Two types of phenomenal instructions for size and distance judgments of objects presented on a two-dimensional plane

Demand characteristics were studied in a simple situation in which observers made size and distance estimates of stimuli presented on a two-dimensional linear perspective drawing. Half the Ss were asked questions stressing phenomenal report: The other half were asked the same questions preceded by instructions stressing the objective nature of the stimulus configuration but requesting, nonetheless, phenomenal report. Instructions resulted in a significantly greater perspective size illusion but did not affect the distance estimates. No meaningful correlations between size and distance estimates were found.     

A simple histological technique for localizing electrode tracks and lesions within the brain.

Histological procedures are necessary in brain stimulation or lesion work to determine the neural area which has been stimulated or damaged. Preparation of brain tissue often involves embedding and staining techniques that require specialized training, and the expense of a technician and a large assortment of special apparatus and supplies. In addition, the results of such techniques are unavailable for at least several days. A photographic method, which requires little special skill and a minimal amount of apparatus, is described here. Results can be available within minutes after the subject is sacrificed. This method has been shown to be adequate for the gross determination of lesion boundaries and electrode or cannula tip loci in brains of rats, cats, and squirrel monkeys.     

Several methods for teaching serial position sequences to monkeys

Three keys were available for monkeys to press. The objective was to teach the animals to press the keys in sequences up to 10 members in length. With fading procedures, a light that cued the correct key at a given serial member of the sequence faded out slightly each time the animal selected it, and became slightly brighter after the animal made an error at that sequence member. The correct keys were faded out, starting from the end of the sequence and proceeding toward the beginning. With control procedures, the cue lights were turned off suddenly, rather than being faded gradually. In almost every instance, the animals learned a longer series of unlighted key positions with the fading procedures than they did when each key-light was turned off suddenly. Also, requiring the animals to press a series of keys cued by lights before they could reach the sequence members they were to learn hampered them in learning the later serial members. By using several different sequences, it was possible to replicate these findings within the individual animal.