Definition: To what extent does the study allow us to draw conclusions about a causal effect between two or more constructs? Issues: Selection, maturation, history, mortality, testing, regression towrd the mean, selection by maturation, treatment by mortality, treatment by testing, measured treatment variables Increase: Eliminate the threats, above all do experimental manipulations, random assignment, and counterbalancing.

Reliability and validity

http://www.40hz.net/engel_2010_curr_opin.pdf

Beta-band oscillations--signalling the status quo?

In this review, we consider the potential functional role of beta-band oscillations, which at present is not yet well understood. We discuss evidence from recent studies on top-down mechanisms involved in cognitive processing, on the motor system and on the pathophysiology of movement disorders that suggest a unifying hypothesis: beta-band activity seems related to the maintenance of the current sensorimotor or cognitive state. We hypothesize that beta oscillations and/or coupling in the beta-band are expressed more strongly if the maintenance of the status quo is intended or predicted, than if a change is expected. Moreover, we suggest that pathological enhancement of beta-band activity is likely to result in an abnormal persistence of the status quo and a deterioration of flexible behavioural and cognitive control.

https://www.healio.com/psychiatry/journals/psycann/1976-12-6-12/{806b8887-c02e-40c8-a228-57f1cdb2bdba}/the-stress-of-life.pdf

The stress of life

Contemporary Sociology 7(5) (September 1978):566—68. When the intellectual history of our times comes to be written, that peculiarly Left Bank mixture of Marxism and structuralism now in fashion will be among the most puzzlingofourideastoevaluate.Aliteral “archeology of knowledge” (the title of one of Foucault’s earlier books) will be required to sort out the valuable from the obvious rubbish. I suspect that in this exercise the iconographers of the present (like Barthes) will fare less well than those who have read the past. Of such “historians” (a description which does not really cover his method) Foucault is the most dazzlingly creative. Discipline and Punish (which, shamefully, has taken over two years to be translated into English) follows Madness and Civilization (1961) and The Birth of the Clinic (1971) as the next stage in Foucault’s massive project of tracing the genealogy of control institutions (asylums, teaching hospitals, prisons) and the human sciences symbiotically linked with them (psychiatry, clinical medicine, criminology, penology). His concern throughout is the relationship between power and knowledge, the articulation of each on the other. Here (as he makes explicit in an interview recently published in the English journal, Radical Philosophy) he opposes the humanist position that, once we gain power, we cease to know——it makes us blind—— and that only those who keep their distance from power, who are no way implicated in tyranny, can attain the truth. For Foucault, such forms of knowledge as psychiatry and criminology (with its “garrulous discourses” and “intermidable [sic] repetitions”) are directly related to the exercise of power. Power itself creates new objects of knowledge and accumulates new bodies of information. Thus to “liberate scientific research from the demands of monopoly capitalism” can only be a slogan. Placing such programmatic Big Issues on one side, though, a superficial first reading of the book mightstartatthelevelofitssubtitle, “The Birth of the Prison.” The key historical transition——at the end of the eighteenth century——is from punishment as torture, a public spectacle, to the more economically and politically discreet prison sentence. The body as the major target of penal repression disappears: within a few decades, the grisly spectacles of torture, dismemberment, exposure, amputation, and branding are over. Interest is transferred from the body to the mind; a coercive, solitary, and secret mode of punishment replaces one that was representative, scenic, and collective. Gone is the liturgy of torture and execution, where the triumph of the sovereign was symbolized in the processions, halts at crossroads, public readings of the sentence even after death, where the criminal’s corpse was exhibited or burnt. In its place comes a whole technology of subtle power. When punishment leaves the domain of more or less everyday perception and enters into abstract consciousness, it does not become less effective. But its effectiveness arises from its inevitability not its horrific theatrical intensity. The new power is not to punish less but to In Retrospect: 1978 29

https://journals.sagepub.com/doi/pdf/10.1177/0094306118815499a

Discipline and Punish: The Birth of the Prison:

Mixed methods research is viewed as the third methodological movement and as an approach it has much to offer health and social science research. Its emergence was in response to the limitations of the sole use of quantitative or qualitative methods and is now considered by many a legitimate alternative to these two traditions. Purists’ view of the dichotomy between positivist and non-positivist philosophies is prevalent; however, mixed methods afford researchers an opportunity to overcome this ‘false dichotomy’. The philosophical underpinning of pragmatism allows and guides mixed methods researchers to use a variety of approaches to answer research questions that cannot be addressed using a singular method. In particular, healthcare researchers may benefit from the opportunity to use such a dynamic approach to address the complex and multi-faceted research problems often encountered in the health care sector.

