Does Corticothalamic Feedback Control Cortical Velocity Tuning?

Abstract

The thalamus is the major gate to the cortex and its contribution to cortical receptive field properties is well established. Cortical feedback to the thalamus is, in turn, the anatomically dominant input to relay cells, yet its influence on thalamic processing has been difficult to interpret. For an understanding of complex sensory processing, detailed concepts of the corticothalamic interplay need yet to be established. To study corticogeniculate processing in a model, we draw on various physiological and anatomical data concerning the intrinsic dynamics of geniculate relay neurons, the cortical influence on relay modes, lagged and nonlagged neurons, and the structure of visual cortical receptive fields. In extensive computer simulations we elaborate the novel hypothesis that the visual cortex controls via feedback the temporal response properties of geniculate relay cells in a way that alters the tuning of cortical cells for speed.Published as Neural Computation 13 (2001), pp. 327-355.

Looking back: corticothalamic feedback and early visual processing

“…This model readily accounts for the aforementioned experimental data, but it also makes some interesting predictions that remain to be tested -for example, that the sensitivity of LGN neurons to orientation discontinuities at low contrast should be twice that at high contrast, and that responses to drifting gratings should be less linear at spatial frequencies where layer 6 cells give robust responses. Other work has shown how a model of visual processing that includes top-down corticogeniculate feedback might contribute to the dynamics of binocular vision [44,45], to perceptual grouping [46], to brightness perception and illusory contours [47], and to the temporal response properties of geniculate relay cells in a way that alters the speed tuning of cortical cells [48].…”

Role of centrifugal projections to the olfactory bulb in olfactory processing

“…The roles of cortical feedback loops in sensory processing are of interest to the neuroscience community and have been extensively studied with respect to visual processing and attention (see, e.g., Vidyasagar and Urbas 1982;Funke and Eysel 1992;McClurkin et al 1994;Hillenbrand and van Hemmen 2001;Eyding et al 2003).…”

A Neurophysiological Perspective on a Preventive Treatment against Schizophrenia Using Transcranial Electric Stimulation of the Corticothalamic Pathway

“…The layer VI CT pathway also exerts a great influence on the state of the membrane potential of the TC neurons, as well as on ongoing and function-related thalamic activities. More specifically, the CT neurons shape the spatiotemporal receptive fields of TC cells [209,210] and play an essential role in the coordination of widespread coherent oscillations [211]. Importantly, the CT innervation, mediated by both NMDA and non-NMDA receptors [212], is more effective to the TRN than to TC neurons [174].…”