Acquisition of locational information about reference points during locomotion with and without a concurrent task: Effects of number of reference points

Maintenance of orientation relative to reference points along a locomotion path and acquisition of locational information about these reference points were investigated by requiring subjects with and without a concurrent backwards counting task to walk in alleys and estimate direction and distance to the reference points when stopped. One or three reference points were presented on each trial in different groups of subjects. Acquisition of locational information was indicated by decreased latencies and variable errors with repeated exposure to the same locomotion path. Neither the larger number of reference points nor the concurrent task seemed to affect acquisition, but both lead to increased latencies indicating that the subjects under these conditions were unable to keep track of the locations of the reference points whilst walking. However, they may still have been able to infer these locations after the locomotion path had been traversed.     

Acquisition of locational information about reference points during blindfolded and sighted locomotion: Effects of a concurrent task and locomotion paths

Acquisition of cognitive maps (locational information about reference points) was investigated by requiring subjects to walk repeatedly according to paths consisting of 2, 4 and 6 linear segments. The starting point of each path was designated as a reference point, to which direction and distance were estimated by the subjects at the end of the path. Acquisition was indicated by the finding that variable errors and latencies decreased across blocks of trials. Interfering with central processing of locational information during locomotion by means of a concurrent task, while impairing orientation performance, did not seem to prevent acquisition. As suggested by an increase in latencies with the number of path segments, the subjects performing the concurrent task may have been able to infer and store the location of the starting point after walking. Finally, orientation performance did not improve for blindfolded subjects, probably because they were unable to use stored information about locations.     

Processing of information about location during locomotion: Effects of a concurrent task and locomotion patterns

How maintenance of orientation during locomotion in unfamiliar environments is accomplished was investigated by having subjects walk behind a moving light line (1.12 m/sec) in a dark room and, from a stopping point, numerically estimate direction and distance to the starting point. Two linear distances (5.0–8.4 m) and the angle of direction change (45, 90, and 135 deg) were orthogonally varied as 12 locomotion patterns. Eight high-school students were assigned to each of three conditions, two in which the starting point was invisible, one in which it was visible. In one of the former conditions the subjects counted backwards rapidly during walking. Lower accuracy and longer latency times were found in the counting condition whilst the other two conditions differed only slightly. The results suggested that accurate maintenance of orientation is achieved by recurrent encoding, coordination and decoding of information about direction change and locomotion distance, processes which demand central processing capacity and therefore are interfered with by a concurrent task.     

Order information in short-term memory and time estimation

In previous experiments, the amount of interference between time production and visual or memory search tasks was shown not to be related to the level of difficulty of the search task per se, but instead to the amount of processing in short-term memory required in the search task. The first experiment of the present study verified whether the amount of interference between time production and a short-term memory task may be related to the level of difficulty of the short-term memory task. Two versions of a memory task, with and without processing of order information, were combined with a temporal interval production task in a concurrent processing condition. As is shown in a control reaction time task, processing order information increased the level of difficulty of the memory search task. In the concurrent processing condition, the interference between short-term memory processing and time production was stronger when the level of difficulty of the short-term memory search task was increased by requiring that order information be processed. The results of Experiment 2 showed that the amount of interference between a similar short-term memory task and time production seems not to be related to the amount of order information that must be maintained during the time production task. This dissociation between the effects of processing and the maintenance of order information is compatible with a similar dissociation, observed in previous experiments, between the effects of processing and those of maintaining item information in short-term memory on concurrent time production.     

Memory access: The effects of fact-oriented versus problem-oriented acquisition

This study examined the effects of similarity between the processing of acquisition and the processing of test materials on performance in a problem solving task. Previous work by Perfetto, Bransford, and Franks (1983) demonstrated that uninformed subjects’ failure to utilize relevant acquisition information in a later problem solving task is the result of a failure to spontaneously access such information. The present study demonstrated that spontaneous access can be enhanced when both acquisition and test materials are processed in a similar manner, that is, in a problem-oriented manner. Furthermore, the present findings indicate that the processing similarity leading to enhanced access is specific to particular acquisition and test items, rather than a general problem solving set induced at acquisition and the subsequent testing situation. Results are interpreted within a transfer-appropriate processing perspective.     

