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Biomedical subjects

J R Skoyles

Publications and source records attributed to J R Skoyles.

13 recordsLinked to original sources
PubMed2002

Is autism due to cerebral-cerebellum disconnection?

Autism has been linked to thalidomide exposure at 20-24 days gestation. At this stage, the embryo is roughly the size of this 'C', and has yet to develop its brain (except for brainstem cranial motor nerve nuclei). The neuropathology responsible for autism is presently unknown, but whatever it is, it must logically be one that can be induced by such an early occurring brainstem cranial motor nerve nuclei defect. Many mental faculties impaired in autism (such as theory of mind) depend upon the prefrontal cortex. The maturation of cerebral-cerebellar connections, due to oddities in axon development, is vulnerable to pre-existing brainstem nuclei integrity. Many higher cognitions (including prefrontal ones) are dependent upon these links raising the possibility that abnormalities in them might produce autism. I conjecture that impaired cerebral-cerebellar connections, whether caused early, as by thalidomide, or later (including postnatally) by other factors, is the missing neuropathological cause of autism.

Animals↗
PubMed1998

Speech phones are a replication code.

Our ability to map sound into pronunciation--vocal imitation--is necessary for vocabulary learning, and so the existence of language. It is also unexplained. Here I show that speech is imitable due because of the brain's use of the innate sensitivities of the vertebrate auditory system for speech motor targets. Their public nature enables speech to transmit articulation information. These units I suggest closely link with phones, the minimal unit of speech segmentation. The conjecture that phones function as a replicative code removes five unexplained anomalies in language science: (i) why nearly eight hundred phones exist but any language uses only a tiny subset of them (evolutionarily this makes no sense); (ii) why newborn infants hear phones of all languages; (iii) why animals also hear them; (iv) why the Wernicke's and Broca's areas arose from homologous areas in primates which process imitation, and why (v) in humans these areas process nonspeech imitation.

Animals↗
PubMed1998

Motor perception and anatomical realism in Classical Greek art.

The rise of anatomical realism in sculpture with the Classical Greeks puzzles art historians. Recently, it has been discovered that the motor cortex perceives motor actions. I argue that Classical artists discovered a new aesthetic based on using art to stimulate not just, as previously, the visual cortex, but also the motor one.

Anatomy↗
PubMed1997

Evolution's 'missing link': a hypothesis upon neural plasticity, prefrontal working memory and the origins of modern cognition.

Many activities such as reading, mathematics and chess depend upon cognitive processes which arose after our evolution. Why could they arise if not evolved? I argue four things fortuitously came together to make our nonevolved cognitive skills possible: (i) neural plasticity; (ii) large functionally uncommitted prefrontal, temporal and parietal cerebral cortices; (iii) the ability of their neural circuits (due to neural plasticity), if trained, to take on novel symbolic and nonsymbolic skills; and (iv) a large prefrontal cortex which could use its working memory as a tuition management sketch pad in which to train them. Pre-evolved for other reasons, these four (together with invented symbolic systems and technology) together enable modern humans to 'upgrade' our already evolved cognitive skills to do new and nonevolved things.

Animals↗
PubMed1994

Disposition of milrinone in patients after cardiac surgery.

We have evaluated the disposition of milrinone in seven patients with low cardiac output after elective cardiac surgery involving cardiopulmonary bypass. Patients received a loading dose of milrinone 50 micrograms kg-1 given over 10 min followed immediately by an infusion of 0.5 microgram kg-1 min-1, continued for a minimum of 5 h. Plasma concentrations of milrinone were measured at designated intervals during the infusion and for 6 h after its termination, by high pressure liquid chromatography. Concentrations greater than 100 ng ml-1 were produced in all patients within 2 min of starting the loading dose and were maintained for the duration of the infusion. Volume of distribution, clearance and terminal half-life were similar to those found in patients with chronic cardiac failure.

Adult↗
PubMed1993

Comparison of the haemodynamic effects of enoximone and piroximone in patients after cardiac surgery.

We have compared the haemodynamic effects of the imidazole derivative phosphodiesterase inhibitors enoximone and piroximone in patients with low cardiac output after cardiac surgery. Ten patients (group E) received enoximone and 10 patients (group P) received piroximone, both at a loading dose of 0.5 mg kg-1 followed by an infusion of 5 micrograms kg-1 min-1. In both groups the main changes with time were increases in cardiac index (maximum 24.5% in group E, 25.8% in group P) and decreases in systemic vascular resistance (maximum 26.8% in group E and 24.8% in group P). There were moderate increases in heart rate (maximum 11.3% in group E and 13% in group P) but a greater percentage decrease in mean arterial pressure in group E (maximum 11.9% vs 7.9%) with time. One patient in group E developed hypertension during the loading dose. Two patients in group E and two in group P developed hypotension during the loading dose. One patient in group E developed ventricular extrasystoles which may have been related to the drug being studied.

Aged↗