1 2 3 4 5 6 Emotional mental imagery generation during spontaneous future thinking - 7 relationship with optimism and negative mood 8 9 10 Julie L. Ji 1, Fionnuala C. Murphy 2, Ben Grafton 1, Colin MacLeod 1, Emily A. 11 Holmes 3 12 13 1 School of Psychological Science, University of Western Australia, Australia 14 2 Medical Research Council Cognition and Brain Sciences Unit, University of 15 Cambridge, Cambridge, UK 16 3 Department of Psychology, Uppsala University, Sweden 17 18 19 *Corresponding author information: Dr Julie Lin Ji, M304, University of Western 20 Australia, 35 Stirling Highway, Perth WA 6009, Australia (e-mail: 21 [email protected]). 22 23 1 24 Abstract 25 Optimism is known to buffer against negative mood, thus understanding the factors that 26 contribute to individual variation in optimism may inform interventions for mood disorders. 27 Preliminary evidence suggests that the generation of mental imagery-based representations 28 of positive relative to negative future scenarios is related to optimism. This study investigated 29 the hypothesis that a lower tendency to generate positive relative to negative mental imagery 30 during spontaneous future thinking would be associated with elevated negative mood via its 31 relationship to lower optimism. Participants (N = 44) with varied levels of naturally occurring 32 negative mood reported current levels of optimism and the real-time occurrence and 33 characteristics of spontaneous thoughts during a sustained attention computer task 34 designed. Consistent with hypothesis, lower optimism statistically mediated the relationship 35 between lower proportional frequency of positive relative to negative mental imagery during 36 spontaneous future thinking and elevated negative mood. Further, the relationship between 37 emotional mental imagery and optimism was found for future, but not past, thinking, nor for 38 verbal future or past thinking. Thus, a greater tendency to generate positive rather than 39 negative imagery-based mental representations when spontaneously thinking about the 40 future may influence how optimistic one feels, which in turn may influence one’s level of 41 negative mood. 42 [Word count: 200] 43 Keywords: mental imagery, spontaneous future thinking, optimism, negative mood 44 45 46 2 47 Negative mood states such as feeling sad, anxious and unhappy are common in daily 48 life, and at any one time, with some individuals experiencing higher levels of negative mood 49 than others at any one time. Researchers have sought to understand the cognitive factors 50 driving heightened negative mood, as it may inform intervention development for prevalent 51 mood dysregulation conditions such as depression and anxiety. 52 One factor known to drive the degree of negative mood is optimism, the generalised 53 feeling that one’s own future will turn out well (Carver, Scheier, & Segerstrom, 2010). It is 54 well established that those who are optimistic tend to experience less negative emotional 55 and physiological impacts under stress (Brydon, Walker, Wawrzyniak, Chart, & Steptoe, 56 2009; Carver & Gaines, 1987; Scheier & Carver, 1985; Segerstrom, Taylor, Kemeny, & 57 Fahey, 1998). On the other hand, theory and evidence suggests that negative views of one’s 58 future is one factor driving heightened levels of depression and anxiety (Abramson, 59 Metalsky, & Alloy, 1989; Beck, Rush, Shaw, & Emery, 1979; Miloyan, Bulley, & Suddendorf, 60 2016; Miranda & Mennin, 2007; Muris & Van Der Heiden, 2006; Pyszczynski, Holt, & 61 Greenberg, 1987; Roepke & Seligman, 2016; Strunk, Lopez, & DeRubeis, 2006). Given that 62 optimism buffers against negative mood, understanding factors that drive variation in how 63 optimistic we feel may illuminate new pathways to reducing mood disturbance. 64 Emotional future mental imagery and optimism 65 As the future does not exist, it is likely that our mental representations of the future 66 influences how optimistic we feel. Researchers have postulated that the human capacity to 67 generate mental imagery-based representations of future scenarios that could occur is an 68 important form of future thinking as it allows individuals to simulate and predict possible 69 future outcomes (Bulley, Redshaw, & Suddendorf, 2019; Schacter, Benoit, & Szpunar, 70 2017). Mental imagery refers to internally generated sensori-perceptual experiences that can 71 function as a weak form of veridical perception (Pearson, Naselaris, Holmes, & Kosslyn, 72 2015), thus mental imagery-based representations of future scenarios can allow individuals 73 to pre-experience what might happen in an as-if-real manner (Ji, Heyes, MacLeod, & 74 Holmes, 2016; Lang, 1979; Moulton & Kosslyn, 2009). 