Attention to Visual Feedback in Motor Learning

Visual guidance and movement to a stop were used to train subjects to make a simple movement without experiencing error in practice. Movement to a stop led to test performance as accurate as that after training with KR, but visual guidance did not. If a continuous visual cue as well as a stop were present during practice, subjects also performed less accurately, although they did not need to attend to the visual cue. All types of training were better than no training at all. Results are discussed in terms of the role of visual feedback in the development and assessment of programs for movement.     

Attention to visual feedback in motor learning

Visual guidance and movement to a stop were used to train subjects to make a simple movement without experiencing error in practice. Movement to a stop led to test performance as accurate as that after training with KR, but visual guidance did not. If a continuous visual cue as well as a stop were present during practice, subjects also performed less accurately, although they did not need to attend to the visual cue. All types of training were better than no training at all. Results are discussed in terms of the role of visual feedback in the development and assessment of programs for movement.     

The effect of visual guidance on the acquisition of a simple motor task

Subjects were required to learn to depress a bar using concurrent visual feedback, which was removed for test. The overshooting found in test is attributed to visual dominance of the feedback traces; the way in which it occurs is not clear, since the reduction of the ratio of movement to display gain from 1:15 to 1:7.5 did not reduce overshooting. Performance improved after extended practice, but the direction of error remained positive. The results are discussed in terms of motor programming and feedback control of movement and are interpreted as evidence against Adams' (1971) two-trace theory.     

Distributed Control in Rapid Sequential Aiming Responses

The preparation and on-line control of short, rapid sequential aiming responses were studied in 3 experiments. Participants (N = 12 in Experiments 1 and 2, and 20 in Experiment 3) produced 3-segment responses (a) within self-initiation, simple reaction time (RT), and choice RT paradigms (Experiment 1); (b) without visual feedback under self-initiation conditions (Experiment 2); and (c) with and without visual feedback under simple RT conditions (Experiment 3). In all conditions in which participants initiated movement in response to an external imperative signal, the 2nd response segment was performed consistently slower than preceding and succeeding response segments. That pattern of segmental movement times was found whether or not visual feedback was available but was not evident when participants self-initiated their responses with or without visual feedback. The findings rule out the possibility that subjects' use of visual feedback is responsible for the slowing of the 2nd response segment under RT conditions and suggest that the programming of rapid sequential aiming responses can be distributed in pre- and postinitiation intervals.     

Attentional capture of objects referred to by spoken language

Participants saw a small number of objects in a visual display and performed a visual detection or visual-discrimination task in the context of task-irrelevant spoken distractors. In each experiment, a visual cue was presented 400 ms after the onset of a spoken word. In experiments 1 and 2, the cue was an isoluminant color change and participants generated an eye movement to the target object. In experiment 1, responses were slower when the spoken word referred to the distractor object than when it referred to the target object. In experiment 2, responses were slower when the spoken word referred to a distractor object than when it referred to an object not in the display. In experiment 3, the cue was a small shift in location of the target object and participants indicated the direction of the shift. Responses were slowest when the word referred to the distractor object, faster when the word did not have a referent, and fastest when the word referred to the target object. Taken together, the results demonstrate that referents of spoken words capture attention.     

Peak velocity as a cue in audiovisual synchrony perception of rhythmic stimuli

This study investigated audiovisual synchrony perception in a rhythmic context, where the sound was not consequent upon the observed movement. Participants judged synchrony between a bouncing point-light figure and an auditory rhythm in two experiments. Two questions were of interest: (1) whether the reference in the visual movement, with which the auditory beat should coincide, relies on a position or a velocity cue; (2) whether the figure form and motion profile affect synchrony perception. Experiment 1 required synchrony judgment with regard to the same (lowest) position of the movement in four visual conditions: two figure forms (human or non-human) combined with two motion profiles (human or ball trajectory). Whereas figure form did not affect synchrony perception, the point of subjective simultaneity differed between the two motions, suggesting that participants adopted the peak velocity in each downward trajectory as their visual reference. Experiment 2 further demonstrated that, when judgment was required with regard to the highest position, the maximal synchrony response was considerably low for ball motion, which lacked a peak velocity in the upward trajectory. The finding of peak velocity as a cue parallels results of visuomotor synchronization tasks employing biological stimuli, suggesting that synchrony judgment with rhythmic motions relies on the perceived visual beat.     

