Patterns of Human Interlimb Coordination Emerge from the Properties of Non-Linear,Limit Cycle Oscillatory Processes

The present article represents an initial attempt to offer a principled solution to a fundamental problem of movement identified by Bernstein (1967), namely, how the degrees of freedom of the motor system are regulated. Conventional views of movement control focus on motor programs or closed-loop devices and have little or nothing to say on this matter. As an appropriate conceptual framework we offer Iberall and his colleagues’ physical theory of homeokinetics first elaborated for movement by Kugler, Kelso, and Turvey (1980). Homeokinetic theory characterizes biological systems as ensembles of non-linear, limit cycle oscillatory processes coupled and mutually entrained at all levels of organization. Patterns of interlimb coordination may be predicted from the properties of non-linear, limit cycle oscillators. In a set of experiments and formal demonstrations we show that cyclical, two-handed movements maintain fixed amplitude and frequency (a stable limit cycle organization) under the following conditions: (a) when brief and constantly applied load perturbations are imposed on one hand or the other, (b) regardless of the presence or absence of fixed mechanical constraints, and (c) in the face of a range of external driving frequencies from a visual source. In addition, we observe a tight phasic relationship between the hands before and after perturbations (quantified by cross-correlation techniques), a tendency of one limb to entrain the other (mutual entrainment) and that limbs cycling at different frequencies reveal non-arbitrary, sub-harmonic relationships (small integer, subharmonic entrainment). In short, all the above patterns of interlimb coordination fall out of a non-linear oscillatory design. Discussion focuses on the compatibility of these results with past and present neurobiological work, and the theoretical insights into problems of movement offered by homeokinetic physics. Among these are, we think, the beginnings of a principled solution to the degrees of freedom problem, and the tentative claim that coordination and control are emergent consequences of dynamical interactions among non-linear, limit cycle oscillatory processes.     

Assessing Measurement and Predictive Invariance of the Toronto Alexithymia Scale–20 in U.S. Anglo and U.S. Hispanic Student Samples

We collected data from a predominately Anglo American student sample in the Southeastern United States and a predominately Hispanic student sample in the Southwestern United States. Along with an assessment of internal consistency reliability, we examined measurement invariance of the Toronto Alexithymia Scale–20 (TAS–20) using confirmatory factor analysis. We also assessed the predictive invariance of the TAS–20. Results indicate that 2 of the 3 TAS–20 subscales demonstrated satisfactory internal consistency reliability across samples. Items from the TAS–20 subscales demonstrated measurement invariance of the latent means. The relationship between 2 measures of emotional dysfunction and the TAS–20 also demonstrated slope and intercept invariance, indicating equivalent validity.     

Unpacking the Racial Disparity in Crime from a Racialized General Strain Theory Perspective

ABSTRACT

Criminologists have long theorized the relationship between race and crime using traditional criminological theories, suggesting that Blacks simply experience more factors conducive to crime than Whites. Race scholars have criticized this “add and stir” approach and, instead, argue for race-based explanations. Racialized General Strain Theory (RGST) is the first traditional approach to address this call to action. To date, however, little research has fully assessed RGST’s propositions. Using the Project on Human Development in Chicago Neighborhoods, we find mixed support for RGST. Findings also suggest racial differences in experiences and responses to strain are much more complicated than originally theorized.     

Which Source Possesses the Best Data on the Empirical Aspects of Criminal Events? A Theory of Opportunity and Necessary Conditions

ABSTRACT

Offenders and nonoffenders possess valuable information about crime. But which possesses the best data? This is a complex issue, so I narrow my focus to data on empirical aspects of criminal events. Drawing on the necessary conditions perspective, I theorize that a source’s possession 1) of data varies directly with its involvement in cases; 2) of representative data varies inversely with nonrandom involvement in cases and nonrandom siphoning off from the larger group to which it belongs; and, 3) of accurate data varies inversely with time since involvement in cases. Those general principles suggest that offenders, especially active ones, possess the most data, representative data, and accurate data on empirical aspects of criminal events. I conclude by discussing the implications of those general principles for observation research, sources’ possession of subjective data, and their possession of empirical data on other criminological events, specifically victimization and policing.     

Principles of Occupational Therapy Group Outcome Assessment in Mental Health

In today's penurious health care climate, occupational therapists must scrutinize their practice and substantiate their interventions in order to remain viable service providers. This article proposes a method of occupational therapy outcomes assessment in mental health care that is rooted in client-centered functional outcomes. Since little consensus exists on which instruments are most effective, this article begins with an outline of broadly accepted principles for assessment of patient outcomes in mental health. Next, we describe a practical method for selecting outcomes measures in interdisciplinary settings. Finally, we offer pragmatic solutions to address barriers to outcome assessment.     

