Two-choice Discrimination Task Research Articles

Interaction of reward, punishment, and sex in a two-choice discrimination task with children.

Interaction of reward, punishment, and sex in a two-choice discrimination task with children.

Effect of brain bisection on capacity for cross comparison of patterned visual input

Cats learned to use the relations between pattern elements as cues for response in abstract two-choice discrimination tasks. For example, differently oriented pairs of stripe patterns (horizontal-vertical or vertical-horizontal) constituted the positive, food-rewarded alternative, and pairs of patterns oriented the same way (H-H, V-V) were negative. The subjects were then given tests with components of the pairs relayed to the separate eyes so that correct response required central cross integration of the pair elements. Normal subjects and subjects with either optic chiasm or the caudal two-thirds of the corpus callosum sectioned could perform the tasks at a high accuracy level; but when both structures were sectioned, there was a sizable performance loss. Such surgery did not completely interrupt interhemispheric information transfer, however, because subjects were still able to perform consistently at an above-chance level (the surgery did effectively eliminate interhemispheric discrimination habit transfer—subjects learned contradictory habits with the separate eyes). The rostral third of the corpus callosum may play a role in such transfer—one subject performed at the 65–70% level following section of the chiasm and caudal two-thirds of the corpus callosum. With subsequent section of the rostral callosal fibers, there was a reduction in performance to the chance level.

Relationship between activity level and delay of reinforcement in the retarded

Thirty mentally retarded children enrolled in a trainable special education class were given a simple two-choice discrimination task under a 12-second delay of reinforcement condition. While performing the task, the children were seated in a stabilimetric chair which recorded the gross activity of the child. The children were ranked from the highest to the lowest on activity as measured by the stabilimetric chair. The upper-quartile group (high active) was compared with the lower quartile (low active) on the number of correct responses given during the discrimination task. Although there was no significant difference in the mean CA and mean MA of the two groups, the low-active group produced significantly more correct responses in the 80 learning trials than did the high-active group.

EFFECT OF NOVELTY ON CHOICES MADE BY PRESCHOOL CHILDREN IN A SIMPLE DISCRIMINATION TASK.

On the second trial of a two-choice discrimination task more Ss shifted to the untried object than chose the same object selected on trial 1. These response shifts occurred more often following a nonreinforced first choice. A third, incorrect stimulus added to the complex on one of three later trials was selected more often than either of the other two stimuli present. Children who made this choice had a higher error rate on preceding and following trials. The trial on which the new stimulus was introduced did not affect the probability of choosing it.