Going beyond heart rate: autonomic space and cardiovascular assessment of mental workload

Psychophysiological assessment of pilot mental workload using heart rate should be augmented with an autonomic space model of cardiovascular function. This model proposes that autonomic nervous system influences on the heart may change with psychological processing in ways that are not evident in heart rate. A method of mental-workload assessment was proposed that used multiple psychophysiological measures of cardiovascular responsivity to derive the underlying sympathetic and parasympathetic information needed to represent the autonomic space for heart rate. Principal-components analysis was used to extract Sympathetic and Parasympathetic components from heart period, residual heart period. respiratory sinus arrhythmia, and Traube-Hering-Mayer wave in three experiments that manipulated perceptual/central processing and physical task demands. This initial evaluation of the method concluded that the autonomic components were valid and that the components had greater diagnosticity, and for some manipulations greater sensitivity, than heart rate. These results support the contention that the Sympathetic and Parasympathetic components provided increased precision for mental-workload assessment.     

A review and critique of the process approach in neuropsychological assessment

This paper surveys the process approach literature with an emphasis on higher level cognitive functions like attention and concentration, learning and memory, and problem solving and executive functioning. In particular, it discusses organizational strategies and kinds of errors found on a variety of tests as well as behavioral, situational, and interpersonal issues as they relate to test procedures. It critiques the process approach and suggests future directions.     

Globalised Religion?: The ‘parliament of the world's religions’ (Chicago 1993) in theoretical perspective

This paper tests the hypothesis that contemporary global and globalised religion as exemplified in the Chicago ‘Parliament of the World's Religions’ of 1993 may be regarded as a resource which is central, rather than marginal to current human concerns in a threatened world. The paper is structured as follows. First, a short personal narrative gives some sense of what happened at the Parliament, and how this affected one of those present. Second, as a means of conveying the scale of the meeting, a brief content analysis and interpretation of the programme shows how (within certain limits) collaboration was made possible. Third, three insights are drawn from current sociology that facilitate an informed, albeit preliminary, evaluation of the Parliament as emancipatory event. These are: i) recent globalisation theory of the world system (Roland Robertson and Peter Beyer); ii) differentiation in a social reality understood as an “economy of signs and space”; (Scott Lash and John Urry); and in) the search for “meta‐theory”; in the “condition of post‐modernity”; (David Harvey). Fourth, some implications of the analysis and interpretation are drawn out which suggest that religion can be understood as a differentiated global resource, an ambiguous, yet dynamic form of ‘cultural capital’ of vital import in an era of post‐materialist value formation. Fifth, in conclusion, it is argued that thus understood the globalised religion represented by the 1993 ‘Parliament of the World's Religions’ has wider implications for the study of contemporary religion and forms of religiosity. Religion returns from the theoretical and cultural periphery (a marginalisation promoted by traditional secularisation theory) into a close relation to the core issues of our time. This is an optimistic interpretation of an event, the significance of which, in the opinion of this writer, should not be underestimated in the evaluation of religion as global resource.     

Does Christianity make a difference?

The human person makes great demands on the physician and calls for unique attention. Hence the doctor-patient relationship calls for the highest ideals of kindness, patience, trustworthiness, generosity and skill. The Catholic physician brings to these demands a specific meaning: ministering to the sick is to see Christ in them and to show Him to them.     

Vibrotactile pattern discrimination and communality at several body sites

In a series of experiments, the effects of spatial layout on vibrotactile pattern perception were explored by testing the ability to discriminate between two sequentially presented patterns that share active elements in the same spatial locations. Two-dimensional displays were used in order to examine the functional relationship between discrimination performance and patterncommunality, defined as the sharing elements, on different body sites. Accuracy of discrimination judgments was inversely proportional to communality, regardless of the number of pattern elements. For compact arrays fitted to the finger, palm, and thigh, the effects of communality appeared equivalent. The similarity between finger and thigh functions is remarkable, considering the dramatic differences between these sites in receptor components and structure. When these data were compared with those from arrays with distributed contactors, performance was substantially better with well-separated pattern elements. Such findings help to explicate how information from apposed patterns can best be delivered to the skin through tactile communication systems.     

Within-category discrimination of musical chords: Perceptual magnet or anchor?

