Visual statistical learning in the newborn infant

Statistical learning – implicit learning of statistical regularities within sensory input – is a way of acquiring structure within continuous sensory environments. Statistics computation, initially shown to be involved in word segmentation, has been demonstrated to be a general mechanism that operates across domains, across time and space, and across species. Recently, statistical leaning has been reported to be present even at birth when newborns were tested with a speech stream. The aim of the present study was to extend this finding, by investigating whether newborns’ ability to extract statistics operates in multiple modalities, as found for older infants and adults. Using the habituation procedure, two experiments were carried out in which visual sequences were presented. Results demonstrate that statistical learning is a general mechanism that extracts statistics across domain since the onset of sensory experience. Intriguingly, present data reveal that newborn learner’s limited cognitive resources constrain the functioning of statistical learning, narrowing the range of what can be learned.     

Constructing desirable identities--self-presentation in psychotherapy and daily life: comment on Kelly (2000)

A. E. Kelly's (2000) thesis that psychotherapy clients benefit from withholding negative information is considered in light of current social-psychological theory and research. Positive illusions about oneself are associated with indexes of mental health; this is consistent with treating therapy as positive identity development. Self-presentation can shape self-concept, even apart from the feedback that an audience might provide; the social construction of identity is a powerful process, suggesting that withholding negative and presenting only positive information is adaptive. However, evidence concerning the level of identification of one's actions suggests complexities in understanding ways clients might deal with disclosing negative information; the authors argue that the impact on self-concept is probably more complex than A. E. Kelly's characterization and that the implications are of a broader scope than indicated so far.     

The Ebbinghaus illusion modulates visual search for size-defined targets: evidence for preattentive processing of apparent object size

Five search experiments investigated whether the apparent size of objects is, like their retinal size, coded in preattentive vision. Observers searched for a target circle that was either larger or smaller than distractor circles, with both types of test circles surrounded by context circles modulating apparent size (i.e., the Ebbinghaus illusion). The size ratio between the test and the context circles was manipulated in such a way that the test circles were surrounded by, for example, smaller context circles (making the larger target appear even larger) or by larger context circles (making the smaller distractors appear even smaller). Under optimal conditions, the detection reaction times were independent of the number of test circles in the display, and the Ebbinghaus illusion facilitated the detection of the target even in comparison with control conditions without any context circles. This finding is consistent with preattentive, spatially parallel processing of apparent size.     

How owls structure visual information

Recent studies on perceptual organization in humans claim that the ability to represent a visual scene as a set of coherent surfaces is of central importance for visual cognition. We examined whether this surface representation hypothesis generalizes to a non-mammalian species, the barn owl (Tyto alba). Discrimination transfer combined with random-dot stimuli provided the appropriate means for a series of two behavioural experiments with the specific aims of (1) obtaining psychophysical measurements of figure–ground segmentation in the owl, and (2) determining the nature of the information involved. In experiment 1, two owls were trained to indicate the presence or absence of a central planar surface (figure) among a larger region of random dots (ground) based on differences in texture. Without additional training, the owls could make the same discrimination when figure and ground had reversed luminance, or were camouflaged by the use of uniformly textured random-dot stereograms. In the latter case, the figure stands out in depth from the ground when positional differences of the figure in two retinal images are combined (binocular disparity). In experiment 2, two new owls were trained to distinguish three-dimensional objects from holes using random-dot kinematograms. These birds could make the same discrimination when information on surface segmentation was unexpectedly switched from relative motion to half-occlusion. In the latter case, stereograms were used that provide the impression of stratified surfaces to humans by giving unpairable image features to the eyes. The ability to use image features such as texture, binocular disparity, relative motion, and half-occlusion interchangeably to determine figure–ground relationships suggests that in owls, as in humans, the structuring of the visual scene critically depends on how indirect image information (depth order, occlusion contours) is allocated between different surfaces. Electronic Publication     

