Schizotypy and hemisphere function—I : Theoretical considerations and the measurement of schizotypy

This paper brings together, in the context of individual-differences theory, two developing themes in schizophrenia research. One concerns the manifestation, in normal people, of ‘psychotic’ characteristics and their measurement using scales which, unlike the Eysenck P scale, draw their items from the clinical symptomatology of psychosis. Recent work on the so-called ‘borderline states’ is considered especially relevant and a new two-scale questionnaire (STQ) is described which was modelled on the current distinction, in DSM-III, between ‘schizotypal personality disorder’ and ‘borderline personality disorder’. The second theme addressed concerns the possible biological basis of individual differences in ‘schizotypy’. It is argued, in the light of some emerging views about the nature of schizophrenia, that this may lie in the functional and structural properties of hemisphere organization. A suggested strategy for evaluating this theory is an examination of the performance of schizotypal normal Ss on tests of hemisphere function.     

Schizotypy and hemisphere function—III : Performance asymmetries on tasks of letter recognition and local-global processing

Two experiments are reported comparing high and low schizotypal normals on divided field tasks of (a) letter recognition and (b) local-global processing. On the former, low schizotypal Ss showed an expected right visual-field superiority, whereas high schizotypal Ss showed the opposite, in that respect resembling schizophrenic patients. A similar reversed asymmetry was found when the two personality types were compared for local and global processing of letter stimuli, high schizotypals being especially unusual in showing superior local processing for stimuli presented in the left visual field. The results are taken as providing further support for the theory of schizotypy put forward in a previous paper.     

Does Analytic Thinking Insulate Against Pro-Kremlin Disinformation? Evidence From Ukraine

Pro-Kremlin disinformation campaigns have long targeted Ukraine. We investigate susceptibility to this pro-Kremlin disinformation from a cognitive-science perspective. Is greater analytic thinking associated with less belief in disinformation, as per classical theories of reasoning? Or does analytic thinking amplify motivated system 2 reasoning (or “cultural cognition”), such that analytic thinking is associated with more polarized beliefs (and thus more belief in pro-Kremlin disinformation among pro-Russia Ukrainians)? In online (N = 1,974) and face-to-face representative (N = 9,474) samples of Ukrainians, we find support for the classical reasoning account. Analytic thinking, as measured using the Cognitive Reflection Test, was associated with greater ability to discern truth from disinformation—even for Ukrainians who are strongly oriented towards Russia. We find similar, albeit weaker, results when operationalizing analytic thinking using the self-report Actively Open-Minded Thinking scale. These results demonstrate a similar pattern to prior work using American participants. Thus, the positive association between analytic thinking and the ability to discern truth versus falsehood generalizes to the qualitatively different information environment of postcommunist Ukraine. Despite low trust in government and media, weak journalistic standards, and years of exposure to Russian disinformation, Ukrainians who engage in more analytic thinking are better able to tell truth from falsehood.     

Temporal characteristics of a comparator in adaptation to optical tilt

Two groups of eight Ss each and one group of seven Ss were exposed to optical tilts (T) of 50, 40, 30, 20, and 10 deg in succession. Exposure time at each tilt was 3, 15, and 27 min in Groups 1, 2, and 3, respectively. Trend analyses of the functions relating level of adaptation to T showed significant quadratic components for Group 1, quadratic and linear components for Group 2, and only linear components for Group 3. These results were consistent with derivations from a memory-comparator model of perceptual adaptation.     

Interaction of fear effects with habit strength

Four groups of rats received 0, 3, 6 or 9 days of overtraining after having reached stable performance on a continuous reinforcement bar pressing schedule. Half the subjects in each group had previously been designated emotionally reactive or non-reactive in terms of defecation rates in an open-field test. Following training, there were four test days in which bar pressing in each group was examined in the presence or absence of white noise. The major findings were that, in both the reactive and non-reactive groups, white noise produced a fear reaction which significantly depressed bar pressing at low levels of habit strength while having an energizing effect at higher levels. The results were interpreted as supporting Bardach's (1960) hypothesis that anxiety introduced early in practice is more disruptive than when introduced late in practice.     

Looking time: Experimenter and instruction effects

A 2 by 3 factorial design was used to investigate the effects of the instructions and the presence of E on looking time. Two hundred thirty-nine college students viewed 30 colored stimuli of landscapes, single objects, and arrays of objects under three different sets of instructions, with E either present or absent while S viewed the stimuli. The results demonstrated that E’s presence depressed the time spent looking at the stimuli Evidence was also found suggesting that ambiguity in the typical instructions given Ss in looking-time experiments may result in artifactually long looking times. It was concluded that a more appropriate situation to investigate looking time would (1) utilize sham GSR instructions to reduce S’s uncertainty concerning the experiment’s purpose, and (2) arrange for E’s absence while S is viewing the stimuli     

Frequency-selective detection at three signal amplitudes

Using the probe-signal method, frequency-response characteristics were obtained for four Os detecting signals nominally of only 1000Hz under three signal-amplitude conditions: E/N_o=10.0, 12.6, and 15.8. Detection of 1000-Hz signals decreased systematically with signal-amplitude decreases, but signals at 850 Hz and at 1150 Hz were detected at or near the chance level during all signal-amplitude conditions. From the detection performance data, the detectability was inferred for four probe-signal frequencies relative to that of 1000-Hz signals for each of the amplitude conditions. From the curvesofrelative detectability, hal[-detectability bandwidths were estimated. Neither the relative detectability curves nor the half-detectability bandwidths indicate any systematic change in the frequencyselectivebehavior of the auditory O across the signal amplitudes used.     

Classical and bayesian inference in certain latency processes

Certain aspects of point estimation are treated for two kinds of exponential latency processes. The first unitary process is represented by a simple exponential density in which the rate parameter may be viewed as an unknown constant or as a random variable. If a second, slower exponential process is grafted onto the first, there results a postulated two-component latency between stimulus and response. Moments estimators are derived for the two parameters of this latter density, and the relevance of the second parameter to decision time is emphasized.This research was supported in part by National Institutes of Health Grant MH-04439-05. The author would like to express his appreciation to James Baker of Oregon Research Institute for certain helpful comments concerning aspects of this work.