Electrophysiological evidence of central interference in the control of visuospatial attention

Visuospatial attention can be deployed to different locations in space without movement of the eyes. A large body of human electrophysiological studies reveals enhanced sensory-perceptual responses to stimuli that appear at an attended location. However, it is not clear that the mechanisms that underlie visuospatial attention are under the control of attention mechanisms that limit central processing in multiple-task situations. We investigated this question by incorporating a visual task that required the deployment of visuospatial attention as the second task of psychological refractory period (PRP) dual-task paradigms. The N2pc component of the event-related potential was used as an electrophysiological index of the moment-by-moment deployment of visuospatial attention to monitor when and where observers were attending while they performed concurrent central processing known to cause the PRP effect. Electrophysiological evidence shows that central processing interfered with the N2pc, suggesting that visuospatial attention is under the control of capacity-limited central mechanisms.     

The impact of concurrent visual feedback on coding of on-line and pre-planned movement sequences

The purpose of this study was to determine the extent to which participants could effectively switch from on-line (OL) to pre-planned (PP) control (or vice versa) depending on previous practice conditions and whether concurrent visual feedback was available during transfer testing. The task was to reproduce a 2000 ms spatial–temporal pattern of a sequence of elbow flexions and extensions. Participants were randomly assigned to one of two practice conditions termed OL or PP. In the OL condition the criterion waveform and the cursor were provided during movement production while this information was withheld during movement production for the PP condition. A retention test and two effector transfer tests were administered to half of the participants in each acquisition conditions under OL conditions and the other half under PP conditions. The mirror effector transfer test required the same pattern of muscle activation and limb joint angles as required during acquisition. The non-mirror transfer test required movements to the same visual–spatial locations as experienced during acquisition. The results indicated that when visual information was available during the transfer tests performers could switch from PP to OL. When visual information was withdrawn, they shifted from the OL to the PP-control mode. This finding suggests that performers adopt a mode of control consistent with the feedback conditions provided during testing.     

Effects of gaze angle and extraretinal eye movement information on visual locomotion control

This study tested effects of gaze-movement angle and extraretinal eye movement information on performance in a locomotion control task. Subjects hovered in a virtual scene to maintain position against optically simulated gusts. Gaze angle was manipulated by varying the simulated camera pitch orientation. Availability of extraretinal information was manipulated via simulated-pursuit fixation. In Experiment 1, subjects performed better when the camera faced a location on the ground than when it pointed toward the horizon. Experiment 2 tested whether this gain was influenced by availability of appropriate eye movements. Subjects performed slightly better when the camera pointed at nearby than at distant terrain, both in displays that did and in displays that did not simulate pursuit fixation. This suggested that subjects could perform the task using geometric image transformations, with or without appropriate eye movements. Experiment 3 tested more rigorously the relative importance of gaze angle and extraretinal information over a greater range of camera orientations; although subjects could use image transformations alone to control position adequately with a distant point of regard, they required eye movements for optimal performance when viewing nearby terrain.     

Spatial updating of locations specified by 3-d sound and spatial language

Blind and blindfolded sighted observers were presented with auditory stimuli specifying target locations. The stimulus was either sound from a loudspeaker or spatial language (e.g., "2 o'clock, 16 ft"). On each trial, an observer attempted to walk to the target location along a direct or indirect path. The ability to mentally keep track of the target location without concurrent perceptual information about it (spatial updating) was assessed in terms of the separation between the stopping points for the 2 paths. Updating performance was very nearly the same for the 2 modalities, indicating that once an internal representation of a location has been determined, subsequent updating performance is nearly independent of the modality used to specify the representation.     