3 75 Experimental evidence suggests that generating mental imagery-based 76 representations of hypothetical emotional scenarios can influence one’s attitudes towards 77 such scenarios (Benoit, Paulus, & Schacter, 2019). Further, hypothetical emotional 78 scenarios that are imagined more frequently are judged as more realistic and likely to occur, 79 but only when such scenarios are future-oriented, not past-oriented (De Brigard, Szpunar, & 80 Schacter, 2013; Schacter, Benoit, De Brigard, & Szpunar, 2015; Szpunar & Schacter, 2013). 81 Thus, when spontaneously thinking about the future, individuals who tend to generate 82 mental imagery-based representations of positive rather than negative scenarios may also 83 feel more optimistic about what the future holds, compared to those who are less likely to do 84 so. 85 To our knowledge, no study has directly examined the relationship between biases in 86 one’s tendency to generate positive relative to negative mental imagery during spontaneous 87 (uninstructed) future thinking and optimism. However, some researchers have examined the 88 relationship between the ability to generate positive relative to negative future mental 89 imagery and optimism. Such studies have found that, when instructed to deliberately 90 generate mental imagery-based representations of future scenarios in response to emotional 91 verbal cues, lower subjective imagery vividness for positive, but not negative, scenarios is 92 associated with lower optimism (Blackwell et al., 2013; Ji, Holmes, & Blackwell, 2017; 93 Sharot, Riccardi, Raio, & Phelps, 2007). In addition, clinical researchers have found that 94 instructing participants to generate mental imagery representations of one’s best possible 95 self can increase optimism, and to a greater extent than generating mental imagery 96 representations of daily activities (Meevissen, Peters, & Alberts, 2011; Peters, Flink, 97 Boersma, & Linton, 2010). Thus, positive mental imagery about the future appears to be 98 related to one’s level of optimism. However, biases in instructed future mental imagery 99 generation does not directly bear upon biases in one’s tendency to do so spontaneously (i.e. 100 without instructions or task requirements to do so). 101 Preliminary evidence from a recent experience sampling study suggests that 102 anomalies in mental imagery during spontaneous future thinking may be related to optimism 4 103 (Beaty, Seli, & Schacter, 2018). Beaty et al. (2018) sampled the temporal direction and 104 emotional valence of daily cognition across a seven day period, and found that higher 105 optimism was associated with greater emotional positivity of future-oriented thought content, 106 on average (Beaty et al., 2018). Interestingly, optimism was not related to the overall 107 frequency of future thinking, or to the emotional valence of past-oriented thought content. 108 Thus, optimism may be specifically related to positivity of mental imagery-based thoughts 109 during future thinking. However, it is worth noting that the representational format of 110 cognition was not explicitly assessed in Beaty et al. (2018), as the presence mental imagery- 111 based future thinking was indirectly inferred from vividness ratings participants provided for 112 all thoughts. In addition, the valence of thought content was averaged across all future- 113 oriented thoughts, thus whether optimism was associated with higher frequencies of positive 114 relative to negative future thinking remains unclear. 115 The present study 116 While previous research provides encouraging support for the existence of a link 117 between emotional future mental imagery generation and optimism, the relationship between 118 the tendency to generate positive relative to negative mental imagery during spontaneous 119 future thinking and optimism remains to be directly tested. Most importantly, no study has 120 assessed whether optimism mediates the relationship between individual differences in the 121 tendency to generate positive relative to negative mental imagery during future thinking and 122 negative mood. 123 The present study tested the hypothesis that a lower tendency to generate positive 124 relative to negative mental imagery during spontaneous future thinking contributes to lower 125 optimism, which in turn contributes to elevated negative mood. If this is true, then at any 126 given time, individuals experiencing higher negative mood will be less optimistic about the 127 future (prediction 1), and those feeling less optimistic about the future will exhibit lower 128 tendency to generate positive relative to negative mental imagery during spontaneous future 129 thinking (prediction 2). Further, lower optimism will statistically mediate the relationship 5 130 between lower tendency to generate positive relative to negative mental