Stroop effect - The objective of this practical was To test the automaticity of attention using PDF

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The objective of this practical was To test the automaticity of attention using Stroop Colour Word Test. First, theory and general information about attention and the stroop effect has been given in detail which is useful for practical as well as for the theory on attention and practical vivas. The...

Description

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Aim: To test the automaticity of attention using Stroop Colour Word Test

Hypotheses:

Percentage of Correct Responses (accuracy) will be higher for colour congruent word stimuli than percentage of correct responses for colour incongruent word stimuli Introduction Attention In general attention is selectively concentrating on a discrete aspect of information, whether subjective or objective, while ignoring other perceivable information. It is the means through which we actively process a limited information from the large amount of information available through our senses, stored memories and other coginitive processes. (Rao,2003) The four main functions of attention are : 1. Signal detection and vigilance: We try to detect the appearance of a particular stimulus. Air traffic controllers, for example, keep an eye on all traffic near and over the airport. 2. Search: We try to find a signal amidst distracters, for example, when we are looking for our lost cell phone on an autumn leaf-filled hiking path. 3. Selective attention: We choose to attend to some stimuli and ignore others, as when we are involved in a conversation at a party. 4. Divided attention: We prudently allocate our available attentional resources to coordinate our performance of more than one task at a time, as when we are cooking and engaged in a phone conversation at the same time.

Selective Attention The capacity for or process of reacting to certain stimuli selectively when several occur simultaneously is known as selective attention. Attention is a limited resource, so selective attention allows us to tune out unimportant details and focus on what really matters. Colin Cherry conducted experiments to show this process. One experiment was that two auditory messages were presented simultaneously with one presented to each ear. Cherry then asked participants to pay attention to a particular message, and then repeat back what they had heard. He discovered that the participants were able to easily pay attention to one message and repeat it, but when they were asked about the contents of the other message,

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they were unable to say anything about it. Cherry found that when contents of the unattended message were suddenly switched (such as changing from English to German mid-message or suddenly playing backward) very few of the participants even noticed. He referred this as the cocktail party effect. i.e. the process of tracking one conversation in the face of the distraction of other conversations. He observed that cocktail parties are often settings in which selective attention is salient feauture.

The Stroop effect The Stroop effect is a phenomenon that occurs when you must say the colour of a word but not the name of the word. For example, blue might be printed in red and you must say the colour (red) rather than the word (blue). John Ridley Stroop reported this process. When the word is a colour word printed in a mismatched ink colour, this is very difficult to do and results in slow, error-prone responding.

Historical antecedents of stroop effect The roots of Stroop's research are evident 50 years earlier in the work of James McKeen Cattell (1886). Cattell reported that objects (and colours) took longer to name aloud than the corresponding words took to read aloud. Saying "red" to a patch of colour was slower than saying "red" to the word red. This is because, in the case of words and letters, the association between the idea and name has taken place so often that the process has become automatic, whereas in the case of colours and pictures we must by a voluntary effort choose the name". Therefore word reading is automatic due to extensive practice, introducing the concept of automaticity to cognitive science. Automatic processes can be thought of as unintentional, uncontrolled, unconscious, and fast. Under the automaticity account, people cannot comply with an instruction no to read because reading cannot be “turned off”, hence it is guaranteed that incompatible words will cause interference when attempting to name their print colours.

There was no follow-up to Stroop’s work but the study on colour-word interference was reported by Klein in 1964 sing multiple-stimulus cards in much the same format as Stroop had used. Klein sought to understand what aspects of the words interfered with naming colours. To do so, he incorporated several new conditions. In addition to the baseline “colours-alone” card, there were six interference cards. As always, the standard incongruent condition – using words incongruent with the print colours – showed large interference.

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When color words that were not the names of the print colours were substituted, interference was cut in half, implicating a large role for response set in interference. Interference then declined more slowly across colour-related words (e.g., lemon, sky); common, unassociated words (e.g., put, heart); and rare words (e.g., sol, abjure) and fell to its smallest but still reliable level for unpronounceable nonsense syllables (e.g., hjh, gsxrq). Clearly, despite the instruction to ignore the word, subjects cannot do so, and the greater the relevance of the word, the greater is the resulting interference with colour naming.

Three classical experiments of stroop effect In the first experiment, words and conflict-words were used.The task required the participants to read the written color names of the words independently of the color of the ink (for example, they would have to read "purple" no matter what the color of the font). In experiment 2, stimulus conflict-words and color patches were used, and participants were required to say the ink-color of the letters independently of the written word with the second kind of stimulus and also name the color of the patches. If the word "purple" was written in red font, they would have to say "red", rather than "purple". When the squares were shown, the participant spoke the name of the color. In the third experiment, tested his participants at different stages of practice at the tasks and stimuli used in the first and second experiments, examining learning effects

Variants of Stroop Stroop’s gives a template for studying interference. The best known is the picture-word interference task in which a conflicting word is embedded in a picture. As with the classic Stroop task, interference is largely unidirectional: Naming the picture shows interference from the word, but reading the word is hardly influenced by the picture. Other common variants include the directional version in which again reading the word is quite unhampered by the mismatched arrow, but there is substantial interference from the embedded word when identifying the direction of the arrow, and the digit version in which counting the number of digits is impaired when the digits themselves are incompatible with their numerosity. Then is the flanker task wherein identification of the central letter is impaired by flankers that sometimes also serve as central targets (relative to flankers that are never targets).

