THE RELATIONSHIP OF YOGA, BODY AWARENESS, AND BODY RESPONSIVENESS TO SELF-OBJECTIFICATION AND DISORDERED EATING

Study 1 tested whether yoga practice is associated with greater awareness of and responsiveness to bodily sensations, lower self-objectification, greater body satisfaction, and fewer disordered eating attitudes. Three samples of women (43 yoga, 45 aerobic, and 51 nonyoga/nonaerobic practitioners) completed questionnaire measures. As predicted, yoga practitioners reported more favorably on all measures. Body responsiveness, and, to some extent, body awareness significantly explained group differences in self-objectification, body satisfaction, and disordered eating attitudes. The mediating role of body awareness, in addition to body responsiveness, between self-objectification and disordered eating attitudes was also tested as proposed in objectification theory ( Fredrickson & Roberts, 1997 ). Body responsiveness, but not awareness, mediated the relationship between self-objectification and disordered eating attitudes. This finding was replicated in Study 2 in a sample of female undergraduate students. It is concluded that body responsiveness and, to some extent, body awareness are related to self-objectification and its consequences.     

Performance in a substitution task and state anxiety following yoga in army recruits

140 men (M age = 30.3 yr., SD = 5.7) from the Indian army in north India participated in the study. They were naive to yoga and were assigned to yoga and breath awareness groups randomly, with 70 in each group. 20 healthy males of comparable age (M age = 33.7 yr., SD = 7.0) formed a comparison group. Their performance in a digit-letter substitution task and a state anxiety subscale was assessed immediately before and after two 45-min. sessions. The two groups of soldiers practiced either yoga or breath awareness. The comparison group listened to meditation music. Digit-letter substitution scores increased in both groups of army personnel and in the comparison group. State anxiety decreased after yoga and listening to meditation music, but not after breath awareness. This suggests that even in army personnel naive to yoga, a yoga-based intervention or listening to meditation music could reduce anxiety while increasing performance on an attention task.     

Susceptibility to the rubber hand illusion does not tell the whole body-awareness story

The rubber hand illusion (RHI) is an enigmatic illusion that creates a feeling of owning an artificial limb. Enthusiasts of this paradigm assert that it operationalizes bodily self-awareness, but there are reasons to doubt such a clear link. Because little is known about other functional contributions to the RHI, including effects of context-dependent visual processing and cognitive control or the ability to resolve intermodal conflict, we carried out two complementary experiments. In the first, we examined the relationships between the RHI and (1) body awareness, as assessed by the Body Perception Questionnaire (BPQ); (2) context-dependent visual processing, as assessed by the rod-and-frame test (RFT); and (3) conflict resolution, as assessed by the Stroop test. We found a significant positive correlation between the RHI-associated proprioceptive drift and context-dependent visual processing on the RFT, but not between the RHI and body awareness on the BPQ. In the second experiment, we examined the RHI in advanced yoga practitioners with an embodied lifestyle and a heightened sense of their own body in space. They succumbed to the illusion just as much as did yoga-naïve control participants, despite significantly greater body awareness on the BPQ. These findings suggest that susceptibility to the RHI and awareness of one’s own body are at least partially independent processes.     

Improvement in physiological and psychological parameters after 6 months of yoga practice

Yoga is believed to have beneficial effects on cognition, attenuation of emotional intensity and stress reduction. Previous studies were mainly performed on eastern experienced practitioners or unhealthy subjects undergoing concomitant conventional therapies. Further investigation is needed on the effects of yoga per se, as well as its possible preventive benefits on healthy subjects. We investigated the effects of yoga on memory and psychophysiological parameters related to stress, comparing yoga practice and conventional physical exercises in healthy men (previously yoga-naïve). Memory tests, salivary cortisol levels and stress, anxiety, and depression inventories were assessed before and after 6 months of practice. Yoga practitioners showed improvement of the memory performance, as well as improvements in psychophysiological parameters. The present results suggest that regular yoga practice can improve aspects of cognition and quality of life for healthy individuals. An indirect influence of emotional state on cognitive improvement promoted by yoga practice can be proposed.     

