Same–different texture discrimination in pigeons: Testing competing models of discrimination and stimulus integration.

Abstract

The choice behavior of 6 pigeons performing a mulltidimensional same-different texture discrimination was examined. On each trial, they had to choose among 2 choice hoppers depending on whether a color, shape, or redundant (color and shape) target signal was present or not in a textured stimulus. Receiver operating characteristic (ROC) curves were produced by variations in the priori signal presentation probabilities across conditions. Quantitative analyses of these ROC curves were used to evaluate different competing theories of discrimination (signal detection vs. high-threshold-default response models) and information integration (independent observations, additive integration, unidimensional models). The results suggested the structure of the pigeons' choice behavior in this same-different discrimination was best described by an unequal variance signal detection model involving a unidimensional evidence variable (e.g., degree of difference).

Pigeon perception and discrimination of rapidly changing texture stimuli.

“…Because the target was stationary across successive frames in the present experiment and target localization was not required by Cook and Wixted's (1997) choice task, it cannot be determined from these specific data whether a single 100 ms textured flash is also sufficient for actually localizing the target's position in a textured stimulus. For instance, in the present setting this kind of spatial information could have, and likely did, accumulate over frames within a trial.…”

“…If the pigeons are rapidly extracting this type of higher order visual relation from textured stimuli, it would follow that when asked to respond to the presence or absence of a target contrast in a choice task, that controlled brief presentations should be sufficient to support accurate choice responding. By using a texture-based same-different conditional choice discrimination, Cook and Wixted (1997) recently presented evidence, in the context of another issue, that 100 ms presentation times could support above chance same-different discrimination. Together, the pattern of data from these converging lines of texture research suggests that certain kinds of relational information, especially as mediated by early grouping processes, involving the detection of a target (and possibly objects in general) and its likely location in visual space, are available to the pigeons prior to knowledge about other absolute properties, such as its color.…”

“…Our overall goal is to discern the perceptual (Cook, 1992a) and decisional processes (Cook & Wixted, 1997) involved from the point when external visual information first impinges on the animal to its final behavioral reaction to this information. By looking in detail at each aspect of how pigeons accomplish complex visual discriminations, we hope to uncover the cognitive and neural mechanisms used by these visually sophisticated animals and to compare them with those mechanisms found in other types of animals, including humans.…”

Successive two-item same-different discrimination and concept learning by pigeons

“…After learning this discrimination, the degree to which this behavior transfers to novel situations having same and different relations is taken as evidence of concept formation. Using this choice task, it has been found that pigeons, parrots, rhesus monkeys, baboons, and chimpanzees are capable of learning and applying a S/D concept across a wide variety of simultaneously presented visual elements (Bovet and Vauclair, 2001;Cook, 2002a,b;Cook et al, 1995Cook et al, , 1999Cook and Wixted, 1997;Katz et al, 2002;Pepperberg, 1987;Thompson et al, 1997).…”

Shift Learning in Matching-to-Sample Discriminations in Rats as a Function of Overtraining

“…Overtraining facilitated the whole reversal, whereas it retarded the partial reversal. The third method is a same/different response paradigm (Cook, Cavoto, & Cavoto, 1995, 1996Cook, Katz, & Cavoto, 1997;Cook & Wixed, 1997;Fetterman, 1991;Nakagawa, Experiment 3 in 1993a, 2000cWasserman, Hugart, & Kirkpatrick-Steger, 1995;Wright, Santiago, & Sands, 1984;Wright, Santiago, Sands, Kendrick, & Cook, 1985;Wright, Santiago, Urcuioli, & Sands, 1983;Young, Wasserman , & Garner, 1997). In this paradigm, as studied by Nakagawa (1993a), one stimulus having two geometrical figures was presented, and rats were trained to press a left response lever if two geometrical figures were the same, or a right response lever if they were different from each other, to reach a criterion.…”