Startle-elicited Event-Related Potentials to Affective Stimuli are Associated with Recent Illicit Opioid use among Patients Receiving Opioid Agonist Treatment

Opioid use disorder (OUD) has been linked to exaggerated attentional, affective, and arousal responses to opioid-related stimuli, as well as altered responses to other affective (eg, naturally rewarding or aversive) stimuli, particularly blunted responses to pleasant/rewarding stimuli. Both exaggerated responses to drug-related stimuli and reduced response to pleasant stimuli may influence the course of OUD and its treatment, however interpretation of studies thus far is limited by methodological issues. In the present study, we examined subjective ratings, and attenuation of the P3 component of the acoustic startle-evoked event-related potential (as a measure of attention), while viewing neutral, pleasant, unpleasant, and drug-related images. Participants prescribed opioid agonist treatment (OAT) for OUD (n = 82) were compared to a carefully-matched control group (n = 33) and to recently-abstinent participants with OUD (n = 22). Relative to controls, participants prescribed OAT gave higher positive valence ratings of drug images, and blunted valence responses to other affective images, but groups did not differ in terms of arousal ratings or P3 amplitude. Within the OAT group, linear modeling of associations between frequency of recent illicit opioid use and startle P3 amplitude found an association between increased recent illicit opioid use and reduced attention to pleasant, relative to unpleasant, images. The latter finding may have implications for interventions targeting cognitive biases in people with substance use disorder. In particular, they suggest that enhancing attention to pleasant stimuli may be as, if not more important, than the typical approach of trying to reduce attentional bias to drug-related stimuli.

The Effect of Valence and Arousal on Spatial Attention

<p>Conceptual metaphor theory suggests that to mentally represent abstract concepts we use metaphorical associations to map them onto more concrete constructs (Lakoff & Johnson, 1980; 1999). Using a choice reaction time (CRT) task, Meier and Robinson (2004) found that positively valenced words primed attention to higher areas in vertical space, while negatively valenced words primed attention to lower areas in vertical space, consistent with the good is up/bad is down conceptual metaphor. Meier and Robinson (2004; 2005) suggest this provides evidence that emotional words create an automatic and obligatory metaphor-congruent shift in spatial attention, driven by a Valence x Position interaction. However, other research shows that the arousal level, not just the valence of emotional words can affect reaction time (Robinson, Storbeck, Meier & Kirkeby, 2004). This means concluding that valence alone is driving the shift in attention is premature. Furthermore, Brookshire, Irvy and Casasanto (2010) dispute Meier and Robinson’s claim that the relationship between affect and metaphor is automatic, instead suggesting that affect-metaphor associations are optional and only accessed under certain contextual conditions. The purpose of this thesis was therefore two-fold. First, it aimed to explore whether valence, arousal, or an interaction between the two was responsible for driving the metaphor-consistent shift in spatial attention observed by Meier and Robinson (2004). Second, it aimed to progress the discussion about when affective stimuli, in the form of emotional words, automatically activate the good is up/bad is down conceptual metaphor. Three CRT experiments were conducted in which (a) emotional stimulus words were differentiated by arousal level as well as valence and (b) the evaluation of stimulus words’ affective tone (pleasant/unpleasant) was manipulated. A Valence x Position interaction in relation to the good is up but not bad is down conceptual metaphor was found when the valence of priming words was evaluated, suggesting valence, rather than arousal or a combination of both, is driving the affect-metaphor relationship. No evidence for the automatic activation of affect-metaphor associations was found when the word’s affective tone was not evaluated. These findings suggest that while driven by valence, affect-metaphor associations are not fully automatic and occur only under certain contextual conditions. The implications for our understanding of how emotion impacts spatial attention are discussed, suggesting metaphors enrich, rather than monopolise our mental representation of abstract, affective concepts.</p>

The Effect of Valence and Arousal on Spatial Attention

<p>Conceptual metaphor theory suggests that to mentally represent abstract concepts we use metaphorical associations to map them onto more concrete constructs (Lakoff & Johnson, 1980; 1999). Using a choice reaction time (CRT) task, Meier and Robinson (2004) found that positively valenced words primed attention to higher areas in vertical space, while negatively valenced words primed attention to lower areas in vertical space, consistent with the good is up/bad is down conceptual metaphor. Meier and Robinson (2004; 2005) suggest this provides evidence that emotional words create an automatic and obligatory metaphor-congruent shift in spatial attention, driven by a Valence x Position interaction. However, other research shows that the arousal level, not just the valence of emotional words can affect reaction time (Robinson, Storbeck, Meier & Kirkeby, 2004). This means concluding that valence alone is driving the shift in attention is premature. Furthermore, Brookshire, Irvy and Casasanto (2010) dispute Meier and Robinson’s claim that the relationship between affect and metaphor is automatic, instead suggesting that affect-metaphor associations are optional and only accessed under certain contextual conditions. The purpose of this thesis was therefore two-fold. First, it aimed to explore whether valence, arousal, or an interaction between the two was responsible for driving the metaphor-consistent shift in spatial attention observed by Meier and Robinson (2004). Second, it aimed to progress the discussion about when affective stimuli, in the form of emotional words, automatically activate the good is up/bad is down conceptual metaphor. Three CRT experiments were conducted in which (a) emotional stimulus words were differentiated by arousal level as well as valence and (b) the evaluation of stimulus words’ affective tone (pleasant/unpleasant) was manipulated. A Valence x Position interaction in relation to the good is up but not bad is down conceptual metaphor was found when the valence of priming words was evaluated, suggesting valence, rather than arousal or a combination of both, is driving the affect-metaphor relationship. No evidence for the automatic activation of affect-metaphor associations was found when the word’s affective tone was not evaluated. These findings suggest that while driven by valence, affect-metaphor associations are not fully automatic and occur only under certain contextual conditions. The implications for our understanding of how emotion impacts spatial attention are discussed, suggesting metaphors enrich, rather than monopolise our mental representation of abstract, affective concepts.</p>

