Coding for stimulus velocity by temporal patterning of spike discharges in visual cells of cat superior colliculus

Mandl, G.

doi:10.1016/0042-6989(93)90139-n

Cited by 32 publications

(29 citation statements)

References 59 publications

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“…It has been shown recently by Livingstone et al (1996) that in the primary visual cortex of alert monkeys only bursts provided a clear indicator of the presence of a visual stimulus. Burst discharges in the SC have been reported previously by Mandl (1993) in the pretrigeminal cat during moving visual stimulus presentation, and 25% of the responding cells exhibited a 60 -80 Hz burst frequency. We were able to show that such cells synchronize their short spike bursts with a precision of few milliseconds.…”

Section: Precise Burst Synchrony In the Superior Colliculusmentioning

confidence: 83%

Precise Burst Synchrony in the Superior Colliculus of the Awake Cat during Moving Stimulus Presentation

2001

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This study aimed to characterize the synchrony that occurs between cell discharges in the superior colliculus of the awake cat. We trained cats to perform a visual fixation in the presence of a visual moving stimulus and then recorded 686 pairs of neighboring cells in the superior colliculus during task performance. A new method to assess the significance of precise discharge synchronization is described, which permits analysis of nonstationary data. Of 181 pairs with sufficient data for quantitative analysis, 125 showed a cross-correlation histogram (CCH) with features assessed as significant using this approach. CCHs frequently showed an isolated central peak (41 of 125) or a peak flanked by one or two troughs (68 of 125), and in a few cases an oscillatory pattern of ϳ65 Hz (16 of 125). This is in contrast to the oscillation frequency reported for the visual cortex and shows that oscillations in the superior colliculus probably arise from a cortex-independent mechanism.Our method also permits direct quantification of the correlation shift predictors, assessing precise time locking of spikes to the stimulus. Only 1 of 125 cross-correlation shift predictors had a significant central peak, meaning that most of the CCH features were not related to cell discharges time-locked to the stimulus presentation.Further investigation using a burst-jittering method showed that synchrony in the superior colliculus is attributable to precise synchronization of short bursts of spikes. Such synchrony could be related to the network dynamics and the common inhibitory feedback from local interneurons, which would act as temporal selectors of the cells with greatest or fastest response.

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Section: Precise Burst Synchrony In the Superior Colliculusmentioning

confidence: 83%

Precise Burst Synchrony in the Superior Colliculus of the Awake Cat during Moving Stimulus Presentation

2001

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“…2) how long do humans need to observe an object's motion to evaluate its speed? and 3) is the motion speed itself encoded in the neural activity of the human brain as found in animals [Mandl, 1993;Perrone and Thiele, 2001]? Furthermore, we investigated the sources of the MEG responses by means of the single equivalent current dipole (ECD) model and compared the results with the distribution of the cortical activation to the same visual motion stimuli revealed by fMRI study.…”

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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“…The peak of the burst intervals averaged 2.9 Ϯ 1.1 ms (mean Ϯ SD). This peak reaches a clear minimum around 8 ms, providing an operational criterion for classification of burst spikes (Bair et al 1994;Cattaneo et al 1981a,b;DeBusk et al 1997;Mandl 1993). In 5 out of 24 cells, the ACH showed little or no modulation beyond the bursting peak (e.g., Fig.…”

Section: Autocorrelation and Renewal Density Analysismentioning

confidence: 99%

“…Features within autocorrelograms were defined by making quantitative measurements of distinct peaks and valleys: 1) the strength of bursting was quantified by the peak at Ͻ8 ms (Bair et al 1994;Cattaneo et al 1981a,b;DeBusk et al 1997;Mandl 1993), 2) the strength of the bursting refractory period (or the first oscillation peak) was quantified by the difference between the valley immediately after the burst peak and the next peak (after the bursting peak), and 3) the strength of oscillation was quantified by the difference between the second valley and the second oscillation peak. The strength of synchrony was quantified in a similar manner by measuring the peak in the CCH (at or near a lag time of 0 ms).…”

