An inexpensive real-time microcomputer-based cognitive laboratory system

A computer system, based on the Radio Shack Color Computer, for running experiments in cognitive psychology is described. The system was designed according to the following principles: first, all of the equipment should consist of inexpensive, off-the-shelf components; second, the language used to implement experiments should have real-time commands embedded within the character strings to be displayed, and these real-time commands should be interpreted at run time; third, the system should serve multiple subjects, yet one host should be able to run display terminals for several subjects on independent experiments; and fourth, the system should be able to interface to other display devices and other response-recording devices. Two examples of other devices are discussed: an oscilloscope for rapid visual display and an Apple Macintosh for display of pictures.     

A model of visual spatio-temporal memory: The icon revisited

With a minimal set of assumptions resulting from considerations about the perception of temporal structure, we argue for the existence of a spatio-temporal memory established by the mapping of time into simultaneous physical properties. The important point of this model is the distinction between external, physical time and the internal representation of time. An immediate consequence of such a structure is the emergence of properties usually associated with the concept of iconic memory or informational persistence. Some of these properties may hence be regarded as epiphenomena produced by the testing of a spatio-temporal system with tachistoscopic spatial stimuli. The model can explain properties of the immediate memory span, the lack of effect of exposure duration on tachistoscopic report, the partial-report superiority, the decay of iconic memory, and effects of a backward mask. It does not only avoid the incompatibility problems of the frozen-image concept in dynamic vision, but also provides an adequate basis for the processing of time-varying scenes.     

Simultaneous effects and aftereffects of the intensity and success aspect in coping with stresses

Intensity and success of coping processes in achievement-related situations are very often tightly connected. Therefore, the specific empirical status of each of the two aspects is unclear. In the current study a technique is introduced which allows orthogonal variation of both components. 64 subjects were confronted with a simple perceptual-speed task in which objective success rate was held constant by a computer-based adaptive process. Graphic feedback was provided about the objective success rate in relation to one of two different success criteria. For half of the subjects the criterion was above (failure condition) and for the other half it was below (success condition) the adaptively controlled success rate. Intensity, the second between-subjects factor, was manipulated by presenting either a high or a low number of items per time unit. As an additional quasi-experimental factor, the degree of action- vs. state-orientation (Kuhl, 1983) was included. The results showed highly specific effects for both the intensity and the failure/success dimension: High intensity resulted in an increase of electrodermal activity which could be observed throughout a one hour post-stressor phase. The failure/success variation had effects mainly on subjective variables representing appraisal of controllability and produced no after-effects. Especially strong effects on subjective variables could be observed when state-oriented subjects were confronted with both failure and high intensity.     

Preference for Human (vs. Robotic) Labor is Stronger in Symbolic Consumption Contexts

Advances in robotics, automation, and artificial intelligence increasingly enable firms to replace human labor with technology, thereby fundamentally transforming how goods and services are produced. From both managerial and societal points of view, it is therefore important to understand demand‐side incentives for firms to employ human labor. We begin to address this question by examining for which products and services consumers are more likely to favor human (vs. robotic) labor. In six studies, we demonstrate that consumers prefer human (vs. robotic) labor more for products with higher (vs. lower) symbolic value (e.g., when expressing something about one's beliefs and personality is of greater importance). We theorize that this is because consumers have stronger uniqueness motives in more (vs. less) symbolic consumption contexts (and associate human labor more strongly with product uniqueness). In line with this account, we demonstrate that individual differences in need for uniqueness moderate the interaction between production mode and symbolic motives and that a measure of uniqueness motives mediates the effect of consumption context on preferences for human (vs. robotic) production.     

The fast and the slow of skilled bimanual rhythm production: parallel versus integrated timing

Professional pianists performed 2 bimanual rhythms at a wide range of different tempos. The polyrhythmic task required the combination of 2 isochronous sequences (3 against 4) between the hands; in the syncopated rhythm task successive keystrokes formed intervals of identical (isochronous) durations. At slower tempos, pianists relied on integrated timing control merging successive intervals between the hands into a common reference frame. A timer-motor model is proposed based on the concepts of rate fluctuation and the distinction between target specification and timekeeper execution processes as a quantitative account of performance at slow tempos. At rapid rates expert pianists used hand-independent, parallel timing control. In alternative to a model based on a single central clock, findings support a model of flexible control structures with multiple timekeepers that can work in parallel to accommodate specific task constraints.     

Children's reasoning about the causal significance of the temporal order of events

Four experiments examined children's ability to reason about the causal significance of the order in which 2 events occurred (the pressing of buttons on a mechanically operated box). In Study 1, 4-year-olds were unable to make the relevant inferences, whereas 5-year-olds were successful on one version of the task. In Study 2, 3-year-olds were successful on a simplified version of the task in which they were able to observe the events although not their consequences. Study 3 found that older children had difficulties with the original task even when provided with cues to attend to order information. However, 5-year-olds performed successfully in Study 4, in which the causally relevant event was made more salient.     

On the role of verbalization during task set selection: Switching or serial order control?

Recent task-switching work in which paper-and-pencil administered single-task lists were compared with task-alternation lists has demonstrated large increases in task-switch costs with concurrent articulatory suppression (AS), implicating a crucial role for verbalization during switching (Baddeley, Chincotta, & Adlam, 2001; Emerson & Miyake, 2003). Experiment 1 replicated this result, using computerized assessment, albeit with much smaller effect sizes than in the original reports. In Experiment 2, AS interference was reduced when a sequential cue (spatial location) that indicated the current position in the sequence of task alternations was given. Finally, in Experiment 3, switch trials and no-switch trials were compared within a block of alternating runs of two tasks. Again, AS interference was obtained mainly when the endogenous sequencing demand was high, and it was comparable for no-switch and switch trials. These results suggest that verbalization may be critical for endogenous maintenance and updating of a sequential plan, rather than exclusively for the actual switching process.     

Conflict, consciousness, and control

To what degree is executive conflict resolution dependent on conflict awareness? A recent study by Dehaene et al. compared neural responses to conflict elicited through either visible or subliminal primes. Despite behavioral conflict effects for both prime types, neural activity in a control network including the anterior cingulate cortex (ACC) was present only for visible primes. Along with other recent results, these findings have important implications for theories on the relationship between ACC, consciousness, and cognitive control.     

Syntactic priming of relative clause attachments: persistence of structural configuration in sentence production

Three sentence completion experiments will be reported in which participants had to generate German equivalents of "the servant of the actress who..." (NP-of-NP-RC) constructions. Target fragments (which were unconstrained as to whether the relative pronoun permitted high or low attachment) were preceded by constrained prime fragments, which were either structurally congruent with the targets (Experiments 1 and 2) or structurally incongruent with the targets (anaphoric adverbial clauses rather than relative clauses (RCs), Experiment 3). While the first two experiments established reliable repetition of RC attachments between primes and targets, Experiment 3 failed to obtain a significant priming effect, indicating that RC attachment priming is dependent on a syntactic overlap between primes and targets. The results suggest a tendency of language producers to retain hierarchical syntactic relations over consecutive trials. Current models of syntactic priming in production do not offer an explanatory mechanism for this kind of observation as they presently stand.