Well-being and motivational person-environment fit: A time-sampling study of emotions

The report is based on the data of seven studies (altogether 188 persons varying in gender, age, and education level) with the author's time-sampling diary, by which the subjects record their momentary mood, the behaviour setting, other persons present, activities, causal attributions of experienced emotions, and affected motives about four times a day for a period of 30 days. For each pattern of four 16PF second-order factors (median split), the relative frequencies of references to six classes of motives (i.e. the personal motive profiles) and for each of 16 behaviour settings, the relative frequencies by which each of those motives was satisfied in the whole sample of persons (environmental motive profiles) were derived from the diary data. The degree of motivational person–environment fit (P–E fit; correlation of personal and environmental motive profiles) was calculated for each combination of personality structure and behaviour setting. As predicted, a person's well-being in a behaviour setting clearly depends on the motivational P–E fit which explains the intra-individual variance of well-being (across situations) and the intra-situational variance (across persons) in addition to the variance explained by emotional stability and extraversion.     

A modified proportional change model of attitude change by group discussion

The data of two experiments of dyadic group discussion have been reanalysed. An extended proportional change model was designed to explain the actual process of attitude change. The model is defined by two parameters. The first represents the impact of single pro-arguments and single con-arguments on the attitude or decision preference. The second describes the resistance to further change that increases with the distance from the initial position. It was hypothesized that the first parameter should be higher and the second lower, with a similar partner than with a dissimilar one. The prediction was confirmed for the first parameter only. A comparison of the extended proportional change model to related models concludes the report.     

Factorial validity of the 20-item Toronto Alexithymia Scale

The 20-item Toronto Alexithymia Scale (TAS-20) was developed in previous research to measure a general dimension of alexithymia with three inter correlated factors. These three factors reflect distinct facets of the alexithymia construct: (1) difficulty identifying feelings and distinguishing them from the bodily sensations of emotion, (2) difficulty describing feelings to others, and (3) an externally orientated style of thinking. This study tested the three-factor model for the TAS-20, using confirmatory factor analysis, in separate samples of young adults from Germany, Canada, and the United States. The previously established three-factor model was found to be replicable in all three samples. In addition, the full TAS-20 and its three factors demonstrated adequate internal reliability in all three samples. Although evaluation of the convergent, discriminant, and criterion validity of the TAS-20 is required in diverse cultural groups, the present results provide evidence for the factorial validity and internal reliability of the TAS-20.     

Speech perception deficits in Parkinson's disease: underestimation of time intervals compromises identification of durational phonetic contrasts

Besides motor, vegetative, and cognitive signs, patients suffering from Parkinson's disease (PD) may show distinct perceptual deficits such as underestimation of time intervals extending across several seconds. Assuming this impairment also to affect the domain of tens of milliseconds, disrupted encoding of the acoustic speech signal with respect to segment durations conveying linguistic information must be expected. To test this hypothesis, 10 PD patients and matched controls performed an identification task using a series of 10 stimuli derived from the utterance "Boten" (/bo:tn/, 'messengers'; produced with nasal plosion) by exclusive manipulation of occlusion length (110-20 ms in steps of 10 ms). Under these conditions, word-medial silence cues the voicing category of the respective stop consonant. Seven PD subjects showed normal identification curves, i.e., categorized the shortest and longest stimuli with high probability each as the minimal pair cognates "Boden" and "Boten," respectively. In contrast, the remaining three patients labeled all items across the complete range of occlusion lengths as "Boden." A subsequent experiment found a horizontal shift of the identification curves toward larger signal durations (> 120 ms) in these three subjects. Bilateral cerebellar degeneration has been found to yield a different response pattern, i.e., near-chance level of performance. Considering recent information-processing models of scalar interval timing, striatal disorders seem to slow down an oscillatory pacemaker, whereas cerebellar dysfunctions may impair comparison of measured durations with stored reference memory traces.