Spatial limits on the nonvisual self-touch illusion and the visual rubber hand illusion: Subjective experience of the illusion and proprioceptive drift

The nonvisual self-touch rubber hand paradigm elicits the compelling illusion that one is touching one’s own hand even though the two hands are not in contact. In four experiments, we investigated spatial limits of distance (15 cm, 30 cm, 45 cm, 60 cm) and alignment (0°, 90° anti-clockwise) on the nonvisual self-touch illusion and the well-known visual rubber hand illusion. Common procedures (synchronous and asynchronous stimulation administered for 60 s with the prosthetic hand at body midline) and common assessment methods were used. Subjective experience of the illusion was assessed by agreement ratings for statements on a questionnaire and time of illusion onset. The nonvisual self-touch illusion was diminished though never abolished by distance and alignment manipulations, whereas the visual rubber hand illusion was more robust against these manipulations. We assessed proprioceptive drift, and implications of a double dissociation between subjective experience of the illusion and proprioceptive drift are discussed.     

Temporal Disruptions in the “Accurate” Speech of Articulatory Defective Speakers and Stutterers

Durational measures of vocalic steady states and transitions were made on phonetically accurate and fluently produced vowel-plosive, consonant-vowel bisyllables embedded in a carrier phrase. In the first experiment, these measures were taken from the speech of ten articulatory defective adult speakers and ten matched normal speakers. The second experiment analyzed durational measures in the speech of ten adult stutterers and ten matched nonstutterers. Using wideband spectrography, durational measurements were used to infer timing of articulatory movements during the subsegments of the VCV sequences. The results of both experiments suggest that the two groups of speech disordered subjects were able to produce transitional shifts appropriate to the phonetic environment but appeared to delay the initiation of coarticulatory movements. Aberrant speech timing may imply an involvement in the planning or integration of articulatory/coarticulatory movements rather than difficulty with movement execution per se.     

Touching my left elbow: the anatomical structure of the body affects the illusion of self-touch

A self-touch paradigm is used to create the illusion that one is touching one's own left elbow when one is actually touching the examiner's arm. Our new self-touch illusion is sensitive to the anatomical structure of the body: you can touch your left elbow with your right index finger but not with your left index finger. Illusion onset was faster and illusion ratings were higher when participants administered touch using the plausible right index finger compared with the implausible left index finger.     

Embracing Complexity and Seeking Simplicity in Interpersonal Relationships: A Defense of the Subordination-Reactivity Hypothesis

In the target article (Wanic and Kulik 2011), we proposed in the subordination-reactivity hypothesis that women??s (typically) subordinate role in marital relationships renders them physiologically more vulnerable to martial conflict, which may explain partly the finding that marriage generally benefits the health of men more than women. In that article, we noted that our hypothesis should be considered in conjunction with other ??non-mutually exclusive?? relationship processes that also may contribute to the greater health benefit of marriage for men. The accompanying commentaries take issue with our article on the grounds that a) interpersonal relationships and health are multidimensional and complex; b) our subordination-reactivity hypothesis diverges from existing interpersonal theory and research; and c) it is ??almost always?? unwise to ??pit?? one explanation or theory against another. In this response we argue a) the indisputable point regarding the complexity of interpersonal relationships and health does not challenge the validity of our hypothesis; b) our hypothesis, as stated, is not logically inconsistent with the prior interpersonal theory and research cited, and c) there is considerable value to pitting explanations against each other when possible, and arguments to avoid doing so are at odds with fundamental scientific practices.     

Providing support for distinctive processing: the isolation effect in young and older adults

The isolation paradigm is the classic method for studying the effects of distinctiveness on memory (Hunt, 1995). Previous studies using the isolation paradigm with older adults (Bireta, Suprenant, & Neath, 2008; Cimbalo & Brink, 1982; Geraci, McDaniel, Manzano, & Roediger (2009); Vitali et al., 2006) placed the isolated items late in the study list. The current experiments, which are the first to investigate the isolation effect in young and older adults when the isolated item occurs early in the list, were motivated by a new framework for understanding age-related differences in the beneficial effects of distinctive processing. The framework, which is motivated by Hunt's (2006) discussion of distinctiveness and Craik's (1986) environmental support view, proposes that when contextual support is provided for the processing of both the difference and similarity components, older adults are more likely to show beneficial effects of distinctiveness. In Experiment 1, young adults showed both early and late isolation effects, while older adults showed only a late isolation effect. In the first experiment the isolated item was the word "table" in a list of fish names. In Experiment 2, the contrast between the isolated item and background items was increased by isolating numbers in a list of words. In the second experiment older adults, as well as young adults, showed an early isolation effect.     

