LSTM-CNN: An efficient diagnostic network for Parkinson's disease utilizing dynamic handwriting analysis

BACKGROUND AND OBJECTIVES

Dynamic handwriting analysis, due to its noninvasive and readily accessible nature, has emerged as a vital adjunctive method for the early diagnosis of Parkinson's disease (PD). An essential step involves analysing subtle variations in signals to quantify PD dysgraphia. Although previous studies have explored extracting features from the overall signal, they may ignore the potential importance of local signal segments. In this study, we propose a lightweight network architecture to analyse dynamic handwriting signal segments of patients and present visual diagnostic results, providing an efficient diagnostic method.

METHODS

To analyse subtle variations in handwriting, we investigate time-dependent patterns in local representation of handwriting signals. Specifically, we segment the handwriting signal into fixed-length sequential segments and design a compact one-dimensional (1D) hybrid network to extract discriminative temporal features for classifying each local segment. Finally, the category of the handwriting signal is fully diagnosed through a majority voting scheme.

RESULTS

The proposed method achieves impressive diagnostic performance on the new DraWritePD dataset (with an accuracy of 96.2%, sensitivity of 94.5% and specificity of 97.3%) and the well-established PaHaW dataset (with an accuracy of 90.7%, sensitivity of 94.3% and specificity of 87.5%). Moreover, the network architecture stands out for its excellent lightweight design, occupying a mere 0.084M parameters, with only 0.59M floating-point operations. It also exhibits nearly real-time CPU inference performance, with the inference time for a single handwriting signal ranging from 0.106 to 0.220 s.

CONCLUSIONS

We present a series of experiments with extensive analysis, which systematically demonstrate the effectiveness and efficiency of the proposed method in quantifying dysgraphia for a precise diagnosis of PD.

Transforming fatigue assessment: Smartphone-based system with digitized motor skill tests

BACKGROUND

The condition of fatigue is a complex and multifaceted disorder that encompasses physical, mental, and psychological dimensions, all of which contribute to a decreased quality of life. Smartphone-based systems are gaining significant research interest due to their potential to provide noninvasive monitoring and diagnosis of diseases.

OBJECTIVE

This paper studies the feasibility of using smartphones to collect motor skill related data for machine learning based fatigue detection. The authors' main goal is to provide valuable insights into the nature of fatigue and support the development of more effective interventions to manage it.

METHODS

An application for smartphones running on Android OS is developed. Two aim-based reaction tests, an Archimedean spiral test, and a tremor test, were assembled. 41 subjects participated in the study. The resulting dataset consists of 131 trials of fatigue assessment alongside digital signals extracted from the motor skill tests. Six machine learning classifiers were trained on computed features extracted from the collected digital signals.

RESULTS

The collected dataset SmartPhoneFatigue is presented for further research. The real-world utility of this database was shown by creating a methodology to construct a fatigue predictive model. Our approach incorporated 60 distinct features, such as kinematic, angular, aim-based, and tremor-related measures. The machine learning models exhibited a high degree of prediction rate for fatigue state, with an accuracy exceeding 70%, sensitivity surpassing 90%, and an f1-score greater than 80%.

CONCLUSION

The results demonstrate that the proposed smartphone-based system is suitable for motion data acquisition in non-controlled environments and shows promise as a more objective and convenient method for measuring fatigue.

Studies in the Mentality of Literates: 3. Conceptual Structure and Nonsense of Personality Testing