Gradients of interference

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There was no follow-up to his work for about 30 years and it is only in the 1960s that research on this phenomenon resumed as it was the advent of computer-controlled experiments. The study that actually relaunched research on color-word interference was reported by Klein in 1964 using multiple-stimulus cards in much the same format as Stroop had used. Klein sought to understand what aspects of the words interfered with naming colors. To do so, he incorporated several new conditions. In addition to the baseline “colorsalone” card, there were six interference cards. As always, the standard incongruent condition – using words incongruent with the print colors – showed large interference. When color words that were not the names of the print colors were substituted, interference was cut in half, implicating a large role for response set in interference. Interference then declined more slowly across color-related words (e.g., lemon, sky); common, unassociated words (e.g., put, heart); and rare words (e.g., sol, abjure) and fell to its smallest – but still reliable – level for unpronounceable nonsense syllables (e.g., hjh, gsxrq). Clearly, despite the instruction to ignore the word, subjects cannot do so, and the greater the relevance of the word, the greater is the resulting interference with color naming.

Explanations of Stroop: Automaticity Solso explains that automaticity occurs when an action becomes so highly practiced that it happens without intent and little conscious awareness. He goes further to say that automaticity occurs so that we can focus on challenging tasks that require more of our attention. This explanation, when applied to the Stroop effect implies that reading is more automatic then colour naming, and therefore automatic processes interfere with our performance on the Stroop test

Speed of Processing The speed of processing theory mentions that the individual can read words faster than name the colours, it signals that the word information arrives earlier than the colour information which leads to processing confusion and leading to slower reaction time on the colour naming trials. Perceptual Encoding Perceptual encoding refers to assigning symbols to the sensations which indicate that the sensations have meaning. In the Stroop effect, the processing for a single colour or picture

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naming trial consists of perceptual encoding in which the colour or the picture is perceived by the individual (Sensed and given meaning to) and is identified conceptually on the basis of the features of the stimulus. (Maanen, 2007) Two factor model Melara and Algom (2003) found that there are two factors that are responsible for the stroop interference, dimensional imbalance and dimensional uncertainty. Dimensional imbalance refers to how the two dimensions of a stimulus are correlated and how surprising the stimulus is. Dimensional uncertainty refers to how salient the stimulus is in the context of other stimuli. The selective attention is focused on the surprising element, the correlated information. The stroop interference occurs because words are more salient than colours and colours are uncertain than words. Roelof (2003) also proposed a two-factor model which mentions that processing interactions occur in systems that are involved in language production mediated by a supervisory attentional system which has control over the task being performed. He reported that there are different mechanisms for colour naming and word reading, and colour naming is conceptually driven as names are directly connected to the colours and hence extra effort is required unlike the reading of words. Parallel Distributed Processing Model This refers to the processing that while analysing information, the brain develops specific pathways or structures for different tasks. The strength of the pathway matters more, the pathway of reading is stronger than the pathway of colour processing. Automaticity is a function of the strength of the pathway and hence when two parallel systems are activated in the Stroop effect, interference occurs between the weaker (colour processing) and the stronger pathway (automatic reading). (Cohen, 1990) Piaget has articulated that reaction time to Stroop tasks decrease with age, from early childhood to early adulthood. The speed of processing increases with change and there is an efficient cognitive control. These changes can be attributed to development of the working memory or more controlled thought processes. (Kellog,2013)

Applications of Stroop General real life applications for stroop effect include advertisements and presentationspeople who make billboard or magazine ads have to be very careful abou the colour and font of the text that they have printed. The Stroop effect has been used to investigate a person's

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psychological capacities; since its discovery during the twentieth century, it has become a popular neuropsychological test. Stroop test has been widely used to assess the processing ability of the individuals. It makes use of validated psychological tests for assessing the selective attention capability and skills of the individual. It used along with neuropsychology to administer tests to assess the executive abilities of the person. The Stroop test has been used in the diagnosis and characterisation of a number of clinical and neurological disorders. With the help of brain imaging techniques, Stroop is also used to identify the areas of brain that are involved in planning, memory. It is widely used in clinical settings. Other uses include measuring psychological abilities, cognitive flexibility. (Howieson, 2004)

Kahneman & Chajczyk (1983) tested automaticity of reading by effects by color-irrelevant stimuli. 60 undergraduates students were used. They were presented colour bars and words that were conflicting , congruent and neutral. It was found that colour naming was facilitated when the colour names were congruent with colour bars.

