Interstimulus Intervals and Sensory Modality Modulate the Impact of a Cognitive Task on Postural Control

The present literature not only reveals the use of a wide variety of cognitive tasks but variability in their interaction with postural control. The question then arises, as to, whether postural control is sensitive to specific features of a cognitive task. The present experiment assessed the impact of cognitive tasks with interstimulus intervals (ISI) of varied duration and sensory modality on postural control in young adults. Seventeen participants (23.71 ± 1.99 years old) were instructed to stand on a force platform while concurrently performing cognitive tasks with ISIs of two and 5 s. The tasks were presented both, auditorily and visually. The visual tasks consisted of counting the total occurrence of a single digit. The auditory tasks consisted of counting the total occurrence of a single letter. Performing the cognitive tasks with an ISI of 2 s resulted only in an increase in the anteroposterior mean power frequency. Presenting the tasks visually also significantly reduced area of 95% confidence ellipse and AP and mediolateral sway variability. These results may suggest that ISIs can modify postural performance by altering the allocation of attentional focus. Also, presenting tasks using a visual sensory modality appears to yield lower postural sway.     

Spatial and Temporal Adaptations That Accompany Increasing Catching Performance During Learning

During stance, head extension increases postural sway, possibly due to interference with sensory feedback. The sit-to-stand movement is potentially destabilizing due to the development of momentum as the trunk flexes forward and the body transitions to a smaller base of support. It is unclear what role head orientation plays in the postural and movement characteristics of the sit-to-stand transition. The authors assessed how moving from sitting to standing with head-on-trunk extension compared with moving with the head neutral or flexed, or with moving with the head facing forward in space (which would involve head-on-trunk extension, but not head-in-space extension) in healthy, young participants. Head-on-trunk extension increased center of pressure variability, but decreased movement velocities, movement duration, and trunk flexion compared with flexed and neutral head-on-trunk orientations. Similarities in movement characteristics between head-on-trunk extension and the forward head-in-space orientation suggest that stabilizing the head in space does not fully counteract the postural and movement changes due to head-on-trunk extension. Findings suggest that proprioceptive feedback from the neck muscles contributes to the regulation of posture and movement, and therefore should not be overlooked in research on the role of sensory feedback in postural control.     

The Interrelationships Between Anxiety,Motor Performance and Electromyography

Notterman (1975) argued, contrary to my 1974 article, that the data obtained by Notterman and Page (1962) confirm the important role of proprioception in skilled performance. I argue that these data are in fact ambiguous when it comes to distinguishing the effects of proprioception from those of outflow control.     

Multisensory Information in the Control of Complex Motor Actions

ABSTRACT— For many of the complex motor actions we perform, perceptual information is available from several different senses including vision, touch, hearing, and the vestibular system. Here I discuss the use of multisensory information for the control of motor action in three particular domains: aviation, sports, and driving. It is shown that performers in these domains use information from multiple senses—frequently with beneficial effects on performance but sometimes with dangerous consequences. Applied psychologists have taken advantage of our natural tendency to integrate sensory information by designing multimodal displays that compensate for situations in which information from one or more of our senses is unreliable or is unattended due to distraction.     

The Scientific Study of Religion: Its Contribution to the Study of the Bhagavadgītā

Abstract. The Bhagavadg?tā is a popular Hindu text containing eighteen chapters. It begins with the hero, Arjuna, showing a marked unwillingness to engage in combat on the eve of battle. He is finally persuaded to do so by Krishna, who is an incarnation of God. Krishna actually reveals himself as such to an amazed Arjuna in the eleventh chapter. The fact that Arjuna does not immediately heed Krishna's advice to engage in battle after Krishna's sensational self‐disclosure has long puzzled students of the text. It is only at the end of the eighteenth chapter that Arjuna finally shows his readiness to fight. In this essay I argue that the discussion of the nine primary sensory states by Eugene d'Aquili may help resolve this issue and thus provide an instance of a case in which modern scientific study of religion enhances our understanding of a religious phenomenon, as a corrective to the usual charge that it must invariably diminish it.     

Why Are Some Phenomenal Experiences ‘Vivid’ and Others ‘Faint’? Representationalism,Imagery, and Cognitive Phenomenology

One central brand of representationalism claims that the specific phenomenal character of an experience is fully determined by its content. A challenge for this view is that cognitive and perceptual experiences sometimes seem to have the same representational content while differing in phenomenal character. In particular, it might seem that one can have faint imagery experiences or conscious thoughts with the same contents as vivid perceptual experiences. This paper argues that such cases never arise, and that they are probably metaphysically impossible. I also suggest a fully representational account of differences in vividness between phenomenal experiences.     

The influence of external stimulation in missing knowledge retrieval

We investigated the effects of sensory reduction on the retrieval of information during tip-of-the-tongue (TOT) experiences. As conscious access results from severe competition in which external stimuli often have priority, we hypothesised that reducing external stimulation would allow individuals greater access to weakly activated inner knowledge. In Study 1, when participants experienced a TOT while answering a general knowledge question, they were given additional time to find the solution in a restricted (eyes closed?+?silence) or a non-restricted (eyes open?+?ambient noise) external stimulation environment. Results indicated that knowledge was more often retrieved when external stimulation was restricted than when not restricted. This result was replicated in a second study. Using an independent manipulation of the level of auditory and visual stimulation, Study 2 also indicated that the presence of visual stimulation was more disruptive for TOT resolution than the presence of auditory stimulation. Overall, the findings suggest that sensory restriction (especially of visual stimuli) facilitates the retrieval of weakly accessible knowledge through a greater processing of inner stimuli.