The effect of variations of emotional expressions on mnemonic discrimination and traditional recognition memory

Figures & data

Figure 1. Example of a morph within a face identity. The first image (far left) presents the original face image displaying a high intensity happy expression. The second image presents the low intensity happy expression. Third image (middle) presents the original neutral version. The fourth image presents the low intensity fearful expression. The fifth image (far right) presents the original high intensity fearful expression.

Figure 2. A flowchart of the architecture of the experimental task, illustrating block one structure (of 16); the learning items, test items and corresponding correct responses. [To view this figure in color, please see the Online version of this journal.]

Figure 3. Illustration of the experimental comparisons in the emotional discrimination task. [To view this figure in color, please see the Online version of this journal.]

Table 1. Mean proportion of response alternatives (SD) for each item type.

Learning – Test Manipulation		Item Type	Response Alternatives
			“Old Identical”	“Low Similarity” (Dissimilar)	“High Similarity” (Similar)
Overall		Target	0.50 (0.15)	0.14 (0.09)	0.35 (0.09)
		Dissimilar Lure	0.14 (0.08)	0.43 (0.13)	0.43 (0.10)
		Similar Lure	0.21 (0.10)	0.28 (0.12)	0.50 (0.09)
Expressions of Emotional Intensity	Neutral to Low Intensity Happy	Target	0.63 (0.23)	0.06 (0.09)	0.30 (0.20)
		Dissimilar Lure	0.14 (0.13)	0.41 (0.19)	0.44 (0.19)
		Similar Lure	0.19 (0.15)	0.18 (0.15)	0.62 (0.14)
	Neutral to Low Intensity Fearful	Target	0.63 (0.23)	0.06 (0.09)	0.30 (0.20)
		Dissimilar Lure	0.10 (0.10)	0.54 (0.19)	0.36 (0.18)
		Similar Lure	0.13 (0.10)	0.56 (0.15)	0.30 (0.15)
	High Intensity Happy to Low Intensity Happy	Target	0.52 (0.20)	0.17 (0.13)	0.31 (0.15)
		Dissimilar Lure	0.07 (0.07)	0.64 (0.18)	0.29 (0.16)
		Similar Lure	0.26 (0.13)	0.32 (0.17)	0.42 (0.16)
	High Intensity Fearful to Low Intensity Fearful	Target	0.44 (0.19)	0.27 (0.17)	0.27 (0.10)
		Dissimilar Lure	0.16 (0.14)	0.44 (0.21)	0.40 (0.19)
		Similar Lure	0.22 (0.17)	0.45 (0.16)	0.33 (0.13)
	Low Intensity Happy to High Intensity Happy	Target	0.50 (0.17)	0.06 (0.08)	0.43 (0.13)
		Dissimilar Lure	0.15 (0.14)	0.31 (0.16)	0.53 (0.14)
		Similar Lure	0.25 (0.15)	0.15 (0.14)	0.59 (0.16)
	Low Intensity Fear to High Intensity Fearful	Target	0.43 (0.19)	0.14 (0.12)	0.43 (0.15)
		Dissimilar Lure	0.20 (0.14)	0.21 (0.16)	0.57 (0.13)
		Similar Lure	0.24 (0.11)	0.25 (0.17)	0.50 (0.16)

Note: Target items refers to old identical expressions between learning and test, Dissimilar Lure items refers to large changes in expressions (i.e. a new emotional expression), whereas Similar Lure items refers to small changes in expression. Our three items (target, dissimilar and similar Lures) corresponds to prior studies, in which old, foil, and lure items have been used.

Figure 4. An illustration of accurate memory performance for the two memory measures. Mnemonic discrimination performance (left) reflects the participants’ ability to correctly distinguish between similar facial expressions. The facial expressions at learning were presented as neutral and became slightly more emotional (happy or fearful) at test. Traditional recognition accuracy (right) for emotional expressions at learning and test for both high (100%) and low (50%) intensity. [To view this figure in color, please see the Online version of this journal.]

Table 2. Mean proportion of performance for traditional recognition.

Learning – Test Manipulation		Hits		False Alarms		Correct Rejections		Misses		Old/Dissimilar Discrimination
		M (SD)	95% CI	M (SD)	95% CI	M (SD)	95% CI	M (SD)	95% CI	M (SD)	95% CI
Overall		0.50 (0.15)	[0.45 0.56]	0.14 (0.08)	[0.11, 0.17]	0.43 (0.13)	[0.38 0.48]	0.14 (0.10)	[0.10 0.18]	0.37 (0.13)	[0.31 0.42]
Expression of Emotional Intensity	Neutral to High Intensity Happy	0.63 (0.23)	[0.54 0.72]	0.14 (0.13)	[0.09 0.19]	0.41 (0.20)	[0.12 0.15]	0.06 (0.09)	[0.03 0.09]	0.49 (0.22)	[0.41 0.58]
	Neutral to High Intensity Fear	0.63 (0.23)	[0.54 0.72]	0.10 (0.10)	[0.06 0.14]	0.54 (0.19)	[0.24 0.14]	0.06 (0.09)	[0.03 0.09]	0.53 (0.23]	[0.45 0.62]
	High Intensity Happy to High Intensity Fearful	0.52 (0.20)	[0.44 0.60]	0.07 (0.07)	[0.45 0.10]	0.64 (0.18)	[0.15 0.17]	0.17 (0.13)	[0.12 0.22]	0.44 (0.22)	[0.36 0.53]
	High Intensity Fearful to High Intensity Happy	0.44 (0.19)	[0.37 0.51]	0.16 (0.14)	[0.10 0.21]	0.44 (0.21)	[0.18 0.18]	(0.27 0.17)	[0.20 0.33]	0.29 (0.23)	[0.20 0.37]
	Low Intensity Happy to Low Intensity Fearful	0.50 (0.17)	[0.44 0.56]	0.15 (0.14)	0.10 (0.21)	0.32 (0.16	[0.09 0.12]	(0.07 0.08)	[0.03 0.10]	0.35 (0.21)	[0.26 0.43]
	Low Intensity Fearful →Low Intensity Happy	0.43 (0.19)	[0.35 0.50]	0.20 (0.14)	[0.15 0.26]	0.21 (0.16)	[0.11 0.18]	(0.14 0.12)	[0.09 0.18]	0.22 (0.21)	[0.14 0.31]

Note: M  =  mean, SD  =  standard deviation, CI  =  confidence interval.