In this study, third in a series of studies of the relationships between the dominant type of the Word Meaning Structure (WMS) and various psychic processes, response patterns on personality questionnaires with Likert-type response format of individuals with different levels of education (including adult illiterates) in Brazil (N = 102) and in Estonia (N = 520) were assessed with person oriented methods of data analysis. We found that responses to two personality questionnaires (International Personality Item Pool Questionnaire, IPIP-Q60 and Estonian Collectivism Scale, ESTCOL) are inconsistent and do not correspond to theories that underlie construction and interpretation of such assessment tools. Two novel ways to assess inconsistent response patterns were developed. The Consistency Index (CI) characterizes between-item inconsistency and the Determinacy Index (DI) characterizes within-item inconsistency. The dominant type of the WMS and the level of education were related to both CI and DI. Higher level of between-item inconsistency characterizes everyday conceptual thinkers with lower levels of education and higher level of within-item inconsistency was observed among logical conceptual thinkers with higher levels of education. Systematic relationships between WMS and inconsistent patterns of responses indicate that responses on personality questionnaires cannot be interpreted in terms of personality characteristics. The results of our study also provide further support to the idea that dominant type of the WMS is a pervasive characteristic of the psyche and determines qualitatively possibilities and limits of the psychic processes. The results of this study are in agreement with the idea that WMS defines the "Great Divide."

Studies in the mentality of literates: 2. Conceptual structure, cognitive inhibition and verbal regulation of behavior

We studied cognitive inhibitory processes and verbal regulation of behavior of individuals with different levels of education (including adult illiterates) in Brazil (N = 136) and in Estonia (N = 560) with person-oriented methods of data analysis. Our aim was to discover whether dominant type of word meaning structure (WMS) can define the "Great Divide", the single breaking point that universally defines certain direction of subsequent to it cultural evolution. We found that both cognitive inhibition of irrelevant for the task at hand information or actions as well as correct activation of relevant information or actions is significantly more common in individuals who rely predominantly on logical concepts in their thinking. The higher level of education was also associated with more efficient cognitive inhibition and activation. The patterns of test performance also suggest that there can be a qualitative difference in the efficiency of cognitive inhibition-activation processes between everyday conceptual and logical conceptual thinkers. The former group of individuals may achieve much higher performance levels than any individual in the former group. We also discuss cognitive similarities and differences between adults with low or no formal education on the one hand and children and educated adults with brain damage on the other. The results are in agreement with the theory of unilineal hierarchic cultural evolution. Individual psychic development and cultural evolution can be both understood in terms of the WMS development.

Studies in the Mentality of Literates: 1. Conceptual Structure and Aspects of Visual Perception

We studied visual-perceptual abilities of individuals with different levels of education (including adult illiterates) in Brazil (N = 136) and in Estonia (N = 560) with person-oriented methods of data analysis. Our aim was to discover whether dominant type of word meaning structure (WMS) can define the "Great Divide", the single breaking point that universally defines certain direction of subsequent to it cultural evolution. We particularly focused on the everyday concept-logical concept shift that takes place in the formal education system. We found that logical concepts were rarely available for illiterates; availability of logical conceptual thought increases together with the level of education. Most illiterates were able to find figures of concrete objects from complex overlapping and embedded contour figures but none of them could find all abstract figures from the same complex figures. Also none of the illiterates could perform beyond chance level in both mental rotation tasks together. Ability to perform correctly on all visual-spatial tasks increased with the increase in logical concepts and with the increasing level of education. The distribution of respondents according to the WMS level, level of education, and performance on the visual-spatial tasks indicated that individuals are developmentally heterogeneous: achievement of the tertiary level of education and logical conceptual thinking mechanisms does not guarantee high level performance on the visual-spatial tasks. The results are in agreement with the theory of unilineal hierarchic cultural evolution. Individual psychic development and cultural evolution can be both understood in terms of the WMS development.

Studies in the Mentality of Literates: Searching for the Cultural Great Divide at the Individual Level of Analysis

Today it is usually agreed that cultures are different but no culture is more developed than some other. It follows that culture did not develop hierarchically. Otherwise some cultures must be more developed than the others. This position, however, contradicts ample evidence that individual mental development is hierarchical. As culture can develop only on the basis of individual development, cultural development has to be hierarchical too. In this paper a research program to study cultural and individual development in one framework is outlined. Particularly it is discussed whether it is possible to define a Great Divide, a characteristic that would distinguish more developed cultures from less developed cultures today. Both literacy and formal education are rejected as candidates for a Great Divide. Then, following and extending Vygotsky's theory, it is demonstrated that a Great Divide can be defined in terms of the development of word meaning structure (WMS). A novel theory of the development of WMS over five hierarchical stages is shortly described and it is suggested that both individuals and cultures develop over the same stages in invariant order. Particularly differences between everyday and logical (or "scientific" in Vygotsky's terms) concepts are discussed. It is theoretically explained how study of adult individuals can be used to support the presented theory of developmental similarities between cultures and individuals. Specific hypotheses for the study are put forward.

