Imagery ability and the identification of hands: a chronometric analysis

The effect of handedness on mental rotation of hands: a systematic review and meta-analysis

Body-specific mental rotation is thought to rely upon internal representations of motor actions. Handedness is a source of distinctly different motor experience that shapes the development of such internal representations. Yet, the influence of handedness upon hand mental rotation has never been systematically evaluated. Five databases were searched for studies evaluating hand left/right judgement tasks in adults. Two independent reviewers performed screening, data extraction, and critical appraisal. Eighty-seven datasets were included, with 72 datasets pooled; all had unclear/high risk of bias. Meta-analyses showed that right-handers were faster, but not more accurate, than left-handers at hand mental rotation. A unique effect of handedness was found on performance facilitation for images corresponding to the dominant hand. Meta-analyses showed that right-handers were quicker at identifying images of right hands than left hands-a dominance advantage not evident in left-handers. Differing hand representations (more lateralised hand dominance in right-handers) likely underpin these findings. Given potential differences between hand preference and motor performance, future research exploring their distinct contributions to mental rotation is warranted.

CHRONIC RESPONSES OF PHYSICAL AND IMAGERY TRAINING ON PARKINSON’S DISEASE

ABSTRACT Introduction Physical and motor imagery training is known to induce positive results in the quality of life of patients with neurodegenerative diseases. However, it is not known which effects are achievable when both types of training are combined. Objective This study aimed to investigate the effects of a combination of physical and imagery training on neurotrophin levels, the perception of body dimensions and activities of daily living (ADL) in individuals with Parkinson’s disease (PD). Methods Over an 8-week period, thirteen subjects underwent one hour of aerobic training in combination with twice-weekly imagery training (MIT). The following parameters were measured: brain-derived neurotrophic factor (BDNF) serum levels, level of dependence for activities of daily living (ADLs – Basic [ABDL] and Instrumental [AIDL]), perception of body dimensions and hand laterality test. Results Physical training combined with MIT increased serum BDNF levels in a non-statistically significant manner by 128.08% (88.81 ± 111.83 pg/ml versus 202.56 ± 183.43 pg/ml, p= 0.068). Delta BDNF showed a mean variation of 218.05 ± 547.55% (ES = 1.04). Perception of body dimensions and hand recognition reaction time both improved, but not in a non-statistically significant manner. ADLs (9.52% in ABDLs and 17.76% in AIDLs) improved in a statistically significant manner. Conclusion Despite the small number of subjects, study limitations, and the fact that most results were non-statistically significant, the results obtained here indicate clinical improvement associated with the neurotrophic action of BDNF on the perception of body dimensions and the functional capacity of Parkinson’s disease subjects. Level of evidence II, Therapeutic studies–Investigation of treatment results.

Effects of hand orientation on motor imagery--event related potentials suggest kinesthetic motor imagery to solve the hand laterality judgment task

Motor imagery (MI) refers to the process of imagining the execution of a specific motor action without actually producing an overt movement. Two forms of MI have been distinguished: visual MI and kinesthetic MI. To distinguish between these forms of MI we employed an event related potential (ERP) study to measure interference effects induced by hand orientation manipulations in a hand laterality judgement task. We hypothesized that this manipulation should only affect kinesthetic MI but not visual MI. The ERPs elicited by rotated hand stimuli contained the classic rotation related negativity (RRN) with respect to palm view stimuli. We observed that laterally rotated stimuli led to a more marked RRN than medially rotated stimuli. This RRN effect was observed when participants had their hands positioned in either a straight (control) or an inward rotated posture, but not when their hands were positioned in an outward rotated posture. Posture effects on the ERP-RRN have not previously been studied. Apparently, a congruent hand posture (hands positioned in an outward rotated fashion) facilitates the judgement of the otherwise more demanding laterally rotated hand stimuli. These ERP findings support a kinesthetic interpretation of MI involved in solving the hand laterality judgement task. The RRN may be used as a non-invasive marker for kinesthetic MI and seems useful in revealing the covert behavior of MI in e.g. rehabilitation programs.

On the demystification of mental imagery

What might a theory of mental imagery look like, and how might one begin formulating such a theory? These are the central questions addressed in the present paper. The first section outlines the general research direction taken here and provides an overview of the empirical foundations of our theory of image representation and processing. Four issues are considered in succession, and the relevant results of experiments are presented and discussed. The second section begins with a discussion of the proper form for a cognitive theory, and the distinction between a theory and a model is developed. Following this, the present theory and computer simulation model are introduced. This theory specifies the nature of the internal representations (data structures) and the processes that operate on them when one generates, inspects, or transforms mental images. In the third, concluding, section we consider three very different kinds of objections to the present research program, one hinging on the possibility of experimental artifacts in the data, and the others turning on metatheoretical commitments about the form of a cognitive theory. Finally, we discuss how one ought best to evaluate theories and models of the sort developed here.