Roelof (2003) attributed this interference in colour naming due to the fact that colour naming and word reading require two different pathways and colour naming is conceptually driven and hence requires more effort

According to experiment conducted by Brown, Joneleit , Robinson & Brown (2002) there is involuntariness criterion for automaticity in the Stroop task, particularly when word reading is viewed in the context of a skilled performance as we are skilled to understand congruent things around us.

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Method Experimental Design was followed Experimental Design Table Independent Variable Dependent Variable Controls (IV)

Methods of Control Organismic

(DV)

variables

Correct recall of

Exposure

The exposure time

Interest,

containing colour

the response

time

was kept to two

Motivation,

incongruence and

(Accuracy)

seconds per slide.

Alertness,

The lists

colour congruence

Familiarity,

words.

Expectations of the Number of

The subject was

exposures

exposed to each list

Length of the

twice. Each list contained

list

25 colour words. List 1 had colour congruent words and List 2 had colour incongruent

Criteria for

words. All the five

colour

colours- Green,

congruent

Orange, Pink,

stimulus

Purple, Yellow were written in the same ink as the name of the colour. The words were presented

Criteria for

randomly. The five colours

incongruent

were written in the

subject.

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colour

ink different from

stimulus

the name of the colour. Green was written in colours except Green. The words were presented

Similarity in

randomly. All the words were

structure of

presented against a

the stimulus

white background, the font size was kept constant, the font style was same throughout, the words were placed at the centre and the lettering (The way words were written) were neither too thick or

Time gap

too thin. No time gap was given between the exposure and the response, a time gap of 2 minutes was given between the first trial of congruentincongruent word stimulus and the second trial of incongruent-

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congruent colour Sequence of

stimulus. The first list

the trial

(congruentincongruent) was chosen for the first trial, it was randomly chosen and in the second trial, the reverse order was followed, the incongruentcongruent list was

Reaction

shown first. The

time

participant was asked to respond before the next slide appeared automatically (2

Extraneous

seconds) The experiment

variables

was conducted in a well-lit room, the individual was given time to adjust to the place. The room was free from noise or any sort of distractions.

Material Required

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●Two lists with colour words - one ink colour congruent and the other ink colour ● Two sheets corresponding to the word lists to be presented were prepared for recording of oral responses of the subject by the experimenter ● A computer with slide-show presentation set at the pace of one slide per two seconds ● Two pens ● Blank sheets for recording introspective report & behavioural report ● Screen Preliminaries Name- Kritika Sex : Female Age- 20 Qualification – BA(H) History Procedure The subject was called to the psychology laboratory. The laboratory was well lit and noise free. She was asked to feel comfortable . A brief conversation was undertaken with her so as to build a rapport. The subject was then given the instructions .The preliminaries were taken and the experiment was then conducted.

Rapport formation “How are you Kritika?” “I am fine, how are you?” “I am also good , how was your day?” “My day was tiring but I feel comfortable here” “What do you like to do in your free time?” “I like to paint and talk to friends” “Oh, wow that is great” “Let’s start then” Instructions This is a simple experiment on attention. I will be showing you slides with the name of a color written on it. Your task is to tell me the ink color in which the color name is written. For

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example, if the color name is the word “PURPLE” is written in ‘BLACK’, your response should be ‘BLACK’, not ‘PURPLE’. You should tell me the color in which each word is written in. Before the trials, I will give you a ‘ready’ signal by saying ‘Ready’, and you have to focus your attention on the ‘*’ that appears on a blank slide. As soon as you see this slide, with the color name written on it, you will give me the response by telling me the name of the ink color. Make sure that your response to each word comes before the next ‘*’. This way, I will show you different slides one at a time for a very short duration. Now, I will give you some practice trials. Have you understood? Shall we begin?

Precautions : 1. The laboratory conditions should be maintained as far as possible. 2. The computers should be checked thoroughly before they are put to use for the experiment. 3. No feedback should be given to the subject while the experiment is being conducted. Introspective Report “The experiment was very interesting. I had psychology in class 12th but now it felt good doing a psychology experiment after two years. This one was very interesting as I enjoyed it. It looked like a game, and I am curious to know my results too now. I really want to know how I focused on the ink and why I could not at other times” Behavioural Report The subject was very cooperative. She was sitting with back straight and looking and listening to the experimenter very attentively. She was excited for the experiment. She was curious to know her results too.

Result Table 1 The number and percentage of correct responses in both congruent and incongruent lists

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Number of correct

Percentage of

Number of correct

Percentage of

responses

correct responses

responses

correct responses

(congruent list) 50/50

(congruent list) 100%

(incongruent list) 47/50

(incongruent list) 94%

Figure 1 The percentage of correct responses in both congruent and incongruent lists

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Incongruent word colour Congr...