scholarly journals Auditory motion does not modulate spiking activity in the middle temporal and medial superior temporal visual areas

2018 ◽  
Vol 48 (4) ◽  
pp. 2013-2029 ◽  
Author(s):  
Tristan A. Chaplin ◽  
Benjamin J. Allitt ◽  
Maureen A. Hagan ◽  
Marcello G. P. Rosa ◽  
Ramesh Rajan ◽  
...  
Keyword(s):  
Auditory Motion ◽  
Middle Temporal ◽  
Medial Superior Temporal ◽  
Visual Areas ◽  
Spiking Activity

scholarly journals Auditory Motion Does Not Modulate Spiking Activity in the Middle Temporal and Medial Superior Temporal Visual Areas

2017 ◽  
Author(s):  
Tristan A. Chaplin ◽  
Benjamin J. Allitt ◽  
Maureen A. Hagan ◽  
Marcello G.P. Rosa ◽  
Ramesh Rajan ◽  
...  
Keyword(s):  
Visual Motion ◽  
Exact Nature ◽  
Sources Of Information ◽  
Auditory Motion ◽  
Visual Motion Perception ◽  
Middle Temporal ◽  
Medial Superior Temporal ◽  
Random Dot Patterns ◽  
High Level ◽  
Spiking Activity

AbstractThe integration of multiple sensory modalities is a key aspect of brain function, allowing animals to take advantage of concurrent sources of information to make more accurate perceptual judgments. For many years, multisensory integration in the cerebral cortex was deemed to occur only in high-level “polysensory” association areas. However, more recent studies have suggested that cross-modal stimulation can also influence neural activity in areas traditionally considered to be unimodal. In particular, several human neuroimaging studies have reported that extrastriate areas involved in visual motion perception are also activated by auditory motion, and may integrate audio-visual motion cues. However, the exact nature and extent of the effects of auditory motion on the visual cortex have not been studied at the single neuron level. We recorded the spiking activity of neurons in the middle temporal (MT) and medial superior temporal (MST) areas of anesthetized marmoset monkeys upon presentation of unimodal stimuli (moving auditory or visual patterns), as well as bimodal stimuli (concurrent audio-visual motion). Despite robust, direction selective responses to visual motion, none of the sampled neurons responded to auditory motion stimuli. Moreover, concurrent moving auditory stimuli had no significant effect on the ability of single MT and MST neurons, or populations of simultaneously recorded neurons, to discriminate the direction of motion of visual stimuli (moving random dot patterns with varying levels of motion noise). Our findings do not support the hypothesis that direct interactions between MT, MST and areas low in the hierarchy of auditory areas underlie audiovisual motion integration.

scholarly journals Differential activation of the middle-temporal complex to visual stimulation in migraineurs

Cephalalgia ◽  
2010 ◽  
Vol 31 (3) ◽  
pp. 338-345 ◽  
Author(s):  
Andrea Antal ◽  
Rafael Polania ◽  
Katharina Saller ◽  
Carmen Morawetz ◽  
Carsten Schmidt-Samoa ◽  
...  
Keyword(s):  
Visual Stimulation ◽  
Cortical Folding ◽  
Anterior Portion ◽  
Posterior Portion ◽  
Temporal Area ◽  
Middle Temporal ◽  
Medial Superior Temporal ◽  
Visual Areas ◽  
The Individual ◽  
Interictal State

Objective: Differences between people with and without migraine on various measures of visual perception have been attributed to abnormal cortical processing due to the disease. The aim of the present study was to explore the dynamics of the basic interictal state with regard to the extrastriate, motion-responsive middle temporal area (MT-complex) with functional magnetic resonance imaging (fMRI) at 3 tesla using coherent/incoherent moving dot stimuli. Method: Twenty-four migraine patients (12 with aura [MwA], 12 without aura [MwoA]) and 12 healthy subjects participated in the study. The individual cortical folding pattern was accounted for by using a cortical matching approach. Results: In the inferior-posterior portion of the MT-complex, most likely representing MT, control subjects showed stronger bilateral activation compared to MwA and MwoA patients. Compared with healthy controls MwoA and MwA patients showed significantly stronger activation mainly at the left side in response to visual stimulation in the superior-anterior portion of the MT-complex, representing the medial-superior temporal area (MST). Conclusion: Our findings strengthen the hypothesis that hyperresponsiveness of the visual cortex in migraine goes beyond early visual areas, even in the interictal period.

