Facilitation of learning spatial relations among locations by visual cues: Implications for theoretical accounts of spatial learning

Human participants searched in a real environment or interactive 3-D virtual environment open field for four hidden goal locations arranged in a 2 × 2 square configuration in a 5 × 5 matrix of raised bins. The participants were randomly assigned to one of two groups: cues 1 pattern or pattern only. The participants experienced a training phase, followed by a testing phase. Visual cues specified the goal locations during training only for the cues 1 pattern group. Both groups were then tested in the absence of visual cues. The results in both environments indicated that the participants learned the spatial relations among goal locations. However, visual cues during training facilitated learning of the spatial relations among goal locations: In both environments, the participants trained with the visual cues made fewer errors during testing than did those trained only with the pattern. The results suggest that learning based on the spatial relations among locations may not be susceptible to cue competition effects and have implications for standard associative and dual-system accounts of spatial learning.     

Facilitation of learning spatial relations among locations by visual cues: generality across spatial configurations

Spatial pattern learning permits the learning of the location of objects in space relative to each other without reference to discrete visual landmarks or environmental geometry. In the present experiment, we investigated conditions that facilitate spatial pattern learning. Specifically, human participants searched in a real environment or interactive 3-D computer-generated virtual environment open-field search task for four hidden goal locations arranged in a diamond configuration located in a 5 × 5 matrix of raised bins. Participants were randomly assigned to one of three groups: Pattern Only, Landmark + Pattern, or Cues + Pattern. All participants experienced a Training phase followed by a Testing phase. Visual cues were coincident with the goal locations during Training only in the Cues + Pattern group whereas a single visual cue at a non-goal location maintained a consistent spatial relationship with the goal locations during Training only in the Landmark + Pattern group. All groups were then tested in the absence of visual cues. Results in both environments indicated that participants in all three groups learned the spatial configuration of goal locations. The presence of the visual cues during Training facilitated acquisition of the task for the Landmark + Pattern and Cues + Pattern groups compared to the Pattern Only group. During Testing the Landmark + Pattern and Cues + Pattern groups did not differ when their respective visual cues were removed. Furthermore, during Testing the performance of these two groups was superior to the Pattern Only group. Results generalize prior research to a different configuration of spatial locations, isolate spatial pattern learning as the process facilitated by visual cues, and indicate that the facilitation of learning spatial relations among locations by visual cues does not require coincident visual cues.     

The effect of reduced spatial cues on the learning of successive visual reversals

The performance of rats over 12 brightness discrimination reversals was studied under two experimental conditions. Under one condition all visual cues external to the apparatus were eliminated so that only the relative positions of the discriminanda could serve as a visual cue to spatial position. Under the other condition all visual cues to position were eliminated. Under the former condition performance deteriorated with successive reversals but under the latter condition performance improved. Implications of these results for theories of successive reversal improvement were discussed and two possible explanations were suggested.     

An initial search for visual overshadowing

A consistent, albeit fragile, finding over the last couple of decades has been that verbalization of hard-to-verbalize stimuli, such as faces, interferes with subsequent recognition of the described target stimulus. We sought to elicit a similar phenomenon whereby visualization interferes with verbal recognition--that is, visual overshadowing. We randomly assigned participants (n?=?180) to either concrete (easy to visualize) or abstract (difficult to visualize) sentence conditions. Following presentation, participants were asked to verbalize the sentence, visualize the sentence, or work on a filler task. As predicted, visualization of an abstract verbal stimulus resulted in significantly lower recognition accuracy; unexpectedly, however, so did verbalization. The findings are discussed within the framework of fuzzy-trace theory.     

An initial search for visual overshadowing

A consistent, albeit fragile, finding over the last couple of decades has been that verbalization of hard-to-verbalize stimuli, such as faces, interferes with subsequent recognition of the described target stimulus. We sought to elicit a similar phenomenon whereby visualization interferes with verbal recognition—that is, visual overshadowing. We randomly assigned participants (n?=?180) to either concrete (easy to visualize) or abstract (difficult to visualize) sentence conditions. Following presentation, participants were asked to verbalize the sentence, visualize the sentence, or work on a filler task. As predicted, visualization of an abstract verbal stimulus resulted in significantly lower recognition accuracy; unexpectedly, however, so did verbalization. The findings are discussed within the framework of fuzzy-trace theory.     

Auditory spatial pattern perception aided by visual choices

Summary Thirty-six human subjects, facing a panel of 100 loud-speakers, were requested to match sounds outlining geometrical and alphabetical patterns with visual pattern choices, which were given to them on a folder. The listeners' correct responses were found to be above chance. Geometrical patterns were better perceived when transmitted at the sound frequency of 800 cps as compared to 6400 cps. The number of visual pattern choices given with the sound pattern presentations affected the number of correct responses. The results indicate that the perception of acoustic spatial patterns depends on mechanisms different from those defining the spatial localization of single acoustic signals.This work was supported by the Swiss National Science Foundation, Grants 3.74.68, 4.0120.70 and 4.0860.73 to E. Perret.     