Why Behavioral Indicators May Fail to Reveal Mental States: Individual Differences in Arousal-Movement Pattern Relationships

It is commonly assumed that behavior reflects the mental states of individuals. However, recent attempts to detect human states of mind via behavioral indicators have not always been successful; behavioral indicators may be unreliable and invalid. In this study we show that one of the common behavioral indicators, change in the overall amount of movement, correlated well with changes in the skin conductance level (SCL) at the group level, which reflects changes in arousal. At the individual level, however, changes in the SCL were related to movement patterns only in about half of the individuals. It is also noteworthy that the level of movement-SCL correlation was very highly predictable by certain social and cognitive characteristics of the individuals. Our results suggest that behavioral indicators may in many cases fail to predict mental states at the individual level.

Drawing as a verbally mediated activity: A study of relationships between verbal, motor, and visuospatial skills and drawing in children

The present studies analysed drawing as a system rather than a unitary ability. The aim was to investigate whether and which language factors influence drawing performance and drawing development. In two studies of 2- to 11-year-old children drawing as a system of components was investigated. Tests were designed to measure motor output, imagery, memory, perception, and verbal abilities. The analysis of relationships between drawing measures and putative components of a drawing system revealed that all of the proposed components independently affected drawing development. Results of analyses of the data from younger and older children separately suggest that different components of a system are crucial for drawing development at different phases of development.

Activity Theory Is a Dead End for Cultural-Historical Psychology

In this article, activity theory is analysed. Specific examples for the analysis are taken from Ratner’s (2000) article on emotions. It is concluded that activity theory in general and Ratner’s approach in particular are deficient at three different levels of analysis: from a general theoretical approach to the study of mind to specific details of how particular mental phenomena and their development are studied. Reasons are proposed for why activity theory in principle cannot solve those deficiencies. It is proposed that Vygotsky’s cultural-historical psychology may be more suitable for understanding the human mind and its genesis.

How Should Culture be Studied?

What should be studied in order to understand culture depends on how culture is defined. Different definitions imply different methods and research questions. Sneddon (2003) suggests that, to understand culture, it is necessary to study cultural activities, tacit and explicit representations. I propose that Sneddon's account is incomplete; there are more than only two kinds of representations that should be differentiated. In addition, there is no way to study representations without studying activities. Thus, it is necessary to understand what kinds of representations can be studied through different activities. I also draw attention to communication, which is not just another cultural activity, but rather a very special social-cultural activity through which limits of sensory-based information processing can be transcended.

How Culture Transforms Mind: A Process of Internalization

In this article a new definition of internalization is proposed, according to which internalization is a process whereby two different mechanisms of information processing, non-verbal ('sensory') thinking and conventional language, that have been differentiated from the 'natural' processes in the course of development become united within a new mental structure. The result of internalization is the development of semiotically mediated, 'cultural' mental operations. Components of the definition, the concept of a structure, of dynamicity (development), of natural and cultural processes, and of semiotic mediation are discussed in relation to one another. The result allows the conceptualization of what makes human environments specific so that only that environment is sufficient for the development of human mind; and what makes human children specific so that only they take advantage of what the human environment affords in a manner not attainable by other animal species.

What Characterizes Language That Can Be Internalized: A Reply to Tomasello

Tomasello disagrees with my position that language is the only human artefact that potentiates internalization. Tomasello's position seems to imply that language can be only verbal. My position is that every object or behavioural act is a symbol if it has all of the following characteristics: symbol must be an object or phenomenon that can be directly perceived through sense organs; meaning of symbols must be shared by organisms; symbols must refer to objects, events or phenomena; it must be possible to use a symbol differently from its referents. Internalization is possible only by means of symbols with such characteristics.