Suppressor effects and age differences in the expression of anxious emotion

This study examined the role of suppressor effects on age differences in anxious emotion. Children and adolescents (n = 1099) ages 7–18 years were assessed for separation anxiety, social anxiety, and generalized anxiety. Results of zero-order correlations indicated a significant negative association between age and separation anxiety but no association for social anxiety and generalized anxiety. However, semi-partial correlations indicated the presence of a cooperative suppressor effect such that the associations between age and social anxiety as well as age and generalized anxiety symptoms became significant and positive and the association with separation anxiety became larger in a simultaneous regression analysis of each facet with age. Similar effects occurred when controlling for hyperarousal in an ANCOVA across grade levels. Results suggest that attempts to understand developmental differences in anxious emotion in childhood and adolescence will be facilitated by parsing facets of anxious emotion and attention to potential suppressor effects.     

The relationship between Revised Reinforcement Sensitivity Theory (rRST), handedness and indecision

Indecisiveness is an inability to make a decision, manifest across a number of behaviours. We explore the influence that both direction and strength of hand preference may have on this construct, examining it in relation to the revised Reinforcement Sensitivity Theory (rRST). Frost and Shows’ (1993) Indecisiveness Scale was administered to 328 undergraduates (221 females), alongside the Edinburgh Handedness Inventory (Oldfield, 1971) and Carver and White’s (1994) BIS/BAS scales. Simple correlations showed left-handers had a positive relationship between strength of handedness and BIS. In right-handers, strength and aversive indecision were positively correlated. Regression analysis demonstrated no significant relationship between hand strength and indecision, but that indecision was related to all three measures of rRST. Consistent with previous work, BIS was positively related to all indecision but particularly aversive, while BAS was negatively related to indecision but most strongly the avoidant category. We found that FFFS is more closely related to aversive than avoidant indecision. The relationship between rRST and indecision may be influenced by handedness; for right-handers the same pattern was found, but in left-handers BAS was not a significant predictor of indecision, BIS only predicted aversive indecision and FFFS predicted all three categories.     

Interracial Couples: Situational Factors in White Male Reactions

Two problems in the measurement of prejudice are the theoretical orientation underlying its measurement and the sensitivity of prejudice measures to social desirability. Most previous studies of prejudice have either not attempted to use sexual threat as a measurement model or have been plagued by other measurement problems. By introducing an unobtrusive procedure that overcomes those measurement problems, this study has tested a sexual-threat model as well as an incentive-conflict model. It was found that sexual threat does affect responses to interracial couples but that those responses are also affected by the value support that interracial couples provide for white norms, as predicted by incentive conflict.     

Facing being: the significance of Thomist ontological epistemology to realism in post-Kantian philosophy

The Kantian ‘Copernican Revolution’ contained in his Prologomena and The Critique of Pure Reason deemed metaphysical statements to be ‘transcendental illusions’, so directing metaphysics to its dearth. As a consequence, no longer could objects be known ‘in-themselves’ by the sensorily-reliant human. This perceived impossibility of metaphysical knowledge in the turn to the subject from Kant through Nietzsche's rejection of true knowledge has heavily inclined Continental Philosophy to an anti-metaphysical quandary. Analytic Philosophy is no different following the influence of Carnap, Wittgenstein and Rorty upon its own ‘linguistic turn’. An inevitable consequence of things not being knowable in themselves is the philosophical distance from ‘the world’, which Stephen Hawking has argued, makes the philosophical enterprise ‘dead’. In dialogue with this widespread decline in metaphysics, I will attempt to reclaim realist metaphysics through the employment of a Thomist paradigm. If philosophy is to be relevant to the knowledge economy, it is compelled to be in relation with what is. Thus, in my theoretical framework, being will be considered as central to all knowledge systems seeking to correspond to ‘hard’ science. The Thomist realist natural philosophy of ‘scientia’ – wherein truth is conformed with being – will be at the core of the argument. This paper challenges the ignoring of being because extant reality is composed of all that is, continuously faced and never evadable. Consequently, Thomism is recaptured as significant to post-Kantian philosophy as Aquinas articulated a means through which the thinking subject engages with being through sensation and cognition.     

That's disgusting! …, but very amusing: Mixed feelings of amusement and disgust

This study examines mixed feelings of amusement and disgust. Participants (N=102) reported their affect before and after watching a film clip depicting disgusting humour. While watching the clip participants were instructed to take the perspective of either an uninvolved observer or of the clip's protagonist. As expected this clip produced mixed feelings of amusement and disgust, and perspective moderated changes in affect and mixed feelings. Disgust increased equally in both conditions and amusement increased only in the observer condition. As a result mixed feelings of amusement and disgust were more intense in the observer condition. As the first study to demonstrate moderation of mixed feelings, this work adds to the extant literature on mixed feelings and has implications for emotion research.