Stimulus-response function at several levels of background luminance, in the cat visual areas 17 and 18.

Stimulus-response curves of simple cells of the visual cortex were obtained by using 500-msec stationary stimuli. Background influence on single unit responses was studied. The contrast sensitivity of simple cells increases as a function of background luminance.

Acid-base equilibrium during acute long-lasting experiments in artificially ventilated cats.

Experiments were carried out to study blood acid-base equilibrium in the cat during experiments with artificial ventilation. Blood acid-base equilibrium was examined in the arterial and venous blood by analyzing pH, carbon dioxide and oxygen partial pressure, and plasma bicarbonates. Artificial ventilation was regulated on the basis of this analysis; CO2 concentration in expired air was monitored throughout the experiment.

Maintained activity of single neurons in the cat visual cortex at different levels of retinal adaptation.

The influence of ambient illumination on the maintained electrical activity of single neurons of the cat visual cortex was studied by using the closed chamber technique for extracellular recordings. Several levels of light background within the scotopic-mesopic range were explored. Phasic and tonic changes in firing rate were observed following a background change.

Responses of simple and non-oriented cells to stimuli of variable duration in areas 17 and 18 of cat visual cortex.

Single unitresponses to photic stimuli of variable duration were studied in the cat visual areas 17 and 18. The closed-chamber technique was used to record extracellularly impulsive electrical activity in locally anaesthetized, Flaxedil-paralyzed and artificially ventilated cats. Stimulus duration ranges between 0.