. We show for the first time that prior exposure to higher, relative to lower, intensities of blue-enriched light speeds response times to left, but not right, hemifield visual stimuli, via an asymmetric effect on right-hemisphere parieto-occipital α-power. Our data give rise to the tantalising possibility of light-based interventions for right hemisphere disorders of spatial attention.

scholarly journals Erratum: Corrigendum: Ocular exposure to blue-enriched light has an asymmetric influence on neural activity and spatial attention

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Daniel P. Newman ◽  
Steven W. Lockley ◽  
Gerard M. Loughnane ◽  
Ana Carina P. Martins ◽  
Rafael Abe ◽  
...  
Keyword(s):  
Spatial Attention ◽  
Neural Activity ◽  
Ocular Exposure

Methylphenidate reduces orienting bias in healthy individuals

2021 ◽  
pp. 026988112199688
Author(s):  
Leehe Peled-Avron ◽  
Hagar Gelbard Goren ◽  
Noa Brande-Eilat ◽  
Shirel Dorman-Ilan ◽  
Aviv Segev ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Asymmetric Effect ◽  
Healthy Individuals ◽  
Double Blind ◽  
Spatial Orienting ◽  
Individual Trait ◽  
Neurological Patients ◽  
Dopamine Signaling ◽  
First Time ◽  
Neural Effect

Background: Healthy individuals show subtle orienting bias, a phenomenon known as pseudoneglect, reflected in a tendency to direct greater attention toward one hemispace. Accumulating evidence indicates that this bias is an individual trait, and attention is preferentially directed contralaterally to the hemisphere with higher dopamine signaling. Administration of methylphenidate (MPH), a dopamine transporter inhibitor, was shown to normalize aberrant spatial attention bias in psychiatric and neurological patients, suggesting that the reduced orienting bias following administration of MPH reflects an asymmetric effect of the drug, increasing extracellular dopamine in the hemisphere with lower dopamine signaling. Aim: We predicted that, similarly to its effect on patients with brain pathology, MPH will reduce the orienting bias in healthy subjects. Methods: To test this hypothesis, we examined the behavioral effects of a single dose (20 mg) of MPH on orienting bias in 36 healthy subjects (18 females) in a randomized, double-blind placebo-controlled, within-subject design, using the greyscales task, which has been shown to detect subtle attentional biases in both patients and healthy individuals. Results/outcomes: Results demonstrate that healthy individuals vary in both direction and magnitude of spatial orienting bias and show reduced magnitude of orienting bias following MPH administration, regardless of the initial direction of asymmetry. Conclusions/interpretations: Our findings reveal, for the first time in healthy subjects, that MPH decreases spatial orienting bias in an asymmetric manner. Given the well-documented association between orienting bias and asymmetric dopamine signaling, these findings also suggest that MPH might exert a possible asymmetric neural effect in the healthy brain.

Unwanted reflex-like saccades in visual extinction patients

1999 ◽  
Vol 22 (4) ◽  
pp. 683-683 ◽  
Author(s):  
Alessandra Fanini ◽  
Carlo Alberto Marzi
Keyword(s):  
Reaction Time ◽  
Right Hemisphere ◽  
Visual Stimuli ◽  
Reaction Time Task ◽  
Time Task ◽  
Right Hemisphere Damage ◽  
Visual Extinction ◽  
Manual Reaction Time

We studied patients with left visual extinction following right hemisphere damage in a simple manual reaction time task using brief visual stimuli. With unilateral lateralized stimuli the patients showed a high proportion of unwanted, reflex-like saccades to either side of stimulation. In contrast, with bilateral stimuli there was an overall decrease in the proportion of unwanted saccades, and the vast majority of them were directed toward the ipsilesional side. The implications of these results for the Findlay & Walker model are discussed.

scholarly journals Overnight transdermal scopolamine patch administration has no clear effect on cognition and emotional processing in healthy volunteers

2018 ◽  
Vol 33 (2) ◽  
pp. 255-257 ◽  
Author(s):  
Bernard R Bukala ◽  
Michael Browning ◽  
Philip J Cowen ◽  
Catherine J Harmer ◽  
Susannah E Murphy
Keyword(s):  
Working Memory ◽  
Healthy Volunteers ◽  
Emotional Processing ◽  
Cholinergic Receptor ◽  
Double Blind ◽  
Muscarinic Cholinergic Receptor ◽  
Clear Effect ◽  
Antidepressant Effects ◽  
Muscarinic Cholinergic ◽  
First Time

There has been increasing interest in the antidepressant effects of the muscarinic cholinergic receptor antagonist scopolamine. Here we assess, for the first time, whether a transdermal scopolamine patch is sufficient to induce changes in cognition that are consistent with the reported cognitive and antidepressant effects of scopolamine. A scopolamine or placebo patch was administered to healthy volunteers ( n=33) for 17 h in a double-blind, between-subject procedure. There was no clear effect of scopolamine patch on emotional cognition, verbal or working memory, suggesting that the effective dose of scopolamine available through the patch is too low to represent a viable antidepressant mechanism.

scholarly journals Revisiting Persistent Neuronal Activity During Covert Spatial Attention

2021 ◽  
Vol 15 ◽  
Author(s):  
Julian L. Amengual ◽  
Suliann Ben Hamed
Keyword(s):  
Spatial Attention ◽  
Neural Representation ◽  
Persistent Activity ◽  
Sources Of Information ◽  
Multiple Sources ◽  
Oscillatory Dynamics ◽  
Attention Orienting ◽  
Related Information ◽  
Attention Tasks ◽  
Reduction Methods

