MODULATION OF AUDITORY AND VISUAL PROCESSING BY DELTA-9-TETRAHYDROCANNABINOL AND CANNABIDIOL: AN FMRI STUDY

Abstract Objective The study was conducted to determine age-associated changes in functional brain response, measured with fMRI, during visual discrimination with regard to three elementary components of visual perception: shape, location, and velocity. A secondary aim was to validate the method used to isolate the hypothesized brain regions associated with these perceptual functions. Method Items from the Visual Assessment Battery (VAB), a simultaneous match-to-sample task, assessed visual discrimination in 40 healthy adults during fMRI. Participants were aged 51-91 and recruited from a larger community sample for a study on normal aging. The tasks were designed to isolate neural recruitment during discrimination of either location, shape, or velocity by using tasks that were identical aside from the perceptual skill required to complete them. Results The Location task uniquely activated the dorsal visual processing stream, the Shape task the ventral stream, and the Velocity task V5/MT. Greater age was associated with greater neural recruitment, particularly in frontal areas (uncorrected voxel-level p < .001, family-wise error cluster-level p□.05). Conclusions Results validated the specialization of brain regions for spatial, perceptual, and movement discriminations and the use of the VAB to assess functioning localized to these regions. Anterior neural recruitment during visual discrimination increases with age.

Download Full-text

ID 315 – Altered default mode network connectivity during visual processing in patients with mild cognitive impairment (an fMRI study)

Clinical Neurophysiology ◽

10.1016/j.clinph.2015.11.245 ◽

2016 ◽

Vol 127 (3) ◽

pp. e73-e74

Author(s):

L. Krajcovicova ◽

M. Barton ◽

N. Elfmarkova ◽

M. Mikl ◽

R. Marecek ◽

...

Keyword(s):

Cognitive Impairment ◽

Mild Cognitive Impairment ◽

Default Mode Network ◽

Visual Processing ◽

Network Connectivity ◽

Default Mode ◽

Fmri Study

Download Full-text

Visual Processing of Coherent Rotation in the Central Visual Field: An fMRI Study

Perception ◽

10.1068/p3427 ◽

2003 ◽

Vol 32 (10) ◽

pp. 1247-1257 ◽

Cited By ~ 9

Author(s):

Mervi Könönen ◽

Ari Pääkkönen ◽

Maija Pihlajamäki ◽

Kaarina Partanen ◽

Pasi A Karjalainen ◽

...

Keyword(s):

Visual Field ◽

Visual Processing ◽

Central Visual Field ◽

Fmri Study

Download Full-text

Inversion effect in the visual processing of Chinese character: An fMRI study

Neuroscience Letters ◽

10.1016/j.neulet.2010.04.075 ◽

2010 ◽

Vol 478 (2) ◽

pp. 107-111 ◽

Cited By ~ 3

Author(s):

Jizheng Zhao ◽

Jiangang Liu ◽

Jun Li ◽

Jimin Liang ◽

Lu Feng ◽

...

Keyword(s):

Visual Processing ◽

Chinese Character ◽

Inversion Effect ◽

Fmri Study

Download Full-text

Erratum: Modulation of Auditory and Visual Processing by Delta-9-Tetrahydrocannabinol and Cannabidiol: an fMRI Study

Neuropsychopharmacology ◽

10.1038/npp.2011.58 ◽

2011 ◽

Vol 36 (8) ◽

pp. 1778-1778 ◽

Cited By ~ 1

Author(s):

Toby T Winton-Brown ◽

Paul Allen ◽

Sagnik Bhattacharrya ◽

Stefan J Borgwardt ◽

Paolo Fusar-Poli ◽

...

Keyword(s):

Visual Processing ◽

Fmri Study

Download Full-text

Reprint of: Visual processing of words in a patient with visual form agnosia: A behavioural and fMRI study

Cortex ◽

10.1016/j.cortex.2015.10.001 ◽

2015 ◽

Vol 72 ◽

pp. 97-114 ◽

Cited By ~ 3

Author(s):

Cristiana Cavina-Pratesi ◽

Mary-Ellen Large ◽

A. David Milner

Keyword(s):

Visual Processing ◽

Visual Form ◽

Fmri Study

Download Full-text

Planning Functional Grasps of Simple Tools Invokes the Hand-independent Praxis Representation Network: An fMRI Study

Journal of the International Neuropsychological Society ◽

10.1017/s1355617716001120 ◽

2017 ◽

Vol 23 (2) ◽

pp. 108-120 ◽

Cited By ~ 16

Author(s):

Łukasz Przybylski ◽

Gregory Króliczak

Keyword(s):

