Does self-perception change explain the foot-in-the-door effect?

Consent to perform a small favor increases a respondent's susceptibility to perform a relatively large favor. This phenomenon, known as the foot-in-the-door effect, is considered to result from induced self-perception changes: the respondent comes to feel helpful for doing the small favor and complies again later out of a desire to maintain the instilled self-view. This study did not find a link between self-perception changes and large-request compliance in 2 experiments, although manipulations successfully altered self-rated helpfulness. Specifically, self-rated helpfulness increased (in Experiments 1 & 2) if participants' consent to a small favor brought social approval, and the ratings decreased (in Experiment 2) when social feedback for the small favor contained consensus information (i.e., indicated everyone else was also doing the favor). However, the ratings failed to predict either foot-in-the-door effects actually observed or compliance generally. Preexperimental gender differences in self-perceived helpfulness, in which women construed themselves to be more helpful than men, did successfully predict compliance with the large request. Implications for a theory of foot-in-the-door are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The propensity of the "highly hypnotizable" to act as if highly hypnotizable.

Assessed the tendency of hypnotically suggestible Ss to act as if hypnotically suggestible. 24 high and 24 low suggestible (determined using the Carleton University Responsiveness to Suggestion Scale) psychology students rated the aesthetic attractiveness of geometric figures. Prior to this task, information about how other Ss had rated the figures was provided. In a relevant data condition, information about others' ratings included appraisals apparently made by highly suggestible persons. In an irrelevant data condition, none of the information about others' ratings made reference to hypnotic suggestibility. The tendency to role enact as if highly suggestible was exhibited only within the relevant data condition and only by high suggestibles. Results cannot be explained in terms of hypnotically enhanced compliance because no hypnosis was present when the enactment occurred. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnotic elimination of prism-induced aftereffects: Perceptual effect or responses to experimental demands?

Two experiments assessed adaptation to displacing prisms in hypnotically limb-anesthetized Ss. Exp I with 18 college students disconfirmed the hypothesis that the displacement aftereffect is eliminated in limb-anesthetized hypnotic Ss who adapt to prisms in the absence of a visual target. Such Ss showed as large a displacement aftereffect as control Ss who received neither a hypnotic induction procedure nor an anesthesia suggestion. Exp II with 30 undergraduates demonstrated that under some testing conditions hypnotic Ss complied with experimental demands and eliminated the behavioral but not the perceptual component of the aftereffect. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnotically induced limb anesthesia and adaptation to displacing prisms: A failure to confirm.

Tested 3 groups of 10 undergraduates for accuracy of pointing at a visual target before and after wearing displacing prisms. One group consisted of highly susceptible Ss given a hypnotic suggestion for limb anesthesia following the pretest, and a 2nd group included low susceptible Ss instructed to fake limb anesthesia. A control group unselected on susceptibility received no special instructions. The high susceptibles reported significantly greater felt anesthesia than Ss in the other 2 treatments. Nevertheless, Ss in all 3 groups showed very large displacement errors (i.e., errors in pointing) following prism removal. Results fail to confirm reports that placement errors were eliminated by hypnotic suggestion in highly susceptible Ss. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A social-cognitive skills approach to the successful modification of hypnotic susceptibility.

120 undergraduates who were low and medium in hypnotic susceptibility were administered cognitive strategy and instructional set information and practiced responding to test suggestions to enhance susceptibility. Those in 1 modification treatment received this information both from the experimenter and by observing a videotaped female who responded successfully to suggestions and reported on the cognitive strategies she used to do so. Those in a 2nd modification treatment received the information and practice but were not exposed to the model. Low and medium susceptibles in a 3rd condition (practice alone) received a hypnotic induction procedure and practice suggestions but neither modification information nor modeling. No-treatment controls performed a filler task. All Ss were posttested on 2 susceptibility scales. Results show that information plus modeling produced significantly greater increments on all objective and subjective indices of susceptibility on both posttests than did practice-alone or control treatments. Susceptibility increments in the information without model treatment always fell between those of the model and practice-alone treatments. In the modeling treatment, over half of the initial low susceptibles and over two-thirds of the initial medium susceptibles scored as high susceptibles on both posttests. Findings provide strong support for a social-cognitive skill formulation of hypnotic susceptibility. (49 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Short-term plasticity in hindlimb motoneurons of decerebrate cats