Tactile expectations and the perception of self-touch: An investigation using the rubber hand paradigm

The rubber hand paradigm is used to create the illusion of self-touch, by having the participant administer stimulation to a prosthetic hand while the Examiner, with an identical stimulus (index finger, paintbrush or stick), administers stimulation to the participant’s hand. With synchronous stimulation, participants experience the compelling illusion that they are touching their own hand. In the current study, the robustness of this illusion was assessed using incongruent stimuli. The participant used the index finger of the right hand to administer stimulation to a prosthetic hand while the Examiner used a paintbrush to administer stimulation to the participant’s left hand. The results indicate that this violation of tactile expectations does not diminish the illusion of self-touch. Participants experienced the illusion despite the use of incongruent stimuli, both when vision was precluded and when visual feedback provided clear evidence of the tactile mismatch.     

The Effect of Paired Muscle Stimulation on Preparation for Movement

Paired muscle stimulation is used clinically to facilitate the performance of motor tasks for individuals with motor dysfunction. However, the optimal temporal relationship between stimuli for enhancing movement remains unknown. We hypothesized that synchronous, muscle stimulation would increase the extent to which stimulated muscles are concurrently prepared for movement. We validated a measure of muscle-specific changes in corticomotor excitability prior to movement. We used this measure to examine the preparation of the first dorsal interosseous (FDI), abductor digiti minimi (ADM), abductor pollicis brevis (APB) muscles prior to voluntary muscle contractions before and after paired muscle stimulation at four interstimulus intervals (0, 5, 10, and 75 ms). Paired muscle stimulation increased premovement excitability in the stimulated FDI, but not in the ADM muscle. Interstimulus interval was not a significant factor in determining efficacy of the protocol. Paired stimulation, therefore, did not result in a functional association being formed between the stimulated muscles. Somatosensory potentials evoked by the muscle stimuli were small compared to those commonly elicited by stimulation of peripheral nerves, suggesting that the lack of functional association formation between muscles may be due to the small magnitude of afferent volleys from the stimulated muscles, particularly the ADM, reaching the cortex.     

The Anatomy of a Philosophical Hoax

This article reflects upon the state of the philosophical profession vis‐à‐vis a close reading of the hoax perpetrated against the International Journal of Badiou Studies in 2016. This hoax is not a subversive act of disciplinary criticism (as the hoaxers contend). Rather, it is a poorly disguised attempt to enforce a partisan and myopic conception of philosophy and to delegitimize an entire subfield of philosophical production—namely, continental philosophy. The hoax is symptomatic of a deeper problem that plagues the profession today: the willingness exhibited by many philosophers to police the boundaries of the discipline by engaging in what we call “acts of force.” The prevalence of acts of force demonstrates that professional philosophy is shaped not only by the giving and taking of reasons but also by shopworn disciplinary tribalisms (for example, continental versus analytic) and asymmetrical power relations involving agents with unequal amounts of social, professional, and philosophical capital.     

Mediating relationship between body mass index and the direct measures of the Theory of Planned Behaviour on physical activity intention

This research examines (a) the interrelationships between body mass index (BMI), the direct measures of the Theory of Planned Behaviour (TPB) and physical activity intention and (b) the potential mediation effects of the direct measures of the TPB in the relationship between BMI and physical activity intention in a sample of Australian adults. A total sample of 1,062 respondents participated in a computer-assisted telephone-interview (CATI) survey comprised of a standardised introduction; questions regarding TPB and physical activity; and standard demographic questions. BMI for each participant was calculated from self-reported height and weight. Separate regression analyses were performed to examine the mediating effects of each of the direct measures of the TPB on the predictive relationship between the BMI and physical activity intention, as proposed by Baron and Kenny (Journal of Personality and Social Psychology, 51(6), 1173 - 1182, 1986). Findings indicated that the direct measure of attitude and perceived behavioural control mediated the relationship between BMI and physical activity intention. However, the direct measure of subjective norm failed to act as a mediating mechanism. To date there has been no research that has examined the mechanism by which body mass may affect physical activity behaviour. Given the current focus for health promotion specialists on promoting physical activity as a strategy for reducing overweight and obesity, a theoretical understanding of weight-related barriers to physical activity may aid in the development of future interventions and community physical activity programs, particularly those targeting overweight and obese populations.