Recent speech research has begun to evaluate the internal structure of categories. In one such study, Kuhl (1991) found that discrimination was poorer for vowel stimuli that were more representative of the category (prototype, or P, set) than it was for less representative stimuli (nonprototype, or NP, set). This finding was interpreted as indicating that a category prototype may function as a “perceptual magnet,” effectively decreasing perceptual distance, and thus discriminability, between stimuli. The present study examines the function of prototypes in a musical category—another natural, but nonspeech category. Paralleling the Kuhl study, representative (P) and less representative (NP) sets of major triad stimuli were constructed, based on equal temperament. Musically experienced subjects rated the stimuli in each set for goodness as a major triad, with the highest rated stimulus serving as a prototype standard for a subsequent discrimination task. Results from the discrimination task demonstrated better performance in the P context than in the NP context. The current nonspeech results indicate that a prototype functions as an anchor rather than a magnet. In addition to providing a natural, nonspeech standard for comparison with speech findings, the results provide some important insights into the nature of musical categories.     

Time,change, and motion: The effects of stimulus movement on temporal perception

The effects of stimulus motion on time perception were examined in five experiments. Subjects judged the durations (6–18 sec) of a series of computer-generated visual displays comprised of varying numbers of simple geometrical forms. In Experiment 1, subjects reproduced the duration of displays consisting of stationary or moving (at 20 cm/sec) stimulus figures. In Experiment 2, subjects reproduced the durations of stimuli that were either stationary, moving slowly (at 10 cm/sec), or moving fast (at 30 cm/sec). In Experiment 3, subjects used the production method to generate specified durations for stationary, slow, and fast displays. In Experiments 4 and 5, subjects reproduced the duration of stimuli that moved at speeds ranging from 0 to 45 cm/sec. Each experiment showed that stimulus motion lengthened perceived time. In general, faster speeds lengthened perceived time to a greater degree than slower speeds. Varying the number of stimuli appearing in the displays had only limited effects on time judgments. Other findings indicated that shorter intervals tended to be overestimated and longer intervals underestimated (Vierordt’s law), an effect which applied to both stationary and moving stimuli. The results support a change model of perceived time, which maintains that intervals associated with more changes are perceived to be longer than intervals with fewer changes.     

A behavioral link between the oculomotor and cardiovascular systems

Although the eyes and the heart serve very different purposes, each receives autonomic innervation. Capitalizing on recent theoretical and technological innovations in the understanding and assessment of oculomotor and cardiovascular behavior, three experiments measured behavioral covariation between the oculomotor and cardiovascular systems. Measures of dark focus and dark vergence indexed oculomotor tone, and the spectral decomposition of variations in heart rate indexed cardiovascular control mechanisms. In Experiment 1, individual differences in cardiovascular parameters could predict individuals’ dark vergence (R²=.806) but not their dark focus (R²=.404). In Experiment 2, the same parameters were measured from subjects who experience either panic attacks (n=11) or blood phobia (n=9). Heart rate was positively correlated with dark vergence and the two subject groups were separable based on both oculomotor and cardiovascular variables. Using a within-subjects approach, Experiment 3 found that both dark vergence and dark focus tended to be nearer during sympathetic dominance of the heart than during parasympathetic dominance, within-subjects variations in cardiovascular parameters could predict dark focus, and between-subjects variations in interbeat intervals could predict dark vergence. Shared patterns of autonomic activation may be responsible for this eye-heart link.     

Book reviews

Integrative Psychological and Behavioral Science -     

The time course of recognition of novel melodies

Seven experiments explored the time course of recognition of brief novel melodies. In a continuous-running-memory task, subjects recognized melodic transpositions following delays up to 2.0 min. The delays were either empty or filled with other melodies. Test items included exact transpositions (T), same-contour lures (SC) with altered pitch intervals, and different-contour lures (DC). DCs differed from Ts in the pattern of ups and downs of pitch. With this design, we assessed subjects’ discrimination of detailed changes in pitch intervals (T/SC discrimination) as well as their discrimination of contour changes (T/DC). We used both artificial and “real” melodies. Artificial melodies differed in conformity to a musical key, being tonal or atonal. After empty delays, T/DC discrimination was superior to T/SC discrimination. Surprisingly, after filled delays, T/SC discrimination was superior to T/DC. When only filled delays were tested, T/SC discrimination did not decline over the longest delays. T/DC performance declined more than did T/SC performance across both empty and filled delays. Tonality was an important factor only for T/SC discrimination after filled delays. T/DC performance was better with rhythmically intact folk melodies than with artificial isochronous melodies. Although T/SC performance improved over filled delays, it did not overtake T/DC performance. These results suggest that (1) contour and pitch-interval information make different contributions to recognition, with contour dominating performance after brief empty delays and pitch intervals dominating after longer filled delays; (2) a coherent tonality facilitates the encoding of pitch-interval patterns of melodies; and (3) the rich melodic—rhythmic contours of real melodies facilitate T/DC discrimination. These results are discussed in terms of automatic and controlled processing of melodic information.