Music sight-reading expertise, visually disrupted score and eye movements

Previous studies have shown that performance at a defined level of music sight reading for pianists (6th Grade) is predictive of eye movement patterns (Waters, 1998) and that such patterns resemble those of text reading experts (Furneaux & Land, 1999; Sloboda, 1974; Truitt, 1997; Wolf, 1976). However, little is known about how expertise might affect eye movement patterns when the score has been visually disrupted using notational features that are unexpected or outside conventional presentation.The current project examined the effect of altering features of the music score on eye movement patterns of expert and non-expert music sight readers. Participants sight read specifically composed musical excerpts, which were then re-presented with the bar-lines removed, altered inter-note spacing and unpredictable beaming directions. Fixation and saccade characteristics were measured and compared between the two performances. It was expected that expert music sight readers would be most affected when the score was disrupted as they would be less capable of grouping notes into familiar, single units for efficient visual processing. Expert sight readers performed significantly faster than non-experts in both conditions: p<0.0001. Saccadic latency increased significantly for experts in the disrupted condition: p=0.0259, while non-experts increased slightly, not reaching significance. This suggests that the disruption of visual expectation was sufficient to cause a lengthening of saccade programming in the experts - an indication of interference with the chunking process. The resultant EM patterns for the non-experts demonstrated heightened non-expert behaviours: increased fixations of shorter duration.

Optimising the Structure-Function Relationship at the Locus of Deficit in Retinal Disease

Technologies such as optical coherence tomography have facilitated the visualization of anatomical tissues such as that of the retina. The availability of in vivo retinal anatomical data has led to the hypothesis that it may be able to accurately predict visual function from anatomical information. However, accurate determination of the structure-function relationship has remained elusive in part due to contributions of non-retinal sources of variability, thus imposing potential limitations in the fidelity of the relationship. Furthermore, differences in manifestation of functional loss due to different retinal loci of change (inner retina or outer retinal elements) have also been the subject of debate. Here, we assessed the application of a novel, more objective psychophysical paradigm to better characterize the relationship between functional and structural characteristics in the eye. Using ocular diseases with known loci of anatomical change (glaucoma, inner retinal loss; and retinitis pigmentosa, outer retinal loss), we compared conventional more subjective psychophysical techniques that may be contaminated by the presence of non-retinal sources of variability with our more objective approach. We show that stronger correlations between underlying retinal structure and visual function can be achieved across a breadth of anatomical change by using a more objective psychophysical paradigm. This was independent of the locus of structural loss (at the ganglion cells for glaucoma or photoreceptors for retinitis pigmentosa), highlighting the role of downstream retinal elements to serve as anatomical limiting factors for studying the structure-function relationship. By reducing the contribution of non-retinal sources of variability in psychophysical measurements, we herein provide a structure-function model with higher fidelity. This reinforces the need to carefully consider the psychophysical protocol when examining the structure-function relationship in sensory systems

Context and Crowding in Perceptual Learning on a Peripheral Contrast Discrimination Task: Context-Specificity in Contrast Learning

Perceptual learning is an improvement in sensitivity due to practice on a sensory task and is generally specific to the trained stimuli and/or tasks. The present study investigated the effect of stimulus configuration and crowding on perceptual learning in contrast discrimination in peripheral vision, and the effect of perceptual training on crowding in this task. 29 normally-sighted observers were trained to discriminate Gabor stimuli presented at 9° eccentricity with either identical or orthogonally oriented flankers with respect to the target (ISO and CROSS, respectively), or on an isolated target (CONTROL). Contrast discrimination thresholds were measured at various eccentricities and target-flanker separations before and after training in order to determine any learning transfer to untrained stimulus parameters. Perceptual learning was observed in all three training stimuli; however, greater improvement was obtained with training on ISO-oriented stimuli compared to CROSS-oriented and unflanked stimuli. This learning did not transfer to untrained stimulus configurations, eccentricities or target-flanker separations. A characteristic crowding effect was observed increasing with viewing eccentricity and decreasing with target-flanker separation before and after training in both configurations. The magnitude of crowding was reduced only at the trained eccentricity and target-flanker separation; therefore, learning for contrast discrimination and for crowding in the present study was configuration and location specific. Our findings suggest that stimulus configuration plays an important role in the magnitude of perceptual learning in contrast discrimination and suggest context-specificity in learning