Persistent activity has been observed in the prefrontal cortex (PFC), in particular during the delay periods of visual attention tasks. Classical approaches based on the average activity over multiple trials have revealed that such an activity encodes the information about the attentional instruction provided in such tasks. However, single-trial approaches have shown that activity in this area is rather sparse than persistent and highly heterogeneous not only within the trials but also between the different trials. Thus, this observation raised the question of how persistent the actually persistent attention-related prefrontal activity is and how it contributes to spatial attention. In this paper, we review recent evidence of precisely deconstructing the persistence of the neural activity in the PFC in the context of attention orienting. The inclusion of machine-learning methods for decoding the information reveals that attention orienting is a highly dynamic process, possessing intrinsic oscillatory dynamics working at multiple timescales spanning from milliseconds to minutes. Dimensionality reduction methods further show that this persistent activity dynamically incorporates multiple sources of information. This novel framework reflects a high complexity in the neural representation of the attention-related information in the PFC, and how its computational organization predicts behavior.

scholarly journals Functional but not obligatory link between microsaccades and neural modulation by covert spatial attention

2021 ◽  
Author(s):  
Baiwei Liu ◽  
Anna C Nobre ◽  
Freek van Ede
Keyword(s):  
Spatial Attention ◽  
Neural Activity ◽  
Alpha Activity ◽  
Spatial Modulation ◽  
Fixational Eye Movements ◽  
Neural Modulation ◽  
Gaze Behaviour ◽  
Eeg Alpha ◽  
Eeg Alpha Activity ◽  
Spatial Modulations

Covert spatial attention is associated with spatially specific modulation of neural activity as well as with directional biases in fixational eye-movements known as microsaccades. Recently, this link has been suggested to be obligatory, such that modulation of neural activity by covert spatial attention occurs only when paired with microsaccades toward the attended location. Here we revisited this link between microsaccades and neural modulation by covert spatial attention in humans. We investigated spatial modulation of 8-12 Hz EEG alpha activity and microsaccades in a context with no incentive for overt gaze behaviour: when attention is directed internally within the spatial layout of visual working memory. In line with a common attentional origin, we show that spatial modulations of alpha activity and microsaccades co-vary: alpha lateralisation is stronger in trials with microsaccades toward compared to away from the memorised location of the to-be-attended item and occurs earlier in trials with earlier microsaccades toward this item. Critically, however, trials without attention-driven microsaccades nevertheless showed clear spatial modulation of alpha activity - comparable to the neural modulation observed in trials with attention-driven microsaccades. Thus, directional biases in microsaccades are correlated with neural signatures of covert spatial attention, but they are not a prerequisite for neural modulation by covert spatial attention to be manifest.

scholarly journals Emotion Modulation of the Body-Selective Areas in the Developing Brain

2019 ◽  
Author(s):  
Paddy Ross ◽  
Beatrice de Gelder ◽  
Frances Crabbe ◽  
Marie-Hélène Grosbras
Keyword(s):  
Conflict Of Interest ◽  
Right Hemisphere ◽  
Brain Activity ◽  
The Body ◽  
Childhood And Adolescence ◽  
Body Perception ◽  
Body Area ◽  
Potential Conflict ◽  
First Time ◽  
Posterior Superior Temporal Sulcus

AbstractEmotions are strongly conveyed by the human body and the ability to recognize emotions from body posture or movement is still developing through childhood and adolescence. To date, there are very few studies exploring how these behavioural observations are paralleled by functional brain development. Furthermore, there are currently no studies exploring the development of emotion modulation in these areas. In the current study, we used functional magnetic resonance imaging (fMRI) to compare the brain activity of 25 children (age 6-11), 18 adolescents (age 12-17) and 26 adults while they passively viewed short videos of angry, happy or neutral body movements. We observed that when viewing bodies generally, adults showed higher activity than children bilaterally in the body-selective areas; namely the extra-striate body area (EBA), fusiform body area (FBA), posterior superior temporal sulcus (pSTS) and amygdala (AMY). Adults also showed higher activity than adolescents, but only in right hemisphere body-selective areas. Crucially, however, we found that there were no age differences in the emotion modulation of activity in these areas. These results indicate, for the first time, that despite activity selective to body perception increasing across childhood and adolescence, emotion modulation of these areas in adult-like from 7 years of age.Conflict of InterestThe author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Spatial Orienting Controlled without Awareness: A Semantically Based Implicit Learning Effect

1996 ◽  
Vol 49 (2) ◽  
pp. 490-518 ◽  
Author(s):  
Anthony J. Lambert ◽  
Alexander L. Sumich
Keyword(s):  
Implicit Learning ◽  
Spatial Attention ◽  
Learning Effect ◽  
Target Location ◽  
Response Times ◽  
Semantic Category ◽  
Detection Task ◽  
Word Target ◽  
Spatial Orienting ◽  
Predictive Relationship

Three experiments tested whether spatial attention can be influenced by a predictive relation between incidental information and the location of target events. Subjects performed a simple dot detection task; 600 msec prior to each target a word was presented briefly 5° to the left or right of fixation. There was a predictive relationship between the semantic category (living or non-living) of the words and target location. However, subjects were instructed to ignore the words, and a post-experiment questionnaire confirmed that they remained unaware of the word-target relationship. In all three experiments, given some practice on the task, response times were faster when targets appeared at likely ( p = 0.8), compared to unlikely ( p = 0.2) locations, in relation to lateral word category. Experiments 2 and 3 confirmed that this effect was driven by semantic encoding of the irrelevant words, and not by repetition of individual stimuli. Theoretical implications of this finding are discussed.

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