An overview of mixed methods research

Oscillations in local field potentials in the β-frequency band (13-35 Hz) are a pervasive feature of human and nonhuman primate motor cortical areas. However, the function of such synchronous activity across populations of neurons remains unknown. Here, we test the hypothesis that β activity may promote existing motor set and posture while compromising processing related to new movements. Three experiments were performed. First, healthy subjects were instructed to make reaction time movements of the outstretched index finger in response to imperative cues triggered by transient increases in corticospinal synchrony, as evidenced by phasic elevations of β-frequency band microtremor and intermuscular synchrony. Second, healthy subjects were instructed to resist a stretch to the index finger triggered in the same way. Finger acceleration in the reaction time task and transcortical components of the stretch reflex were measured and compared with those elicited by random cue or stretch presentation. Finally, we sought a correlation between finger acceleration in the reaction time task and cortical synchrony directly measured from the electrocorticogram in two patients undergoing functional neurosurgery. We demonstrate that movements are slowed and transcortical responses to stretch are potentiated during periods of elevated β-band cortical synchrony. The results suggest that physiological periods of β synchrony are associated with a cortical state in which postural set is reinforced, but the speed of new movements impaired. The findings are of relevance to Parkinson's disease, in which subcortical and cortical β-band synchronization is exaggerated in the setting of increased tone and slowed movements.

https://www.jneurosci.org/content/jneuro/25/34/7771.full.pdf

Existing motor state is favored at the expense of new movement during 13-35 Hz oscillatory synchrony in the human corticospinal system

BackgroundQualitative descriptive designs are common in nursing and healthcare research due to their inherent simplicity, flexibility and utility in diverse healthcare contexts. However, the applic...

An overview of the qualitative descriptive design within nursing research

Excessive synchronization of neural activity in the beta frequency band ( approximately 20 Hz) within basal ganglia circuits might contribute to the paucity and slowness of movement in Parkinson's disease (PD). Treatment with dopaminergic drugs reduces the background level of beta frequency band synchronization in the subthalamic nucleus (STN), but has not been shown to increase the proportion of beta activity that is suppressed before voluntary movement in PD. We assessed changes in the event-related desynchronization (ERD) in the beta frequency band of local field potential signals from the region of the STN in 14 patients with PD as they performed self-paced movements of a joystick before and after levodopa administration. The dopamine precursor, levodopa, increased the duration and magnitude of the premovement beta ERD, but did not alter postmovement synchronization in the beta band. Both the latency and magnitude of the beta ERD inversely correlated with the degree of motor impairment. These findings suggest that the beta ERD recorded in the STN area reflects motor-preparative processes that are at least partly dependent on dopaminergic activity within the basal ganglia.

Levodopa-induced modulation of subthalamic beta oscillations during self-paced movements in patients with Parkinson's disease.

Activation of the basal ganglia has been shown during the preparation and execution of movement. However, the extent to which the activation during movement is related to efferent processes or feedback-related motor control remains unclear. We used motor imagery (MI), which eliminates peripheral feedback, to further investigate the role of the subthalamic area in the feedforward organization of movement. We recorded local field potential (LPF) activity from the region of the subthalamic nucleus (STN) in eight patients with Parkinson's disease off dopaminergic medication during performance of a warned reaction time task. Patients were instructed to either extend the wrist [motor execution (ME)], to imagine performing the same task without any overt movement (MI), or, in a subgroup, to perform a non-motor visual imagery (VI) task. MI led to event-related desynchronization (ERD) of oscillatory beta activity in the region of the STN in all patients that was similar in frequency, time course and degree to the ERD occurring during ME. The degree of ERD during MI correlated with the ERD in trials of ME and, like ME, was accompanied by a decrease in cortico-STN coherence, so that STN LFP activity during MI was similar to that in ME. The ERD in ME and MI were both significantly larger than the ERD in VI. In contrast, event-related synchronization (ERS) was significantly smaller in trials of MI, and even smaller in trials of VI, than during ME. The data suggest that the activity in the region of the human STN indexed by the ERD during movement is related to the feedforward organization of movement and is relatively independent of peripheral feedback. In contrast, sensorimotor feedback is an important factor in the ERS occurring in the STN area after completion of movement, consistent with a role for this region in trial-to-trial motor learning or the re-establishment of postural set following movements.

/pdf/modulation-of-beta-oscillations-in-the-subthalamic-area-vhhls5jyf0.pdf

Louise Doyle

Papers

An overview of mixed methods research

Existing motor state is favored at the expense of new movement during 13-35 Hz oscillatory synchrony in the human corticospinal system

An overview of the qualitative descriptive design within nursing research

Levodopa-induced modulation of subthalamic beta oscillations during self-paced movements in patients with Parkinson's disease.

Modulation of beta oscillations in the subthalamic area during motor imagery in Parkinson's disease