The operation of voluntary processes can contaminate the study of Pavlovian conditioned responses in humans. The problem of voluntary control had apparently been solved by about 1940, particularly in human eyelid conditioning. Nonetheless, the problem returned in the early 1950s, calling forth a variety of methodological procedures for removing voluntary responses and/or voluntary-responding subjects from eyelid-conditioning data. During the 1960s, disagreement arose regarding the efficiency and comparability of alternative data-correction procedures; the rationale for data-correction; and whether, and under (...) what experimental conditions, eyelid-conditioning data ought to be corrected for voluntary responding. Circumstances that supported voluntary-response methodology are described, and points at which the methodology conflicted with the technical background of Pavlovian conditioning are noted. A diagnosis is offered for the failure, between 1950 and 1980, to solve again the problem of volition. (shrink)

In a previous paper it was suggested that specific concepts are needed in the psychological sciences and the basic mental triad was described as a useful tool to further our understanding of mentation. It was stated that the sensori-motor reflex principle cannot describe and explain mental phenomena, because the reflex is basically a mechanistic occurrence, while mental phenomena differ in essence from mechanisms. Since conditioned reflexes can be conceived as sensori-motor reflexes with another, non-mechanistic factor superimposed, similarities and (...) contrasts between reflexes and conditioned reflexes were taken as the material from which one can develop new thoughts about mentation. Reflex shutting of the eyelid, caused by direct contact between cornea and a small, invisible foreign body was compared with and contrasted to shutting the eye before a large, visible object thrusting toward the eye. It was shown that reflexes occur in response to a stimulus after the stimulus has been applied, while conditioned reflexes seem to anticipate the stimulus. This was taken as evidence that conditioned reflexes have a protensive character, have a relationship to the future, which sensori-motor reflexes lack. This difference in time relationship was developed into the statement that the difference between mechanisms and mental phenomena lies in their different relationship to the future. The need for specific concepts to describe mental phenomena stems from the inability of the reflex principle to deal with the protensive tendency of mental phenomena and to fill this need the concept of the basic mental triad was offered. This principle consists of three interdependent, interwoven phases: the triad connects with the past through condensation of some of the subject's past experience into a vaguely formed conglomerate; it connects with the future by projecting the condensed past into the future; the central phase of the triad is the act within the present instant, where a synthesis of past, present and future is accomplished. (shrink)

Some of my mental states are conscious and some of them are not. Sometimes I am so focused on the wine in front of me that I am unaware that I am thinking about it; but sometimes, of course, I take a reflexive step back and become aware of my thinking about the wine in front of me. What marks the difference between a conscious mental state and an unconscious one? In this paper, I focus on Durand of St.-Pourçain’s rejection (...) of the higher-order theory of state consciousness, according to which a mental act is conscious when there is another, suitably related, mental (reflex) act that exists at the same time with it. Durand rejects such higher-order theories on the grounds that they violate the thesis that a given mental power can have or elicit only one mental act at a given time. I first go over some of Durand’s general arguments for this thesis. I then turn to Durand’s application of the thesis to the issue of state consciousnes and reflex acts. I close by considering the objection that Durand’s same-order theory of state consciousness makes consciousness ubiquitous. (shrink)

This study investigated the neuromodulatory effects of transspinal stimulation on soleus H-reflex excitability and electromyographic activity during stepping in humans with and without spinal cord injury. Thirteen able-bodied adults and 5 individuals with SCI participated in the study. EMG activity from both legs was determined for steps without, during, and after a single-pulse or pulse train transspinal stimulation delivered during stepping randomly at different phases of the step cycle. The soleus H-reflex was recorded in both subject groups under (...) control conditions and following single-pulse transspinal stimulation at an individualized exactly similar positive and negative conditioning-test interval. The EMG activity was decreased in both subject groups at the steps during transspinal stimulation, while intralimb and interlimb coordination were altered only in SCI subjects. At the steps immediately after transspinal stimulation, the physiological phase-dependent EMG modulation pattern remained unaffected in able-bodied subjects. The conditioned soleus H-reflex was depressed throughout the step cycle in both subject groups. Transspinal stimulation modulated depolarization of motoneurons over multiple segments, limb coordination, and soleus H-reflex excitability during assisted stepping. The soleus H-reflex depression may be the result of complex spinal inhibitory interneuronal circuits activated by transspinal stimulation and collision between orthodromic and antidromic volleys in the peripheral mixed nerve. The soleus H-reflex depression by transspinal stimulation suggests a potential application for normalization of spinal reflex excitability after SCI. (shrink)

Why was Ivan Pavlevich Pavlov so widely celebrated in the decades after 1900? As his story of the 'freedom reflex' illustrates, Pavlov often overstated his observations. By calling all innate behaviour a reflex and all learned behaviour a conditional reflex, he meant to eliminate consciousness and volition from science. Pavlov's universal reflex explanation became the prototype for behaviourism.

