Herbranson, W. T., Fremouw, T., & Shimp, C. P. (2002).
Categorizing a moving target in terms of its speed, direction, or both.
Journal of the Experimental Analysis of Behavior,
78, 249-270.
Pigeons categorized a moving target in terms of its speed and
direction in an adaptation of the randomization procedure used to
study human categorization behavior (Ashby & Maddox, 1998).
The target moved according to vectors that were sampled with
equal probabilities from two slightly overlapping bivariate
normal distributions with the dimensions of speed and direction.
On the average, pigeons categorized optimally in that they
attended to either speed or direction alone, or divided attention
between them, as was required by different reinforcement
contingencies. Decision bounds were estimated for individual
pigeons for each attentional task. Average slopes and y
intercepts of these individually estimated decision bounds
closely approximated the corresponding values for optimal
decision bounds. There is therefore at least one task in which
pigeons, on the average, display flexibility and quantitative
precision in allocating attention to speed and direction when
they categorize moving targets.
Key words: categorization, moving targets, speed, direction, pigeons