Evaluation and Recall of Valenced Stimuli as a Function of Spatial Positions

<p>Meier and Robinson (2004) had subjects identify pleasant and unpleasant words presented individually either at the top or bottom of a computer screen. Subjects identified pleasant words faster when they appeared at the top of the screen and unpleasant words faster whey they appeared at the bottom of the screen. The authors discussed this finding in terms of metaphors noting that in language good things are often allocated upwards (e.g. “things are looking up for me”) and bad things downwards e.g. (“I’m down in the dumps”). The aim of the present study was to investigate whether this relationship between affective stimuli and visual space occurs automatically (implicitly) or whether explicit processing of affective stimuli is required. A second aim was to investigate if memory for affective words is influenced by spatial location. In Experiments 1 and 2 subjects were shown pleasant and unpleasant words presented either at the top or bottom of a computer screen. Half the words were coloured green and half coloured purple. Subjects had to identify the colour as quickly as possible. No significant interaction between stimulus valence and spatial position was found, nor did recall interact with spatial position. In Experiment 3 subjects had to explicitly identify the valence of the words shown either at the top or bottom of the screen. It was predicted that positive stimuli would be explicitly evaluated faster and recalled more accurately when shown at the top of the screen, with the opposite holding true for negative stimuli. Participants were quicker to identify positive words at the top of the screen. Recall did not interact with spatial position. Overall the results of this study were broadly supportive of the hypothesis for explicit evaluation but not so for implicit evaluation or recall.</p>

Evaluation and Recall of Valenced Stimuli as a Function of Spatial Positions

<p>Meier and Robinson (2004) had subjects identify pleasant and unpleasant words presented individually either at the top or bottom of a computer screen. Subjects identified pleasant words faster when they appeared at the top of the screen and unpleasant words faster whey they appeared at the bottom of the screen. The authors discussed this finding in terms of metaphors noting that in language good things are often allocated upwards (e.g. “things are looking up for me”) and bad things downwards e.g. (“I’m down in the dumps”). The aim of the present study was to investigate whether this relationship between affective stimuli and visual space occurs automatically (implicitly) or whether explicit processing of affective stimuli is required. A second aim was to investigate if memory for affective words is influenced by spatial location. In Experiments 1 and 2 subjects were shown pleasant and unpleasant words presented either at the top or bottom of a computer screen. Half the words were coloured green and half coloured purple. Subjects had to identify the colour as quickly as possible. No significant interaction between stimulus valence and spatial position was found, nor did recall interact with spatial position. In Experiment 3 subjects had to explicitly identify the valence of the words shown either at the top or bottom of the screen. It was predicted that positive stimuli would be explicitly evaluated faster and recalled more accurately when shown at the top of the screen, with the opposite holding true for negative stimuli. Participants were quicker to identify positive words at the top of the screen. Recall did not interact with spatial position. Overall the results of this study were broadly supportive of the hypothesis for explicit evaluation but not so for implicit evaluation or recall.</p>

The role of previous visual experience in subjective reactions to new affective pictures and sounds.

According to predictive models of emotion, people use their previous experience to construct new affective predictions. We do not live in a stable world, however. Some environments are uncertain, others are not. This study investigated how experiencing certain vs. uncertain probabilistic relationships shapes subjective reactions to new affective stimuli, within and across sensory modalities. Two S1-S2 paradigms were employed as learning and test phases in two experiments. S1s were colored circles, S2s negative or neutral affective pictures or sounds. Participants (N = 192, 179) were assigned to the certain (CG) or uncertain group (UG), and they were presented with 100% (CG) or 50% (UG) S1-S2 congruency between visual stimuli during the learning phase. During the test phase both groups were presented with a new S1-S2 paradigm with a 75% S1-S2 congruency, and visual (Experiment 1) or auditory (Experiment 2) S2s. Participants were asked to rate the expected valence of upcoming S2s (expectancy ratings), or their experienced valence and arousal (valence and arousal ratings). In both experiments, participants in the CG reported more negative expectancy ratings after the S1s previously paired with negative stimuli, whereas no group differences emerged on valence and arousal ratings. Furthermore, when comparing the two experiments, no significant group by experiment interaction was found. Overall, and in line with predictive models, our results suggest that relying on a certain previous experience shapes subjective expectancies toward a coherent labeling of the predicted valence of future stimuli, and that this process develops similarly across sensory modalities.

The goal-relevance of affective stimuli is dynamically represented in affective experience

Affect is a continuous and temporally dependent process that represents an individual's ongoing relationship with its environment. However, there is a lack of evidence on how factors defining the dynamic sensory environment modulate changes in momentary affective experience. Here, we show that goal-dependent relevance of stimuli is a key factor shaping momentary affect in a dynamic context. Participants ( N = 83) viewed sequentially presented images and reported their momentary affective experience after every fourth stimulus. Relevance was manipulated through an attentional task that rendered each image either task-relevant or task-irrelevant. Computational models were fitted to trial-by-trial affective responses to capture the key dynamic parameters explaining momentary affective experience. The findings from statistical analyses and computational models showed that momentary affective experience was shaped by the temporal integration of the affective impact of recently encountered stimuli, and that task-relevant stimuli, independent of stimulus affect, prompted larger changes in experienced pleasantness compared with task-irrelevant stimuli. These findings clearly show that dynamics of affective experience reflect goal-relevance of stimuli in our surroundings.