Cluster analysis reveals distinct patterns of saccade impairment and their relation to cognitive profiles in Parkinson's disease

Saccade performance has been reported to be altered in Parkinson's disease (PD), however, with a large variability between studies as both motor and cognitive impairment interfere with oculomotor control. The aim of this study was to identify different patterns in saccade alterations in PD using a data-driven approach and to explore their relationship with cognitive phenotypes. Sixty-one participants with PD and 25 controls performed eye-tracking (horizontal and vertical prosaccades, antisaccades) and neuropsychological testing. Hierarchical cluster analysis was applied to the eye-tracking data to subsequently compare the clusters based on demographical, clinical and cognitive characteristics. The three identified clusters of saccade alterations differed in cognitive profiles from healthy controls, but not in PD-related motor symptoms or demographics. The rate of directive errors in the antisaccade task was increased in clusters 1 and 2. Further, cluster 1 was defined by a general disinhibition of reflexive saccades and executive dysfunction in the neuropsychological evaluation. In cluster 2, prolonged saccade latencies and hypometria were accompanied by multidomain cognitive impairment. The cluster 3 showed increased antisaccade latency and vertical hypometria despite lack of evidence for cognitive impairment. Our results suggest that there may be at least two opposing patterns of saccade alterations associated with cognitive impairment in PD, which may explain some of the contradictory results of previous studies.     

On assessing the validity of the main diagnosis in patient data bases: The impact of aims for making diagnosis

Computerized medical personal registers are created for administrative purposes but are frequently used in research. It can be shown that this divergence of aims deeply affects the validity of the diagnosis in register research. The diagnostic process is embedded within the process of creating the data base. This process is guided by the aims for making diagnosis. Five different aims for making diagnosis in clinical practice have been analysed and eight suggestions for validity control are proposed on the basis of the study.     

Explanation and interpretation of action

Contrary to what is usually taken for granted, the traditional positivistic and hermeneutic accounts of explanations of human actions do not really contradict one another. There is no logical or epistemological difference between explanations in this area and explanations in the natural sciences. However, if W. V. Quine and D. Davidson are right, there may be an ontological difference between the explanation of natural events and the interpretation of actions.     

New evidence on the nature of the encoding of action events

Differences in recall patterns between subject-performed tasks (SPTs) and verbal materials have been interpreted in terms of SPTs being nonstrategic or automatically encoded. In a series of three experiments, we tested this notion by comparing free recall of SPTs and sentences in conditions of'(1) nondivided versus divided attention for organizable items, (2) organizable versus nonorganizable items, and (3) nondivided versus divided attention for nonorganizable items. It was found that recall of both SPTs and sentences decreased in conditions of divided attention. A decrease in recall was also observed for both types of material when nonorganizable as compared to organizable materials were used. In addition, the degree of clustering was higher for SPTs than for sentences. These data suggest that there is a strategic component involved in the encoding of SPTs. We propose that the action elements of SPTs (e.g., motor features, shape, texture) are automatically encoded, whereas the verbal component is strategically encoded. It is emphasized that organization is an encoding strategy critical to SPT recall.     

The illness reframing process in an ethnic-majority population of older people with incurable cancer: variations of cultural- and existential meaning-making adjustments

Increasing numbers of older people in Western countries are living with incurable cancer as a chronic disease, receiving palliative care from specialised healthcare contexts. The study's aim was to understand variations of cultural- and existential meaning-making adjustments in a Norwegian majority population of older people with incurable cancer. Semi-structured interviews from 21 participants, aged 70–88, were analysed according to three identified types of belief frames: atheistic/humanistic, religious, and spiritual. Kleinman's medical anthropology cultural framework was adapted and applied deductively together with a reframing metaphor concept in a four-part analytic process. Independent of the differences among the types of belief frames and heterogeneous illness reframing processes, changes in the existential cultural dimension seemed to facilitate psychosocial adjustments in relation to illness, daily living, relationships, and surroundings. The results point to the need for collecting and assessing the function of this type of patient information for better understanding the patient's framework of interpretation, and for identifying treatment-planning resources.     