Cue combination in human spatial navigation

This project investigated the ways in which visual cues and bodily cues from self-motion are combined in spatial navigation. Participants completed a homing task in an immersive virtual environment. In Experiments 1A and 1B, the reliability of visual cues and self-motion cues was manipulated independently and within-participants. Results showed that participants weighted visual cues and self-motion cues based on their relative reliability and integrated these two cue types optimally or near-optimally according to Bayesian principles under most conditions. In Experiment 2, the stability of visual cues was manipulated across trials. Results indicated that cue instability affected cue weights indirectly by influencing cue reliability. Experiment 3 was designed to mislead participants about cue reliability by providing distorted feedback on the accuracy of their performance. Participants received feedback that their performance with visual cues was better and that their performance with self-motion cues was worse than it actually was or received the inverse feedback. Positive feedback on the accuracy of performance with a given cue improved the relative precision of performance with that cue. Bayesian principles still held for the most part. Experiment 4 examined the relations among the variability of performance, rated confidence in performance, cue weights, and spatial abilities. Participants took part in the homing task over two days and rated confidence in their performance after every trial. Cue relative confidence and cue relative reliability had unique contributions to observed cue weights. The variability of performance was less stable than rated confidence over time. Participants with higher mental rotation scores performed relatively better with self-motion cues than visual cues. Across all four experiments, consistent correlations were found between observed weights assigned to cues and relative reliability of cues, demonstrating that the cue-weighting process followed Bayesian principles. Results also pointed to the important role of subjective evaluation of performance in the cue-weighting process and led to a new conceptualization of cue reliability in human spatial navigation.     

Visual and haptic feedback contribute to tuning and online control during object manipulation

The authors employed a virtual environment to investigate how humans use haptic and visual feedback in a simple, rhythmic object-manipulation task. The authors hypothesized that feedback would help participants identify the appropriate resonant frequency and perform online control adjustments. The 1st test was whether sensory feedback is needed at all; the 2nd was whether the motor system combines visual and haptic feedback to improve performance. Task performance was quantified in terms of work performed on the virtual inertia, ability to identify the correct rhythm, and variability of movement. Strict feedforward control was found to be ineffective for this task, even when participants had previous knowledge of the rhythm. Participants (N = 11) performed far better when feedback was available (11 times more work, 2.2 times more precise frequency, 30% less variability; p < .05 for all 3 performance measures). Using sensory feedback, participants were able to rapidly identify 4 different spring-inertia systems without foreknowledge of the corresponding resonant frequencies. They performed over 20% more work with 24% less variability when provided with both visual and haptic feedback than they did with either feedback channel alone (p < .05), providing evidence that they integrated online sensory channels. Whereas feedforward control alone led to poor performance, feedback control led to fast tuning or calibration of control according to the resonant frequency of the object, and to better control of the rhythmic movement itself.     

Bimanual circling in deafferented patients: Evidence for a role of visual forward models

The present study investigated the role of ideation and visual feedback, and their interaction in movement control in the absence of somatosensory feedback, with the hypothesis that visual imagery and internal visual models may play a crucial role in performance even without feedback. Two chronically deafferented participants, GL and IW, circled bimanually two occluded cranks first without vision and then with hand‐congruent and hand‐incongruent visual feedback provided by visible flags. Without vision, GL was unable to circle the cranks. In contrast, IW performed spontaneously a symmetric pattern. Again without feedback, IW performed an instructed symmetric crank pattern well, but was unable to perform anti‐phase cranking. With hand‐congruent visual feedback, GL and IW were able to perform both symmetric and anti‐phase movements, with symmetry being more accurate. Visual feedback during preceding trials made possible trials without visual feedback in GL and improved anti‐phase trials in IW. Frequency‐transformed incongruent visual feedback resulted in poor performance in part due to unsuitable hand‐related strategies. However, IW improved in the latter task after detailed explanations of the condition. In conclusion, we suggest that both participants use visual imagery and visual forward models to control their hand movements. Visual updating of the forward model also improves performance with no vision. In addition, IW seemed to have been able to move from a focus on hand position to one on the transformed visual feedback to improve movement control in the incongruent feedback/movement condition.     