Vygotsky's theory on the Procrustes’ bed of linear thinking: Looking for structural–systemic Theseus to save the idea of ‘social formation of mind’

Today Vygotsky's theory is usually associated with a short list of ideas: which includes social formation of the human mind, zone of proximal development, semiotic mediation, and egocentric and inner speech. Vygotsky's theory contains these and many other ideas indeed. In today's interpretation, however, all the mentioned ideas are transformed into slogans with trivial content or even into a set of statements that contradict many facts known about the functioning of the human body and human mind. Vygotsky relied explicitly on epistemology I have called structural–systemic. According to this epistemology, in order to understand human mind scientifically, its structure needs to be discovered. The studies need to reveal the elements from which the mind is composed, the specific relationships between the elements, and qualities of the whole that emerges in the synthesis of the elements. Only developmental studies can answer these questions because the properties of the elements change when integrated into a whole. His epistemology can be opposed to that dominant today, which aims only to the discovery of relationships between events, to the discovery of “causes” that make the “effect” to happen. In Vygotskian structural–systemic perspective, the same theoretical ideas acquire meanings very different from modern interpretations.

Relationships between visual figure discrimination, verbal abilities, and gender

This study investigated the relationships between verbal thinking and performance on visual figure discrimination tasks from a Vygotskian perspective in a large varied adult sample (N = 428). A test designed to assess the structure of word meanings (ie tendency to think in 'everyday' or 'scientific' concepts as distinguished by Vygotsky) together with two contour picture tasks was presented. Visual tasks were a modified version of Poppelreuter's overlapping figures and a picture depicting a meaningful scene. On both tasks concrete objects and abstract meaningless shapes had to be identified. In addition to relationships between visual task performance and word meaning structure, the effects of the meaningful scene and relations with gender were examined. The results confirmed the expected relation between word meaning structure and visual performance. Furthermore, they suggested a specific effect of the meaningful whole and a male advantage, especially for the first task in which women seemed to benefit less from advanced word meaning structure.

Quantitative methods in psychology: inevitable and useless

Science begins with the question, what do I want to know? Science becomes science, however, only when this question is justified and the appropriate methodology is chosen for answering the research question. Research question should precede the other questions; methods should be chosen according to the research question and not vice versa. Modern quantitative psychology has accepted method as primary; research questions are adjusted to the methods. For understanding thinking in modern quantitative psychology, two epistemologies should be distinguished: structural-systemic that is based on Aristotelian thinking, and associative-quantitative that is based on Cartesian–Humean thinking. The first aims at understanding the structure that underlies the studied processes; the second looks for identification of cause–effect relationships between the events with no possible access to the understanding of the structures that underlie the processes. Quantitative methodology in particular as well as mathematical psychology in general, is useless for answering questions about structures and processes that underlie observed behaviors. Nevertheless, quantitative science is almost inevitable in a situation where the systemic-structural basis of behavior is not well understood; all sorts of applied decisions can be made on the basis of quantitative studies. In order to proceed, psychology should study structures; methodologically, constructive experiments should be added to observations and analytic experiments.

Coping strategies, social support, life orientation and health-related quality of life following traumatic brain injury

OBJECTIVE

To study coping strategies, social support and life orientation in patients following moderate and severe traumatic brain injury (TBI) in relation to health-related quality of life.

SUBJECTS

Eighty-five patients with moderate or severe TBI and 68 control persons.

METHODS

Estonian versions of the COPE-D test, the Brief Social Support Questionnaire, the Life Orientation Test and the RAND-36 questionnaire.

RESULTS

Persons with TBI reported using task-oriented and social/emotional support strategies less often and avoidance-oriented strategies more often than control persons (p < 0.05). The social support network, satisfaction with it and optimism as life orientation were lower in the patient group (p < 0.05). Task-oriented coping styles, satisfaction with social support and optimistic life orientation were associated with the majority of the domains of health-related quality of life and resuming work after TBI.

