'nSex associations with attention, Pavlovian and instrumental conditioning'
(AsPredicted #66,739)
Download PDF

---

---

1) Have any data been collected for this study already?
No, no data have been collected for this study yet.

2) What's the main question being asked or hypothesis being tested in this study?
In this study, we test whether the need for sex (nSex; measured via Picture Story Exercise) predicts attentional bias in an eye tracking task (bias task; H1-H6). Additionally, we test whether individuals high in approach-oriented nSex prefer neutral stimuli that have acquired, through training, prediction value for the occurrence of erotic stimuli (classical conditioning task; H7-H13). Further, we test whether nSex promotes the learning of eye-movements reinforced by erotic stimuli (instrumental conditioning task; H14-H16) Specifically, we test the following hypotheses:

Participants with higher scores on an approach-related PSE measure of nSex
1. .. gaze longer at erotic stimuli (here and in the following compared to non-erotic stimuli [neutral, romantic]).
2. .. prefer to initially orient their gaze towards erotic stimuli.
3. .. have greater pupil dilation in response to erotic pictures.
4. .. show less corrugator activity in response to erotic pictures.
5. .. show more zygomaticus activity in response to erotic pictures.
6. .. tend to rate erotic stimuli higher on positive valence and arousal.
7. .. show, during the test relative to the baseline phase, longer gaze duration at erotic stimuli in response to CS+ (erotic stimuli) than to CS- (neutral stimuli), indicative of associative learning of a CS's incentive value.
8. .. show, during the test relative to the baseline phase, a preference to initially orient their gaze to CS+ (erotic stimuli) than to CS- (neutral stimuli), indicative of associative learning of a CS's incentive value.
9. .. show, during the test relative to the baseline phase, wider pupils in response to CS+ (erotic stimuli) than to CS- (neutral stimuli), indicative of associative learning of a CS's incentive value.
10. .. show, during the test relative to the baseline phase, less corrugator activity in response to CS+ than to CS-, indicative of associative learning of a CS's incentive value.
11. .. show, during the test relative to the baseline phase, more zygomaticus activity in response to CS+ than to CS-, indicative of associative learning of a CS's incentive value.
12. .. show a greater pupillary response to erotic US (than non-erotic US).
13. .. show a stronger tendency to subjectively rate erotic stimuli as higher on positive valence and arousal.
14. .. have higher learning gains regarding eye-movements that elicit the presentation of erotic stimuli.
15. .. perform more eye-movements that elicit erotic stimuli.
16. .. show longer viewing time of erotic stimuli in a key-press task.
17. In general, we expect effects for LIWC "sex" category to parallel the effects for the content-coded nSex category, but with weaker effect sizes.

3) Describe the key dependent variable(s) specifying how they will be measured.
PSE nSex imagery will be measured primarily via a preliminary content coding system (see Hinzmann, Stopfer, Schmieg, & Schultheiss, May 2019) differentiating between approach-related imagery (i.e., need for sex, positive anticipation, instrumental activity (excluding avoidance), positive goal attainment, positive goal affect, overall attractiveness, sexual attractiveness, means to an end, promiscuity, erotic atmosphere, secret sex) and avoidance-related imagery (i.e., negative anticipation, instrumental activity (only avoidance), obstacles, negative goal attainment, negative goal affect, jealousy, derogatory comments). In addition, we will also explore to what extent the Linguistic Inquiry and Word Count (LIWC) 2001 category "sex" both by itself and augmented with additional words is suitable predicting the same outcomes as the PSE nSex measure(s).
Initial orientation (first AOI that is entered after stimuli have appeared), average entry time (time a participant's gaze needs to enter AOIs for the first time), and average gaze duration (time a participant's gaze dwells on AOIs) will be assessed using the Tobii Pro TX300 eye-tracker.
Behavioral preferences for erotic vs. non-erotic stimuli will be assessed through a key-press task, which allows participants to increase or decrease the time each stimulus is presented with overall task time held constant at 4 minutes across all participants.
Subjective arousal and valence will be assessed by means of a self-report measure.
Pupil size, a sensitive indicator of sexual arousal, will be assessed using the Tobii Pro TX300 eye-tracker.
Facial affect will be measured via electromyography over the corrugator and zygomatic muscles using the BIOPAC system.

4) How many and which conditions will participants be assigned to?
All participants work on the same experiment.