Intracellular recordings were made from hindlimb motoneurons in decerebrate cats to study how synaptic inputs could affect the threshold at which plateau potentials are activated with current injections through the recording microelectrode in the cell body. This study was prompted by recent evidence that the noninactivating inward currents that regeneratively produce the plateau potentials arise (partly) from dendritic conductances, which may be relatively more accessible to synaptic input than to current injected into the soma. Initially, cells were studied by injecting a slow triangular current ramp intracellularly to determine the threshold for activation of the plateau. In cells where the sodium spikes were blocked with intracellular QX314, plateau activation was readily seen as a sudden jump in membrane potential, which was not directly reversed as the current was decreased. With normal spiking, the plateau activation (the noninactivating inward current) was reflected by a steep and sustained jump in firing rate that was not directly reversed as the current was decreased. Importantly, the threshold for plateau activation (at 34 Hz on average) was significantly above the recruitment level (13 Hz on average). When tonic synaptic excitation [excitatory postsynaptic potentials (EPSPs)] was provided either by stretching the triceps surae muscle or by stimulating its nerve at a high frequency, the threshold for plateau activation by intracellular current injection was significantly lowered (by 12 Hz or 5.8 mV on average, without and with QX314, respectively). Conversely, tonic synaptic inhibition [inhibitory postsynaptic potentials (IPSPs)], provided by appropriate nerve stimulation, significantly raised the plateau threshold (by 19 Hz or 7.6 mV on average). These effects were graded with the intensity of tonic EPSPs and IPSPs. Strong enough EPSPs brought the plateau threshold down sufficiently that it was activated by the intracellular current soon after recruitment. A further increase in tonic EPSPs recruited the cell directly, and in this case the plateau was activated at or before recruitment. The finding that synaptic excitation can produce plateau activation below the recruitment level is of importance for the interpretation of its function. With this low-threshold activation, the plateau potentials are likely important in securing an effective recruitment to frequencies that produce significant force generation and would subsequently have no further affect on the frequency modulation, other than to provide a steady depolarizing bias that would help to sustain firing (cf. self-sustained firing). Additional jumps in frequency after recruitment (i.e., bistable firing) would not be expected.     

Effects of artificial weathering on the mechanical properties of paper‐based materials consolidated with polymeric materials

The study of polymer behavior over time represents the crucial stage in the setup of innovative methodologies for paper restoration. In this research, a series of laboratory simulations by accelerated aging and characterization tests by chemical and physical measurements were carried out on paper samples consolidated both by grafting polymerization with acrylic copolymers and by coating with waterborne polyurethanes with the aim of determining their harmlessness and long‐term effectiveness. In this way, our purpose was not only to verify possible risks for the paper materials but also to determine the advantages and potentialities of new restoration methods through an appropriate and essential working plan of investigations. From our evaluation, both the selected consolidation methods appeared unsuitable to be used in paper restoration because of the damage that they could cause on the paper materials because of their limited durability over time. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Structure of hypnotic test suggestions and attributions of responding involuntarily.

48 hypnotic and task-motivated undergraduates were administered 3 suggestions and 3 directives in counterbalanced order. The directives instructed Ss to make a series of motor responses while the suggestions implied that the same responses occurred involuntarily. Ss displayed greater overt response to directives than suggestions but rated their responses to suggestions as more involuntary than responses to directives. Suggested responses associated with incongruent proprioceptive feedback were rated as less involuntary than responses associated with congruent feedback. Goal-directed fantasy (GDF) was elicited more frequently by suggestions than directives, and GDF correlated with rated involuntariness and hypnotic susceptibility. Findings are consistent with the notions that hypnotic responding is strategic action moderated by Ss' construal of the test situation and that ratings of involuntariness reflect a socially cued interpretation of experience. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spasticity in rats with sacral spinal cord injury

We have investigated sacral spinal cord lesions in rats with the goal of developing a rat model of muscular spasticity that is minimally disruptive, not interfering with bladder, bowel, or hindlimb locomotor function. Spinal transections were made at the S2 sacral level and, thus, only affected the tail musculature. After spinal transection, the muscles of the tail were inactive for 2 weeks. Following this initial period, hypertonia, hyperreflexia, and clonus developed in the tail, and grew more pronounced with time. These changes were assessed in the awake rat, since the tail is readily accessible and easy to manipulate. Muscle stretch or cutaneous stimulation of the tail produced muscle spasms and marked increases in muscle tone, as measured with force and electromyographic recordings. When the tail was unconstrained, spontaneous or reflex induced flexor and extensor spasms coiled the tail. Movement during the spasms often triggered clonus in the end of the tail. The tail hair and skin were extremely hyperreflexive to light touch, withdrawing quickly at contact, and at times clonus could be entrained by repeated contact of the tail on a surface. Segmental tail muscle reflexes, e.g., Hoffman reflexes (H-reflexes), were measured before and after spinalization, and increased significantly 2 weeks after transection. These results suggest that sacral spinal rats develop symptoms of spasticity in tail muscles with similar characteristics to those seen in limb muscles of humans with spinal cord injury, and thus provide a convenient preparation for studying this condition.     

Use of concurrent verbalization to assess the dissociation of conscious controls.

The degree of dissociation of conscious controls that occurred when, according to the neodissociation theory (Hilgard, 1977, 1979), conditions were optimal for such an event was assessed. A task that required subjects to locate specified sentences in a textbook was conducted under these optimal conditions, as well as under conditions that were expected to mitigate against the occurrence of dissociation. The sentence-search task necessitated rehearsal for its successful completion. The correspondence between task rehearsal and task performance did not differ between optimal and mitigating conditions, thus suggesting a failure to dissociate. Nevertheless, search behavior was self-rated as substantially more involuntary under the optimal than under the mitigating conditions. The implications of these findings for the neodissociation and social role theories of hypnosis were discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)