Latent spatial learning in an environment with a distinctive shape

Four experiments were conducted with rats in order to determine whether being placed on a platform in one corner of a rectangular swimming pool results in latent spatial learning. Rats in Experiments 1-3 received four trials a day of being placed on the platform. During a subsequent test trial, in which they were released into the pool without the platform, the rats exhibited a preference for swimming in the correct corners of the pool (those with the same geometric properties as the corner containing the platform during training), than the two remaining, incorrect corners. This effect was seen when the interval between the final placement trial and the test trial was as much as 24 hr (Experiment 2) and after varying numbers of sessions of placement training (Experiment 3). Experiment 4 revealed that when the test took place in a kite-shaped arena, after placement training in a rectangle, a stronger preference was shown for the corner that was geometrically equivalent to the correct rather than the incorrect corners in the rectangle. The placement treatment is said to result in latent spatial learning based on the development of S-S associations.     

Hippocampus lesions impair landmark array spatial learning in homing pigeons: a laboratory study

Hippocampal (HF)-lesioned pigeons display impaired homing ability when flying over familiar terrain, where they are presumably relying on a map-like representation of familiar landmarks to navigate. However, research carried out in the field precludes a direct test of whether hippocampal lesions compromise the ability of homing pigeons to navigate by familiar landmarks. To examine more thoroughly the relationship between hippocampus and landmark spatial learning, control, neostriatum-lesioned, and HF-lesioned homing pigeons were trained on two open field, laboratory, conditional discrimination tasks. One was a visual landmark array task, and the other was a room color discrimination task. For the tasks, the correct of three differently colored food bowls was determined by the spatial relationship among a group of five landmarks and room color, respectively. Intact control birds successfully learned both tasks, while neostriatum-lesioned birds successfully learned the landmark array task-the only task on which they were trained. By contrast, HF-lesioned birds successfully learned the room color task but were unable to learn the landmark array task. The data support the hypothesis that homing performance deficits observed in the field following hippocampal lesions are in part a consequence of an impairment in the ability of lesioned pigeons to use familiar visual landmarks for navigation.     

Failure of a landmark to restrict spatial learning based on the shape of the environment

Rats were required to find a submerged platform in the corner of a swimming pool with a distinctive shape. A landmark near the platform did not interfere with the control acquired by the pool's shape over searching for the platform. This outcome was observed with an overshadowing and a blocking design. A comparison of the ease with which the landmark and the pool's shape gained control over searching for the platform indicates that the failure of overshadowing and blocking was not a consequence of the landmark being less salient than the shape of the pool. The results are not readily explained by theories of associative learning, but they are consistent with the claim that learning about the shape of the environment takes place in a dedicated module, which excludes information about the significance of individual landmarks.     

Effect of absolute spatial proximity between a landmark and a goal

In two experiments rats were trained in a Morris pool to find a hidden platform in the presence of a single landmark. Circular black curtains surrounded the pool, with the single landmark inside this enclosure, so that no other room cues could provide additional information about the location of the platform. This landmark was hung from a false ceiling and rotated from trial to trial, and the position of the platform also changed on each trial, thus preserving a constant relation between the platform and the landmark. In Experiment 1, the position of the landmark was exactly above the hidden platform in Group Above and was relatively close to the hidden platform in Group Near. At the end of acquisition, test trials without the platform revealed a difference between the groups. Although a preference for searching in the correct quadrant of the pool, where the platform should have been, was found in both groups, this preference was significantly higher for Group Above. In Experiment 2, new rats in Group Near were compared to rats for which the position of the landmark was relatively far from the hidden platform in Group Far. Test trials revealed a preference for searching in the correct quadrant of the pool in both groups, but this preference was significantly higher for Group Near. The implication of these results is that the control acquired by a single landmark is different depending on its relative distance from a hidden platform: Closer landmarks acquire better control than distant ones. These results show a clear parallelism in comparison with the effect of absolute temporal proximity of the CS to the US in classical conditioning.     

Blocking of spatial learning between enclosure geometry and a local landmark

In a virtual environment, blocking of spatial learning to locate an invisible target was found reciprocally between a distinctively shaped enclosure and a local landmark within its walls. The blocking effect was significantly stronger when the shape of the enclosure rather than the landmark served as the blocking cue. However, the extent to which the landmark blocked enclosure-shape learning was not influenced by increasing the physical salience of the landmark. The outcomes are the first to suggest that cue-interaction effects, commonly found in human and animal contingency learning experiments, are also found in human spatial learning based on landmarks and enclosure walls. The data are discussed in terms of spatial reference frames.     

Indirect landmark use at 6 months of age in a spatial orientation task

It was hypothesized that 6-month-old infants may be able to use indirect landmarks to locate a goal if (a) the landmarks are sufficiently distinctive and (b) the goal location is between landmarks, rather than on the opposite side of the space as was used in earlier research. Six-month-old infants were tested in a peekaboo paradigm in which they had to turn to a target location after displacement to a novel position. Infants looked to the goal location significantly more in a beacon and an indirect landmarks condition relative to a control and a single landmark condition. These results are discussed in terms of current theories of spatial development.     