No evidence of binding items to spatial configuration representations in visual working memory

When detecting changes in visual features (e.g., colour or shape), object locations, represented as points within a configuration, might also be automatically represented in working memory. If the configuration of a scene is represented automatically, the locations of individual items might form part of this representation, irrespective of their relevance to the task. Participants took part in a change-detection task in which they studied displays containing different sets of items (shapes, letters, objects), which varied in their task relevance. Specifically, they were asked to remember the features of two sets, and ignore the third set. During the retention interval, an audio cue indicated which of the to-be-remembered sets would become the target set (having a 50% probability of containing a new feature). At test, they were asked to indicate whether a new feature was present amongst the target set. We measured binding of individual items to the configuration by manipulating the locations of the different sets so that their position in the test display either matched or mismatched their original location in the study display. If items are automatically bound to the configuration, location changes should disrupt performance, even if they were explicitly instructed not to remember the features of that particular set of items. There was no effect on performance of changing the locations of any of the sets between study and test displays, indicating that the configural representation did not enter their decision stage, and therefore that individual item representations are not necessarily bound to the configuration.     

A consistent but non-coincident visual pattern facilitates the learning of spatial relations among locations

Human participants searched in a dynamic three-dimensional computer-generated virtual-environment open-field search task for four hidden goal locations arranged in a diamond configuration located in a 5 × 5 matrix of raised bins. Participants were randomly assigned to one of two groups: visual pattern or visual random. All participants experienced 30 trials in which four goal locations maintained the same spatial relations to each other (i.e., a diamond pattern), but this diamond pattern moved to random locations within the 5 × 5 matrix from trial to trial. For participants in the visual pattern group, four locations were marked in a distinct color and arranged in a diamond pattern that moved to a random location independent of the hidden spatial pattern from trial to trial throughout the experimental session. For participants in the visual random group, four random locations were marked with a distinct color and moved to random locations independent from the hidden spatial pattern from trial to trial throughout the experimental session. As a result, the visual cues for the visual pattern group were consistent but not coincident with the hidden spatial pattern, whereas the visual cues for the visual random group were neither consistent nor coincident with the hidden spatial pattern. Results indicated that participants in both groups learned the spatial configuration of goal locations and that the presence of consistent but noncoincident visual cues facilitated the learning of spatial relations among locations.     

Ipsilateral inhibition and contralateral facilitation of simple reaction time to non-foveal visual targets from non-informative visual cues

Orienting to an extrafoveal light cue without foveating it induces a temporary inhibition of responses to subsequent targets presented in the same visual hemifield, as evinced from the fact that reaction time (RT) to targets ipsilateral to the cue relative to fixation is longer than RT to targets contralateral to the cue. This study has tested the hypothesis that ipsilateral RT inhibition is associated with contralateral RT facilitation by attempting to divide the difference between ipsilateral and contralateral RTs into costs and benefits. A neutral condition suited to this purpose should involve a cue that does not require a lateral orientation. Such neutral condition was provided by measuring RT to lateralized light targets following a central overhead auditory cue (experiment 1) or a foveal visual cue (experiment 2). In both experiments RT in the neutral condition was intermediate between ipsilateral and contralateral RTs, and the differences reaches significance in the second experiment. Benefits over the neutral condition measured in the contralateral condition were thus associated with costs in the ipsilateral condition. These results suggest that a reciprocal antagonism between opposite turning tendencies underlies the organization of covert orienting. They also agree with general multi-channel theories of selective attention according to which the facilitation of given channels is an obligatory accompaniment of the inhibition of other competing channels and vice versa.     

Separate mechanisms recruited by exogenous and endogenous spatial cues: evidence from a spatial Stroop paradigm

The present experiments tested whether endogenous and exogenous cues produce separate effects on target processing. In Experiment 1, participants discriminated whether an arrow presented left or right of fixation pointed to the left or right. For 1 group, the arrow was preceded by a peripheral noninformative cue. For the other group, the arrow was preceded by a central, symbolic, informative cue. The 2 types of cues modulated the spatial Stroop effect in opposite ways, with endogenous cues producing larger spatial Stroop effects for valid trials and exogenous cues producing smaller spatial Stroop effects for valid trials. In Experiments 2A and 2B, the influence of peripheral noninformative and peripheral informative cues on the spatial Stroop effect was directly compared. The spatial Stroop effect was smaller for valid than for invalid trials for both types of cues. These results point to a distinction between the influence of central and peripheral attentional cues on performance and are not consistent with a unitary view of endogenous and exogenous attention.     

