Attention to Fear-Relevant Stimuli by Adults and Young Children

Transcription

1 Research Article Attention to Fear-Relevant Stimuli by Adults and Young Children Vanessa LoBue and Judy S. DeLoache University of Virginia

2 Fear of snakes found in humans and primates Some theorists hypothesize it is an example of prepared learning Evidence to support the prepared learning theory found in multiple studies Studies on adults, may have developed knowledge and experience with snakes If related to evolution, should have similar results with child participants

3 Participants: year olds, 120 adults 1 target photo among 8 distractor photos 2 target types: threat-relevant & threatirrelevant Used a touch screen to present 9 photos in 3x3 matrix Children given test first followed by their parents

4 7 practice trials to train participants before the actual test trials 2 trials=1 picture, asked to touch it on the screen 2 trials=2 pictures (target + distractor), touch the designated target picture 3 trials=9 picture matrix (1 target + 8 distractors), touch designated target picture 24 actual test trials Latency measured based on target picture, age of participant, and previous experience with snakes

5 Participants were asked to locate either: -one single snake among eight flower targets OR -a lone flower target among eight snakes Hypothesis: -Expect that adults would detect snakes targets faster than flower targets -Would the children show the same pattern of performance?

6 24-3yr olds 24-4yr olds 25-5yr olds 72 parents 55% of the children had some prior experience with snakes.

7 The pattern of responding was the same for all three age groups. The pattern of performance of the children was the same as the adults; the children located the snakes more rapidly than the flower targets. There was no effect of the children's experience with snakes. Adults located the targets significantly faster than the children did.

8 The data shows that young children (pre-school aged) detect threat relevant stimuli more quickly than nonthreat-relevant stimuli. This data supports the claim that humans have a special sensitivity to certain categories of evolutionary significant threatening stimuli. Data results suggest experience with snakes may not play role in human sensitivity to them.

9 Used 2 living things to reduce bias Compared to flowers and snakes Used frogs because they are similar to snakes Only tested three-year-olds No difference among children of different ages 3-year-olds had the least experience with snakes

10 24 3-year-olds and their parents were studied 2 additional 3-year-olds were excluded for not following directions

11 Adults responded quicker No effect of snake experience & no interactions Both groups detected snakes quicker Results were consistent with experiment 1

12 Was done to test the strength of evolutionary visual threat detection under an even more rigorous task than the first two. Caterpillars were the stimuli used, due to caterpillars coming closer to resembling snakes than the plants or frogs used in experiments 1 and 2.

13 Animate object Brightly colored Elongated physical appearance (Note: Not the same pictures as used during the experiment s testing)

14 Qualities of the participants: Twenty-four children the age of 3-years-old (ranging between months). The accompanying twenty-four parents of these children. Seven-teen of the children had previous experience with snakes.

15 The ANOVA statistical measure found significant main effects of screen touching variables for the following: The target stimulus Age Interaction between age and target stimulus. Previous snake experience/exposure had no effect.

16 The general performance for experiment 3 was similar to those of experiment 1 and 2: The adults responded faster than children. Both age groups located the threatening stimuli (snakes) quicker than the nonthreatening yet physically similar stimuli (caterpillars). However, a significant difference for experiment 3 was found in the latency of responding for children.

17 Even children located the threat-relevant target faster than the targets who did not pose a threat, despite similar physical characteristics. Thus, it is viewed that the heightened detection of snakes is due to their distinctive attributes. The results suggest that the experiment reinforces the theory of evolutionary visual threat detection with this further evidence.

18 o The study Detecting the Snake in the Grass determined, through 3 separate experiments that young children, ages 3-5, did show a bias towards detection of visual threat relevant stimuli as had adults in the past as well as in this study. o The study used three separate experiments, each with different comparison stimuli. These 3 experiments used flowers, frogs and caterpillars respectively as threat-irrelevant stimuli. Study one used three age groups, that of 3,4 and 5 year old children whereas studies two and three used 3 year olds only.

19 The third experiment was particularly stringent in controls in that the snakes were compared to caterpillars which have very similar characteristics to that of snakes. This study gives significant support to the idea that there is an evolutionary link to visual threat relevant stimulus detection among children.

20 This study set out to show evidence that an evolutionary link exists that allows rapid visual detection of threat-relevant stimuli among children, a developmental approach. The findings of this study did in fact show evidence that this link exists as previous studies had also found. The major difference in this study was the use of pre-school participants and highly similar threatirrelevant stimuli.

21 The overall premise discussed in this study was that there exists an evolutionary component to visual threat-relevant detection. Previous studies had shown this to be true among adults but that these adults had experience with such stimuli. By engaging participants who were pre-school age, they set out to show stronger empirical evidence that this was not a learned response but one that exists within the neural network of humans.

22 The findings of this study enhance the body of evidence that supports an evolutionary component to visual detection of threatrelevant stimuli among humans. What the study posits for further review are the underlying mechanisms for this particular response as this has yet to be determined.