CONCLUSIONS

To achieve effective rehabilitation and to enhance patients' well-being, it is important to improve the quality and amount of social support network, as well as to support patients' adequate coping efforts for promoting an active lifestyle.

Changes in coping strategies, social support, optimism and health-related quality of life following traumatic brain injury: A longitudinal study

PRIMARY OBJECTIVE

To study longitudinal changes in psychological coping strategies, social support, life orientation and health-related quality of life in the late period after traumatic brain injury (TBI).

SUBJECTS

Thirty-one patients with TBI who were first investigated on average 2.3 years after injury and were prospectively followed on average 5.7 years later.

METHODS

Estonian versions of the COPE-D Test, the Brief Social Support Questionnaire, the Life Orientation Test and the RAND-36 questionnaire.

RESULTS

During the late follow-up period health-related quality of life and resuming work did not improve significantly. Persons with TBI reported an increase in seeking social/emotional support (p<0.05), frequent use of avoidance-oriented styles and reduced use of task-oriented styles. This was accompanied by low social support and low satisfaction with support, both of which were associated with health-related quality of life and resuming work after TBI. Although the patients had become more optimistic (p<0.05), this did not correlate with their health status and social well-being.

CONCLUSIONS

This prospective study revealed maladaptive changes in the profile of coping strategies and an increase in optimism. As social support, satisfaction with support and health-related quality of life did not improve, then rehabilitation, social and psychological support are continuously needed.

Commentary: Activity Theory is a Dead End for Methodological Thinking in Cultural Psychology Too

Reworking cultural psychology's methodology is of utmost importance if the discipline is to progress. This paper explores discussion of micro- and macro-cultural formal and informal methodologies of cultural psychology by Carl Ratner. It is concluded that the activity-theoretical approach to research methodology, applied in the target article, is fundamentally limited and cannot suggest appropriate methodologies that would lead to progress in cultural psychology. Instead, it is suggested that future discussions on methodological thinking should take into account that: (1) methodology is part of a scientific theory, and therefore what is studied must be defined in order to find appropriate methods for studies; (2) qualitative methodology should become the focus of methodology in cultural psychology; (3) the history of psychology contains forgotten but theoretically very rich ideas; and (4) activity theory has fundamental problems which make it inappropriate for showing direction for the development of methodology.

Commentary: Vygotskian Cultural-Historical and Sociocultural Approaches Represent Two Levels of Analysis: Complementarity Instead of Opposition

Matusov distinguishes two usually counterposed modern schools of psychology that stem from Vygotsky's theory, the sociocultural and cultural-historical. I suggest that the sociocultural approach is fundamentally deficient in ignoring a need for cognitive analysis and not taking seriously the notion of hierarchical development. Problems that arise from the acognitive-adevelopmental position of the sociocultural approach are analyzed in respect of three issues: ethnocentrism, the natural-cultural line of development, and testing in education. The cultural-historical approach, in turn, is deficient in ignoring cultural diversity and the content of the psyche. The superficially opposed sociocultural and cultural-historical Vygotskian schools complement each other if it is realized that both schools represent different levels of analysis.

Sometimes one is more than two: when collaboration inhibits knowledge construction

In this paper I suggest that to better understand knowledge construction in science, and the role of social processes and collaboration in it, it is useful to distinguish between "elaborative knowledge" and "emergent knowledge." Elaborative knowledge is constructed for solving clearly defined problems in established theoretical frameworks, and emergent knowledge refers to the knowledge constructed to reach a hierarchically higher and more complex level of scientific understanding. There are also two types of collaboration. On the one hand there is "dialogical collaboration" in which team members contribute to reaching the common clearly defined objective so that a team as a whole becomes qualitatively more complex than its members alone. On the other hand there is "unidirectional collaboration" where the result of collaboration is determined by one person, should be distinguished. There is evidence from multiple perspectives indicating that "elaborative knowledge" can be developed in both kinds of collaboration and sometimes 'dialogical collaboration" is necessary for knowledge construction. However, for building "emergent knowledge," it is argued, only individual or "unidirectional collaboration" is productive, and "dialogical collaboration" can hinder or even prevent the construction of this kind of knowledge.

