1. Introduction
Very often, during the exploration of the environment, we come across elements that can have a positive (e.g., a beautiful villa or urban park) or negative valence (e.g., a degraded place, an overturned garbage can or an episode of violence). These elements can represent landmarks to which we attribute a personal dimension (cf. [
1]) and can be used according to specific spatial strategies: represent a route and orient ourselves during navigation (e.g., << I remember that in front of this beautiful house we turned right >>). Interestingly, it has been shown that these landmarks may differently affect our spatial memory according to their valence (i.e., positive, negative, or neutral). For example, Balaban and colleagues [
2] showed that people were more accurate in remembering directional information (i.e., did you do left or right at landmark X?) associated with negative rather than neutral landmarks. Instead, Piccardi and colleagues [
3] found that participants exposed to both negative and positive rather than neutral landmarks were faster in learning the path connecting them (see also [
4]). Finally, Ruotolo and colleagues [
5] showed that the presence of positive, but not negative, landmarks positioned along a path improved the accuracy of the mental representations of the distances between them and the memory of their absolute position along the path. Moreover, the path was perceived as longer in the presence of negative, rather than positive and neutral landmarks.
In sum, these studies indicate that the influence of emotionally laden landmarks on route representation may vary according to their valence (i.e., positive, negative, or neutral). Specifically, they would suggest that negative landmarks affect mostly observer-based spatial information (e.g., right/left turn information, length of perceived distances), whereas the positive ones seem to facilitate object-based spatial representations (e.g., distances between landmarks and their reciprocal position). However, whatever the effects produced by this type of landmarks, the processes/mechanisms at the basis of these effects are still unknown.
One way to address this issue is to explore the role that basic spatial abilities could have in the spatial representation of landmarks with different valence (e.g., positive, negative, or neutral). For example, it has been shown that individuals with high mental rotation abilities, i.e., the ability to mentally rotate an image along a continuous trajectory in the mental space until it reaches a new orientation [
6,
7,
8], perform better than participants with low mental rotation ability in spatial navigation [
9,
10], wayfinding [
11], orientation, and route learning tasks [
12]. More importantly, Kaltner and Jansen [
13] found that mental rotation performance was enhanced after the presentation of fearful images compared to neutral images. Furthermore, a link between a low performance in visuospatial working memory measured by the Corsi task and topographical disorientation has been suggested (e.g., [
14,
15,
16,
17,
18]). As for the mental rotation task, Palmiero and colleagues [
19] showed that participants’ performance at the Corsi task and its walkable version [
20,
21] improved when emotional stimuli were used as compared to the neutral ones. Finally, another cognitive skill that could be considered is the ability to discriminate left from right (left-right discrimination: LRD; [
22]). When navigating through the environment, we are constantly exposed to right/left decisions (e.g., at the church I turn right, then I go left, etc.), for which left/right identification or discrimination is essential.
In addition to cognitive skills, personality traits can also influence the way we manipulate spatial information [
23,
24]. For example, it has been shown that extroverted people show more exploratory behavior and are more efficient in navigational tasks [
25]. Similarly, Pazzaglia and colleagues [
24] found that performance on wayfinding and route-tracing was positively associated with participants’ agreeableness and conscientiousness, respectively. Instead, people scoring high on psychoticism tend to perform worse in wayfinding tasks [
26]. Considering personality traits in combination with the emotional content of landmarks seems a valuable addition, as it has been suggested that individuals with different personality traits can interpret emotional events differently [
27,
28,
29].
Overall, the above-mentioned evidence suggests that individual factors, i.e., both basic spatial abilities and personality traits, can play a role in how spatial information linked to emotionally laden landmarks is represented in memory. Therefore, the aim of this work was to explore the type of relationship that might exist between basic spatial abilities, personality traits, and representations of emotionally laden landmarks. Furthermore, since it has been suggested that positive and negative stimuli can have different effects depending on whether the spatial information is more observer-based (i.e., to the direction of his/her movement) or object-based (i.e., to the relationship or distance among landmarks), this work also aimed to observe if the role of the spatial abilities and personality traits changes according to the kind of spatial information required.
