The effect of orientation on the clarity of Hermann grid illusory lines.

To test the hypothesis that Hermann grid illusory lines are most clear when the grid is presented at a 45 deg, each of 20 participants underwent 10 trials in each of two conditions ('make the lines least clear' and 'make the lines most clear') which were run using a method of adjustment. A matched-pairs t-test applied to the means of the two conditions was significant beyond the 0.01 level.

Knowledge of pragmatic conversational structure.

Knowledge of conversational pragmatic structure was examined by asking 53 female volunteers to rate the naturalness of three versions of an appointment-making conversation from a beauty salon. One version was the naturally occurring conversation. The other two were its two most frequent reconstructions created by a separate group of subjects asked to put the scrambled natural conversation "back together again.

A study of dark adaptation in ocular hypertensives.

Previous studies of dark adaptation in glaucoma have been hampered by lack of standardization and poor definition of clinical categories. A new method of testing has been used on ocular hypertensives. A modified Goldmann/Weekers adaptometer and an 11 degree centrally fixated test patch were used to obtain two dark adaptation threshold curves for each subject -- one for blue-green and one for yellow.