Modulation of auditory spatial attention by visual emotional cues: differential effects of attentional engagement and disengagement for pleasant and unpleasant cues

Previous research has demonstrated that threatening, compared to neutral pictures, can bias attention towards non-emotional auditory targets. Here we investigated which subcomponents of attention contributed to the influence of emotional visual stimuli on auditory spatial attention. Participants indicated the location of an auditory target, after brief (250 ms) presentation of a spatially non-predictive peripheral visual cue. Responses to targets were faster at the location of the preceding visual cue, compared to at the opposite location (cue validity effect). The cue validity effect was larger for targets following pleasant and unpleasant cues compared to neutral cues, for right-sided targets. For unpleasant cues, the crossmodal cue validity effect was driven by delayed attentional disengagement, and for pleasant cues, it was driven by enhanced engagement. We conclude that both pleasant and unpleasant visual cues influence the distribution of attention across modalities and that the associated attentional mechanisms depend on the valence of the visual cue.     

Perceptual learning in auditory temporal discrimination: No evidence for a cross-modal transfer to the visual modality

Perceptual learning was used to study potential transfer effects in a duration discrimination task. Subjects were trained to discriminate between two empty temporal intervals marked with auditory beeps, using a twoalternative forced choice paradigm. The major goal was to examine whether perceptual learning would generalize to empty intervals that have the same duration but are marked by visual flashes. The experiment also included longer intervals marked with auditory beeps and filled auditory intervals of the same duration as the trained interval, in order to examine whether perceptual learning would generalize to these conditions within the same sensory modality. In contrast to previous findings showing a transfer from the haptic to the auditory modality, the present results do not indicate a transfer from the auditory to the visual modality; but they do show transfers within the auditory modality.     

Test for effects of visual and position cues on T-maze learning in toads

This research was concerned with the effects of different classes of cues on the ability of toads (Bufo marinus) to learn an escape task, discrimination learning, in a T-maze. The cues were either a black or white brightness cue, a right or left position cue, or combinations of brightness and position cues. The toads were given a .6-A shock until they made the correct response. Results suggested that toads are capable of learning a discrimination task based on either a position or brightness cue. However, the rate of learning was influenced by strong aversion to the white arm when escaping from an aversive stimulus. No particular preference for either brightness or position cues was found independent of this aversion.     

The influence of spatial pattern on visual short-term memory for contrast

Several psychophysical studies of visual short-term memory (VSTM) have shown high-fidelity storage capacity for many properties of visual stimuli. On judgments of the spatial frequency of gratings, for example, discrimination performance does not decrease significantly, even for memory intervals of up to 30 s. For other properties, such as stimulus orientation and contrast, however, such “perfect storage” behavior is not found, although the reasons for this difference remain unresolved. Here, we report two experiments in which we investigated the nature of the representation of stimulus contrast in VSTM using spatially complex, two-dimensional random-noise stimuli. We addressed whether information about contrast per se is retained during the memory interval by using a test stimulus with the same spatial structure but either the same or the opposite local contrast polarity, with respect to the comparison (i.e., remembered) stimulus. We found that discrimination thresholds got steadily worse with increasing duration of the memory interval. Furthermore, performance was better when the test and comparison stimuli had the same local contrast polarity than when they were contrast-reversed. Finally, when a noise mask was introduced during the memory interval, its disruptive effect was maximal when the spatial configuration of its constituent elements was uncorrelated with those of the comparison and test stimuli. These results suggest that VSTM for contrast is closely tied to the spatial configuration of stimuli and is not transformed into a more abstract representation.     

Blocking and overshadowing between intra-maze and extra-maze cues: A test of the independence of locale and guidance learning

Rats were trained on an elevated maze where the rewarded alternative was defined either in terms of intra-maze cues (rubber or sandpaper flooring on rewarded and unrewarded arms, regardless of their position) or in terms of extra-maze cues (the correct arm always pointed toward a particular corner of the room, and was sometimes covered with rubber and sometimes with sandpaper), or where both sets of cues were simultaneously relevant. In Experiment 1 rats pretrained with either intra-maze or extra-maze cues alone relevant learned less about the other set of cues than non-pretrained control groups, when, in a second phase of the experiment, both sets of cues were simultaneously relevant. Experiment 2 confirmed that intra-maze cues could block extra-maze cues, and ruled out one alternative explanation of the results of Experiment 1. Experiment 3 showed that extra-maze cues overshadowed intra-maze cues, but that there was no reciprocal overshadowing of extra-maze by intra-maze cues. This was despite the fact that animals learned the intra-maze discrimination significantly faster than the extra-maze discrimination. Experiment 3 also suggested that rats did not solve the extra-maze discrimination by learning to approach or avoid specific extra-maze cues, but rather by locating the correct arm by reference to the entire set of extra-maze cues. The results suggest that locale or place learning and cue or guidance learning, in O'Keefe and Nadel's (1978) terminology, interact with one another in much the same way as does learning about any pair of stimuli in a Pavlovian conditioning experiment.