Müller-Lyer图形中长度加工与时距估计的关系

采用复制法,考察Müller-Lyer错觉条件下,长度加工与时距估计的关系。实验1和实验2分别采用实线段和空线段,结果发现,图形的客观长度越长,估计的时距越长;箭头朝向造成的主观长度错觉对时距估计无影响;时距对长度判断的影响较小。实验3进一步操作线段长度和箭杆方向,发现长度错觉不影响时距估计与错觉量的大小无关。研究表明刺激的客观长度与时间在心理表征上存在自动化的联结,也受到刺激、实验方法和时距等因素的影响。     

Evaluation of Siddha Samadhi Yoga for anxiety and depression symptoms: a preliminary study

Siddha Samadhi Yoga is a program in which meditation is associated with pranayama (breathing exercises). 22 volunteers with anxiety complaints (M age = 42.8 yr., SD = 10.3) were assigned to two groups: 14 attended the yoga group, and 8 attended a waiting-list or control group. They were evaluated before the intervention and 1 month after it on the State-Trait Anxiety Inventory, the Beck Depression Inventory, Tension Feelings Self-evaluation Scales, and the Well-being Self-evaluation Scales. A significant reduction in scores on anxiety, depression, and tension was found in yoga group, as well as an increase in well-being in comparison with the control group.     

Perception without awareness: perspectives from cognitive psychology

Four basic approaches that have been used to demonstrate perception without awareness are described. Each approach reflects one of two types of experimental logic and one of two possible methods for controlling awareness. The experimental logic has been either to demonstrate a dissociation between a measure of perception with awareness and a measure that is sensitive to perception without awareness or to demonstrate a qualitative difference between the consequences of perception with and without awareness. Awareness has been controlled either by manipulating the stimulus conditions or by instructing observers on how to distribute their attention. The experimental findings based on all four approaches lead to the same conclusion; namely, stimuli are perceived even when observers are unaware of the stimuli. This conclusion is supported by results of studies in which awareness has been assessed with either objective measures of forced-choice discriminations or measures based on verbalizations of subjective conscious experiences. Given this solid empirical support for the concept of perception without awareness, a direction for future research studies is to assess the functions of information perceived without awareness in determining what is perceived with awareness. The available evidence suggests that information perceived without awareness both biases what stimuli are perceived with awareness and influences how stimuli perceived with awareness are consciously experienced.     

The Ponzo illusion with auditory substitution of vision in sighted and early-blind subjects

We tested the effects of using a prosthesis for substitution of vision with audition (PSVA) on sensitivity to the Ponzo illusion. The effects of visual experience on the susceptibility to this illusion were also assessed. In one experiment, both early-blind and blindfolded sighted volunteers used the PSVA to explore several variants of the Ponzo illusion as well as control stimuli. No effects of the illusion were observed. The results indicate that subjects focused their attention on the two central horizontal bars of the stimuli, without processing the contextual cues that convey perspective in the Ponzo figure. In a second experiment, we required subjects to use the PSVA to consider the two converging oblique lines of the stimuli before comparing the length of the two horizontal bars. Here we were able to observe susceptibility to the Ponzo illusion in the sighted group, but to a lesser extent than in a sighted non-PSVA control group. No clear effect of the ilusion was obtained in early-blind subjects. These results suggest that, at least in sighted subjects, perception obtained with the PSVA shares perceptual processes with vision. Visual experience appears mandatory for a Ponzo illusion to occur with the PSVA.     

Respiratory Patterns in Students Enrolled in Schools for Disruptive Behaviour Before, During, and After Yoga Nidra Relaxation

This study investigated the effects of one session of Yoga Nidra (relaxation technique) on the breathing patterns/respiratory effort in the thoracic and abdominal chest regions of boys with disruptive behaviour using a Respiratory Inductive Plethysmography (RIP). The participants (n?=?7) were aged 10–15?years and attending NSW, Department of Education (DET) special schools for children with disruptive behaviour (DB). Results were compared with three students (one female) aged 15?years without DB. The seven boys had previously participated in a 13-week yoga program. During this program participants were progressively taught the practice of Yoga Nidra. The comparison group did not participate in the yoga program but underwent the same procedure for collection of data as the yoga group. Using Compumedics “ProFusion Polysomnography (PSG)” software and further analyses in “Polyman” European Data Format?+?(EDF), data were analysed by identifying breathing as unstable or stable. Unstable breathing was identified as fluctuations in rate/s of breathing effort, amplitude, cessation of breath, and thoracic or abdominal predominance. Results indicated that boys with disruptive behaviour generally displayed unstable breathing patterns throughout the pre-recording period and showed more stable breathing during Yoga Nidra compared with pre- or post-recording periods. There were also examples of reductions in thoracic dominance during Yoga Nidra. The comparison group’s breathing patterns throughout the three phases of the process were found to be stable.     

