Behavioral engineering: postural control by a portable operant apparatus

Recent studies suggested a general behavioral engineering approach to behavioral disorders by portable operant treatment instruments. The approach was applied to the problem of poor posture, specifically rounding of the back or slouching. An apparatus was developed that provided a warning stimulus followed by an aversive tone for the duration of slouching. Slouching was thereby punished by onset of the tone, and non-slouching was reinforced by tone termination and postponement. Twenty-five adults wore the apparatus during their normal working day during alternate periods in which the aversive tone was connected and disconnected experimentally. A miniature time-meter recorded the duration of slouching. The results showed that slouching decreased for each subject during each period in which slouching produced the aversive tone. For two subjects, a second control procedure was applied in which slouching terminated the tone. The result was an increase of slouching, demonstrating that the postural changes were controlled by the scheduled relation between the aversive tone and the response, and not by other factors such as simple response feedback. The substantial changes in posture indicate that the present procedure may prove to be an effective treatment alternative and suggests the general value of the behavioral engineering approach.     

The bivalency effect: adjustment of cognitive control without response set priming

The occasional occurrence of bivalent stimuli, that is, stimuli with features relevant to two tasks, slows performance on subsequent tasks with univalent stimuli, including those which have no common features with bivalent stimuli (i.e., the “bivalency effect”). We have suggested that the bivalency effect might stem from an episodic context binding arising from the occasional occurrence of bivalent stimuli. However, as the same response set is used usually for univalent and bivalent stimuli, bivalent stimulus features may be negatively primed via response features. We investigated this possibility in two experiments, in which one group of participants used the same response keys for all tasks and another group used separate response keys. The results showed a comparable bivalency effect in both groups. Thus, it rather results from episodic context binding than from response set priming.     

Surviving without a Brain: A response to McMahan on Personal Identity

Abstract

In his Ethics of Killing: Problems at the Margins of Life, Jeff McMahan defends what he calls the embodied mind view of identity, and then puts forward several arguments in support of the view that physical continuity of the brain is crucial to our survival. He ultimately denies that psychological continuity is of any importance. His strategy is to recommend, by means of thought experiments, intuitions that support the importance of physical continuity of the brain and then argue against the plausibility of the notion of psychological continuity to which psychological theorists appeal. This paper is specifically concerned with the alleged importance of physical continuity to our survival. It responds to the positive and negative aspects of McMahan’s case by arguing that thought experiments that recommend the psychological view are far more compelling than he allows them to be and that psychological theorists can make do with a notion of psychological continuity that is immune to his criticisms.     

No ego-depletion effect without a good control task

The ego-depletion effect refers to a temporary failure of self-control exertion after first performing an effortful task. This phenomenon has experienced a replication crisis in the past few years. In the present series of experiments, we tried to replicate the ego-depletion effect using a 30-min modified Stroop task tapping two executive functions (inhibitory control and cognitive flexibility) as the depleting task. In the first study, we compared the performance of a handgrip endurance task after this depleting task or after a classic control task (i.e., reading color words) and failed to replicate the ego-depletion effect. We showed that the control task induced boredom and subjective fatigue. In a second study, we looked for a better control task and compared the color-word reading task to another possible control task used in the literature (i.e., watching a documentary). Controlling for boredom, subjective fatigue, motivation and affective state, we found that the video task was not boring and did not induce fatigue, drop in motivation or negative affective state, whereas the color-word reading task did. In a third study, we used the video task as the control task and the modified effortful Stroop task used in the first study as the depleting task and succeeded in replicating the ego-depletion effect. This series of experiments illustrates that the choice of an appropriate control task is crucial to observe an ego-depletion effect and that boredom is costly. Consequently, it appears necessary to control for boredom in any future replication study aiming to observe an ego-depletion effect.     

Repeated acquisition of response sequences: stimulus control and drugs.

Pigeons obtained food by making four responses on three keys in a specified sequence, e.g., left, right, center, right. Under the "tandem-learning" condition, all three keys were the same color throughout the response sequence, and the sequence was changed from session to session. After total errors per session (overall accuracy) and within-session error reduction (learning) had stabilized, the effects of varying doses phenobarbital and chlordiazepoxide were assessed. For comparison, the drug tests were also conducted under a "tandem-performance" condition, in which the response sequence was the same from session to session, and under corresponding "chain-learning" and "chain-performance" conditions, where different colored keylights were associated with the response sequence. Under all four baseline conditions, the largest dose of each drug impaired overall accuracy. Under the two learning conditions, the error rate decreased across trials within each session, but the degree of negative acceleration was less in the drug sessions than in the control sessions. In contrast, under the two performance conditions, the error rate was relatively constant across trials, but was higher in the drug sessions than in the control sessions. Of the four baselines, the chain-learning condition was the most sensitive to the drug effects.     