To this aim, participants were requested to perform the Corsi block tapping test (CBT; both forward and reversed version), the Bergen right-left discrimination task (B-RL), a mental rotation task (MR), and to fill out the Ten item personality inventory (TIPI) [
30]. Afterward, they watched three movies of a virtual walk characterized by positive, negative, or neutral landmarks and had to memorize what they saw. After each video, participants were asked to perform two spatial judgment tasks: a route continuation task (RCT, e.g., at landmark X did you do left or right?) and a distance comparison task (DCT, e.g., what was the landmark closest to “X", Y or Z?). Although the current study used some materials and procedures previously used by Ruotolo and colleagues [
5], it differed from the previous one in two fundamental aspects. First, here participants explored three different paths and not only one. Second, while in Ruotolo and colleagues [
5], the relationship between landmarks was investigated with a task that could stress the use of a body-based strategy (i.e., imagine walking from one landmark to another), here the relationship between landmarks was measured with a task that stressed the use of an object-based strategy.
If basic spatial abilities and personality traits play a specific role in the way spatial information of emotionally laden landmarks is memorized, then we expect significant and higher correlations between performance in both spatial tasks (i.e., RCT and DCT) and individual factors in positive and negative conditions rather than in the neutral one. Furthermore, since the CBT measures visuospatial working memory, in a sequential context, it is possible to hypothesize a positive association between performance in this task and the route continuation task. The route continuation task should be also positively associated with the ability to discriminate right and left. Instead, the performance in the MR task should be more positively associated with performance in the distance comparison task. Finally, extroverted/agreeable personality traits should be positively associated with performance in both continuation and comparison tasks. However, the few studies conducted so far on this topic do not provide enough theoretical and/or empirical knowledge to formulate more specific hypotheses about the relationship between spatial abilities, personality traits, type of spatial task, and landmarks’ valence. Therefore, on this part, the current study is largely exploratory.
4. Discussion
This research work was the first to explore the possible role of individual factors, both in terms of basic spatial abilities and personality traits, in the spatial representation of emotionally laden landmarks. To this aim, we asked participants to watch movies of virtual walks along routes characterized by positive, negative, or neutral landmarks. Afterward, they were asked to indicate if, at a specific landmark, they did left or right (route continuation task) and to judge the relative distances between landmarks (distance comparison task). Besides, the individual factors were assessed by asking participants to complete a questionnaire to measure personality traits (TIPI) and to perform three cognitive tasks: a mental rotation task (MR), a task measuring the sequential memory of positions (i.e., Corsi and Corsi reversed), and a task that evaluated the ability to discriminate right from left (i.e., B-RL).
As regards the relationships between individual factors and spatial representations of emotionally laden landmarks, overall results showed significant relationships in the positive and, to a less extent, in the neutral condition. Specifically, if the route was characterized by positive landmarks, then as the ability to correctly remember sequences of positions (i.e., highest score at Corsi and Corsi reversed) increased, so did the accuracy at the route continuation task. This result was in line with several studies that indicate a positive correlation between performance at Corsi task and navigational skills [
21,
36,
37,
38,
39]. Similarly, the results showed that the faster the right-left discrimination task was performed, the more accurate the performance at the route continuation task was in both positive and neutral conditions. This was a new and interesting result because, for the first time, a positive relationship between left/right discrimination and navigational skills was shown. According to Hjelmervik and colleagues ([
22]; see also [
40]), the reason for this effect could be that the ability to discriminate right from left stems from environmental navigation. In fact, the right and left positions vary according to the position that our body assumes in space. Another possibility is that this association is due to the fact that the correct execution of the Bergen R-L test requires a fundamental skill for effective navigation in the environment, namely mental rotation [
9,
10,
11,
12]. However, this hypothesis is not supported by our results, where an association between mental rotation and performance in the route discrimination tasks did not appear. Instead, a strong association between performance at mental rotation task and the distance comparison task appeared. In this case, the faster the participants were in performing the mental rotation task correctly, the faster they were in judging/comparing distances between landmarks. This association appeared for the three emotional conditions, but again to a wider extent in the positive and neutral conditions.
The question at this point is: why has the association between basic spatial abilities and cognitive tasks appeared more in the positive than in the neutral condition and even less in the negative one? It is possible to think that the different cognitive processes were used in the positive, neutral, and negative conditions to perform both route continuation and distance comparison tasks. Specifically, the positive condition seemed to have favored the use of strategies based on visual-spatial working memory, such as mental rotation and visuospatial working memory. This was supported by several studies, showing that a mildly positive mood improves performance in working memory (e.g., [
19,
41,
42]; for reviews: [
43,
44]) and the performance in tasks that call for creative solutions, innovative problem solving, and coping skills [
45,
46,
47,
48,
49,
50,
51,
52]. The reason for this can be found in the “neuropsychological theory of positive mood” [
53]. According to Ashby and colleagues [
53], the positive mood increases dopamine, which is an important underlying biological mechanism for executive control and working memory (WM).