Psychosocial Correlates and Outcomes of Yoga or Walking Among Older Adults

Few researchers have compared psychological correlates and outcomes of yoga with more traditional forms of exercise. The authors' primary aim was to compare changes in the psychosocial outcomes of mood and state anxiety produced by an acute bout of yoga or walking among older adults. The secondary aim was to compare selected psychosocial correlates of activity. Participants were 51 adults who were 50 years of age or older who walked for exercise or participated in a yoga class. Results revealed that yoga participants had significantly greater levels of depression and perceived barriers to exercise, and lower quality of life than did walkers. With control for these differences, yoga practitioners had improved levels of fatigue pre- to postsession, compared with walkers. With control for differences in demographic variables, these changes were no longer significant. It is possible that yoga practitioners seek out mindful-based exercise to cope with greater levels of depression and lower levels of quality of life.     

Visual Perception and Memory Impairments in Children at Risk of Nonverbal Learning Disabilities

Visuospatial working memory (VSWM) and visual perception were examined in two groups aged 11–13, one with children displaying symptoms of nonverbal learning disability (NLD) (n = 18) and the other a control group without learning disabilities (n = 18). The two groups were matched for general verbal abilities, age, gender, and socioeconomic level. The children were presented with VSWM tests involving visual and spatial-simultaneous processes, and also with a classical visual illusion, a classical ambiguous figure, as well as visual perception tests specifically devised for the present study. Results revealed that performance of children at risk of NLD was worse than controls in some VSWM and in visual perception tests without memory involvement; these latter required comparisons of visual stimuli and locations in space with distractors. Moreover, the two groups differed in perceiving the classical ambiguous figure. Findings are discussed in the light of both theoretical and clinical implications.     

An enhanced experimental procedure to rationalize on the impairment of perception of action capabilities

It is well documented that changes in the physiological states of the perceiver–actor influence the perception of action capabilities. However, because experimental procedures of most studies involved a limitless availability for stimuli visual encoding and perceptual strategies, it remains difficult to adopt a single position among the large range of alternative interpretations for impaired perception. A reaching-to-grasp paradigm under breathing restriction was adapted from Graydon et al. (Cogn Emot 26:1301–1305, 2012) to standardize the time for encoding of stimuli information and narrowed the involvement of perceptual strategies. In the present study, we propose a highly controlled environment where the discrete information is presented during 300 ms, congruently with neurophysiological studies focused on visuomotor transformation. An underestimation of the perception of action capabilities is found under breath restriction, suggesting that 300 ms for stimuli encoding is sufficient to induce altered visuomotor brain transformations when limiting the involvement of perceptual strategies. This result suggests that such behavior could refer to an impaired brain potentiation of the perceptual occurrence, providing strong hypotheses on the brain dynamics of sensorimotor integration that underlie impaired perception of action capabilities in stressful situations.     

An Evaluation of the Ability to Voluntarily Reduce the Heart Rate after a Month of Yoga Practice

The study aimed at determining whether novices to yoga would be able to reduce their heart rate voluntarily and whether the magnitude of reduction would be more after 30 days of yoga training. Two groups (yoga and control, n = 12 each) were assessed on Day 1 and on Day 30. During the intervening 30 days, the yoga group received training in yoga techniques while the control group carried on with their routine. At each assessment the baseline heart rate was recorded for one minute, this was followed by a six-minute period during which participants were asked to attempt to voluntarily reduce their heart rate, using any strategy. Both the baseline heart rate and the lowest heart rate achieved voluntarily during the six-minute period were significantly lower in the yoga group on Day 30 compared to Day 1 by a group average of 10.7 beats per minute (i.e., bpm) and 6.8 bpm, respectively (p < .05, Wilcoxon paired signed ranks test). In contrast, there was no significant change in either the baseline heart rate or the lowest heart rate achieved voluntarily in the control group on Day 30 compared to Day 1. The results suggest that yoga training can enable practitioners to use their own strategies to reduce the heart rate, which has possible therapeutic applications.     

The box alignment illusion: An orientation illusion induced by pictorial depth

In four experiments, observers attempted to align two sets of oblique edges to parallel. The contexts for these alignments included lines in isolation (2-D control), lines embedded in orthogonal drawings of same-oriented and different-oriented boxes (3-D objects), and each of these viewed against backgrounds depicting strong linear perspective (3-D backgrounds). A consistent distortion was observed in the alignments of different-oriented boxes relative to control lines, indicating that the parallel lines in these stimuli appeared to diverge toward the top of the picture. Furthermore, thisbox alignment illusion decreased with interstimulus distance, whereas alignment distortions in control lines and same-oriented boxes increased with distance. Viewing the stimuli against 3-D backgrounds produced a dramatic reversal of the illusion, with control lines now appearing to converge more than the boxes. These results suggest that the illusion reflects basic processes involved in pictorial depth perception.     

