Effects of Optic Flow in Motor Cortex and Area 7a

Merchant, Hugo; Battaglia-Mayer, Alexandra; Georgopoulos, Apostolos P.

doi:10.1152/jn.2001.86.4.1937

Cited by 91 publications

(69 citation statements)

References 39 publications

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“…However, our results are seemingly in contradiction with a couple of electrophysiological studies in monkeys: Merchant et al (2001), who reported that M1 neurons modulated their activity in response to optic flow stimuli in different directions, and Suminski et al (2009), who found that visual playback of reaching actions is enough to elicit directional tuning in M1 neurons. It is likely that the fMRI signal may be too crude to detect neuronal features that are seen in a minority of the neuronal population.…”

Section: Discussioncontrasting

confidence: 99%

The Representation of Visual and Motor Aspects of Reaching Movements in the Human Motor Cortex

Eisenberg¹,

Shmuelof²,

Vaadia³

et al. 2011

J. Neurosci.

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The human primary motor cortex (M1) is robustly activated during visually guided hand movements. M1 multivoxel patterns of functional MRI activation are more correlated during repeated hand movements to the same targets than to greatly differing ones, and therefore potentially contain information about movement direction. It is unclear, however, whether direction specificity is due to the motor command, as implicitly assumed, or to the visual aspects of the task, such as the target location and the direction of the cursor's trajectory. To disambiguate the visual and motor components, different visual-to-motor transformations were applied during an fMRI scan, in which participants made visually guided hand movements in various directions. The first run was the "baseline" (i.e., visual and motor mappings were matched); in the second run ("rotation"), the cursor movement was rotated by 45°with respect to the joystick movement. As expected, positive correlations were seen between the M1 multivoxel patterns evoked by the baseline run and by the rotation run, when the two movements were matched in their movement direction but the visual aspects differed. Importantly, similar correlations were observed when the visual elements were matched but the direction of hand movement differed. This indicates that M1 is sensitive to both motor and visual components of the task. However, repeated observation of the cursor movement without concurrent joystick control did not elicit significant activation in M1 or any correlated patterns of activation. Thus, visual aspects of movement are encoded in M1 only when they are coupled with motor consequences.

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Section: Discussioncontrasting

confidence: 99%

The Representation of Visual and Motor Aspects of Reaching Movements in the Human Motor Cortex

Eisenberg¹,

Shmuelof²,

Vaadia³

et al. 2011

J. Neurosci.

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show abstract

“…The function of these neurons appear to be 'defense' related: monkeys (and humans) are exquisitely sensitive to visual, auditory and multisensory looming signals that indicate approaching danger [31][32][33] and microstimulation of the 'polysensory zone' elicits defensive-like movements [34]. Consistent with these findings, visual responses in the primary motor cortex are particularly sensitive to expanding 'looming-like' optic flow stimuli [35].…”

Section: Frontal and Prefrontal Corticesmentioning

confidence: 88%

Is neocortex essentially multisensory?

Ghazanfar

Schroeder

2006

Trends in Cognitive Sciences

1,278

865

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Although sensory perception and neurobiology are traditionally investigated one modality at a time, real world behaviour and perception are driven by the integration of information from multiple sensory sources. Mounting evidence suggests that the neural underpinnings of multisensory integration extend into early sensory processing. This article examines the notion that neocortical operations are essentially multisensory. We first review what is known about multisensory processing in higher-order association cortices and then discuss recent anatomical and physiological findings in presumptive unimodal sensory areas. The pervasiveness of multisensory influences on all levels of cortical processing compels us to reconsider thinking about neural processing in unisensory terms. Indeed, the multisensory nature of most, possibly all, of the neocortex forces us to abandon the notion that the senses ever operate independently during real-world cognition.

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“…Although the experiment was not designed to distinguish between neuronal tuning to direction of movement and tuning to direction or location of the target, the fact that the best tuning in individual LFPs was obtained by alignment to movement onset in most LFPs but also by alignment to cue signal for approximately one-third of the LFPs, hints at a more complex involvement of LFPs in the control of voluntary movements [for tuning without movement, see Georgopoulos et al (1989); for motor cortical responses to visual stimuli, see Merchant et al (2001)]. …”

Section: Discussionmentioning

confidence: 99%

Encoding of Movement Direction in Different Frequency Ranges of Motor Cortical Local Field Potentials

Rickert¹,

Oliveira²,

Vaadia³

et al. 2005

J. Neurosci.

288

254

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Recent studies showed that the low-frequency component of local field potentials (LFPs) in monkey motor cortex carries information about parameters of voluntary arm movements. Here, we studied how different signal components of the LFP in the time and frequency domains are modulated during center-out arm movements. Analysis of LFPs in the time domain showed that the amplitude of a slow complex waveform beginning shortly before the onset of arm movement is modulated with the direction of the movement. Examining LFPs in the frequency domain, we found that direction-dependent modulations occur in three frequency ranges, which typically increased their amplitudes before and during movement execution: Յ4, 6 -13, and 63-200 Hz. Cosine-like tuning was prominent in all signal components analyzed. In contrast, activity in a frequency band Ϸ30 Hz was not modulated with the direction of movement and typically decreased its amplitude during the task. This suggests that high-frequency oscillations have to be divided into at least two functionally different regimes: one Ϸ30 Hz and one Ͼ60 Hz. Furthermore, using multiple LFPs, we could show that LFP amplitude spectra can be used to decode movement direction, with the best performance achieved by the combination of different frequency ranges. These results suggest that using the different frequency components in the LFP is useful in improving inference of movement parameters from local field potentials.

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Effects of Optic Flow in Motor Cortex and Area 7a

Cited by 91 publications

References 39 publications

The Representation of Visual and Motor Aspects of Reaching Movements in the Human Motor Cortex

The Representation of Visual and Motor Aspects of Reaching Movements in the Human Motor Cortex

Is neocortex essentially multisensory?

Encoding of Movement Direction in Different Frequency Ranges of Motor Cortical Local Field Potentials

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