Motor processes in children's imagery: the case of mental rotation of hands

In a mental rotation task, children 5 and 6 years of age and adults had to decide as quickly as possible if a photograph of a hand showed a left or a right limb. The visually presented hands were left and right hands in palm or in back view, presented in four different angles of rotation. Participants had to give their responses with their own hands either in a regular, palms-down posture or in an inverted, palms-up posture. For both children and adults, variation of the posture of their own hand had a significant effect. Reaction times were longer the more awkward it was to bring their own hand into the position shown in the stimulus photograph. These results, together with other converging evidence, strongly suggest that young children's kinetic imagery is guided by motor processes, even more so than adults'.

The influence of spatial reference frames on imagined object- and viewer rotations

The human visual system can represent an object's spatial structure with respect to multiple frames of reference. It can also utilize multiple reference frames to mentally transform such representations. Recent studies have shown that performance on some mental transformations is not equivalent: Imagined object rotations tend to be more difficult than imagined viewer rotations. We reviewed several related research domains to understand this discrepancy in terms of the different reference frames associated with each imagined movement. An examination of the mental rotation literature revealed that observers' difficulties in predicting an object's rotational outcome may stem from a general deficit with imagining the cohesive rotation of the object's intrinsic frame. Such judgments are thus more reliant on supplementary information provided by other frames, such as the environmental frame. In contrast, as assessed in motor imagery and other studies, imagined rotations of the viewer's relative frame are performed cohesively and are thus mostly immune to effects of other frames.

The Verbalizer-Visualizer Questionnaire: a review

The psychometric properties of Richardson's 1977 Verbalizer-Visualizer Questionnaire have been studied by analyzing papers in which this questionnaire was employed. Such review showed that the Verbalizer-Visualizer Questionnaire does not measure a unidimensional construct and does not predict the actual use of mental imagery in thinking. Further, a lack of long-term reliability of the questionnaire emerged. In conclusion, use of the questionnaire to assess the verbal-visual cognitive style appears questionable.

Effects of imagery ability and instructions on recall of information on spatial location

The purpose of this study was to investigate the role of ability to image visually and imagery instructions on recall of information on spatial locations. 18 high and 18 low visual-imagers reproduced six spatial locations in each of six conditions of reproduction: immediate reproduction, 10-sec., 20-sec., 30-sec., and 40-sec. unfilled retention intervals and a 30-sec. distraction condition in which subjects performed a competing visualization task. Half of the high and low visual-imagers received instructions to use visual imagery as a retention strategy, while the others received no instructions. Analysis indicated that high visual-imagers reproduced spatial locations with less error than low visual-imagers. In addition, the distraction condition disrupted recall for all subjects. However, instructions for imagery did not influence recall.

Optical information and practice in the discrimination of 3-D mirror-reflected objects

Two studies of the discrimination of three-dimensional mirror-reflected objects were concerned with the influence of practice and stimulus information for shape, specifically binocular information and perspective transformations. In the first study subjects made 'same-different' responses to successively presented pairs of real objects, under binocular and monocular viewing conditions. In the second study subjects viewed object pairs on a rotating turntable, in five different displays. Neither binocular information nor perspective transformations contributed to isomorph discrimination. In both studies mental rotation and other less well specified strategies were employed. After practice, in contrast to previous reports, five of the six subjects in these studies produced reaction times unrelated to the orientation difference between the objects. These practice effects may reflect either extremely rapid rotation rates, the detection of rotationally invariant features, or the use of multiple strategies.

Imagery Ability in Recall of Distance and Location Information

The role of visual imagery in short-term retention of movement end locations and distances was examined by comparing performances of subjects with extreme scores on the space relations section of the Differential Aptitude Test. Twelve HIGHS and twelve LOWS were tested on reproduction accuracy of six distances and six end locations immediately following presentation a 30-sec rest, a 30 sec imaginal rehearsal condition, and a 30-sec imaginal distraction condition. Initial analysis of the data provided little support for the hypothesis that HIGHS would reproduce criterion locations with more accuracy than LOWS. However, when scores of HIGHS reporting use of an imaginal coding strategy (HIGHS) were compared with LOWS who did not (LOWS), several expected findings were disclosed. HIGHS reproduced end locations with significantly less error in the immediate and imaginal rehearsal conditions, and as expected, accuracy scores for HIGHS and LOWS did not differ for the distance task. The findings suggest that when subjects employ an imaginal coding strategy, visual imagery ability may be an important factor in the retention of location information, but of little functional significance in the recall of distance.