The relationship between types of feedback, gain of a display and feedback precision in acquisition of a simple motor task

Three experiments are reported which investigate the role of concurrent and terminal feedback in the acquisition of a discrete positioning task. Experiments I and II compare the efficiency of concurrent visual feedback (CVF) and terminal visual feedback (TVF) as training methods when the gain of the visual display is varied from 1:1 to 4:1. There is a consistent interaction between feedback method and gain of the display over the recall trials. Concurrent visual feedback is inferior to terminal visual feedback at a gain of 4:1 in Experiment I and when the displayed and actual movement directions differ (Experiment II). Experiment III explores the relationship between concurrent and terminal feedback when feedback is of a digital form and its precision is varied. Concurrent feedback is worse as a training method although there is no interaction between feedback method and precision of feedback. These findings are discussed in the light of a variety of factors which could contribute to the inferiority of concurrent feedback as a training method.     

Evidence for internal representation of a static nonlinearity in a visual tracking task

A group of 24 participants was given over 3 h practice at a visual pursuit tracking task with a pronounced static nonlinearity between movement of the joystick and the resulting deflection of the response cursor. The aim was twofold: (1) to determine whether or not participants compensated for the nonlinearity and (2) to show that any such compensation involved the formation of an internal representation of the nonlinear relationship between movement of the joystick as sensed kinaesthetically and/or visually and movement of the response cursor as sensed visually. Results show that participants introduce partial compensation for the static nonlinearity. Furthermore, partial compensation was present even during open-loop tracking when participants were deprived of visual feedback of the position of the response cursor. This implies that participants are able to form an internal representation of the nonlinear relationship between movement of the joystick and the resulting movement of the response cursor.     

Aging and guided visual search: the role of visual working memory

In the present study, we examined age-related differences in utilizing learned associations to guide visual search. Participants viewed an object cue that was associated with 1 or 2 target colors, followed by a search array. Older adults showed slower RTs, larger visual search slopes, and reduced cue–target association knowledge than did younger adults. We also found increased search RTs and higher error rates when the cue was associated with 2 colors instead of 1. However, visual search slopes did not vary with the number of associated colors. This indicates that participants could activate multiple templates simultaneously to guide the search or retrieve associative information directly from the long-term memory. Furthermore, regression analyses showed that VWMC can predict both visual search performances and cue–target association knowledge. More broadly, our results demonstrate that VWMC can modify the effects of age on cued visual search performance.     

Activation of learned action sequences by auditory feedback

The present research addressed whether auditory feedback associated with a learned action sequence can activate the action representation of that sequence. Nonpianist participants learned to perform two melodies at a piano keyboard repeatedly during a trial. The participants heard feedback either from the melody they were performing (normal feedback) or from the other learned melody (termed alternate feedback). An additional tone functioned as an instruction cue to either switch melodies or continue the current melody. Following the instruction cues, participants typically paused just before switching, and paused similarly during trials with a continue cue. Participants paused longer after a continue cue when they experienced alternate rather than normal feedback. This effect was specific to instruction cues positioned at weak metrical accents—positions at which participants were less likely to switch overall. Feedback did not influence timing on switch trials. These findings indicate that influences of auditory feedback can activate learned action sequences, leading to longer latencies associated with cue evaluation.     

Tool characteristics in imagery of tool actions

Are tool characteristics represented in imagined tool actions? In two experiments participants imagined and executed coloring rectangles with a thick and a thin pen. In Experiment 2, an additional execution condition without visual feedback of coloring allowed us to dissociate between the relevance of kinesthetic and visual feedback. Pen thickness influenced coloring durations in all conditions, indicating that characteristics of a simple tool are represented during imagery. Imagination was shorter than execution, indicating that imagination may be less detailed than execution. Execution without visual feedback was even shorter than imagination, indicating that vision is more important than kinesthesis for differences between imagination and execution, and that either imagining the movement, inhibiting movement execution or imagining the progress of the action is effortful during imagery. In conclusion, characteristics of simple tools are represented in imagined tool actions but the representation of tools’ effects may not always be adequate.     