Vection depends on perceived surface properties

Optic flow provides important information for the perception of self-motion and can be generated by both diffuse and specular reflectance. Previous self-motion research using virtual environments has primarily considered the properties of diffuse optic flow, but not of specular flow. We used graphical simulations to examine the extent to which visually induced self-motion (vection) is robust against the variations in optic flow generated by different surface optics. We found that specular flow alone was capable of generating vection that was equivalent in strength to that generated by diffuse flow (Exp. 1). To test whether this specularly induced vection depends on midlevel visual processing, we measured vection strengths under conditions in which the luminance polarity of specular highlights was inverted. We found that inverting the luminance of specular reflections impaired vection strength, as compared with the vection generated by conditions with ecologically correct diffuse and/or specular flow (Exp. 2). We also found these variations in vection strength were correlated with the perceived relief heights of the surfaces depicted in the image sequences. These findings together suggest that vection can be induced by pure specular flow and that it requires processing beyond the computation of retinal motion velocities-most likely, processes involved in the recovery of 3-D surface shape

Glass-pattern detection is tuned for stereo-depth

AbstractWe investigated the role of disparity information in the detection of global form. Glass patterns, which allow insight into processing at both local and global stages of form analysis, were used as stimuli. We determined how detection of concentric Glass patterns is affected by a disparity difference introduced between partner dots forming local dipoles (Experiment 1), and how detection is affected by the addition of randomly oriented dot-pairs (noise dots) at crossed and uncrossed disparities (Experiment 2). The first experiment showed that detection thresholds increased when partner dots were separated in depth at disparities greater than approximately 17min arc; the second experiment showed that noise dots disrupted the detection of form if they were presented at disparities of between approximately ±20min arc from the Glass pattern’s presentation depth plane. Our findings suggest that disparity information plays a role in the recovery of the image structure and, importantly, local and global form mechanisms were found to be selective for a small range of stereo-depths. We discuss the findings of our study in the light of current evidence indicating that a common neural substrate is responsible for the analysis of form and binocular disparity

A preliminary study : is the metronome harmful or helpful?

The metronome is a frequently used time-keeping tool in music instrument practice. However, if its speed is set beyond a comfortable level for the performer, their eye movement (EM) patterns can betray pressure that might have been placed on the visual processing system. The patterns of the eyes moving forward or back, (saccades); when the eye stops between saccades to take in visual information, (fixations) and/or the time taken to programme a saccade (saccadic latency), are indicative of processing ability and differ with expertise. What is not known is how various levels of speed demand might affect the EM patterns of musicians with differing sight-reading abilities. This study measured the EM patterns of expert and non-expert music sight-readers. Musical excerpts were played on a keyboard – initially at the individual’s fastest speed ensuring accuracy and then at a metronome setting of 120MM. The study showed that imposing excessive relative speed demands on less skilled sight-readers resulted in an inability to sustain performance. While this result might be expected, examination of the EM patterns of the experts indicated that smaller speed increments relative to their fastest accurate speed, resulted in less processing stress

Eye-movement efficiency and sight-reading expertise in woodwind players

The ability to sight-read traditional staff notation is an important skill for all classically trained musicians. Up until now, however, most research has focused on pianists, by comparing experts and novices. Eye movement studies are a niche area of sight-reading research, focusing on eye-hand span and perceptual span of musicians, mostly pianists. Research into eye movement of non-piano sight-reading is limited. Studies into eye movement of woodwind sight-reading were conducted in the 1980s and early 2000s, highlighting the need for new research using modern equipment. This pilot study examined the eye movements of six woodwind (flute, clarinet)undergraduates of intermediate-to-advanced skill level during sight-reading of scores of increased difficulty. The data was analysed in relation to expertise level and task difficulty, focusing on numbers of fixations and fixation durations. The results show that as music examples became more difficult the numbers of fixations increasedand fixation durations decreased;more experienced players with better sight-reading skills required less time to process musical notation; and participants with better sight-reading skills utilised fewer fixations to acquire information visually.The findings confirm that the efficiency of eye movements is related to instrumental and sight-reading expertise, and that task difficulty affects eye movement strategies

The Oculus Rift: a cost-effective tool for studying visual-vestibular interactions in self-motion perception

For years now, virtual reality devices have been applied in the field of vision science in an attempt to improve our understanding of perceptual principles underlying the experience of self-motion. Some of this research has been concerned with exploring factors involved in the visually-induced illusory perception of self-motion, known as vection. We examined the usefulness of the cost-effective Oculus Rift in generating vection in seated observers. This device has the capacity to display optic flow in world coordinates by compensating for tracked changes in 3D head orientation. We measured vection strength in three conditions of visual compensation for head movement: compensated, uncompensated, and inversely compensated. During presentation of optic flow, the observer was instructed to make periodic head oscillations (±22° horizontal excursions at approximately 0.53 Hz). We found that vection was best in the compensated condition, and was weakest in the inversely compensated condition. Surprisingly, vection was always better in passive viewing conditions, compared with conditions where active head rotations were performed. These findings suggest that vection is highly dependent on interactions between visual, vestibular and proprioceptive information, and may be highly sensitive to limitations of temporal lag in visual-vestibular coupling using this system