Habitual Prospective Memory and Aging: Remembering Intentions and Forgetting Actions

Routine or habitual prospective memory tasks (e.g., taking medication) have the potential for creating confusions regarding whether or not an action has already been performed. We developed a laboratory paradigm for examining the kinds of processes thought to be operating in these kinds of tasks. Younger and older participants were asked to perform an action once and only once on each of 11 trials. The results showed that age and divided attention contributed to both omission and repetition errors. This new paradigm reveals memory failures in a habitual prospective memory task, and the results demonstrate that older adults are particularly susceptible to these memory problems.     

Object-centered attention in 8-month-old infants

We examined the extent to which visual orienting in 8-month-old infants shows evidence of being guided by object-based representations. Infants’ preferences to look at conspicuous targets presented on one of two stationary objects were measured following an event (cue) which directed their covert attention to one of the objects. The results indicate that by 8 months of age a cue presented on one part of an object directs attention to the whole object (object-centered attention). This then affects responses to targets that appear elsewhere on the cued object.     

Characteristics of ideal museum exhibits

A method of classifying museum displays in terms of the ways they are perceived by museum visitors is presented. The experimental and analytical procedures used have a number of advantages over multidimensional scaling and clustering techniques and indicate a general method of investigating the ways in which museum visitors perceive relations between real-world objects in a natural setting.     

Affordances and infant learning: A reply to Horowitz

We reply to three major points made by F. Horowitz (1983, Developmental Review, 3, 405–409) in her commentary on the ecological approach to infant knowing presented by E. Goldfield (1983, Developmental Review, 3, 371–404). We first clarify the relation between perceiving and acting from an ecological perspective, and distinguish between affordances as environmental properties scaled to the perceiver/performer and representations as mental structures. We then present a critique of the process of association offered by Horowitz as an explanation of infant learning. Association fails to specify the constraints on what is learned, while the ecological process of noticing affordances, presented by Goldfield, considers such constraints. We conclude by presenting operational criteria for measuring affordances and evidence that perception is scaled to the perceiver/performer.     

Use of contingent lemon juice to eliminate public masturbation by a severely retarded boy

Contingent lemon juice successfully reduced and maintained at zero levels, public masturbatory responses in a severely retarded boy with a four year history of this behavior. Previously, more common procedures (loud “no” plus hand spanking. ignoring) had proven to be ineffective. The lemon juice contingency was shown to be effective in a period of from 13 to 16 days (in both home and school settings) and was easily implemented by a parent, a teacher and a para-professional.     

An empirical test of the covariation analysis in causal attribution

The present investigation was designed to reveal the cognitive inference processes associated with both detection and utilization of covariation information in causal attribution. Male undergraduates were (a) informed that a test was easy or difficult and shown a videotape in which (b) the test-taker's performance was high or low, and (c) covariation between the test-taker's effort expenditure and trial-by-trial outcome was present or absent. High performance was attributed to the test-taker's effort and ability, whereas low performance was attributed to the difficulty of the test. However, recognition of the covariance relationship decreased the attribution of high performance to ability and of low performance to test difficulty and increased the attribution of low performance to effort. Effort attribution in the high performance condition was independent of covariation information. The results are discussed in terms of the relationship between covariation information and typical beliefs about the causes of achievement outcomes.     

Visual search in multicharacter arrays with and without gaps

Subjects searched through briefly presented arrays of letters in a controlled order, indicating quickly which of two possible targets had occurred. Some arrays contained gaps—three missing letters. Reaction time (RT) and accuracy were both improved by a gap after the target; improvement was less when the gap preceded the target. To account for these results, a new model is proposed, one which calls for overlapping processing of successive array items. This is not a “hybrid” model, but a third alternative between the two extremes of serial (zero overlap) and parallel (complete overlap). Quantified, the overlapping model generates U-shaped serial-position curves and produces RT predictions in good accord with our data from arrays with and without gaps. The predicted functions for RT vs. array size are concave upward; however, for arrays of five or less they are virtually linear and not very different in slope for positive and negative trials. Although this model is primarily designed for RT, with some additional assumptions it can be extended to accuracy results.     

Perception of growth: a geometric analysis of how different styles of change are distinguished

Although there have been many demonstrations that human observers can accurately recognize a variety of styles of change, such as rolling, walking, or growing, there are no existing theories capable of explaining how one style of change is distinguished from another. The present article offers a hypothesis that any recognizable style of change is uniquely specified by geometric invariants- the abstract properties of a visual display that are preserved by the change. In an effort to provide an empirical test of this hypothesis, several experiments involving the perception of growth were performed. Observers were required to make perceptual judgments of consequences of facial profiles, each of which was constructed by using a different mathematical transformation. The same pattern of results was obtained on both a free response task and a growth rating task: All transformations that were consistently identified as growth preserved the same geometric invariants.     

Texture perceived with the fingers

Relative assessments of 10 attributes commonly used to describe the texture of liquids on skin were obtained for 14 liquids of widely varying rheological properties. The results were analyzed to show that these judgments can be predicted accurately from the assessments of just three attributes, smoothness, thinness, and warmth. Smoothness was found to be closely related to the forces of contact lubrication, and could be predicted from measurements of coefficients of friction. Thinness was found to be closely related to viscous forces, consistent with other predictions of assessments of thickness and spreadability. Warmth was not studied further. The results show how careful definition of the stimulus on the skin’s surface can sharply simplify the interpretation of the psychophysical experiment.