A Test of the Adams-Creamer Decay Hypothesis for the Timing of Motor Responses

The Adams-Creamer hypothesis states that S uses the decay of proprioceptive feedback from an early portion of a movement to cue a timed response at some later time. This hypothesis was tested by creating passive left-arm movement in one group and withholding it from another, and having Ss make a right-hand response when exactly 2.0 sec. had elapsed since the end of the movement Ss with left-arm feedback had less absolute and algebraic error, and greater within-S consistency than did the no-movement control Ss and, when KR was withdrawn, Ss with left-arm movement regressed less than did Ss without the left-arm movement, which provided 2 lines of support for the decay hypothesis.     

线索类型对阈下注视线索效应的影响

实验结合连续闪烁抑制范式和线索化范式, 通过操纵直视面孔和斜视面孔的呈现方式, 考察了动静线索类型对注视线索效应的影响。结果表明：两种线索在阈上条件都能产生注视线索效应, 且动态线索诱发的效应更大; 无意识条件下有且仅有动态注视线索能诱发注视线索效应。这说明眼睛运动是产生阈下注视线索效应的必要条件; 眼睛运动会增强阈上注视线索效应, 静态注视线索效应依赖于意识。研究结果支持了社会知觉与心理理论交互模型。     

Reactions to objective self-awareness

In order to determine reactions to objective self-awareness, 96 female undergraduates received either positive or negative feedback on a “creativity” task prior to being given an opportunity to write a response to a visual cue. Half of the subjects were made objectively self-aware, via a mirror, during the visual cue task; half were not. In addition, half of the subjects were led to believe that the visual cue task was highly related to creativity, while half learned that the task was low in relevance. A “longer the response, the better” standard of correctness was established for all subjects. As predicted, the results indicated that when made objectively self-aware, subjects who received negative feedback wrote more in response to the visual cue than did those who received positive feedback, a difference which was not obtained for the subjectively self-aware subjects. The task relevance manipulation also produced a significant main effect. A similar pattern of results was obtained on a measure of the time spent on the task. The implications of the results for objective self-awareness theory are considered.     

Online versus offline processing of visual feedback in the control of movement amplitude

Researchers have suggested that visual feedback not only plays a role in the correction of errors during movement execution but that visual feedback from a completed movement is processed offline to improve programming on upcoming trials. In the present study, we examined the potential contribution of online and offline processing of visual feedback by analysing spatial variability at various kinematic landmarks in the limb trajectory (peak acceleration, peak velocity, peak negative acceleration and movement end). Participants performed a single degree of freedom video aiming task with and without vision of the cursor under four criterion movement times (225, 300, 375 and 450 ms). For movement times of 225 and 300 ms, the full vision condition was less variable than the no vision condition. However, the form of the variability profiles did not differ between visual conditions suggesting that the contribution of visual feedback was due to offline processes. In the 375 and 450 ms conditions, there was evidence for both online and offline control as the form of the variability profiles differed significantly between visual conditions.     

Interviewing preschoolers from low- and middle-SES communities: a test of the narrative elaboration recall improvement technique.

Tested the effectiveness of Narrative Elaboration (NE), a memory enhancement and interview preparation technique, with 99 preschool children from middle- and low-socioeconomic status (SES) communities. Half were trained with the NE intervention to utilize generic visual cue cards to provide forensically relevant details within four information categories: participants, settings, actions, conversation. One day after the NE training, interviewers asked participants to recount an event staged 1 week earlier. Analyses revealed that NE-trained children from both SES levels recalled significantly more about the event than control children, without producing more errors, particularly when given an opportunity to elaborate on initial free recall using the visual cue cards. No such difference in free recall alone was found. Additionally, preschoolers from low-SES communities generated more errors than their middle-SES counterparts, regardless of treatment condition.     

Working memory can enhance unconscious visual perception

We demonstrate that unconscious processing of a stimulus property can be enhanced when there is a match between the contents of working memory and the stimulus presented in the visual field. Participants first held a cue (a colored circle) in working memory and then searched for a brief masked target shape presented simultaneously with a distractor shape. When participants reported having no awareness of the target shape at all, search performance was more accurate in the valid condition, where the target matched the cue in color, than in the neutral condition, where the target mismatched the cue. This effect cannot be attributed to bottom-up perceptual priming from the presentation of a memory cue, because unconscious perception was not enhanced when the cue was merely perceptually identified but not actively held in working memory. These findings suggest that reentrant feedback from the contents of working memory modulates unconscious visual perception.