Hierarchical and parallel mechanisms in the organization of visual cortex

Stone, Jonathan; Dreher, Bogdan; Leventhal, Audie G.

doi:10.1016/0165-0173(79)90010-9

Cited by 393 publications

(158 citation statements)

References 235 publications

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“…Moreover, there is evidence that the presence of gratings oriented orthogonally to the preferred orientations of cortical cells can inhibit the cell's response to optimal stimuli (Morrone et al, 1982;Petrov et al, 1980). Morrone et al (1982) report that this cross-orientation inhibition is stronger in simple cells than in complex cells, and there is evidence that simple cells receive their input primarily from x cells (sustained cells) whereas complex cells received their input primarily from y cells (transient cells; e.g., Lennie, 1980;Stone, Dreher, & Leventhal, 1979). In view of the evidence that transient channels respond best to low spatial frequencies while sustained channels respond best to high spatial frequencies (e.g., Breitmeyer, 1975;Burbeck & Kelly, 1981;Harwerth & Levi, 1978;Tolhurst, 1975aTolhurst, , 1975b, it might be suggested that the asymmetric interference observed in the experiment could be attributed to inhibition of sustained channels by transient channels.…”

Section: Resultsmentioning

confidence: 99%

Asymmetric interference between components of suprathreshold compound gratings

Hughes

1986

Perception & Psychophysics

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Observers were presented with compound gratings consisting of a high-(5.0 cycles/deg, cpd) and a low-frequency (0.5 cpd) sinusoid. The orientation of each component was independent and varied randomly between horizontal and vertical. The observers were instructed to signal the orientation of one component (the target) and ignore the other. The dependent measure was the observers' choice reaction time (CRT) to signal the orientation ofthe target grating. CRTs to lowfrequency targets were similar whether or not the high-frequency component was present, but CRTs to high-frequency targets were slowed by the presence of the low-frequency component. This asymmetric interference was obtained when the contrasts of the individual components were adjusted so as to produce equivalent CRTs when each was presented alone. Reducing the lowfrequency contrast below the level needed to match the CRTs generated less interference, and in some cases generated asymmetric interference favoring the high-frequency component. The magnitude oflow-frequency interference was also reduced when the stimulus onsets were gradual rather than abrupt. CRTs to compounds in which the component orientations were always the same but varied randomly across trials produced little evidence of a redundancy gain, and the obtained redundancy effect was less than that predicted from a simple model of suprathreshold probability summation between independent frequency and orientation-specific channels. The results are considered in terms of inhibitory interactions between transient and sustained channels.

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Section: Resultsmentioning

confidence: 99%

Asymmetric interference between components of suprathreshold compound gratings

Hughes

1986

Perception & Psychophysics

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“…Apart from previously reported morphological and physiological differences of cells belonging to Y and W channels (for review, see Stone, 1983;Burke et al, 1998;Casagrande and Xu, 2004), this is a new feature distinguishing these two pathways.…”

Section: Discussionmentioning

confidence: 99%

Variability of Visual Responses of Superior Colliculus Neurons Depends on Stimulus Velocity

Mochol

Wójcik²,

Wypych³

et al. 2010

J. Neurosci.

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Visually responding neurons in the superficial, retinorecipient layers of the cat superior colliculus receive input from two primarily parallel information processing channels, Y and W, which is reflected in their velocity response profiles. We quantified the timedependent variability of responses of these neurons to stimuli moving with different velocities by Fano factor (FF) calculated in discrete time windows. The FF for cells responding to low-velocity stimuli, thus receiving W inputs, increased with the increase in the firing rate. In contrast, the dynamics of activity of the cells responding to fast moving stimuli, processed by Y pathway, correlated negatively with FF whether the response was excitatory or suppressive. These observations were tested against several types of surrogate data. Whereas Poisson description failed to reproduce the variability of all collicular responses, the inclusion of secondary structure to the generating point process recovered most of the observed features of responses to fast moving stimuli. Neither model could reproduce the variability of low-velocity responses, which suggests that, in this case, more complex time dependencies need to be taken into account. Our results indicate that Y and W channels may differ in reliability of responses to visual stimulation. Apart from previously reported morphological and physiological differences of the cells belonging to Y and W channels, this is a new feature distinguishing these two pathways.

