Tracing the timing of human analysis of motion and chromatic signals from occipital to temporo-parieto-occipital cortex: A transcranial magnetic stimulation study

Anand, Sulekha; Olson, Justin; Hotson, John R.

doi:10.1016/s0042-6989(98)00025-x

Cited by 28 publications

(20 citation statements)

References 52 publications

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“…Finally, it is also possible that TMS will act on both parameters (x-intercept and slope), inducing a leftward shift and an increase in slope. It is important to note that in all these cases, the y-intercept (the threshold when no noise has been added to the stimulus) will increase, which is consistent with the general observation that TMS interferes with perceptual sensitivity, such as has been shown for motion direction discriminations when TMS is applied over V5/MT (Anand et al 1998;Beckers and Homberg 1992;Beckers and Zeki 1995;Hotson et al 1994;Hotson and Anand 1999;Matthews et al 2001;Sack et al 2006). …”

supporting

confidence: 76%

The effect of TMS on visual motion sensitivity: an increase in neural noise or a decrease in signal strength?

Ruzzoli

Abrahamyan

Clifford

et al. 2011

Journal of Neurophysiology

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Ruzzoli M, Abrahamyan A, Clifford CW, Marzi CA, Miniussi C, Harris JA. The effect of TMS on visual motion sensitivity: an increase in neural noise or a decrease in signal strength? J Neurophysiol 106: 138-143, 2011. First published May 4, 2011 doi:10.1152/jn.00746.2010The underlying mechanisms of action of transcranial magnetic stimulation (TMS) are still a matter of debate. TMS may impair a subject's performance by increasing neural noise, suppressing the neural signal, or both. Here, we delivered a single pulse of TMS (spTMS) to V5/MT during a motion direction discrimination task while concurrently manipulating the level of noise in the motion stimulus. Our results indicate that spTMS essentially acts by suppressing the strength of the relevant visual signal. We suggest that TMS may induce a pattern of neural activity that complements the ongoing activation elicited by the sensory signal in a manner that partially impoverishes that signal. V5/MT; single pulse of transcranial magnetic stimulation IN BEHAVIORAL STUDIES THAT employ transcranial magnetic stimulation (TMS), the most often analyzed dependent variables are accuracy and reaction time (for a review, see Sandrini et al. 2011). Both of these variables are affected by the signal-tonoise ratio: higher ratios are associated with greater accuracy and shorter reaction times (cf. the linking hypothesis: Teller 1984). TMS has an effect on this ratio (Harris et al. 2008;Rauschecker et al. 2004;Sack et al. 2006;Silvanto et al. 2008) by reducing the strength of the signal (Harris et al. 2008), increasing the neural noise (Ruzzoli et al. 2010), or both.The "virtual lesion" hypothesis, by analogy with animal and human neuropsychological studies, states that TMS-induced effects are interpretable as a temporary and reversible halt of the functionality of the stimulated area as a consequence of the discharge of magnetic pulses (Pascual-Leone et al. 1999;Walsh and Cowey 1998). Although the virtual lesion is the most common theoretical framework used to interpret the behavioral effects of TMS, it does not provide a clear explanation of the underlying neural mechanisms . Recent human (Harris et al. 2008;Ruzzoli et al. 2010;Silvanto et al. 2008) Harris and colleagues (2008) used an added noise paradigm (Pelli and Farell 1999) to compare the functional effects of TMS on signal strength vs. noise. They applied a single pulse of TMS (spTMS) to the occipital pole while subjects discriminated the orientation of sinusoidal luminance gratings to which were added varying levels of spatial white noise. The orientation detection thresholds were established using an adaptive staircase procedure. The primary aim of that experiment was to ascertain the impact of TMS on the linear function between the square of the detection thresholds (contrast energy) and the square of the amount of noise added to the stimulus [noise variance (2 )]. Harris et al. (2008) found that the slope of the psychometric function increased more than double when spTMS was applied to visual cortex, compared with ...

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supporting

confidence: 76%

The effect of TMS on visual motion sensitivity: an increase in neural noise or a decrease in signal strength?

Ruzzoli

Abrahamyan

Clifford

et al. 2011

Journal of Neurophysiology

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“…Consistent with monkey electrophysiology (see Born and Bradley, 2005) and human neuroimaging (see Orban et al, 2003), several TMS studies (Beckers and Zeki, 1995;Anand et al, 1998;Walsh et al, 1998;Hotson and Anand, 1999;Silvanto et al, 2005;Sack et al, 2006;Laycock et al, 2007) have shown that hMT/V5ϩ plays a key role in visual-motion processing. TMS of this region also affects visuomotor coordination: it reduces the spatial accuracy of reaching to stationary objects after adaptation to background motion (Whitney et al, 2007), and the movement speed to catch horizontally moving targets (Schenk et al, 2005).…”

Section: Discussionmentioning

confidence: 56%

Contributions of the Human Temporoparietal Junction and MT/V5+ to the Timing of Interception Revealed by Transcranial Magnetic Stimulation

Bosco¹,

Carrozzo²,

Lacquaniti³

2008

J. Neurosci.

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To intercept a fast target at destination, hand movements must be centrally triggered ahead of target arrival to compensate for neuromechanical delays. The role of visual-motion cortical areas is unclear. They likely feed downstream parietofrontal networks with signals reflecting target motion, but do they also contribute internal timing signals to trigger the motor response? We disrupted the activity of human temporoparietal junction (TPJ) and middle temporal area (hMT/V5ϩ) by means of transcranial magnetic stimulation (TMS) while subjects pressed a button to intercept targets accelerated or decelerated in the vertical or horizontal direction. Target speed was randomized, making arrival time unpredictable across trials. We used either repetitive TMS (rTMS) before task execution or doublepulse TMS (dpTMS) during target motion. We found that after rTMS and dpTMS at 100 -200 ms from motion onset, but not after dpTMS at 300 -400 ms, the button-press responses occurred earlier than in the control, with time shifts independent of target speed. This suggests that activity in TPJ and hMT/V5ϩ can feed downstream regions not only with visual-motion information, but also with internal timing signals used for interception at destination. Moreover, we found that TMS of hMT/V5ϩ affected interception of all tested motion types, whereas TMS of TPJ significantly affected only interception of motion coherent with natural gravity. TPJ might specifically gate visual-motion information according to an internal model of the effects of gravity.

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“…Previous online TMS studies on the role of V1 in motion perception have typically found a single, broad (Anand et al, 1998;Hotson and Anand, 1999) or a single narrow period (Beckers and Zeki, 1995;Laycock et al, 2007) of V1 activity. Only Silvanto et al (2005b) and the current study have found evidence for distinct early and late periods of V1 activity (although such evidence has been obtained in other domains such as figure-ground segregation; Heinen et al, 2005).…”

Section: Discussionmentioning

confidence: 99%

The role of early visual cortex (V1/V2) in conscious and unconscious visual perception

2010

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Tracing the timing of human analysis of motion and chromatic signals from occipital to temporo-parieto-occipital cortex: A transcranial magnetic stimulation study

Cited by 28 publications

References 52 publications

The effect of TMS on visual motion sensitivity: an increase in neural noise or a decrease in signal strength?

The effect of TMS on visual motion sensitivity: an increase in neural noise or a decrease in signal strength?

Contributions of the Human Temporoparietal Junction and MT/V5+ to the Timing of Interception Revealed by Transcranial Magnetic Stimulation

The role of early visual cortex (V1/V2) in conscious and unconscious visual perception

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