Visual Search

Visual Search

Introduction

Visual Search

Visual search is a sort of perceptual task that requires attention which involves the visual environment active scan for a specific feature or object (the target) among other features or objects (the distractors) (Hollingworth, 2012). Visual search can occur either with or without moving an eye. This ability of consciously locating an object (target) amongst a stimuli complex array (distractors) has been widely studied over the past forty years. Examples of this can be observed in daily life like picking a product from the shelf in supermarket, animals looking for food in between the leaves piles, trying to search friend in a huge crowd and playing visual search tasks like 'Where's Wally'.

Majority of the visual search paradigms have utilized the movements of eye as a means to calculate the extent of attention given to stimuli. Although, vast research to date recommends that movements of eye move independent of attention and thus is not a trustworthy method for examining the attention role in this instance. The research on behaviour that focus the time of reaction has great dominance in this field and up till now is extremely noteworthy and reliable. Previous studies that were conducted on visual searche utilizes the reaction time denoted as “RT” for measuring the time taken for detecting the target among the objects or features that are distractors. It could be exemplify as a green square that is target, among red circles set that are distractors in this case. There are two types of visual search, one is feature search and other is conjunction search.

Feature Search

Feature search synonymized as efficient search or disjunctive search. Feature search was presented by Treisman and Gelade in the year 1980 (Triesman & Gelade, 1980). This is characterized as a parallel method in which the target as well as the distractors are maximally distinctive, separated by a single property, for example shape, colour, size or orientation. An illustration of this could be to select a red circle spotted inside a black circles group. The control of one characteristic means this sort of search is extremely effective giving brisk reaction times and giving a 'pop out' impact. Previous studies recommends that as the amount of distractors enhances around or against the target, reaction times remain unchanged, therefore the 'pop out' impact is as successful with four distractors as it might be with forty. During feature search, bottom-up processing (driven by stimuli) presupposes utilizing notable characteristics of the target empowering it to 'pop out', it means that the search is extremely efficient.

Conjunction Search

Conjunction search also known as inefficient search. It was also presented by Treisman and Gelade in the year 1980 (Triesman & Gelade, 1980). Conjunction search takes place when the target as well as distractors impart likenesses in more than one single visual property, for example colour, size, shape and orientation. It can be exemplified as whether the target is a horizontal black line whereas the distractors are composed of white lines that are horizontal and white and black lines ...