Fixed set in the perception of size in relation to lightness

When control subjects compared the sizes of two circles of different lightness, the lightness-size illusion was observed, i.e., the darker circle was perceived to be smaller. However, after experimental subjects were shown a large, light circle and a smaller, darker circle repeatedly, the subjective size of the dark circle increased. It decreased after repeated exposures to a small, light circle and a large, dark one. These changes in perception were assumed to be contrast effects produced by an experimentally fixed set and were similar to changes observed when the same method was previously applied by this author to the size-weight illusion. Despite differences in modality and dimension of perception, every application of the fixed-set method resulted in analogous patterns. When the situation of the set-fixing experiment and that of the critical experiment were similar to each other, the fixed set was activated more and greater contrast effects were produced.     

The effects of arm length,size of angle,and spatial separation on Morinaga’s illusion

The effects of arm length, spatial separation between angles, size of angle, and practice on the degree of misalignment in a modified version of Morinaga’s illusion were assessed. Size of angle was manipulated between subjects (n=15/group), whereas arm length, spatial separation, and practice were varied within subjects. Results showed: (1) that as the length of the arm increased, the degree of illusion decreased; (2) that as spatial separation increased, the degree of illusion increased; and (3) an interaction between size of angle and practice. The results were related to Day et al.’s (1982) assimilation theory of Morinaga’s illusion.     

Control of the corridor illusion in baboons (Papio papio) by gradient and linear-perspective depth cues

The corridor illusion was recently demonstrated in baboons with background pictures containing rich depth information (Barbet and Fagot 2002, Behavioural Brain Research 132 111-115). In the current research we determined the contribution of gradient texture and perspective lines to that illusion. In experiment 1, the corridor illusion was tested in two baboons, with pictures of a hallway as backgrounds, or the same image of the hallway represented by perspective lines. Findings confirmed that the baboons experience the corridor illusion with the picture of the hallway, and showed that this illusion remained with the perspective-line backgrounds. The same procedure was adopted in experiment 2, but with a hallway drawn from gradient textures. The two baboons experienced the illusion in this experiment too. Thus both gradient and perspective line cues convey sufficient information to control the corridor illusion in baboons. In baboons, the processing of these two kinds of depth cues interacts with the perception of object size, suggesting homologous processes of pictorial depth perception in humans and non-human primates.     

Vertical-horizontal illusion present for sighted but not early blind humans using auditory substitution of vision

This experiment was undertaken to investigate the effect of sensory modality (vision vs. audition) and of visual status (early blind vs. sighted) on susceptibility to the vertical-horizontal illusion. Early blind volunteers and blindfolded sighted subjects explored variants of the vertical-horizontal illusion using a device that substituted audition for vision, whereas sighted subjects from an independent group inspected the same stimuli visually. Sensitivity to the vertical-horizontal illusion, including an illusion of moderate strength when using the sensory substitution device, was observed only in the two sighted groups. The existence of an illusion effect when using such a device supports the idea of a visual perception provided by sensory substitution, whereas the attenuation of the vertical-horizontal illusion strength is consistent with the visual field shape theory (Künnapas, 1955a). The absence of the illusion effect in early blind subjects suggests that the sensory experience influences the nature of perception and that the visual experience plays a crucial role in the vertical-horizontal illusion, in accordance with the size-constancy scaling theory (Gregory, 1963).     

Visual and haptic perception of the horizontal-vertical illusion

The horizontal-vertical illusion consists of two lines of the same length (one horizontal and the other vertical) at a 90 degree angle from one another forming either an inverted-T or an L-shape. The illusion occurs when the length of a vertical line is perceived as longer than the horizontal line even though they are the same physical length. The illusion has been shown both visually and haptically. The present purpose was to assess differences between the visual or haptic perception of the illusions and also whether differences occur between the inverted-T and the L-shape illusions. The current study showed a greater effect in the haptic perception of the horizontal-vertical illusion than in visual perception. There is also greater illusory susceptibility of the inverted-T than the L-shape.     

The visuomotor system resists the horizontal-vertical illusion

The effect of the horizontal-vertical illusion on the visual and visuomotor systems was investigated. Participants (N = 8) viewed horizontal and vertical lines in an inverted-T stimulus and judged whether the two line segments were the same or different lengths. Participants also reached out and grasped either the vertical or the horizontal line segment of the stimulus. Perceptually, participants succumbed to the illusion; that is, they judged Ts of equal horizontal and vertical line lengths to be different and Ts of unequal line lengths to be the same. When reaching toward the same stimuli, however, the size of their grip aperture was scaled appropriately for the various line lengths. Thus, whereas the perceptual system succumbed to the illusion, the visuomotor system did not. Those results support a model proposed by M. A. Goodale and A. D. Milner (1992), who posited separate cortical pathways for visual perception and visually guided action.