Retroactive inhibition as a function of the conceptual structure of original and interpolated lists

Subjects learned either a hierarchically structured serial list of concept instances or a list made up of the same words but without structure. These two original lists were followed by one of four interpolated lists varying in number of hierarchical levels and consisting of new instances of the concepts which occurred in the original lists. Recall of the original structured list showed heavy retroactive inhibition, with the magnitude being independent of the number of conceptual levels in the interpolated lists. For the unstructured original list, retroactive inhibition decreased as the number of conceptual levels in the interpolated list increased. Some mechanisms believed involved in producing these outcomes were discussed.     

Size contrast as a function of conceptual similarity between test and inducers

In four experiments, the effect of the semantic relationship between test and inducing stimuli on the magnitude of size contrast in an Ebbinghaus-type illusion was explored. In Experiments 1 and 2, the greatest illusion was found when test and inducing stimuli were identical in shape and differed only in size. Decreased size contrast was found when inducing stimuli were drawn from the same category as the test stimulus, but were not visually identical. Even less size contrast was found when inducing stimuli were from a near conceptual category, with the least effect when they were drawn from a completely different category. In Experiment 3, it was demonstrated that even if test and inducing stimuli are drawn with identical geometric elements, the size contrast illusion is greatly reduced if they represent apparently different conceptual categories (through the manipulation of orientation and perceptual set). In Experiment 4, any geometric or spatial confounds were ruled out. These results suggest that size contrast is strongly influenced by the conceptual similarity between test and inducing stimuli.     

Object memory and change detection: dissociation as a function of visual and conceptual similarity

People often fail to detect a change between two visual scenes, a phenomenon referred to as change blindness. This study investigates how a post-change object's similarity to the pre-change object influences memory of the pre-change object and affects change detection. The results of Experiment 1 showed that similarity lowered detection sensitivity but did not affect the speed of identifying the pre-change object, suggesting that similarity between the pre- and post-change objects does not degrade the pre-change representation. Identification speed for the pre-change object was faster than naming the new object regardless of detection accuracy. Similarity also decreased detection sensitivity in Experiment 2 but improved the recognition of the pre-change object under both correct detection and detection failure. The similarity effect on recognition was greatly reduced when 20% of each pre-change stimulus was masked by random dots in Experiment 3. Together the results suggest that the level of pre-change representation under detection failure is equivalent to the level under correct detection and that the pre-change representation is almost complete. Similarity lowers detection sensitivity but improves explicit access in recognition. Dissociation arises between recognition and change detection as the two judgments rely on the match-to-mismatch signal and mismatch-to-match signal, respectively.     

Concepts and conceptual structure

Research and theory on categorization and conceptual structure have recently undergone two major shifts. The first shift is from the assumption that concepts have defining properties (the classical view) to the idea that concept representations may be based on properties that are only characteristic or typical of category examples (the probabilistic view). Both the probabilistic view and the classical view assume that categorization is driven by similarity relations. A major problem with describing category structure in terms of similarity is that the notion of similarity is too unconstrained to give an account of conceptual coherence. The second major shift is from the idea that concepts are organized by similarity to the idea that concepts are organized around theories. In this article, the evidence and rationale associated with these shifts are described, and one means of integrating similarity-based and theory-driven categorization is outlined.     

Aging and perceived event structure as a function of modality

The majority of research on situation model processing in older adults has focused on narrative texts. Much of this research has shown that many important aspects of constructing a situation model for a text are preserved and may even improve with age. However, narratives need not be text-based, and little is known as to whether these findings generalize to visually-based narratives. The present study assessed the impact of story modality on event segmentation, which is a basic component of event comprehension. Older and younger adults viewed picture stories or read text versions of them and segmented them into events. There was comparable alignment between the segmentation judgments and a theoretically guided analysis of shifts in situational features across modalities for both populations. These results suggest that situation models provide older adults with a stable basis for event comprehension across different modalities of expereinces.     

Policy conflict and policy change as a function of task characteristics 1. The effects of cue validity and function form

Brehmer, B. & Kostron, L. Policy conflict and policy change as a function of task characteristics. I. The effects of cue validity and function form. Scand. J. Psychol., 1973, 14, 44–55.-Policy conflict and policy change in the "lens model" interpersonal conflict paradigm were studied as a function of the distribution of cue validities in a two-cue task with one linear and one nonlinear cue. Agreement was higher in the conditions where the linear cue was more valid than the nonlinear cue than in the conditions where the nonlinear cue was more valid than the linear cue. This was primarily due to the fact that the subjects' policies were more consistent in predominantly linear conditions. The amount of policy change in the various conditions suggested that the subjects' behavior was the result of a compromise between conflict reduction and task adaptation.     

Resistance to persuasive messages as a function of majority and minority source status

Three experiments examined the extent to which attitudes following majority and minority influence are resistant to counter-persuasion. In Experiment 1, participants’ attitudes were measured after being exposed to two messages which argued opposite positions (initial pro-attitudinal message and subsequent, counter-attitudinal counter-message). Attitudes following minority endorsement of the initial message were more resistant to a (second) counter-message than attitudes following majority endorsement of the initial message. Experiment 2 replicated this finding when the message direction was reversed (counter-attitudinal initial message and pro-attitudinal counter-message) and showed that the level of message elaboration mediated the amount of attitude resistance. Experiment 3 included conditions where participants received only the counter-message and showed that minority-source participants had resisted the second message (counter-message) rather than being influenced by it. These results show that minority influence induces systematic processing of its arguments which leads to attitudes which are resistant to counter-persuasion.     

Proactive inhibition as a function of orienting task characteristics

Two release from proactive inhibition experiments were conducted, in which orienting tasks were employed to direct subjects' attention to particular features of words. Experiment 1 employed two such tasks which emphasized either semantic or nonsemantic features, while both orienting tasks in Experiment 2 directed attention to semantic features of words. Although significant release was obtained with a change in task in these experiments, the level was considerably lower in Experiment 2 than in Experiment 1. The data were interpreted in terms of a theoretical orientation that emphasizes item differentiation as a major determinant of retrieval probability. It was argued that the degree of differentiation depends to some extent on the specific tasks employed and the extent to which they direct attention to different word features.