Subcortical connections of visual areas MST and FST in macaques

1992 ◽  
Vol 9 (3-4) ◽  
pp. 291-302 ◽  
Author(s):  
Driss Boussaoud ◽  
Robert Desimone ◽  
Leslie G. Ungerleider
Keyword(s):  
Basal Forebrain ◽  
Optic Tract ◽  
Movement Control ◽  
Reticular Nucleus ◽  
Pontine Nuclei ◽  
Subcortical Structures ◽  
Middle Temporal ◽  
Medial Superior Temporal ◽  
Visual Areas ◽  
Visual Area Mt

AbstractTo examine the subcorctical connections of the medial superior temporal and fundus of the superior temporal visual areas (MST and FST, respectively), we injected anterograde and retrograde tracers into 16 physiologically identified sites within the two areas in seven macaque monkeys. The subcortical connections of MST and FST were found to be very similar. Both areas were found to be reciprocally connected with the pulvinar, mainly with its medial subdivision, and with the claustrum. Nonreciprocal projections from both MST and FST were consistently found in the striatum (caudate and putamen), reticular nucleus of the thalamus, and the pontine nuclei. The labeled terminals in the pons were in the dorsolateral, lateral, dorsal, and peduncular nuclei. Additional nonreciprocal projections were found in one MST and one FST case to the nucleus of the optic tract, and, in one FST case, to the lateral terminal nucleus. Finally, three cases showed a nonreciprocal projection to FST from the basal forebrain. The subcortical structures containing label following MST and FST injections were largely the same as those labeled after injections of the middle temporal visual area (MT), but the label within each structure after MST and FST injections was more widespread than that from MT, overlapping the distribution of label that has been reported after injections of parietal visual areas. This finding is consistent with the known contributions of MST and FST to the functions of parietal cortex, such as eye-movement control.

Visual response properties of neurons in four extrastriate visual areas of the owl monkey (Aotus trivirgatus): a quantitative comparison of medial, dorsomedial, dorsolateral, and middle temporal areas

1981 ◽  
Vol 45 (3) ◽  
pp. 397-416 ◽  
Author(s):  
J. F. Baker ◽  
S. E. Petersen ◽  
W. T. Newsome ◽  
J. M. Allman
Keyword(s):  
Receptive Fields ◽  
Field Size ◽  
Visual Response ◽  
Response Properties ◽  
Middle Temporal ◽  
Optimal Direction ◽  
Visual Areas ◽  
Direction Of Movement ◽  
Owl Monkeys ◽  
The Difference

1. The response properties of 354 single neurons in the medial (M), dorsomedial (DM), dorsolateral (DL), and middle temporal (MT) visual areas were studied quantitatively with bar, spot, and random-dot stimuli in chronically implanted owl monkeys with fixed gaze. 2. A directionality index was computed to compare the responses to stimuli in the optimal direction with the responses to the opposing direction of movement. The greater the difference between opposing directions, the higher the index. MT cells had much higher direction indices to moving bars than cells in DL, DM, and M. 3. A tuning index was computed for each cell to compare the responses to bars moving in the optimal direction, or flashed in the optimal orientation, with the responses in other directions or orientations within +/- 90 degrees. Cells in all four areas were more sharply tuned to the orientation of stationary flashed bars than to moving bars, although a few cells (9/92( were unresponsive in the absence of movement. DM cells tended to be more sharply tuned to moving bars than cells in the other areas. 4. Directionality in DM, DL, and MT was relatively unaffected by the use of single-spot stimuli instead of bars; tuning in all four areas was broader to spots than bars. 5. Moving arrays of randomly spaced spots were more strongly excitatory than bar stimuli for many neurons in MT (16/31 cells). These random-dot stimuli were also effective in M, but evoked no response or weak responses from most cells in DM and DL. 6. The best velocities of movement were usually in the range of 10-100 degrees/s, although a few cells (22/227), primarily in MT (14/69 cells), preferred higher velocities. 7. Receptive fields of neurons in all four areas were much larger than striate receptive fields. Eccentricity was positively correlated with receptive-field size (r = 0.62), but was not correlated with directionality index, tuning index, or best velocity. 8. The results support the hypothesis that there are specializations of function among the cortical visual areas.

scholarly journals Hierarchy of direction-tuned motion adaptation in human visual cortex

2012 ◽  
Vol 107 (8) ◽  
pp. 2163-2184 ◽  
Author(s):  
Hyun Ah Lee ◽  
Sang-Hun Lee
Keyword(s):  
Prolonged Exposure ◽  
Tuning Curve ◽  
Population Activity ◽  
Motion Adaptation ◽  
Temporal Area ◽  
Dynamic Stimuli ◽  
Tuning Curves ◽  
Medial Superior Temporal ◽  
Cortical Responses ◽  
Visual Areas

Prolonged exposure to a single direction of motion alters perception of subsequent static or dynamic stimuli and induces substantial changes in behaviors of motion-sensitive neurons, but the origin of neural adaptation and neural correlates of perceptual consequences of motion adaptation in human brain remain unclear. Using functional magnetic resonance imaging, we measured motion adaptation tuning curves in a fine scale by probing changes in cortical activity after adaptation for a range of directions relative to the adapted direction. We found a clear dichotomy in tuning curve shape: cortical responses in early-tier visual areas reduced at around both the adapted and opposite direction, resulting in a bidirectional tuning curve, whereas response reduction in high-tier areas occurred only at around the adapted direction, resulting in a unidirectional tuning curve. We also found that the psychophysically measured adaptation tuning curves were unidirectional and best matched the cortical adaptation tuning curves in the middle temporal area (MT) and the medial superior temporal area (MST). Our findings are compatible with, but not limited to, an interpretation in which direct impacts of motion adaptation occur in both unidirectional and bidirectional units in early visual areas, but the perceptual consequences of motion adaptation are manifested in the population activity in MT and MST, which may inherit those direct impacts of adaptation from the directionally selective units.

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