Possible interpretation of subjective complaints in patients with spontaneous subarachnoid haemorrhage

OBJECTIVE

To analyse factors related to subjective non-cognitive and cognitive complaints in patients with spontaneous subarachnoid haemorrhage.

SUBJECTS

Twenty-seven patients with subarachnoid haemorrhage and 27 age-, sex- and education-matched healthy controls.

METHODS

A battery of cognitive tests measuring visuo-spatial abilities, verbal abilities, and fine-motor skill, Brief Social Support Questionnaire, and Life Orientation Scale were individually presented to all participants.

RESULTS

Cognitive complaints were related to low social support but not to cognitive performance. Complaints about headaches and dizziness were also related to decreased cognitive performance. Above-normal optimistic life-orientation was related to the absence of complaints in patients with subarachnoid haemorrhage. Healthy participants were best discriminated from patients with subarachnoid haemorrhage by less satisfactory social support system and decreased fine motor skills in the latter group.

CONCLUSION

Change in social support network may be an important resource for increasing quality of life in patients with subarachnoid haemorrhage not only through help provided by supporters but also indirectly, through increasing subjective well-being. The absence of subjective complaints in patients with subarachnoid haemorrhage is not necessarily related to better objective condition but rather to inadequately optimistic life orientation.

Relationships between personality structure, structure of word meaning, and cognitive ability: A study of cultural mechanisms of personality

Native-born Estonian men (N=912), 17-68 years old, participated in a study on relationships between personality characteristics, dominant structure of word meaning ("everyday concepts" thinking or "scientific concepts" thinking), and level of cognitive ability. Individuals who primarily used everyday concepts thinking or who possessed relatively low levels of cognitive ability did not reveal a coherent Big Five personality structure, whereas individuals who primarily used scientific concepts thinking or possessed high levels of cognitive ability did. Thus, personality may be shaped by a cultural factor--word meaning structure. Earlier studies, which seem to support the idea that Big Five personality structure is a biologically determined human universal, suffer from serious sampling problems and insufficient data analyses.

Coping strategies in patients following subarachnoid haemorrhage

OBJECTIVES

To assess psychological coping strategies and their relationship with outcome in patients after primary subarachnoid haemorrhage (SAH).

PATIENTS AND METHODS

In 51 unselected patients (24 males, 27 females; mean age 46 years) in an average 15.7+/-12.0 months after SAH usage of coping strategies were assessed by means of Estonian COPE-D test with 15 four-items scales and compared to those obtained from 51 age-, sex- and education-matched healthy persons. The data were analysed according to age, sex and education of the patients, initial severity of disease, localization of aneurysm and outcome characteristics.

RESULTS

Patients after SAH reported using social support strategy less than control persons (P<0.05) with a tendency of using acceptance-oriented strategy. Task-oriented coping styles were less used (P<0.05) by patients with severe initial state, who had more marked late disability and dependence in daily living. Healthy women used social support more than men; patients and control persons 50 years or older used task-oriented strategies less than younger persons (P<0.05).

CONCLUSION

The structure of coping strategies used by patients after SAH differs compared to healthy persons. The differences in using coping strategies are related to age of the patients, functional state and degree of adaptation after SAH.

Paradoxical facilitation of a free recall of nonwords in persons with traumatic brain injury

Brain damage is usually associated with behavioral deficits. However, there is an increasing amount of evidence that lesions of some brain regions are associated with improvements instead of impairments of certain behaviors. We report the results of a study of free recall performance in subjects with traumatic brain injury. One-fourth of the subjects displayed above-normal performance in recall of nonwords. No such facilitation was found with nine lists of words.