A computer-aided procedure for measuring Hebb-Williams maze performance.

We describe a shortened procedure for testing mice over a 5-day interval on a swimming version of the Hebb-Williams maze. The mice are given 1 day of adaptation training, and are tested over the next 4 days on Hebb-Williams problems 1, 6, 12, and 5, in that order. As an animal swims through one of the maze problems, the computer screen shows the maze pattern, and an observer traces the path taken with a computer mouse. The computer program, Observe Software, stores the path sequence, determines the error score for that trial, and sends the information to a spreadsheet where it is available for statistical analyses.

A computer-aided procedure for measuring Lashley III maze performance.

As an animal swims through the Lashley III maze, an observer types into a Macintosh computer the path taken. The computer program, Observe Software, then breaks the string of choices into two-step sequences and counts the number of such sequences. These data are then sent to a spreadsheet, where the sequences are sorted into forward and backward responses. Forward choices are Correct Path, T Choice Errors and Cul Entry Errors. All backward choices are errors, by definition. They are classified as T Choices, Cul Entries, Cul Exits, and Return to Start. The animal's behavior is then described by the various error classes plus a measure called Learning Index. Examples of learning by rats and mice are presented.

Toy play, play tempo, and reaction to frustration in infants.

Measures of toy play including duration and tempo of play were obtained for a combined sample of 7 male and 5 female infants 22 to 26 mo. of age. Additional measures of reaction to frustration were obtained during a second session where toys were placed out of reach of the subjects. Measures of frustration included crying, squirm/escape attempts, and non-crying vocalizations. Several correlations between toy play and reaction to frustration were found and were indicative of a general relationship between response persistence during play and attempts to escape from the frustrating situation.

Drinking of ethanol by adult and infant rhesus monkeys (Macaca mulatta).

Levels of voluntary consumption of ethanol were obtained which were sufficient for use in developing a nonhuman primate model of heavy drinking.

Stimulus self-selection and the assessment of visual preferences in four-month-old infants.

A self-stimulation choice technique was used to assess visual preferences in 4-mo--ld infants for slides of stimuli-depicting smiling vs neutral facial expressions. Preferential self-selection of stimuli did not occur even in the presence of preferential looking responses by infants.

Conspecific images as elements of compound stimuli controlling operant responding in female rhesus monkeys.

Six adult female rhesus monkeys (Macaca mulatta) performed food-reinforced button presses in a compound stimulus discrimination paradigm. Three subjects were trained on a compound stimulus consisting of a color motion picture of an adult male rhesus superimposed over a homogeneous blue field of color. A second group of three subjects was trained on a compound consisting of a color slide depicting an adult male rhesus and the blue field. Subsequent testing of relative stimulus control exerted by either compounds, conspecific stimuli (movie-slide) or blue field alone was carried out. Results indicated that for the movie group, stimulus control was attenuated when either the conspecific stimulus or blue field was presented as a single S+ stimulus compared to tests using the compound stimulus as S+. Subjects in the movie group shared attention to both constituent elements of the compound. Statistically significant differences in stimulus control between compound, conspecific stimulus, and blue field were not found for the slide group. Superior control by the compound movie-blue field was explained as the result of increased visual salience of an altered (blue) conspecific image.