Incidental retrieval-induced forgetting of location information

Retrieval-induced forgetting (RIF) has been studied with different types of tests and materials. However, RIF has always been tested on the items' central features, and there is no information on whether inhibition also extends to peripheral features of the events in which the items are embedded. In two experiments, we specifically tested the presence of RIF in a task in which recall of peripheral information was required. After a standard retrieval practice task oriented to item identity, participants were cued with colors (Exp. 1) or with the items themselves (Exp. 2) and asked to recall the screen locations where the items had been displayed during the study phase. RIF for locations was observed after retrieval practice, an effect that was not present when participants were asked to read instead of retrieving the items. Our findings provide evidence that peripheral location information associated with an item during study can be also inhibited when the retrieval conditions promote the inhibition of more central, item identity information.     

On the coding of spatial information

Two experiments studied recall of objects and their locations in an intentional-incidental learning paradigm. When studying spatial information, the usual incidental condition is not truly incidental, because subjects often deliberately use locations to help organize objects for recall. Therefore, a true incidental task was devised in which neither objects nor locations were expected to be recalled and for which explicit encoding of locations was irrelevant. There was only a small loss in recall of objects or their locations in a true incidental condition. It was concluded that a great deal of location information is automatically coded into long-term memory storage in the sense that active processing is not required. The data were contrasted with incidental processing of other attributes, such as color. Although adults performed better than children, there were no age-related interactions, indicating similarity of functioning at all ages studied.     

Learning motor synergies makes use of information on muscular load

Prism adaptation, a form of procedural learning, requires the integration of visual and motor information for its proper acquisition. Although the role of the visual feedback has begun to be understood, the nature of the motor information necessary for the development of the adaptation remains unknown. In this work we have tested the idea that modifying the arm load at different stages of the adaptation process, and the ensuing change of motor information perceived by the subjects, would modify the final properties of the adaptation. We trained a set of subjects to throw balls to a target while wearing prism glasses and varied the weight of their arms at different time points during the task. We observed that the acquisition of the adaptation was not affected by the change in load. However, its persistence (i.e., the aftereffect) was reduced when tested under a weight condition different from the training trials. Furthermore, when the training weight conditions were restored later during testing, a second, late aftereffect was unmasked, suggesting that the missing aftereffect did not disappear but had remained latent. Our results show that the internal representation of a motor memory incorporates information about load conditions and that the memory stored under a specific weight condition can be fully retrieved only when the original training condition is restored.     

The effects of routine strength on adaptation and information search in recurrent decision making

The strength of decision routines was manipulated within a computer-controlled micro world simulation involving recurrent decision making. During a learning phase, participants were led to prefer a certain brand of an industrial good either about 15 times in a weak routine or about 30 times in a strong routine condition. In the test phase of Experiment 1, participants were confronted with changes in the microworld that rendered the routine obsolete. Routine maintenance over a series of repeated acquisition decisions was assessed as the major dependent variable. Although new information clearly suggested that a deviation from the routine would be beneficial, strong routine participants were more likely to maintain the routine compared to weak routine participants and a control group in which a comparable option (same outcome probabilities as the routine) carried an unfamiliar brand label. Experiment 2 investigated the effects of routine strength on information search. After having learned the routine, participants were asked to make one final decision involving the routine. The task was either framed as being similar to the learning task or as being novel. Before making the final decision, participants were asked to consider new information about the alternatives. Strong routine participants in the familiar task condition preferred information that favored the routine and avoided unfavorable information. If the task was framed as being novel, such confirmation biases disappeared completely. In contrast, weak routine participants exhibited a moderate confirmation bias in their searches independent from task framing.     

