Control of stimulus-response translation in dual-task performance

In contradiction to stimulus-response- (S-R-) translation bottleneck models of dual-task control, stimulus processing in a primary task is affected by its compatibility with the response in a secondary, later performed task (Hommel, 1998a)- an indication of parallel S-R translation. Here we show that this backward-compatibility effect is independent of working-memory load, whether this is induced by an extra memory task (Experiment 1) or by increasing the number of S-R alternatives in the primary task (Experiment 2). However, backward effects occur even when the secondary task is no longer carried out (Experiment 3) and they are strongly affected by the inconsistency of previously used S-R mappings (Experiment 4). These findings suggest that S-R translation is (or can be) capacity-independent and automatic even under multiple-task conditions, and that it is mediated by direct S-R associations that emerge after only little practice.     

A restraint system for the psychophysiological study of dogs

The present report describes a system for continuous psychophysiological study of the dog in a relatively flexible restraint harness that maintains the animal in a constant directional orientation, but allows him to assume any of a number of standing, sitting, or lying positions. The system permits the concurrent monitoring of behavioral and physiological processes under both acute and chronic conditions. A harness consisting of a leather collar and two body yokes is suspended from a pivoting metal hanger assembly. The harness is integrated with an isolation hamber equipped with automatic food, ater, stimulus, and response devices. Techniques for installing and maintaining dogs in the harness are described. A system for the continuous monitoring of cardiovascular functions and some experimental uses of the restraint system are suggested.     

The use of partial temporal information in dating personal events

Memory & Cognition - The use of different types of partial temporal information is shown to affect dating accuracy and the distribution of errors in event dating. Several different types of...     

The use of partial information on weights in multicriteria decision problems

This paper addresses multicriteria decision problems in which only partial information is given in the decision-making process. We generalize existing results about preference relations induced by nonnegative inverse matrices, allowing linear relations on weights with upper and lower bounds. In addition we develop conditions for additional information that preserve the special properties studied and show how to incorporate the new information to the model. © 1998 John Wiley & Sons, Ltd.     

Differential use of partial information by good and poor readers

Two interpretations of the poor readers' deficit are examined. According to one interpretation, poor readers are primarily deficient in use of phonetic information, and, thus, their deficit is specific to reading or at least to use of language. A second interpretation is that good and poor readers differ in their ability or tendency to use stimulus attributes—that is, partial information for stimulus identity—and, thus, their deficit is not specific to reading. Three experiments provide evidence favoring the second interpretation. Good and poor readers perform differently in tests of memory—whether or not the stimulus items are coded phonetically—when information about stimulus identity is incomplete due to memory loss and the response measure is sensitive to partial-information use in guessing. Likewise, the two groups perform differently in a perceptual task when information for stimulus identity is partial, but they perform at similar levels when information is complete.     

A psychophysiological model of emotion space.

Despite a wide variety of emotions that can be subjectively experienced, the emotion space has consistently revealed a low dimensionality. The search for corresponding somato-visceral response patterns has been only moderately successful. The authors suggest a solution based on an assumed parallelism between emotion coding and color coding. According to the color detection model proposed by Sokolov and co-workers, neurons responsible for color detection are triggered by a combination of excitations in a limited number of input cells. Similarly, a limited number of input channels may feed complex emotion detectors being located on a hypersphere in a four-dimensional emotion space, the three angles of which correspond to emotional tone, intensity, and saturation, in parallel to hue, lightness, and saturation in color perception. The existence of such a four-dimensional emotion space in the subjective domain is shown by using schematic facial expressions as stimuli. A neurophysiological model is provided in which reticular, hypothalamic, and limbic structures constitute input channels of an emotion detecting system, thus acting as the first layer of emotion predetectors. Hypothalamic neurons with differential sensitivity for various transmitters may elicit a subsequent selective activation in a second layer of predetectors at the thalamic level. The latter are suggested to trigger emotion detectors located in cortical areas, the action of which should be revealed by measures of central nervous system activity. Preliminary results from evoked potential studies show that switching between schematic faces that express different emotions may be used as an objective measure for establishing a psychophysiological emotion space.     

Stress modulates the use of spatial versus stimulus-response learning strategies in humans

Animal studies provided evidence that stress modulates multiple memory systems, favoring caudate nucleus-based "habit" memory over hippocampus-based "cognitive" memory. However, effects of stress on learning strategy and memory consolidation were not differentiated. We specifically address the effects of psychosocial stress on the applied learning strategy in humans. We designed a spatial learning task that allowed differentiating spatial from stimulus-response learning strategies during acquisition. In 13 subsequent trials, participants (88 male and female students) had to locate a "win" card out of four placed at a fixed location in a 3D model of a room. Relocating one cue in the last trial allowed inferring the applied learning strategy. Half of them participated first in the "Trier Social Stress Test." Salivary cortisol and heart rate measurements were taken. Stressed participants used a stimulus-response strategy significantly more often than controls. Subsequent verbal report revealed that spatial learners had a more complete awareness of response options than stimulus-response learners. Importantly, learning performance was not affected by stress. Taken together, stress prior to learning facilitated simple stimulus-response learning strategies in humans-at the expense of a more cognitive learning strategy. Depending on the context, we consider this as an adaptive response.     

Extraversion and sleep: A psychophysiological study of the arousal hypothesis

In order to examine Eysenck's (1967) hypothesis concerning the relationship between extraversion and arousal, autonomic measures were taken from introverts and extraverts immediately before sleep and during 6 hr of sleep. Introverts and extraverts did not differ in heart rate (HR) or skin-potential response rate (SPR) during the pre-sleep period. A variety of sleep-related measures of arousal provided no strong support for the hypothesis that introverts are more aroused than extraverts. The only consistent autonomic difference between introverts and extraverts during sleep was a tendency for introverts to have higher SPRs in the second 3 hr of the night. The results are discussed in terms of the level of environmental stimulation present in the experimental conditions, and suggestions are made for future sleep studies of the relationship between extraversion and arousal.     