5) Specify exactly which analyses you will conduct to examine the main question/hypothesis.
All tests focus on PSE approach-related nSex (content-coded) but will also explore effects on LIWC 2001 "sex", plus further augmentations and machine-learning approaches.
Linear regression (LR) with nSex as IV and
1. .. gaze duration of erotic stimuli as DV.
2. .. amount of occurrences of initial orientation towards erotic stimuli as DV.
3. .. pupil dilation of erotic stimuli as DV.
4. .. corrugator activity of erotic stimuli as DV.
5. .. zygomaticus activity of erotic stimuli as DV.
6. .. subjective valence and arousal towards erotic stimuli as DVs.
RM-ANCOVA with stimulus type (CS+, CS-) as within-subjects variable,
7. .. baseline gaze duration and task version (pairing of CS and US) as covariates, nSex as continuous predictor, and gaze duration during the test phase as DV.
8. .. baseline amount of occurrences of initial orientation and task version (pairing of CS and US) as covariates, nSex as continuous predictor, and amount of occurrences of initial orientation during the test phase as DV.
9. .. baseline pupil size and task version (pairing of CS and US) as covariates, nSex as continuous predictor, and pupil dilation during the test phase as DV.
10. .. baseline corrugator activity and task version (pairing of CS and US) as covariates, nSex as continuous predictor, and corrugator activity during the test phase as DV.
11. .. baseline zygomaticus activity and task version (pairing of CS and US) as covariates, nSex as continuous predictor, and zygomaticus activity during the test phase as DV.
12. LR with nSex as the IV and pupil dilation in response to erotic US as the DV.
13. Two LRs with nSex as the IV and subjectively reported valence and arousal towards erotic stimuli as DVs.
14. RM-ANCOVA with block (1 vs. 2 vs. 3 vs. 4), stimulus type (erotic vs. control), contingency (pre-switch vs. post-switch) as within-subjects factors, nSex as continuous predictor, task version (erotic pre-switch left vs. erotic pre-switch right) as the covariate, and entry times as the DV.
15. LR predicting amount of eye-movements towards the erotic/neutral US in free-choice-trials with task version (erotic pre-switch left vs. erotic pre-switch right) as the covariate and predictor nSex.
16. Two LRs with nSex as the IV and overall erotic-stimulus viewing time (as % of total time), and erotic-stimulus and neutral-stimulus key presses ("up", "down") as DVs.
17. H1 to H14 will be repeated for LIWC category "sex".

6) Describe exactly how outliers will be defined and handled, and your precise rule(s) for excluding observations.
For PSE nSex motive scores and the LIWC 'sex' words, participants will be excluded if they fail to write stories > 30 words for each PSE picture stimulus. Outliers in motive scores will be identified via histograms and Shapiro-Wilk tests. If necessary, transformations (sqrt (1 + score) or log(1+score)) will be used to rein in outliers. If inclusion/exclusion of outliers changes results substantially and outliers cannot clearly be attributed to an invalid response process, findings will be reported for analyses including and excluding the outliers. In general, analyses involving a specific variable or set of variables will always use the maximum N available for data in all variables. If there is clear evidence that a participant did not follow instructions, her/his task-specific or all data, respectively, will be dropped from the data set. All such exclusions and their reasons will be transparently reported in the research report. In the KPT, to test the robustness of results, we will use mean and median values. In the pupillometry data, eye blinks will be removed from the data. Eye blinks are characterized by a rapid decrease in pupil size, followed by a period of missing data, followed by a rapid increase in pupil size. We will use linear interpolation to deal with eye blinks. In the spatial eye-tracker data, participants will be excluded if their work on the respective task or data quality was insufficient (>20% of critical trials invalid due to data loss or gaze not leaving fixation cross-AOI; >20% overall data loss in critical trials; accuracy > 2; precision > 1; n of warnings > 0.8*n of trials; stereotypical right or left gaze pattern).

7) How many observations will be collected or what will determine sample size?
No need to justify decision, but be precise about exactly how the number will be determined.
Based on previous studies testing hypotheses related to PSE-assessed motives and eye-tracker data and that have yielded, for instance, an r of .17 for the correlation of nPower with gaze towards anger faces (Janson et al, under revision), we aim to recruit and test 300 participants to arrive at a net sample of N = 270, which would provide 80% power to detect an effect of r = .17 at p < .05.

8) Anything else you would like to pre-register?
(e.g., secondary analyses, variables collected for exploratory purposes, unusual analyses planned?)
Hormones will be assessed by means of saliva samples that will be collected before the computerized study. Body measures such as ulna, fibula, and digit ratio (2D:4D) will be taken and their associations with nSex scores and score changes as well as affective responses to erotic (versus neutral) stimuli explored. Personality tests and demographic variables will be analyzed in an exploratory fashion.