Cone signal interactions in direction-selective neurons in the middle temporal visual area (MT)

Barberini, Crista L.; Cohen, Marlene R.; Wandell, Brian A.; Newsome, William T.

doi:10.1167/5.7.1

Cited by 73 publications

(33 citation statements)

References 61 publications

(75 reference statements)

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“…CP has been demonstrated previously at the SU level for perceptual judgments of motion direction Barberini et al, 2005;Purushothaman and Bradley, 2005), motion speed (Liu and Newsome, 2005), coarse binocular disparity (Uka and DeAngelis, 2004), structure-from-motion (Bradley et al, 1998;Dodd et al, 2001), and for detection of coherent motion onset (Cook and Maunsell, 2002). To our knowledge, the current data provide the first demonstration of a CP effect for LFP signals, but the effect was detectable only for frequencies above 40 Hz.…”

Section: Spectral Contamination From Spikes?supporting

confidence: 75%

“…A significant CP reflects an unusually close relationship between neural firing and behavior, strengthening the case that the neuron(s) under study contributes to perceptual judgments Dodd et al, 2001;Cook and Maunsell, 2002;Uka and DeAngelis, 2004;Barberini et al, 2005;Liu and Newsome, 2005;Purushothaman and Bradley, 2005).…”

Section: Differences Between Lfp and Mu Datamentioning

confidence: 67%

“…CP is a metric that captures trial-totrial relationships between neural responses and psychophysical choices in a two-alternative, forced-choice discrimination task, assuming repeated identical presentations of a weak stimulus Dodd et al, 2001;Cook and Maunsell, 2002;Uka and DeAngelis, 2004;Barberini et al, 2005;Liu and Newsome, 2005;Purushothaman and Bradley, 2005).…”

Section: Methodsmentioning

confidence: 99%

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Local Field Potential in Cortical Area MT: Stimulus Tuning and Behavioral Correlations

2006

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Low-frequency electrical signals like those that compose the local field potential (LFP) can be detected at substantial distances from their point of origin within the brain. It is thus unclear how useful the LFP might be for assessing local function, for example, on the spatial scale of cortical columns. We addressed this problem by comparing speed and direction tuning of LFPs obtained from middle temporal area MT with the tuning of multiunit (MU) activity recorded simultaneously. We found that the LFP can be well tuned for speed and direction and is highly correlated with that of MU activity, particularly for frequencies at and above the gamma band. LFP tuning is substantially poorer for lower frequencies, although tuning for direction extends to lower frequencies than does tuning for speed. Our data suggest that LFP signals at and above the gamma band reflect neural processing on the spatial scale of cortical columns, within a few hundred micrometers of the electrode tip. Consistent with this notion, we also found that frequencies at and above the gamma band measured during a speed discrimination task exhibit an effect known as "choice probability," which reveals a particularly close relationship between neural activity and behavioral choices. In the LFP, this signature of the perceptual choice comprises a shift in relative power from low-frequency bands (␣ and ␤) to the gamma band. It remains to be determined how LFP choice probability, which is a temporal signature, is related to conventional choice probability effects observed in spike rates.

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Section: Spectral Contamination From Spikes?supporting

confidence: 75%

Section: Differences Between Lfp and Mu Datamentioning

confidence: 67%

Section: Methodsmentioning

confidence: 99%

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Local Field Potential in Cortical Area MT: Stimulus Tuning and Behavioral Correlations

2006

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“…We also observed relatively weak responses to S-cone stimuli in areas typically associated with "dorsal" or motion processing pathways: hMT+ and V3a-an observation that is consistent with several other imaging and single unit studies (Barberini, Cohen, Wandell, & Newsome, 2005;Seidemann, Poirson, Wandell, & Newsome, 1999;Wandell et al, 1999).…”

Section: Contrast Effects On Luminance and S-cone Stimulisupporting

confidence: 91%

Differential attentional modulation of cortical responses to S-cone and luminance stimuli

Wang

Wade

2011

Journal of Vision

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Neural signals driven by short-wave-sensitive (S) cones are, to a large degree, anatomically and functionally separate from the achromatic luminance pathway until at least one synapse into V1. Attentional mechanisms that act at an anatomically early stage in V1 may, therefore, affect S-cone and luminance signals differently. Here, we used a steady-state visually evoked potential (SSVEP) paradigm combined with electrical source imaging to study the effects of contrast and attention on neural responses to both chromatic S-cone isolating and achromatic stimuli in five human visual areas including V1. The responses to these gratings were affected very differently by changes in contrast and attention. Increasing cone contrast increased the response amplitude for both types of stimulus. For the S-cone-defined stimuli, we also observed a systematic decrease in the response phase of the first harmonic with increasing stimulus contrast, but there was no corresponding change in phase for the first harmonic of the luminance probes. Attending to the contrast of the grating increased the amplitude and phase of luminance-driven responses but had no effect on S-cone-driven responses. We conclude that while attentional modulation can be observed in achromatic pathways as early as V1, attention may not affect SSVEP signals generated by S-cone stimuli.

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“…However, although Nagai et al also checked color integration effects using similar stimuli, they did not find significant integration effects for color signals. If only the luminance (or brightness) signal is integrated along a long-range apparent motion path, lowlevel motion mechanisms seem to underlie the integration effect; for example, motion mechanisms composed of large-receptive fields that are sensitive only to luminance signals may contribute to the integration effect, though such mechanisms are rather unlikely considering color selectivity of MT neurons (Barberini et al, 2005;Seidemann et al, 1999). In contrast, if such integration also occurs for the chromatic domain, diverse mechanisms that mediate cognition of different kinds of visual information regarding visual objects including brightness and color such as the object file concept (Kahneman et al, 1992) can also be a potent candidate.…”

Section: Introductionmentioning

confidence: 99%

Color Signal Integration for Color Discrimination along a Long-range Apparent Motion Trajectory

2013

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In contrast to the classical view that fundamental visual attributes such as color and motion are independently processed in the visual system (e.g. Livingstone and Hubel, 1987;Marr, 1982), recent studies have revealed various forms of cross-attribute interactions, such as averaging of color appearance along the motion trajectory of an object . In this study, we investigated whether such color signal integration along a motion trajectory can be induced only by motion mechanisms having large receptive fields, without simple integration within direction-selective neurons with small receptive fields, like those in V1. The stimulus consisted of discs with long-range apparent motion along a circular trajectory. The stimulus onset asynchrony (SOA) between disc presentations controlled the strength of the apparent motion perception. We measured observers' sensitivity in detecting color modulation on the discs. The results showed that the measured sensitivity was lowest at SOAs corresponding to the strongest motion perception. This can be interpreted as follows: color signals were integrated along an apparent motion path, and this integration reduced chromatic sensitivity by averaging color signals. Another experiment that controlled apparent motion perception in a different way also supported this idea. However, this integration effect seemed to be linked to responses of motion detectors for the apparent motion stimuli, not directly to perceptual motion representation in the visual system. These results suggest that the human visual system handles color information from retinal inputs regarding moving objects based not only on a retinotopic coordinate but also on object-based coordinates, even when the moving object yields only long-range apparent motion.

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Cone signal interactions in direction-selective neurons in the middle temporal visual area (MT)

Cited by 73 publications

References 61 publications

Local Field Potential in Cortical Area MT: Stimulus Tuning and Behavioral Correlations

Local Field Potential in Cortical Area MT: Stimulus Tuning and Behavioral Correlations

Differential attentional modulation of cortical responses to S-cone and luminance stimuli

Color Signal Integration for Color Discrimination along a Long-range Apparent Motion Trajectory

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