Good Enough for an Affair. Self‐Enhancement of Attractiveness,Interest in Potential Mates and Popularity as a Mate

Using data from the Berlin Speed Dating Study, we tested rival hypotheses concerning the effects of self‐enhancement of attractiveness on dating outcomes. Three hundred eighty‐two participants took part in one of the 17 speed‐dating sessions. After each speed‐dating interaction, participants indicated how interesting they found the respective person as a long‐term and short‐term partner. Using social relations analyses, we computed perceiver effects (being more or less choosy) and target effects (being rated as more or less interesting) of long‐term and short‐term partner ratings. Self‐enhancement was operationalized as the discrepancy between self‐rated attractiveness and four components of actual attractiveness (observer‐rated facial and vocal attractiveness, height and body mass index). Results indicated that self‐enhancers were less choosy with respect to their interest for short‐term partners, which was especially true for men, but more choosy with respect to long‐term partners. With regard to popularity as a mate, potential partners indicated that they found self‐enhancers more interesting as short‐term partners but not as long‐term partners. As self‐enhancement is a key component of narcissism, these results are consistent with findings that narcissists perceive many sexual affairs as an achievement, while preferring selected ‘trophy’ long‐term partners, and narcissists have a charming appeal for short‐term, but not lasting, social relationships. Copyright © 2015 European Association of Personality Psychology     

An application of the optic sphere theory in discrimination of slant with minimal information

In Johansson and Börjesson (1989), a new theory of visual space perception—the optic sphere theory—was presented in which the hemispheric shape of the retina is utilized for determination of slant of plane surfaces in wide-angle perception. The process of the optic sphere mechanism can be described as the projection of a translating distal line on the optic sphere, and an extrapolation of this projection to a great circle. The determination of the 3-D slant of the distal line is made by identification of points of no change on the great circle during its rotation. The main objective of the present study was to investigate this process as applied to central stimulation of the retina with reduced and minimal information of slant or horizontal orientation. Each stimulus pattern consisted of either two continuous lines or two pairs of dots in motion presented on a computer screen. The pairwise lines and the pairs of dots defined simulated 3-D slants (or horizontal orientations) of different magnitude within each pair, and the subjects' task was to discriminate between these simulated slants. It was shown that the simulations evoke percepts of 3-D slants, and of horizontal orientations, and that it is possible to discriminate between them even from minimal information (pairs of dots). Further, the empirical findings of Börjesson (1994) indicated that longer extrapolations of the projected arc to a point of no change yield less accurate discriminations of slant. We failed to replicate this in Experiment 4, in which case stimulus variables that covaried with extrapolation length were eliminated or minimized. It is suggested that this raises some doubt about discrimination accuracy as dependent on extrapolation length per se. The overall conclusion, however, is that the optic sphere theory represents a possible explanation of, or analogy to, the process utilized by the visual system for determination of the simulated 3-D slants and horizontal orientations in the present study.     

Gender differences in episodic memory

The relationship between gender and memory has been largely neglected by research, despite occasional studies reporting gender differences in episodic memory performance. The present study examined potential gender differences in episodic memory, semantic memory, primary memory, and priming. Five hundred thirty women and 470 men, randomly sampled from the city of Umeå, Sweden, 35–80 years of age, participated in the study. There were no differences between men and women with regard to age or education, or on a measure of global intellectual functioning. As has been demonstrated previously, men outperformed women on a visuospatial task and women outperformed men on tests of verbal fluency. In addition, the results demonstrated that women consistently performed at a higher level than did men on the episodic memory tasks, although there were no differences between men and women on the tasks assessing semantic memory, primary memory, or priming. The women’s higher level of performance on the episodic memory tasks could not be fully explained by their higher verbal ability.