Time is a river without banks: a response to Connolly's 'Frozen time and endless analyses'

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Freedom in responsibility: a response.

This paper is a critical response to Elisabeth Gr?b-Schmidt's article "Freedom in responsibility: On the relevance of 'sin' as hermeneutic guiding principle in bioethical decision making." Gr?b-Schmidt's chief contention is that ethics begins with anthropology, and that moral responsibility is thereby grounded within a set of given limits. Freedom is distorted into sin when these limits are transgressed. My principal complaint is that her account of the relationship between freedom and sin is grounded in a tragic ontology. Alternatively, I contend that anthropology is grounded in Christology in which freedom is a gift of the Spirit. Consequently, sin is not so much tragic as it marks a refusal of humans to accept their divine election. The issues of human cloning and embryonic stem-cell research are used to exemplify what difference these respective differences might make in a process of moral deliberation.     

Acquisition and maintenance of matching without a required observing response

Two experiments demonstrated that matching-to-sample performance was improved when an explicit observing response was required to the sample stimulus. The first experiment demonstrated that fewer training sessions were required to establish matching with than matching without such a response. The second experiment demonstrated the dependence of established matching accuracy upon this observing response and the development in two of three subjects of a new overt observing response even when none was required by the experimenter.     

Timing without a timer.

Inferred-process theories propose various internal timing mechanisms to provide discriminative stimuli for temporal control of behavior. Biobehaviorally informed computer simulations indicate that timing may emerge from the action of reinforcement on neural circuits without the need to postulate timers of any sort.     

Contingency learning without awareness: evidence for implicit control

The results of four experiments provide evidence for controlled processing in the absence of awareness. Participants identified the colour of a neutral distracter word. Each of four words (e.g., MOVE) was presented in one of the four colours 75% of the time (Experiments 1 and 4) or 50% of the time (Experiments 2 and 3). Colour identification was faster when the words appeared in the colour they were most often presented in relative to when they appeared in another colour, even for participants who were subjectively unaware of any contingencies between the words and the colours. An analysis of sequence effects showed that participants who were unaware of the relation between distracter words and colours nonetheless controlled the impact of the word on performance depending on the nature of the previous trial. A block analysis of contingency-unaware participants revealed that contingencies were learned rapidly in the first block of trials. Experiment 3 showed that the contingency effect does not depend on the level of awareness, thus ruling out explicit strategy accounts. Finally, Experiment 4 showed that the contingency effect results from behavioural control and not from semantic association or stimulus familiarity. These results thus provide evidence for implicit control.     

Attention control and the antisaccade task: a response time distribution analysis

In three experiments response time (RT) differences between correct prosaccade and antisaccade trials were examined via distribution analyses by fitting an ex-Gaussian function to individual RT distributions. Experiment 1 demonstrated that antisaccades are slower than prosaccades and this difference is due to both a shift in the overall distribution as well as a lengthening of the tail of the distribution. Experiment 2 demonstrated that manipulating foreperiod duration led to changes in both accuracy and RT for antisaccades but not prosaccades. Furthermore, the change in RT for antisaccades resulted in a lengthening in the tail of the distribution but not a shift in the distribution. Finally, Experiment 3 demonstrated that with sufficient practice performance on antisaccades was equated with performance on prosaccades in terms of both accuracy and RT. An examination of the RT distributions suggested that practice led to parallel changes in both the mean of the distribution and the tail of the antisaccade distribution. These results are interpreted within a two-factor theory of attention control that suggests that performance on antisaccades is driven by both competition resolution and goal-maintenance abilities.     

Treating homosexuality: a response to Yarhouse.

Professor Mark A. Yarhouse proposes an 'identity synthesis' model of sexual modification therapy for homosexuals. This model is meant primarily to target the process by which one's sexual identity is synthesized, rather than the changing of sexual orientation itself. I highlight some of the advantages of Yarhouse's model along with some of its potential pitfalls. My primary point of departure with Yarhouse concerns how one ought to direct those self-identified homosexual clients who fall within our clinical sphere of influence and who, in the end, contrary to our better judgment, decide that they would like to pursue a course of "homosexualization." Based on the "autonomy" - emphasizing aspects of the identity synthesis model, it appears that Yarhouse is willing to sanction the referral of certain clients to "therapists" who are willing to facilitate these clients' homosexualization. I do not believe that Christians involved in the care of homosexuals can licitly participate in such referrals.