PSYC3318 Lecture Notes - Lecture 2: Lateral Geniculate Nucleus, Detection Theory, Visual Field Test
Document Summary
Riddoch 1917- motion perception can be unaffected in a scotoma. Braak et al 1971- found subjects who had no lateral geniculate nucleus still showed op to kinetic nystagmus. Db- using eye movement to localise an unseen target. Eyemovements showed a systematic relationship to the target position in the experimental condition- within 20 degrees of the targets fixation. Eye movements slowed by distractor in blind field. Slower response time in distracted condition is attributed to competing eye movement signals being generated by the superior colliculus following the onset of the distractor. Blindsight type 1- the ability of subjects with clinically blind field defects to detect, localize and discriminate visual stimuli of which the subjects say they are completely unaware. Type 2- which they might be aware but not in the sense of experiencing a visual percept. An island of normal cortex could support residual vision. It may need corresponding signals from neighbouring areas to lead conscious vision.