Novel-view scene recognition relies on identifying spatial reference directions

Five experiments investigated whether observer locomotion provides specialized information facilitating novel-view scene recognition. Participants detected a position change after briefly viewing a desktop scene when the table stayed stationary or was rotated and when the observer stayed stationary or locomoted. The results showed that 49° novel-view scene recognition was more accurate when the novel view was caused by observer locomotion than when the novel view was caused by table rotation. However such superiority of observer locomotion disappeared when the to-be-tested viewpoint was indicated during the study phase, when the study viewing direction was indicated during the test phase, and when the novel test view was 98°, and was even reversed when the study viewing direction was indicated during the test phase in the table rotation condition but not in the observer locomotion condition. These results suggest scene recognition relies on the identification of the spatial reference directions of the scene and accurately indicating the spatial reference direction can facilitate scene recognition. The facilitative effect of locomotion occurs because the spatial reference direction of the scene is tracked during locomotion and more accurately identified at test.     

Mindsets and pre-conscious open-mindedness to incidental information

Mindset theory (Gollwitzer, 1990) proposes that deliberative mindsets are marked by more open-minded processing of information, whereas implemental mindsets are characterized by more closed-minded processing. Accordingly, deliberative and implemental mindsets should differ in selective processing of incidental information when performing a central task. In three experiments, participants in deliberative and implemental mindsets performed a computer task while randomly presented incidental, unavoidable words. A subsequent recognition memory test assessed selective processing of these incidental words. Results revealed that deliberative mindsets led to superior recognition memory, suggesting increased open-mindedness to processing incidental information. Implications for mindset and goal theories are discussed.     

Lateralized effects of target location on reaction times when preparing for manual aiming at a visual target

To elucidate the temporal characteristics of information processing for motor action differing in complexity in relation to both perceptual and cognitive information processing, we investigated whether the reaction times (RTs) to a visual target would be affected by task complexity (finger lifting or manual aiming), pre-cueing (with a pre-cue or without a pre-cue), or target location (five horizontal positions). Using the right hand, seven right-handed subjects performed two tasks, finger lifting and manual aiming at a target, with or without a pre-cue. The pre-cue announced the location of the target to be presented. An ANOVA showed significant interactions between task and location and between pre-cue and location with no significant interaction between task and pre-cue, indicating that the task-location interaction does not depend on whether or not a pre-cue is given. The manual-aiming RTs were longer than the finger-lifting RTs, and the effects of the target location on the RTs differed for finger lifting and manual aiming. It can be assumed that the longer RTs of manual aiming reflect the time for information processing that is needed when preparing for the aiming action per se, which is an extra movement performed in addition to the simple initiation of finger lifting. Differential RTs (DRTs) calculated by subtracting the finger-lifting RTs from the aiming RTs were therefore examined. The DRTs significantly differed for target locations (i.e., a lateralized effect), with the DRTs for an ipsilateral target appearing to be significantly shorter than those for contralateral and central targets. The lateralized effect appearing on the DRTs may be mediated by the processing of visual-spatial information about visual targets as motor preparations are made for manual aiming.     

Working memory in older subjects: Dealing with ongoing and stored information in language comprehension

The purpose of this experiment was to investigate the role of aging in working memory (WM), or at least the part involved in language comprehension, e.g., a double function of processing the ongoing information and keeping in memory the product of this processing. Young and older subjects were asked to simultaneously detect incongruities in sentences and keep increasing longer series of words (3, 4, or 5) in memory. The difficulty of incongruity detection was manipulated by variation of the number of intervening words (0, 6, or 12) between two critical words. Incongruity detection was assumed to be linked to the processing of information function of working memory. The concurrent mnemonic load consisted of material previously processed, and was assumed to be linked to the storage function of WM. Results showed that an increment in incongruity-detection difficulty led to a greater decrement in accuracy in older than in young subjects, indicating an impairment in the information-processing function. On the other hand, an increment in concurrent mnemonic load led to a slightly smaller decrement in accuracy in older subjects. Furthermore, fewer words from this mnemonic load were recalled in older subjects. It is suggested that older subjects are impaired in coping with both requirements of the task, and tend to sacrifice the storage of information recently processed to devote their resources to the immediate processing component of the task. These results are discussed in relation to their implications for language comprehension.     