Lateral stimulus-response compatibility effects in the oculomotor system.

Eye movement reaction time (RT) was measured in simple and choice RT situations in which monaural tones were presented to the left or right ear. In the choice RT conditions, tones of one frequency signaled a left looking response and tones of another frequency signaled a right looking response. In the simple RT condition, tones were presented in 2 blocks signaling right or left looking responses. RTs were measured by electro-oculogram (EOG), with electrodes placed over the outer canthus of each eye. In the choice RT condition, oculomotor RTs were faster when the tones signaling right or left looking were presented in the ears corresponding to the direction of looking than when they occured in the opposite ear. No such correspondence was present in the simple RT condition. Ss also performed a manual choice RT task. The lateral stimulus- response (S-R) compatibility effects obtained confirmed previous findings and were of the same magnitude as those obtained in the oculomotor response modality. Asymmetry in correlations between oculomotor and manual compatibility effects suggests differential hemispheric mediation.     

A parallel distributed processing model of stimulus-stimulus and stimulus-response compatibility.

A parallel distributed processing (PDP) model is proposed to account for choice reaction time (RT) performance in diverse cognitive and perceptual tasks such as the Stroop task, the Simon task, the Eriksen flanker task, and the stimulus-response compatibility task that are interrelated in terms of stimulus-stimulus and stimulus-response overlap (Kornblum, 1992). In multilayered (input-intermediate-output) networks, neuron-like nodes that represent stimulus and response features are grouped into mutually inhibitory modules that represent stimulus and response dimensions. The stimulus-stimulus overlap is implemented by a convergence of two input modules onto a common intermediate module, and the stimulus-response overlap by direct pathways representing automatic priming of outputs. Mean RTs are simulated in various simple tasks and, furthermore, predictions are generated for complex tasks based on performance in simpler tasks. The match between simulated and experimental results lends strong support for our PDP model of compatibility.     

Chronic stress modulates the use of spatial and stimulus-response learning strategies in mice and man

Acute stress modulates multiple memory systems in favor of caudate nucleus-dependent stimulus-response and at the expense of hippocampus-dependent spatial learning and memory. We examined in mice and humans whether chronic stress has similar consequences. Male C57BL/6J mice that had been repeatedly exposed to rats ("rat stress") used in a circular hole board task significantly more often a stimulus-response strategy (33%) than control mice (0%). While velocity was increased, differences in latency to exit hole, distance moved or number of holes visited were not observed. Increased velocity and performance during retention trials one day later indicates altered emotionality and motivation to explore in rat stressed mice. Forty healthy young men and women were split into "high chronic stress" and "low chronic stress" groups based on their answers in a chronic stress questionnaire ("Trier Inventory of Chronic Stress"-TICS) and trained in a 2D task. A test trial immediately after training revealed that participants of the "high chronic stress" group used the S-R strategy significantly more often (94%) than participants of the "low chronic stress" group (52%). Verbal self-reports confirmed the strategy derived from participants' choice in the test trial. Learning performance was unaffected by the chronic stress level. We conclude that one consequence of chronic stress is the shift to more rigid stimulus-response learning, that is accompanied by changes in motivational factors in mice.     

A further study of partial reinforcement in the turtle

Two matched groups of mature painted turtles, Chrysemys picta picta, were trained in a simple runway, one with partial and the other with consistent reinforcement, following which both groups were extinguished. The partially reinforced animals ran more slowly in acquisition, but showed somewhat greater resistance to extinction. The results are compared with those obtained in analogous experiments with other animals.     

A psychophysiological study of auditory illusions of approach and withdrawal in the context of the perceptual environment

Auditory perception of the depth of space is based mainly on spectral and amplitude changes of sound waves originating from the sound source and reaching the listener. The perceptive illusion of movement of an auditory image caused by changes in amplitude and/or frequency of the signal tone emanating from an immobile loudspeaker was studied. Analysis of data obtained from the participants revealed the diapason of combinations of amplitude and frequency changes for which the movement direction was perceived similarly by all participants, despite significantly different movement assessment criteria. Additional auditory and visual information of the conditions of radial movement (near or far fields) determined listeners' interpretation of changes in the signal parameters. The data obtained about the perception of approach and withdrawal models are evidence of the fact that the principal cues of the perception of the distance of immobile sound sources manifests similarly to that of an auditory image moving along a radial axis.     

A psychophysiological study on the function of the response‐stop in the Eriksen task1,2

Abstract: In the Eriksen task, we examined the hypothesis ( Iwaki, 1998 ) that a negative event‐related potential, which was enlarged at the frontal site synchronized with the presentation of an erroneous response causing stimulus, is related to the response‐stop function. Fourteen subjects responded selectively with their hands to the stimuli that consisted of a central target letter and surrounding compatible noise letters (e.g., HHHHH) or incompatible noise (e.g., SHHHS for small‐conflict condition or SSHSS for large‐conflict). The results showed that the increased negativity for the incompatible stimuli was synchronized with the stimulus onset but not with the response. Based on the hypothesis above, it is predicted that greater enhancement of an erroneous response by a stimulus causes the response‐stop to work harder in order to avoid an error, and this results in the larger negativity. This was supported by the evidence showing that the negativity was largest for the large‐conflict incompatible stimulus, followed by the small‐conflict, and then the compatible. We also discuss the possibility that the negativity is the NO‐GO potential concerned with the response‐stop function.