VISUAL SEARCH TASKBrendan Ahern, Nathan MacIntyre-Hayes,

& Cierra Tompkins

Research Question Question: How does adding features in a

conjunction search affect reaction time (RT)? Hypothesis: Reaction time will increase

with the addition of features, however when the feature stands out from the distractors reaction time will

Conjunction search: When the target is a combination of two or more features

Feature search: The target is defined by a single feature

Methods The # of distractors was held constant

at 40 Independent variable: # of features

Dependent variable: reaction time There were 4 sets of searches. Each Set

of searches had 3 trials. Each Trial was presented in random order.

Methods Ex: The first search set was a Feature

Search. The Features search trials were presented in slides, 3, 13 and 21.

23 participants RT averages were first calculated for

each trial Then the RT averages for each trial

were used to calculate the Average RT for the Search Set.

Data Recording Sheet

Methodology Feature Search ( Search Set #1) 1.

Target =

The purpose of the feature search trial was to roughly gauge neutral response time.

Trial 1 Av RT = 1.19 Trial 2 Av RT = 1.47 Trial 3 Av RT = 1.26 Search Set # 1 Total Av RT =

1.25

Conjunction Search Set # 1 Target =

two features Trial 1 Av RT = 1.92 Trial 2 Av RT= 2.11 Trial 3 Av RT= 1.48

Conjunction Search Set # 1 Total Av RT = 1.83

Conjunction Search Set # 2 Target =

3 features

Trial 1 Av RT = 2.47 Trial 2 Av RT = 3.56 Trial 3 Av RT = 2.12

Conjunction Search Set # 2 Av RT= 2.71

Conjunction Search Set # 3 Target =

4 features

Trial 1 Av RT= 2.41 Trial 2 Av RT= 2.35 Trial 3 Av RT= 2.00

Conjunctive Search Set # 3 Total Av RT= 2.25

Results

Feature Search

Conjunctive Search A

Conjunctive Search B

Conjunctive Search C

0

0.5

1

1.5

2

2.5

3

Reac

tion

Tim

e (s

)

Results Elapsed time to locate target was in

conjunctive searches Conjunction search #1 RT Conjunction search #2 RT Conjunction search #3 RT

Feature searches required time to find target

Conclusion Hypothesis: Reaction time increased

with the addition of features to a target, and decreased when the features made the target more apparent

Limitations and Future Considerations

Limitations: Method of Recording: Info was passed from

BrendanNathanParticipantBrendan. RT data was rounded down to compensate for the delay.

Recording error: Accidents happen -Data for Participants (P) 6, 19, 8 and 10. For P6, FS 3 For P8, CS1b For P10,CS1 c For P16,CS1 c For P19, FS3 The RT data due to these errors was brought down to 0. The “0” value

from these trials were not included in the calculation of the average. Prior knowledge:

Participants were encouraged not to look at the trial before they participated, and we moved our experiment into the hallway.

Type of distractor as mediating variable: See Conjunction Search Set # 3

Limitations and Future Considerations

Future considerations: Conjunctive search : Feature search Better method to record elapsed reaction

time Does target location influence reaction

time?

Questions?