Magnetic response of human extrastriate cortex in the detection of coherent and incoherent motion

Lam, Khanh; Kaneoke, Yoshiki; Gunji, Atsuko; Yamasaki, Hiroshi; Matsumoto, Eriko; Naito, Takashi; Kakigi, Ryusuke

doi:10.1016/s0306-4522(00)00037-3

Cited by 46 publications

(25 citation statements)

References 44 publications

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“…The iso-contour map (in the red frame in Fig. 1b) suggests activation in the temporo-occipital areas of both hemispheres, which is consistent with previous MEG (Bundo et al, 2000;Lam et al, 2000;Maruyama et al, 2002;Nakamura et al, 2003) and functional magnetic resonance imaging studies (Rees et al, 2000). The latter component was defined as the spatial distribution of the peak MEG response averaged with respect to manual responses.…”

Section: Resultssupporting

confidence: 86%

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Estimation of the Timing of Human Visual Perception from Magnetoencephalography

Amano¹,

Goda²,

Nishida³

et al. 2006

J. Neurosci.

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To explore the timing and the underlying neural dynamics of visual perception, we analyzed the relationship between the manual reaction time (RT) to the onset of a visual stimulus and the time course of the evoked neural response simultaneously measured by magnetoencephalography (MEG). The visual stimuli were a transition from incoherent to coherent motion of random dots and an onset of a chromatic grating from a uniform field, which evoke neural responses in different cortical sites. For both stimuli, changes in median RT with changing stimulus strength (motion coherence or chromatic contrast) were accurately predicted, with a stimulus-independent postdetection delay, from the time that the temporally integrated MEG response crossed a threshold (integrator model). In comparison, the prediction of RT was less accurate from the peak MEG latency, or from the time that the nonintegrated MEG response crossed a threshold (level detector model). The integrator model could also account for, at least partially, intertrial changes in RT or in perception (hit/miss) to identical stimuli. Although we examined MEG-RT relationships mainly for data averaged over trials, the integrator model could show some correlations even for single-trial data. The model predictions deteriorated when only early visual responses presumably originating from the striate cortex were used as the input to the integrator model. Our results suggest that the perceptions for visual stimulus appearances are established in extrastriate areas [around MT (middle temporal visual area) for motion and around V4 (fourth visual area) for color] ϳ150 -200 ms before subjects manually react to the stimulus.

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Section: Resultssupporting

confidence: 86%

“…1a). Previous studies suggest that a motion stimulus of this type selectively activates higher visual areas, including MT/V5 (Bundo et al, 2000;Lam et al, 2000;Maruyama et al, 2002;Nakamura et al, 2003).…”

Section: Resultsmentioning

confidence: 98%

Estimation of the Timing of Human Visual Perception from Magnetoencephalography

Amano¹,

Goda²,

Nishida³

et al. 2006

J. Neurosci.

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“…As compared to earlier studies, however, we demonstrate that these processes affect incoherent, as well as coherent motion processing, suggesting that decoding of coherent from incoherent motion, a process that takes place within dorsal stream regions such as MT (Lam et al, 2000;McKeefry et al, 1997;Previc et al, 2000;Rees et al, 2000;Ulbert et al, 2001), is relatively intact. In addition, motion-processing deficits were significantly related to deficits in functioning of the magnocellular visual system, which provides low-level input to the dorsal stream.…”

Section: Discussioncontrasting

confidence: 51%

“…As a result, individual MT neurons show motion sensitivity across extensive regions of visual space (Felleman and Van Essen, 1991;McKeefry et al, 1997;Orban et al, 2004). Within MT, neurons show similar initial sensitivity to motion whether it occurs in random directions across the visual field (incoherent motion) or in organized flow across space (coherent motion) (Lam et al, 2000;McKeefry et al, 1997;Previc et al, 2000;Ulbert et al, 2001). However, neuronal outputs in MT are different to coherent vs. incoherent motion (Rees et al, 2000;Ulbert et al, 2001), suggesting that MT itself is responsible for decoding motion patterns across the visual field.…”

