Spontaneous allocation of visual attention: dominant role of uniqueness

Common sense suggests that unique or abruptly changing (transient) elements in a visual scene often draw attention involuntarily. Visual search studies paint a seemingly different picture, however: Unique items usually draw attention involuntarily only when observers seek a unique target. One type of transient— abrupt onsets—draws attention involuntarily, but only when the observer is seeking an onset (Folk, Remington, & Johnston, 1992). One way of reconciling common-sense with these findings is to suppose that when people view a scene with no specific goal or task, they adopt adefault set, which might prioritize novelty and/or transients. In two experiments, 336 subjects saw a single display of six items for 900 msec, expecting to have to describe it (Experiment 1) or make an aesthetic judgment about it (Experiment 2). One item in the display was either uniquely flashing (surrounded by static items) or uniquely static (surrounded by flashing items). In both studies, the unique item, even if static, was more often reported than the nonunique item, with flashing items enjoying an additional advantage.     

Probing memory with conceptual cues at multiple retention intervals: a comparison of forgetting rates on implicit and explicit tests

The time courses for implicit and explicit conceptual tests of memory were compared in two experiments. In Experiment 1, participants encoded target words by judging the apparent pleasantness of their meaning. Immediately thereafter or 48 h later, retrieval cues were presented to different groups of participants for either an implicit or an explicit free-association task. Whereas explicit test performance showed a decline over the 48-h delay, implicit test performance was statistically unaltered. In Experiment 2, memory was tested at five retention intervals, lasting up to 3 weeks. The forgetting functions of both implicit and explicit tests conformed to a logarithmic function. Despite the large conceptual priming effect, which resulted from relational encoding instructions, implicit memory performance still declined at a much slower rate than did performance on the cued-recall test. We argue that because nominal conceptual cues were held constant across the implicit and the explicit conditions, the observed dissociation in performance supports a memory systems approach.     

Shared neighborhood effects in masked orthographic priming

Several studies have found effects of orthographically related masked nonword primes on lexical decisions to target words. These effects have been explained by the neighborhood characteristics of the target word (Forster, 1987), but the neighborhood characteristics of the prime in combination with the target are also found to be important (Hinton, Liversedge, & Underwood, 1998). In this study, we present a new account of masked form-priming effects based on the shared neighborhood of prime and target. Shared neighbors are words that are activated by both prime and target. According to the interactive activation model (McClelland & Rumelhart, 1981), shared neighborhood determines the size of priming effects. This prediction was tested and confirmed in a masked priming experiment that manipulated the shared neighborhood density of complete primes.     

Ethics and engineering courses at Delft University of Technology: Contents, educational setup and experiences

This article reports on the development and teaching of compulsory courses on ethics and engineering at Delft University of Technology (DUT). Attention is paid to the teaching goals, the educational setup and methods, the contents of the courses, involvement of staff from engineering schools, experiences to date, and challenges for the future. The choices made with respect to the development and teaching of the courses are placed within the European and Dutch context and are compared and contrasted with the American situation and experiences. Previous versions of this article were presented at the meeting of the SEFI Working Group on Engineering Ethics in Rzeszow, Poland, April 29–May 1, 1999 and at the SEFI Annual Conference in Zurich, Switzerland, September 1–3, 1999.     

Language and space: some interactions

Is language linked to mental representations of space? There are several reasons to think that language and space might be separated in our cognitive systems, but they nevertheless interact in important ways. These interactions are evident in language viewed as a means of communication and in language considered a form of representation. In communication, spatial factors may be explicit in language itself, such as the spatial-gestural system of American Sign Language. Even the act of conversing with others is a spatial behavior because we orient to the locations of other participants. Language and spatial representations probably converge at an abstract level of concepts and simple spatial schemas.     

Face recognition and emotional valence: processing without awareness by neurologically intact participants does not simulate covert recognition in prosopagnosia

Covert face recognition in neurologically intact participants was investigated with the use of very brief stimulus presentation to prevent awareness of the stimulus. In Experiment 1, skin conductance response (SCR) to photographs of celebrity and unfamiliar faces was recorded; the faces were displayed for 220 msec and for 17 msec in a within-participants design. SCR to faces presented for 220 msec was larger and more likely to occur with familiar faces than with unfamiliar faces. Face familiarity did not affect the SCR to faces presented for 17 msec. SCR was larger for faces of good than for faces of evil celebrities presented for 17 msec, but valence did not affect SCR to faces displayed for 220 msec. In Experiment 2, associative priming was found in a face familiarity decision task when the prime face was displayed for 220 msec, but no facilitation occurred when primes were presented for 17 msec. In Experiment 3, participants were able to differentiate evil and good faces presented without awareness in a two-alternative forced-choice decision. The results provide no evidence of familiarity detection outside awareness in normal participants and suggest that, contrary to previous research, very brief presentation to neurologically intact participants is not a useful model for the types of covert recognition found in prosopagnosia. However, a response based on affective valence appears to be available from brief presentation.     

Stronger suboptimal than optimal affective priming?

The finding of stronger affective priming in less conscious (suboptimal) conditions than in fully conscious (optimal) conditions (S. T. Murphy & R. B. Zajonc, 1993) is theoretically important because it contradicts notions that emotions are primarily reflected by conscious states. In 2 experiments, this pattern of results was obtained. Happy and angry faces were presented both optimally and suboptimally and were masked by unknown ideographs. In Experiment 1, instructions for the conscious and less conscious affective priming conditions were matched, and affective ratings of ideographs were determined. In Experiment 2, a more implicit affective measure (facial electromyography of musculus zygomaticus major and musculus corrugator supercilii) served as the dependent variable. Stronger suboptimal than optimal affective priming was found in both experiments. It is concluded that stronger suboptimal than optimal processing is characteristic for affective processing and that it can also be found when instructions are matched and when a more implicit measure is assessed.