Another interesting result obtained with this study is represented by the relationships between personality traits and spatial memory tasks. Specifically, as the scores on the agreeableness scale, which is a tendency to be altruistic, trusting, modest, and compliant [
54,
55], increased, so did the accuracy at the route continuation task in the positive condition and, to a less extent, in the neutral condition. These results seemed to be also in line with what found by Pazzaglia and colleagues [
24]. However, literature provides no conceptual rationale for a relationship between agreeableness and cognitive ability in general (e.g., [
56,
57,
58]). Since this association appeared to be particularly significant in the positive and neutral condition but not in the negative one, it is possible that individuals with higher levels of agreeableness could be less prone to process and remember negative stimuli [
59]. In line with this, it has been shown that people who are higher in agreeableness show higher emotional sensitivity, lower variability of sadness, and more positive subjective evaluations of daily incidents [
27]. In contrast, a positive relationship appeared between emotional stability and openness and response times at the distance comparison task in the negative condition: The higher scores at emotional stability (i.e., low neuroticism) and openness scales, the more time to perform the distance comparison task. This result was probably due to the fact that less neurotic people tend to be less influenced by negative stimuli than more neurotic people [
60]. This, in turn, could have led to less emphasis on the emotional content of negative landmarks. However, these latter results should be taken carefully as they did not survive correction for multiple comparisons.
Finally, as regards the influence of emotions on spatial representations, the results showed that the emotional valence of the landmarks did not influence the participants’ performance in the route continuation but only in the distance comparison task. Specifically, participants were more accurate in judging what landmark was closest to the target one, especially when dealing with positive rather than neutral and negative landmarks. These results supported our hypotheses for the distance comparison task but not for the route continuation task. In fact, we expected participants to memorize more accurately the landmarks’ directional information, especially when the latter was negative rather than neutral or positive. This is because, as stated also by Chan and colleagues [
61], memorization of spatial information of negative landmarks should have an evolutionary/adaptive relevance, i.e., it is safer to remember spatial information about negative elements in order to avoid them in future explorations. Instead, in contrast with previous evidence (e.g., [
2,
61]), we did not find negative images improving memorization of spatial information. We argued that this was due to the fact that the negative images we used were not as impressive or scary as compared to those used in other studies. In fact, Chan and colleagues [
61] used pictures of “mutilated bodies” and explicit “scenes of violence” as negative images. These negative stimuli could, in turn, have had a stronger impact on participants’ spatial memory, and, contrary to what we found, could have revealed major differences among negative, positive, and neutral conditions.
On the other side, the advantage we observed for the positive condition in the distance comparison task was in line with the evidence shown in past studies but also contained elements of novelty. In fact, several studies have shown that a positive mood has beneficial effects on visual-spatial tasks (e.g., [
3,
4]). For example, Ruotolo and colleagues [
5] showed that participants were more accurate in imagining the distances between different landmarks when they had a positive rather than negative or neutral value. However, the task used by Ruotolo and colleagues [
5] required a more egocentric or body-based strategy to be performed, as participants were asked to imagine themselves walking from one landmark to another. Instead, here for the first time, we showed that the presence of positive landmarks facilitated the use of a more allocentric strategy. In fact, in the distance comparison task, the three landmarks were shown to the participant as if they were a sort of abstract map, and their task was to compare the distances between these landmarks regardless of the participants’ position.
Before concluding, it is important to indicate some of the limitations of the current study. First, some relevant factors or individual differences that might also play a fundamental role in the way we represented spatial information were not considered. For example, several studies have shown differences related to gender (e.g., [
62,
63,
64,
65,
66,
67]) in combination with age (e.g., [
68,
69]), spatial experience, and familiarity with the environment [
67,
70,
71,
72,
73,
74]. Second, this study shows some of the most important factors associated with processing of positive stimuli, but unfortunately failed to shed light on what strategies might be used in the condition with negative stimuli. Third, the correlations were limited to the two spatial judgment tasks used in this study. Therefore, future studies should assess the weight of other individual factors by using also other kinds of spatial tasks that assess other aspects of route representations.