Immediate and delayed recall of a small-scale spatial array

The study examined people's spatial memory of a small-scale array of objects. Earlier work has primarily relied on short-retention intervals, and to date it is not known whether performance is affected by longer intervals between learning and recall. In the present investigation, university students studied seven target objects. Recall was tested immediately after learning and after an interval of seven days. Performance was found to be similar in the immediate and delayed conditions, and the results suggested that recall was facilitated by egocentric and intrinsic cues. The findings are discussed with reference to recent investigations that have shown task parameters can influence spatial recall.     

Horizontal saccadic eye movements enhance the retrieval of landmark shape and location information

Recent work has demonstrated that horizontal saccadic eye movements enhance verbal episodic memory retrieval, particularly in strongly right-handed individuals. The present experiments test three primary assumptions derived from this research. First, horizontal eye movements should facilitate episodic memory for both verbal and non-verbal information. Second, the benefits of horizontal eye movements should only be seen when they immediately precede tasks that demand right and left-hemisphere processing towards successful performance. Third, the benefits of horizontal eye movements should be most pronounced in the strongly right-handed. Two experiments confirmed these hypotheses: horizontal eye movements increased recognition sensitivity and decreased response times during a spatial memory test relative to both vertical eye movements and fixation. These effects were only seen when horizontal eye movements preceded episodic memory retrieval, and not when they preceded encoding (Experiment 1). Further, when eye movements preceded retrieval, they were only beneficial with recognition tests demanding a high degree of right and left-hemisphere activity (Experiment 2). In both experiments the beneficial effects of horizontal eye movements were greatest for strongly right-handed individuals. These results support recent work suggesting increased interhemispheric brain activity induced by bilateral horizontal eye movements, and extend this literature to the encoding and retrieval of landmark shape and location information.     

Transfer of persistence to the acquisition of a new behaviour

Two experiments tested whether the degree of effort required for the reinforcement of one behaviour would affect the acquisition of a second behaviour. In the first experiment, rats were placed in a conditioning chamber and: (a) were required to press a lever for food pellets on a fixed ratio schedule, (b) received free presentation of the pellets, or (c) did not receive pellets. Next, all rats were rewarded for a new behaviour, round trips across the length of a runway. As predicted, the fixed-ratio group had the greatest shuttle rate. In the second experiment, two groups were required to press a lever, and the number of presses per pellet was varied. For two other groups not required to press the lever, the amount of food presented per approach to the feeder was varied. The greater required number of lever presses and the lesser number of pellets per approach to the feeder produced the higher subsequent shuttle rates. Two alternative explanations were compared: the degree of accustomed effort per reinforcer becomes a learned component of behaviour, or high effort increases the habituation of frustration-produced disruptive responses.     

Dissecting the geometric module: a sense linkage for metric and landmark information in animals' spatial reorientation

Disoriented children can use geometric information in combination with featural information to reorient themselves in large but not in small spaces; somewhat similar effects have been found in nonhuman animals. These results call for an explanation. We trained young chicks to reorient to find food in a corner of a small or a large rectangular room with a distinctive featural cue (a blue wall) -- a task similar to that used with children. Then we tested the chicks after displacement of the feature to an adjacent wall. In the large enclosure, chicks chose the corner that maintained the correct arrangement of the featural cue with respect to sense, whereas in the small enclosure, they chose the corner that maintained the correct metrical arrangement of the walls with respect to sense. On the basis of these findings, we propose a simple model that can explain the effects of room size on spatial reorientation.     

Intrinsic orientation and study viewpoint in recognizing spatial structure of a shape

Two experiments dissociated the roles of intrinsic orientation of a shape and participants’ study viewpoint in shape recognition. In Experiment 1, participants learned shapes with a rectangular background that was oriented differently from their viewpoint, and then recognized target shapes, which were created by splitting study shapes along different intrinsic axes, at different views. Results showed that recognition was quicker when the study shapes were split along the axis parallel to the orientation of the rectangular background than when they were split along the axis parallel to participants’ viewpoint. In Experiment 2, participants learned shapes without the rectangular background. The results showed that recognition was quicker when the study shape was split along the axis parallel to participants’ viewpoint. In both experiments, recognition was quicker at the study view than at a novel view. An intrinsic model of object representation and recognition was proposed to explain these findings.     

The performance and observation of action shape future behaviour

The observation of other people’s actions plays an important role in shaping the perceptual, cognitive, and motor processes of the observer. It has been suggested that these social influences occur because the observation of action evokes a representation of that response in the observer and that these codes are subsequently accessed by other cognitive systems to modify future behaviour. In the case of social search and movement tasks, the observation-evoked response code is thought to activate the same mechanisms that are activated following internally-generated response codes. In support of this hypothesis, the present study revealed that the magnitudes of the between-person inhibition of return (IOR) effects were correlated with within-person IOR effects. These findings provide substantial support for the link between observation-evoked response codes and social cognitive effects.     