Methodological issues in judgment and decision-making research: Concurrent verbal protocol validity and simultaneous traces of process

This paper examines two dimensions of concurrent verbal protocol validity. First, whether verbalization affects process and outcome (reactivity) was examined by comparing concurrent verbal protocol traces with those from a computer search process tracing method, the latter being a complete trace of information acquisition from experimental materials. Earlier findings that verbalization affects time were confirmed. However, verbalization did not affect amount and pattern of acquisition or accuracy of judgments. Second, whether concurrent verbal protocols are complete was examined by comparing concurrent verbal protocol and computer traces that were simultaneously obtained in a treatment in which subjects verbalized as they acquired information from the computer. The verbal traces less completely captured information acquisition behavior than computer search. This suggests that, although concurrent verbal protocols provide greater insight into decision behavior than computer search, the latter is a more reliable information-acquisition trace. Thus, if information acquisition is of primary interest and if computer search activities can be naturally integrated into performing the primary task, computer search is preferred to concurrent verbal protocols. However, if information use or retrieval from long-term memory is of primary interest, concurrent verbal protocols are preferred to computer search. Finally, this paper examined whether the simultaneous use of concurrent verbal protocols and computer search provides traces of information acquisition and use that are as complete as when each method is independently applied. Although computer search tended to limit subjects verbalizations of evaluative operators, this effect may be eliminated by practice on the computer prior to collecting data.     

Age-related differences and the role of augmented visual feedback in learning a bimanual coordination pattern

The purpose of this study was to investigate the effects of aging and the role of augmented visual information in the acquisition of a new bimanual coordination pattern, namely a 90° relative phase pattern. In a pilot study, younger and older adults received augmented visual feedback in the form of a real-time orthogonal display of both limb movements after every fifth trial. Younger adults acquired this task over three days of practice and retained the task well over periods of one week and one month of no practice while the older adults showed no improvement at all on the task. It was hypothesized that the amount of augmented information was not sufficient for the older adults to overcome the strong tendency to perform natural, intrinsically stable coordination patterns, which consequently prevented them from learning the task. The present study evaluated the age-related role of augmented visual feedback for learning the new pattern. Participants were randomly assigned within age groups to receive either concurrent or terminal visual feedback after every trial in acquisition. In contrast to the pilot study, all of the older adults learned the pattern, although not to the same level as the younger adults. Both younger and older adults benefitted from concurrent visual feedback, but the older adults gained more from the concurrent feedback than the younger adults, relative to terminal feedback conditions. The results suggest that when learning bimanual coordination patterns, older adults are more sensitive to the structure of the practice conditions, particularly the availability of concurrent visual information. This greater sensitivity to the learning environment may reflect a diminished capacity for inhibitory control and a decreased ability to focus attention on the salient aspects of learning the task.     

The Effects of Hippocampal and Area Parahippocampalis Lesions in Pigeons: II. Concurrent Discrimination and Spatial Memory

Two experiments were conducted to examine the effects of bilateral hippocampus (Hp) and area parahippocampalis (APH) lesions in pigeons on the acquisition of a visual and spatial task. In Experiment 1, pigeons were trained on three successive six-pair concurrent discrimination tasks, each using a novel set of stimuli. There was no difference between control unoperated pigeons and Hp-APH pigeons in terms of the number of sessions required to learn either the first, second, or third concurrent discrimination task. In Experiment 2, the same pigeons were trained on an open-field spatial task similar in many ways to the radial-arm maze task used with rats. In contrast to the absence of impairments on the visual concurrent discrimination task, pigeons with Hp-APH lesions were severely impaired on the acquisition of the spatial task. These findings support the view that the Hp-APH in pigeons is important for the processing of spatial, rather than visual information.