Section: Auto-and Cross-correlationmentioning

confidence: 99%

“…Bursts have been operationally defined from an extracellular perspective as 2 or more spikes with intervals Յ8 ms (Bair et al 1994;Cattaneo et al 1981a,b;DeBusk et al 1997;Mandl 1993). Intracellular studies have typically shown bursts to be intrinsic, resulting from Na ϩ currents (Brumberg et al 2000;Franceschetti et al 1995) or Ca 2ϩ currents (Traub and Miles 1991) that lead to nonlinear changes in firing based on changes in the membrane potential (Agmon and Connors 1989;Gray and McCormick 1996;Traub and Miles 1991).…”

Section: Introductionmentioning

confidence: 99%

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Gamma Oscillation Maintains Stimulus Structure-Dependent Synchronization in Cat Visual Cortex

Samonds

Bonds²

2005

Journal of Neurophysiology

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Samonds, Jason M. and A. B. Bonds. Gamma oscillation maintains stimulus structure-dependent synchronization in cat visual cortex. J Neurophysiol 93: [223][224][225][226][227][228][229][230][231][232][233][234][235][236] 2005. First published July 28, 2004; doi:10.1152/jn.00548.2004. Visual cortical cells demonstrate both oscillation and synchronization, although the underlying causes and functional significance of these behaviors remain uncertain. We simultaneously recorded single-unit activity with microelectrode arrays in supragranular layers of area 17 of cats paralyzed and anesthetized with propofol and N 2 O. Rate-normalized autocorrelograms of 24 cells reveal bursting (100%) and gamma oscillation (63%). Renewal density analysis, used to explore the source of oscillation, suggests a contribution from extrinsic influences such as feedback. However, a bursting refractory period, presumably membrane-based, could also encourage oscillatory firing. When we investigated the source of synchronization for 60 cell pairs we found only moderate correlation of synchrony with bursts and oscillation. We did, nonetheless, discover a possible functional role for oscillation. In all cases of crosscorrelograms that exhibited oscillation, the strength of the synchrony was maintained throughout the stimulation period. When no oscillation was apparent, 75% of the cell pairs showed decay in their synchronization. The synchrony between cells is strongly dependent on similar response onset latencies. We therefore propose that structured input, which yields tight organization of latency, is a more likely candidate for the source of synchronization than oscillation. The reliable synchrony at response onset could be driven by spatial and temporal correlation of the stimulus that is preserved through the earlier stages of the visual system. Oscillation then contributes to maintenance of the synchrony to enhance reliable transmission of the information for higher cognitive processing. I N T R O D U C T I O NSensory perception relies on the classification of sensory information in relation to past experiences. A neurophysiological correlate has been described based on the relationships between neurons' spike trains and the formation of cell assemblies (Hayek 1952;Hebb 1949). The spatiotemporal relationships of spike trains provide a robust and flexible system of classification that provides enhancement through associations (Hebb 1949) and depends on contextual changes, as well as short-and long-term response history (Hayek 1952). Milner (1974) and von der Malsburg (1981) developed this theory to provide a framework for many perceptual phenomena that remain unexplained. Their elaborations are termed correlation theory or temporal binding theory, where perceptually related features are linked through correlated firing among subpopulations of cells. The original basis of the cell assembly theory was that relationships were formed between cells based on anatomical connections (Hayek 1952;Hebb 1949). However, acknowledging the dynamic and a...

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Coding for stimulus velocity by temporal patterning of spike discharges in visual cells of cat superior colliculus

Cited by 32 publications

References 59 publications

Precise Burst Synchrony in the Superior Colliculus of the Awake Cat during Moving Stimulus Presentation

Precise Burst Synchrony in the Superior Colliculus of the Awake Cat during Moving Stimulus Presentation

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

Gamma Oscillation Maintains Stimulus Structure-Dependent Synchronization in Cat Visual Cortex

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