Time course of grouping of shape by perceptual closure: effects of spatial proximity and collinearity

We examined time course of grouping of shape by perceptual closure in three experiments using a primed matching task. The gaps between the closure-inducing contours varied in size. In addition, depending on the distribution of the gaps along the closure-inducing contours--occurring at straight contour segments or at the point of change in contour direction--collinearity was either present or absent. In the absence of collinearity, early priming of the shape was observed for spatially close fragments, but not for spatially distant fragments. When collinearity was available, the shape of both spatially close and spatially distant fragments was primed at brief exposures. These results suggest that spatial proximity is critical for the rapid grouping of shape by perceptual closure in the absence of collinearity, but collinearity facilitates the rapid grouping of shape when the closure-inducing fragments are spatially distant. In addition, shape priming persisted over time only when the collinear fragments were spatially close, suggesting that a stable representation of shape depends both on collinearity and spatial proximity between the closure-inducing fragments.     

Perceived warmth and competence of others shape voluntary deceptive behaviour in a morally relevant setting

The temptation to deceive others compares to a moral dilemma: it involves a conflict between the temptation to obtain some benefit and the desire to conform to personal and social moral norms or avoid aversive social consequences. Thus, people might feel different levels of emotional and moral conflict depending on the target of the deception. Here we explored, in a morally relevant setting, how social judgements based on two fundamental dimensions of human social cognition – ‘warmth’ and ‘competence’ – impact on the decision to deceive others. Results revealed independent effects for warmth and competence. Specifically, while people are less inclined to deceive for self-gain those individuals they perceive as warm, they also tend to lie more to highly competent others. Furthermore, the perceived warmth and competence modulated the general tendency to reduce deceptive behaviour when there was a risk of disclosure compared to when the lying was anonymous, highlighting the importance of these judgements in social evaluation processes. Together, our results demonstrate that the emotional costs and personal moral standards that inhibit engagement in deceptive behaviour are not stable but rather malleable according to the target and the consequences of the deception.     

Transfer of spatial context from visual to haptic search

Under incidental learning conditions, spatial layouts can be acquired implicitly and facilitate visual search (contextual-cueing effect). We examined whether the contextual-cueing effect is specific to the visual modality or transfers to the haptic modality. The participants performed 320 (experiment 1) or 192 (experiment 2) visual search trials based on a typical contextual-cueing paradigm, followed by haptic search trials in which half of the trials had layouts used in the previous visual search trials. The visual contextual-cueing effect was obtained in the learning phase. More importantly, the effect was transferred from visual to haptic searches; there was greater facilitation of haptic search trials when the spatial layout was the same as in the previous visual search trials, compared with trials in which the spatial layout differed from those in the visual search. This suggests the commonality of spatial memory to allocate focused attention in both visual and haptic modalities.     

Influence of a beacon on spatial learning based on the shape of the test environment.

In 5 experiments rats were required to escape from a triangular shaped pool by swimming to a submerged platform. The principal group of interest in each experiment received training with a beacon attached to the platform. The purpose of the experiments was to assess if the beacon overshadowed (Experiments 1-4) or blocked (Experiment 5) learning about the position of the platform with reference to the shape of the pool. The platform was located in the center of the pool for the first 2 experiments and in a corner for the remaining experiments. Although there was an overshadowing effect in Experiment 1, the remaining experiments failed to reveal any disruptive influence of the beacon on learning based on the shape of the pool. Moreover, in Experiments 3-5 there was an indication that the beacon facilitated such learning. The results suggest that spatial learning based on the shape of a test environment may not take place in the same way as that based on more discrete landmarks.     

Individually tailored internet-based cognitive behaviour therapy for older adults with anxiety and depression: a randomised controlled trial

Mixed anxiety and depression is common among older adults. The aim of the study was to compare the effects of an eight-week-long tailored internet-supported cognitive behaviour therapy (ICBT) programme and to compare against the provision of weekly general support. A second aim was to investigate if pre-treatment cognitive flexibility and self-reported cognitive problems would predict outcome. We included 66 older adults (aged over 60 years) with mixed anxiety/depression following media recruitment and randomised them into treatment and control groups. We also included a one-year follow-up. As a measure of executive function, we used the Wisconsin Card Sorting Test (perseverative errors) and the Cognitive Failures Questionnaire during the pre-treatment phase. Results showed a moderate between-group effect on the main outcome measure, the Beck Anxiety Inventory (BAI) (d= .50), favouring the treatment group. Nearly half (45.5%) of that group were classified as responders. One person (3%) in the treatment group deteriorated. There were significant correlations between perseverative errors and outcome (on the BAI r = ?.45), but not among self-reported cognitive function. We conclude that guided, tailored ICBT may be effective for some older adults and that the role of cognitive function needs to be investigated further.