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Biomedical subjects

G Hauske

Publications and source records attributed to G Hauske.

7 recordsLinked to original sources
PubMed1989

Temporal pattern discrimination within the receptive field of cat retinal ganglion cells.

ON-center and OFF-center receptive fields of cat retinal ganglion cells can be divided into two categories: sensitive (type N) and insensitive (type L) to three statistical temporal visual stimuli with different second order statistics but identical first order statistics (Tsukada et al. 1982). The temporal pattern sensitivity of type N response is closely related to the nonlinear stage of Y cells depending on the interaction between center and surround mechanism. The temporal pattern sensitivity of type N responses has a spatial profile within the receptive field; it is highly sensitive in the center region of the receptive field and less sensitive toward the field periphery. The temporal pattern sensitivity in the center region of the receptive field to statistical properties (irregular or regular) of a surrounding flash annulus shows modulation like a switching element: when the surrounding area is stimulated by a more regular flash stimulus with normal distribution of inter-stimulus intervals the system is sensitive (switching on) to the temporal pattern, while a change to an irregular one with an exponential distribution makes it insensitive (switching off) to the temporal pattern.

Animals↗
PubMed1987

Saccadic eye movements and the detection of fast-moving gratings.

Experiments are presented in which the effect of saccadic eye movements on the visibility of sinusoidal gratings drifting with velocities between 2 deg/s and 400 deg/s is investigated. The results demonstrate that saccades are highly useful for detecting this class of stimuli. Due to a saccade, otherwise subthreshold stimuli become visible as short, distinct flashes of the seemingly stationary pattern. The paper analyzes in detail the dependence of the amount of facilitation on saccade size and relative direction and isolates the additional effect of saccadic suppression. A simple model is proposed which predicts the experimental findings.

Eye Movements↗
PubMed1986

Adaptive gain control of saccadic eye movements.

Properties of gain adaptivity in the saccadic system were studied. Subjects had to track a target which moved in single or double steps. The first target step which elicited the primary saccade had an amplitude in the range of 8-16 deg. The primary saccade triggered a further target displacement of 4 deg either in the same or--in different experimental sessions--in the opposite direction of the first target step. These consistent intrasaccadic target displacements lead to adaptive changes of saccadic amplitudes. The experimental data show that the saccadic system adapts to the stimulus sequence in a simple, parametric manner, namely by changing its gain. Consequently, it is assumed that a single gain element determines saccade sizes for all target eccentricities. Further, it is shown that adaptation has different time courses for gain increase and decrease, and its performance is close to completeness. The results are discussed with respect to the undershooting behaviour of goal-directed saccades and the functional demands to the saccadic system.

Adaptation, Ocular↗