Left Hemisphere ◽

Tool Use ◽

Visual Processing ◽

Hand Movement ◽

Dominant Hand ◽

Functional Magnetic Resonance ◽

Resonance Imaging ◽

Object Categories ◽

Fmri Study ◽

Neuropsychological Evidence

AbstractObjectives: Neuropsychological and neuroimaging evidence indicates that tool use knowledge and abilities are represented in the praxis representation network (PRN) of the left cerebral hemisphere. We investigated whether PRN would also underlie the planning of function-appropriate grasps of tools, even though such an assumption is inconsistent with some neuropsychological evidence for independent representations of tool grasping and skilled tool use. Methods: Twenty right-handed participants were tested in an event-related functional magnetic resonance imaging (fMRI) study wherein they planned functionally appropriate grasps of tools versus grasps of non-tools matched for size and/or complexity, and later executed the pantomimed grasps of these objects. The dominant right, and non-dominant left hands were used in two different sessions counterbalanced across participants. The tool and non-tool stimuli were presented at three different orientations, some requiring uncomfortable hand rotations for effective grips, with the difficulty matched for both hands. Results: Planning functional grasps of tools (vs. non-tools) was associated with significant asymmetrical increases of activity in the temporo/occipital-parieto-frontal networks. The greater involvement of the left hemisphere PRN was particularly evident when hand movement kinematics (including wrist rotations) for grasping tools and non-tools were matched. The networks engaged in the task for the dominant and non-dominant hand were virtually identical. The differences in neural activity for the two object categories disappeared during grasp execution. Conclusions: The greater hand-independent engagement of the left-hemisphere praxis representation network for planning functional grasps reveals a genuine effect of an early affordance/function-based visual processing of tools. (JINS, 2017, 23, 108–120)

Download Full-text

How Negative Emotion Enhances the Visual Specificity of a Memory

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2007.19.11.1872 ◽

2007 ◽

Vol 19 (11) ◽

pp. 1872-1887 ◽

Cited By ~ 85

Author(s):

Elizabeth A. Kensinger ◽

Rachel J. Garoff-Eaton ◽

Daniel L. Schacter

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Visual Processing ◽

Negative Emotion ◽

Functional Magnetic Resonance ◽

Resonance Imaging ◽

Visual Detail ◽

Fmri Study ◽

The Right ◽

With Memory

Some studies have suggested that emotion primarily increases memory for “gist,” and does not enhance memory for detail. There are, however, some instances in which negative objects (e.g., snake, grenade) are remembered with more visual detail than neutral objects (e.g., barometer, blender). In the present functional magnetic resonance imaging (fMRI) study, we examined the encoding processes that lead a person to remember the exact visual details of negative and neutral objects, and to remember which of two decisions were made about the objects (a size decision or an animacy decision). The enhancement in memory for a negative item's visual details appeared to result from enhanced visual processing: The right fusiform gyrus, a region known to be critical for processing exemplar-specific details, showed a greater extent and magnitude of activity during the successful encoding of negative objects. Activity in the right amygdala also corresponded with memory for visual detail, although it did not relate to memory for the task performed with the item. These data provide strong evidence that engagement of some amygdalar regions can correspond with enhanced memory for certain types of details, but does not ensure successful encoding of all contextual details.

Download Full-text

Neural and computational processes of accelerated perceptual awareness and decisions: A 7T fMRI Study

10.1101/2021.07.22.453451 ◽

2021 ◽

Author(s):

Shivam Kalhan ◽

Jessica McFadyen ◽

Naotsugu Tsuchiya ◽

Marta Garrido

Keyword(s):

Visual Processing ◽

Response Times ◽

Computational Modelling ◽

Occipital Lobe ◽

Conscious Perception ◽

Perceptual Awareness ◽

Evidence Accumulation ◽

Fearful Faces ◽

Fmri Study ◽

Neural Computations

Rapidly detecting salient information in our environments is critical for survival. Visual processing in subcortical areas like the pulvinar and amygdala have been shown to facilitate unconscious processing of salient stimuli. It is unknown, however, if and how these areas might interact with cortical networks to facilitate faster conscious perception of salient stimuli. Here we investigated these neural processes using 7T functional Magnetic Resonance Imaging (fMRI) in concert with computational modelling while participants (n = 32) engaged in a breaking continuous flash suppression paradigm (bCFS) in which fearful and neutral faces are initially suppressed from conscious perception but then eventually breakthrough into awareness. We found that participants reported faster breakthrough times for fearful faces compared to neutral faces. Drift-diffusion modelling suggested that perceptual evidence was accumulated at a faster rate for fearful faces compared to neutral faces. For both neutral and fearful faces, faster response times coincided with greater activity in the amygdala (specifically within its subregions, including superficial, basolateral and amygdalo-striatal transition area) and the insula. Faster rates of evidence accumulation coincided with greater activity in frontoparietal regions and the occipital lobe, as well as the amygdala. Overall, our findings suggest that hastened perceptual awareness of salient stimuli recruits the amygdala and, more specifically, is driven by accelerated evidence accumulation in fronto-parietal and visual areas. In sum, we have uncovered and mapped distinct neural computations that accelerate perceptual awareness of visually suppressed faces.

Download Full-text