The nature and time course of sleep onset mentation was studied in the home environment using the Nightcap, a reliable, cost-effective, and relatively noninvasive sleep monitor. The Nightcap, linked to a personal computer, reliably identified sleep onset according to changes in perceived sleepiness and the appearance of hypnagogic dream features. Awakenings were performed by the computer after 15 s to 5 min of sleep as defined by eyelid quiescence. Awakenings from longer periods of sleep were associated with an increase (...) in reported sleepiness, a decrease in the length of mentation reports, a decrease in the frequency of reports of normal, wake-like thoughts, an increase in the frequency of “unusual thoughts,” and increased frequencies of formal dream features, including visual hallucination, self-representation, fictive movement, narrative plot, and bizarreness. While sleep-onset reports can include all features of rapid eye movement dream reports, the number of such features is markedly reduced at sleep onset, suggesting that this mentation is a greatly diminished version of REM dreaming. (shrink)

The original, prescientific Western belief that the mantis is a pious, helpful creature became a widely held explanation for the mantid's unique resting posture, and for one of its cryptic displays. This belief was a characteristic part of a broader discourse about nature in which ancient authority, religious beliefs, and superstition, but few original observations, mixed freely. Gradually, the belief in mantid gentleness and piousness became a commonplace through the continual retelling of the myths and superstitions surrounding this fascinating insect.By (...) the seventeenth century, a growing interest in observation had begun to replace blind reliance on established wisdom and ancient authority. However, the various young sciences to which the period gave rise did not progress equally, and neither did the subdisciplines within each scientific field; biology, especially entomology, was particularly slow to free itself from past beliefs and contemporary superstitions. In the specific case of the praying mantis, the situation may have been at its worst.Early observers of nature found evidence that seemed, at first, to disconfirm the well-established belief that mantids are gentle creatures. These few observers, faced with startling firsthand information about mantid voraciousness, created a new characterization of mantids as merciless predators and then often juxtaposed the two images in their descriptions. However, it was not until the beginning of the nineteenth century that the two characterizations-gentleness versus cruelty— became reconciled.An amalgamation of these seemingly mutually exclusive characterizations was achieved by an interesting accommodation of each to the other. That is, while it could no longer be maintained that mantids are simply gentle insects, neither could it be accepted that they are all cruelty and viciousness. The melding of the two characterizations yielded a hybrid explanation which claimed that the praying mantis actually hastwo sides to its character! On the one hand, and like other creatures, mantids must nourish themselves, and do so quite reasonably by capturing small insects for food. However, even when “well nourished,” and without “the excuse of hunger,” their other, vicious side may surface; when this happens, the darkest of behaviours, cannibalism, is the result.To understand the remainder of the story one must pause to consider what had happened in the other sciences up to this point. In the mid-seventeenth century, professional scientific societies were established throughout Europe. The societies, and the various journals and periodicals that they produced or encouraged, represented an institutionalization of both science and its special, structured discourse. However, as we have stated, entomology lagged behind; and in the case of some insects, superstitions and anthropomorphisms did not fade from descriptions of their behavior for centuries to come.By the time the new scientific discourse was applied to mantids the creatures were already firmly shackled with a dual personality, and this assumption was never challenged. In fact, it was functionally impossible to disconfirm. Captures of small prey were considered part of the mantid's normal side; captures of large prey were considered part of the mantid's abnormal side. There was no alternative explanation.As luck would have it, by the time that the strictures of scientific discourse had tightened sufficiently to disallow the use of anthropomorphisms in the explanation of insect behavior, another acceptable explanation of mantid cannibalism became immediately available: cannibalism became part of mantid mating behavior. That is, the fundamental explanatory model remained unchanged; it was merely couched in more appropriate terms. The acceptance of this new explanation for cannibalism was virtually immediate and complete. For instance, no one ever asked the following questions: If the headless male remains able to mate as a putative precaution against female cannibalism, for what reason does the headless female remain able to fashion “a perfectly constructed ootheca”? Or: If female-on-male cannibalism plays a role in mating behavior, what role is played by genderindifferent cannibalism, especially that among immature mantids? The latter phenomena were simply ignored — they were just uninteresting artifacts of insect life. However, the grand logic of nature was immediately apparent in the headless male's ability to mate. The ruling theory, to use Chamberlin's term, had been able to accommodate itself to, and assimilate, the new scientific discourse. It remained unscathed.A persistent question posed by several historians of this particular topic has been, Why did not the results of Ken Roeder's experiments debunk the myth that males are regularly cannibalized by the females with which they mate? The reason, which we hope is now clear, is that there were two interdependent ruling theories operating here. If one accepts the argument that mantids' cannibalism is simply a normal part of their prey-catching behavior, then one attacks not only the theory that mantids have two separate predatory strategies, but also the more recent theory that mantids have evolved to be the ideal fly-catching machines. This second theory found its first confirming support in the centuries-old practice of feeding flies to captive mantids. Again, the disconfirming evidence of mantids eating prey of various sizes had no impact on the theory. Confirming observations were accepted: disconfirming observations were seen as anomalies.Additional confirmation of both ruling theories was garnered in experiments done in the mid-twentieth century. These experiments were based on the assumption that the original conceptualizations were correct, and consequently they did not test other hypotheses. The combined strength of the two theories is evidenced especially in the Raus' failure to account for the fact that their empirical observations were at odds with many of the conclusions that they drew, and in the fact that Roeder's work is still used to support the belief in the regularity of mating-related cannibalism despite the fact that Roeder, himself, argued the opposite. with both theories well entrenched, it is virtually impossible to promote an alternative theory of mantid behavior: namely, that mantids are generalized, opportunistic predators that manage to survivein spite of the fact that cannibalism sometimes occurs. (shrink)