Section: Introductionmentioning

confidence: 99%

Magnocellular contributions to impaired motion processing in schizophrenia

Kim

Wylie

Pasternak

et al. 2006

Schizophrenia Research

131

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Patients with schizophrenia show impairments in motion processing, along with deficits in lower level processing primarily involving the magnocellular visual pathway. The present study investigates potential magnocellular contributions to impaired motion processing in schizophrenia using a combined neurophysiological and behavioral approach. As compared to prior motion studies in schizophrenia, thresholds were determined for both incoherent and coherent visual motion. In this study, velocity discrimination thresholds were measured for schizophrenia patients (n = 14) and agematched normal control subjects (n = 16) using a staircase procedure. Early visual processing was evaluated using steady-state visual evoked potentials (ssVEP), with stimuli biased toward activation of either the magnocellular or parvocellular visual pathways through luminance contrast manipulation. Patients with schizophrenia showed poor velocity discrimination for both incoherent and coherent motion, with no significant group × task interaction. Further, when coherent motion performance was measured at individually determined incoherent motion thresholds, accuracy levels for patients were similar to controls, also indicating similarity of deficit for incoherent vs. coherent motion discrimination. Impairments in velocity discrimination correlated significantly with reduced amplitude of ssVEP elicited by magnocellular -but not parvocellular -selective stimuli. This study demonstrates that deficits in motion processing in schizophrenia are significantly related to reduced activation of the magnocellular visual system. Further, this study supports and extends prior reports of impaired motion processing in schizophrenia, and indicates significant bottom-up contributions to higher-order cognitive impairments.

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“…MEG has been used to locate cortical regions involved in visual motion detection and to investigate temporal activity patterns [Ahlfors et al, 1999;Anderson et al, 1996;Bundo et al, 2000;Ffytche et al, 1995;Kaneoke et al, 1997;Lam et al, 2000;Patzwahl et al, 1996;Uusitalo et al, 1997;Vanni et al, 1997;Watanabe et al, 2001].…”

Section: Introductionmentioning

confidence: 99%

Visual detection of motion speed in humans: spatiotemporal analysis by fMRI and MEG

Kawakami

Kaneoke

Maruyama

et al. 2002

Human Brain Mapping

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Humans take a long time to respond to the slow visual motion of an object. It is not known what neural mechanism causes this delay. We measured magnetoencephalographic neural responses to light spot motion onset within a wide speed range (0.4-500 degrees /sec) and compared these with human reaction times (RTs). The mean response latency was inversely related to the speed of motion up to 100 degrees /sec, whereas the amplitude increased with the speed. The response property at the speed of 500 degrees /sec was different from that at the other speeds. The speed-related latency change was observed when the motion duration was 10 msec or longer in the speed range between 5 and 500 degrees /sec, indicating that the response is directly related to the speed itself. The source of the response was estimated to be around the human MT+ and was validated by functional magnetic imaging study using the same stimuli. The results indicate that the speed of motion is encoded in the neural activity of MT+ and that it can be detected within 10 msec of motion observation. RT to the same motion onset was also inversely related to the speed of motion but the delay could not be explained by the magnetic response latency change. Instead, the reciprocal of RT was linearly related to the reciprocal of the magnetic response latency, suggesting that the visual process interacts with other neural processes for decision and motor preparation.

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Magnetic response of human extrastriate cortex in the detection of coherent and incoherent motion

Cited by 46 publications

References 44 publications

Estimation of the Timing of Human Visual Perception from Magnetoencephalography

Estimation of the Timing of Human Visual Perception from Magnetoencephalography

Magnocellular contributions to impaired motion processing in schizophrenia

Visual detection of motion speed in humans: spatiotemporal analysis by fMRI and MEG

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