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“…Although this hierarchical scheme is oversimplified in that it omits factors such as parallel processing and feedback interactions, it is thought to faithfully represent at least the initial stages of cortical sensory processing (Stone et al, 1979;Felleman and Van Essen, 1991;Iwamura, 1993).…”

Section: Abstract: Somatosensory Cortex; Voltage-sensitive Dyes; Glumentioning

confidence: 99%

Thalamic-Evoked Synaptic Interactions in Barrel Cortex Revealed by Optical Imaging

2000

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We used optical imaging of voltage-sensitive dye signals to study the spatiotemporal spread of activity in the mouse barrel cortex, evoked by stimulation of thalamocortical afferents in an in vitro slice preparation. Stimulation of the thalamus, at low current intensity, results in activity largely restricted to a single barrel, and to the border between layers Vb and VI. Low concentrations of the GABA A receptor antagonist bicuculline increase the amplitude of the optical signals, without affecting their spatiotemporal propagation. Higher concentrations of bicuculline result in paroxysmal activity, which propagates via intracolumnar and intercolumnar excitatory pathways. Enhancing the activity of NMDA receptors, by removing Mg 2ϩ from the extracellular solution, dramatically alters the spatiotemporal pattern of excitation: activity spreads to supragranular and infragranular layers and adjacent barrel columns. This enhanced propagation is suppressed by the NMDA receptor antagonist AP5. A similar enhancement of activity propagation can be produced by stimulating the thalamus with a short, high-frequency pulse train. Application of AP5 suppresses the frequency-dependent spread of activity. These findings indicate that the spatiotemporal spread of activity in the barrel cortex is altered by varying the temporal patterns of thalamic inputs, via an NMDA receptor-mediated mechanism, and suggest that a similar process occurs during repetitive whisking activity. Key words: somatosensory cortex; voltage-sensitive dyes; glutamate; NMDA; GABA; epilepsy; temporal coding; mouseProcessing of sensory information in the cerebral cortex can be described as a hierarchical process, in which inputs from "specific" thalamic nuclei are integrated by their postsynaptic cortical targets, which, in turn, provide inputs to neurons in other layers of the same functional column and subsequently to adjacent columns (Gilbert, 1992;Keller, 1995;Rauschecker et al., 1997). Although this hierarchical scheme is oversimplified in that it omits factors such as parallel processing and feedback interactions, it is thought to faithfully represent at least the initial stages of cortical sensory processing (Stone et al., 1979;Felleman and Van Essen, 1991;Iwamura, 1993).To understand the mechanisms underlying cortical sensory processing, it is necessary to determine how thalamic inputs are integrated by their postsynaptic cortical neurons and propagated via intracolumnar and intercolumnar cortical pathways. This requires methods to identify discrete functional columns and to reveal the spatiotemporal propagation of thalamic inputs within and among these columns. In the present study we took advantage of a functional imaging approach (see Orbach and Cohen, 1983;Cinelli and Salzberg, 1987;Yuste et al., 1997;Keller et al., 1998) to investigate intracortical processing of thalamic inputs in the somatosensory cortex and its modulation by glutamatergic and GABAergic processes.The somatosensory cortex of certain rodent species contains representations of the my...

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Hierarchical and parallel mechanisms in the organization of visual cortex

Cited by 393 publications

References 235 publications

Asymmetric interference between components of suprathreshold compound gratings

Asymmetric interference between components of suprathreshold compound gratings

Variability of Visual Responses of Superior Colliculus Neurons Depends on Stimulus Velocity

Thalamic-Evoked Synaptic Interactions in Barrel Cortex Revealed by Optical Imaging

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