Can people identify original and manipulated photos of real-world scenes?

Cognitive Research: Principles and Implications

Table 5 Results of the GEE binary logistic and linear regression models to determine variables that predict accuracy in the detect and locate tasks

Predictor	B	OR [95% CI]	p
Detect (DL and DnL)
Response time
Accuracy	0.13	1.14 [1.10, 1.18]	<0.001
d'	−0.01	0.99 [0.98, 1.01]	0.40
c	0.004	1.00 [0.99, 1.01]	0.42
General belief about percentage of images manipulated = High (71–100%)
Accuracy	0.16	1.18 [1.02, 1.36]	0.03
d'	0.09	1.09 [0.97, 1.23]	0.14
c	−0.04	0.96 [0.90, 1.03]	0.25
Gender = Female
Accuracy	−0.01	0.99 [0.86, 1.15]	0.92
d'	−0.03	0.97 [0.86, 1.09]	0.60
c	−0.01	0.99 [0.93, 1.06]	0.82
Interest in photography = Interested
Accuracy	0.17	1.19 [1.02, 1.39]	0.03
d'	0.04	1.04 [0.92, 1.18]	0.56
c	−0.05	0.95 [0.89, 1.02]	0.18
Frequency of taking photos = Daily/weekly
Accuracy	−0.01	0.99 [0.84, 1.17]	0.91
d'	−0.07	0.93 [0.82, 1.07]	0.31
c	−0.05	0.95 [0.88, 1.02]	0.18
Locate (DL and nDL)
Response time	0.10	1.11 [1.08, 1.14]	<0.001
General belief about percentage of images manipulated = High (71–100%)	−0.01	0.99 [0.87, 1.12]	0.84
Gender = Female	−0.10	0.91 [0.80, 1.03]	0.14
Interest in photography = Interested	0.16	1.17 [1.02, 1.34]	0.02
Frequency of taking photos = Daily/weekly	−0.08	0.92 [0.80, 1.06]	0.27
Detect and locate (DL)
Response time: detect	0.17	1.19 [1.15, 1.23]	<0.001
Response time: locate	0.13	1.14 [1.11, 1.18]	<0.001
General belief about percentage of images manipulated = High (71–100%)	0.05	1.05 [0.91, 1.20]	0.51
Gender = Female	−0.13	0.88 [0.77, 1.01]	0.07
Interest in photography = Interested	0.20	1.22 [1.06, 1.41]	0.01
Frequency of taking photos = Daily/weekly	−0.09	0.92 [0.78, 1.07]	0.28

B and odds ratios (OR) estimate the degree of change in (a) accuracy on the task (based on the manipulated image trials), (b) d', or (c) c associated with one unit change in the independent variable. An odds ratio of 1 indicates no effect of the independent variable on accuracy; values of 1.5, 2.5, and 4.0 are generally considered to reflect small, medium, and large effect sizes, respectively (Rosenthal, 1996). The category order for factors was set to descending to make the reference level 0. The reference groups are: General beliefs about percentage of images manipulated = Low (0–70%), Gender = Male, Interest in photography = Not Interested, Frequency of taking photos = Monthly/yearly/never. For response time (RT) we divided the data into eight equal groups with level 1 representing the slowest RTs (detect ≥47.1 s; locate ≥18.9 s) and level 8 the fastest (detect ≤8.1 s; locate ≤2.7 s). The 14 subjects who chose not to disclose their gender were excluded from these analyses, leaving a total sample of n = 645. Because we did not have a fixed number of choices per condition in the location task, we were unable to calculate the degree of change in d' or c associated with the predictor variables