Infants were tested for recognition and discrimination of expressions. Ten-month olds familiar with a mix of happy and surprised expressions demonstrated generalized discrimination of positive affect. Only after seven months does dependence on the presence of expression-specific features for affect recognition and discrimination diminish. (BC)

Confirms the existence of a right-hemisphere advantage in the process of discriminating between face stimuli. The advantage was weaker in females than in males. No hemispheric transfer of learning was observed. Subjects were 18 infants of 42 weeks who were presented with an operant conditioning situation in which they discriminated between their…

Six experiments examined infants' ability to associate nonsense words with two causal actions: pushing and pulling. Eighteen-month-olds, but not 14-month-olds, formed word-action associations. Fourteen-month-olds discriminated a change in label but not a change in action when the other was held constant. When language labels were replaced with…

This rejoinder to a critique of the authors' research on speech perception deficits in poor readers answers the specific criticisms and reaffirms their conclusion that the difficulty some poor readers have with rapid /ba/-/da/ discrimination does not stem from difficulty in discriminating the rapid spectral transitions at stop-vowel syllable…

Examined representation of pictorial exemplars of humans by 3- and 4-month olds. Results demonstrated an asymmetry regarding the exclusivity of categorical representations formed for humans and non-human animals. Categorical representations for humans included exemplar information, whereas categorical representation for non-human animals was based…

Investigated early determinants of infants' self--other discrimination when presented with a live image of themselves or another person that was either contingent or contingent with delay. Found that infants 4 months and older perceived and acted differently when facing the image of themselves compared to that of another; 9-month-olds showed more…

The perirhinal cortex is known to be important for memory, but there has recently been interest in the possibility that it might also be involved in visual perceptual functions. In four experiments, we assessed visual discrimination ability and visual discrimination learning in severely amnesic patients with large medial temporal lobe lesions that…

Previous studies have shown that after being trained on A-B and A-C match-to-sample tasks, adults match not only same-class B and C stimuli (equivalence) but also BC compounds with same-class elements and with different-class elements (BC-BC). The assumption was that the BC-BC performances are based on matching equivalence and nonequivalence…

This experiment examined the effects of reinforcement probability on resistance to change of remembering and response rate. Pigeons responded on a two- component multiple schedule in which completion of a variable-interval 20-s schedule produced delayed matching-to-sample trials in both components. Each session included four delays (0.1 s, 2 s, 4…

Children often perseverate, repeating prior behaviors when inappropriate. This work tested the roles of verbal labels and stimulus novelty in such perseveration. Three-year-old children sorted cards by one rule and were then instructed to switch to a second rule. In a basic condition, cards had familiar shapes and colors and both rules were stated…

This article proposes and tests a formal cognitive model for the go/no-go discrimination task. In this task, the performer chooses whether to respond to stimuli and receives rewards for responding to certain stimuli and punishments for responding to others. Three cognitive models were evaluated on the basis of data from a longitudinal study…

When an odor is paired with a delayed illness, rats acquire a relatively weak odor aversion. In contrast, rats develop a strong aversion to an olfactory cue paired with delayed illness if it is presented simultaneously with a gustatory cue. Such a conditioning effect has been referred to as taste-potentiated odor aversion learning (TPOA). TPOA is…

The study was designed to investigate the learning processes in discrimination shift learning, in terms of developmental views of "logical manipulation by classification." Tasks comparing sizes of intradimensional value-classes and comparing sizes of interdimensional value-classes were devised in order to measure subjects' levels of…

Studies hypothesized and tested that a judge's discriminal process is a sample from a normal distribution of all possible discriminal processes for the MMPI stimulus set; that standard deviations of two distributions of binary MMPI decisions are equal; and that discriminative capacities of judges remain fixed from one decision session to the next.…

Two studies of 7-year-olds and college students tested the hypothesis of a developmental difference in the degree to which subjects' memory performance was controlled by categorical properties vs. specific instance properties of test items. (GO)