How Body Asymmetries Determine Accessibility in Spatial Frameworks

Spatial frameworks are a class of spatial mentalmodel that code locations of objects relative to the body axes. Spatial frameworks predict accessibility of spatial relations from memory primarily on the basis of the relative asymmetry of the body axes, such that highly asymmetric axes lead to faster retrieval of information. The present research examined how bodily asymmetries affect retrieval. Experiment 1 contrasted two theoretical accounts. The Salience Account proposes that relative degrees of asymmetry render axes differentially salient, and hence differentially foregrounded in one's mental model. The Direction Decision Account proposes that an explicit decision process is necessary to access specific locations along body axes. The ease of the decision process presumably depends on the degree of asymmetry that exists to discriminate poles along a body axis. The spatial framework pattern of accessibility was observed both when subjects identified specific directions of objects and when subjects identified just the axis to which objects were associated, supporting the Salience Account. Experiment 2 investigated whether lateralization affects accessibility from spatial frameworks. Performance of highly lateralized individuals did not differ from that of weakly lateralized individuals.     

The colour-matching functions and visual research

The following points are examined: the problem of how to define the colour of a stimulus used in visual research; the limited relation of the colour-matching functions to the spectral sensitivity curves of the individual colour receptors in the retina; and the case for abandoning luminance as a colorimetric variable and lightness as a colour appearance variable.     

Implicit Learning of an Invariant: Just Say No

Following exposure to 30 four-digit numbers containing an invariant “3”, subjects are found falsely to recognize novel four-digit numbers containing this invariant (positives) in preference to novel numbers that do not contain the invariant (negatives). Despite this false recognition, they are generally unable to report the rule relating test positives to the positives seen during the learning phase. This finding has been taken to show implicit learning of a rule. Two experiments are reported here which show that it is not necessary to learn this rule in order to perform at above-chance levels on this test. Most of the effect can be explained in terms of the rejection of particularly distinctive test items that are more prevalent in the test negatives. This rejection appears to be mediated by knowledge that is potentially explicit as opposed to implicit, and we present tentative evidence that it is rule-based as opposed to analogic.