A demonstration of gaze following in 3- to 6-month-olds

An adult, with a puppet held at shoulder height on either side (within the infant's visual field), interacted with 3- to-6-month-olds, turning her head intermittently to talk to a puppet. Seventy- three percent of infants' first eye-turns were in the direction of the adult head-turn.     

Implicit learning: Indirect, not unconscious

Dienes and Berry (1997) argue that there really are two kinds of knowledge, implicit and explicit, that can be characterized through a subjective threshold. We argue that the subjective threshold does not separate two forms of knowledge, but instead two uses of knowledge, for two different purposes. With Neal and Hesketh (1997), we suggest that an understanding of learning will be better served by investigating the processing that occurs under various circumstances than by attempting to isolate learning that occurs with awareness from that which occurs without it.     

Chicks Injected with Antisera to either S-100α or S-100β Protein Develop Amnesia for a Passive Avoidance Task

The cellular expression of S-100β protein is upregulated in Alzheimer's disease and in Down's syndrome, and this protein has been implicated in memory-related processes in laboratory animals. However, the possibility that the α subunit of S-100 is also involved in memory has not yet been examined. In the present study, day-old black Australorp white Leghorn cockerel chicks (Gallus domesticus) received injections of monoclonal antisera to S-100α (1:50) or S-100β (1:500) into each hemisphere immediately after training on a one-trial passive avoidance task. The chicks displayed significantly lower retention levels than control birds that had been injected with antisera to carbonic anhydrase, or with saline (p< .01). S-100α antisera had an amnestic effect when injected between 0 and 20 min after training, with memory deficits occurring from 30 min postlearning, at the point of transition between the A and the B phases of the Gibbs-Ng intermediate memory stage. By contrast, the S-100β antisera needed to be injected either 5 min before or immediately after training and produced amnesia 10 min earlier, at the start of the A phase of the intermediate memory stage. We conclude that the two subunits of the S-100 protein are required at different points in the sequence of events leading to the consolidation of passive avoidance memory.     

A human-centered approach for designing World-Wide Web browsers

Because the World-Wide Web has features that are not found in traditional information systems, it has some unique problems pertaining to human use, such as the difficulty of searching for specific information. This paper describes human cognitive limitations pertinent to the design of Web browsers and provides a conceptual model for human information processing on the Web. It also compares user strategies and use of browser functions for two tasks that differ in the specificity of the information that is to be retrieved. General principles and specific recommendations for the design of Web browsers are derived from these considerations.     

Spline smoothing with model-based penalties

Nonparametric regression techniques, which estimate functions directly from noisy data rather than relying on specific parametric models, now play a central role in statistical analysis. We can improve the efficiency and other aspects of a nonparametric curve estimate by using prior knowledge about general features of the curve in the smoothing process. Spline smoothing is extended in this paper to express this prior knowledge in the form of a linear differential operator that annihilates a specified parametric model for the data. Roughness in the fitted function is defined in terms of the integrated square of this operator applied to the fitted function. A fastO(n) algorithm is outlined for this smart smoothing process. Illustrations are provided of where this technique proves useful.     

Set- and Element-Level Stimulus-Response Compatibility Effects for Different Manual Response Sets

In a previous study of two-choice reactions, pairings of spatial stimuli with bimanual presses made on a keyboard and verbal stimuli with unimanual aimed movements made on a display screen showed higher set-level compatibility than the opposite pairings; element-level compatibility (i.e., mapping) effects were also larger for the conditions with high set-level compatibility than for those whose set-level compatibility was low. In the 4 experiments described here, the relevant factors were isolated, allowing the determinants of those compatibility differences to be evaluated in more detail. Forty-eight students participated in Experiment 1, and 24 each in Experiments 2, 3, and 4. The primary determinant of the set-level compatibility variation was whether the response alternatives involved 1 or 2 effectors, but the differences in element-level compatibility effects were determined primarily by the distinction between responding on the screen as opposed to on the keyboard. Implications for models of stimulus-response compatibility are examined.     

False Consensus,Stereotypic Cues,and the Perception of Integrative Potential in Negotiation1

We argue that negotiators' fixed-sum perceptions are caused by the same judgment process that creates false consensus. Bargainers' reliance on their own preferences as a cue to others' preferences leads them to anticipate a fixed-sum conflict. When presented with stereotypic cues, subjects in a negotiating experiment anticipated the variable-sum nature of the task and subsequently realized highly efficient settlements extremely quickly. Surprisingly, even when the party's preferences were unrepresentative of the stereotype, agreements were no less efficient than in the absence of the cue. The implications of these findings for bargaining research and practice are discussed.