Topic: Unconscious Perception

Order Description
Although this is a lab report, they have provided the Method and Results section for us, as well as some references although 3 more are required. What I need is the introduction (approx 500 words), discussion (approx 1000 words) and conclusion (approx 500 words). I will attach the assignment details.

PSY20006 Cognition and Human Performance
Assessment 2: Lab report overview

Introduction
One of the interesting things about human cognition is that even if we are not aware of many things in the environment, we often process them anyway (Deutsch & Deutsch, 1963). Evidence for this comes from many different experimental paradigms (e.g., Merikle, Smilek, & Eastwood, 2001). It is important to know what type of stimuli are likely to get processed out of awareness, and the different extent to which they are processed compared to when attention is directed at them. If, for example, unattended stimuli only ever had their early visual features processed, it would not be as interesting compared to if other aspects of them, such as their meaning, were also processed. Most people argue that the amount of processing that occurs with unconscious stimuli is less than with conscious stimuli. Emotional content can however also modulate how information is processed. The overarching aim of this research study is to better understand conscious as opposed to unconscious processing of information. As such, you need to find evidence for the idea that unconscious stimuli may not be processed to the same extent as conscious stimuli.
Masked primes have been used to investigate the difference in processing of unconscious and conscious stimuli. Masked primes are words that have been masked so that you are not aware of them. In this report, you will need to define and understand what masked semantic priming is. We used primed words and control (unprimed) words to explore this question (so ‘priming’ is the first independent (within-subjects) variable). To examine the process of masked semantic priming, the following experimental design was run. The primes used were varied, using primes of negative, neutral and positive emotional valence; emotional valence was therefore the second (between-groups) independent variable. The reason different emotional valence primes were used was to examine whether emotional loaded words were processed differently (i.e., unconsciously) as opposed to neutral words. As such, to support your predictions you make you need to find evidence for this; that is, that words with different types of emotional valence might be processed differently.
It is also possible that individual characteristics may influence how a person perceives and responds to emotionally valanced stimuli. To examine this we used two scales, the Spielberger State-Trait Anxiety Index (SSTAI; Spielberger, Gorsuch, Lushene, Vagg, & Jacobs, 1983) and the Oxford Happiness Questionnaire (OHQ; Hills & Argyle, 2002). You need to find evidence to support selection of this variable - that is, that individual differences in these characteristics might predict and influence results on the emotionally-valanced stimuli processing.

A bit about the data set
Stimuli Type: The three groups which differ on meaning judgement instruction (negative, neutral or positive valence)
Primed and Control Reaction Time: the time taken to complete the judgement task for either related (primed) or unrelated (control) word pairs
Priming Effect: The difference between reaction times for primed and control word pairs.
SSTAI and OHS: The two different scales have been turned into z-scores. Z-scores are normalized scores that have a mean of zero and a SD of 1. If you have a high z-score with the STAI, you have high anxiety. If you have a high value on the Oxford Happiness index, you have high happiness.

Method
Participants
One hundred and forty-four students from a medium sized university in Melbourne participated in the experiment. All claimed to be native speakers of English.
Materials
Words and Nonwords: Ninety prime-target word triplets were used. The triplets were such that they included two primes and a target word. One of the primes (the control) was semantically unrelated to the target word (e.g., WALL-cat) and the other was semantically related (e.g., DOG-cat). Of the 90 triplets, one-third of the targets had positive emotional valence, one-third had neutral emotional valence, and one-third had negative emotional valence. The word pairs were also balanced on a range of other characteristics like letter length and frequency they appear in the human language. A set of practice words pairs was also used.
In terms of the stimulus presentation, the stimuli always appeared in the centre of the screen. The timing was as follows: (a) a forward letter mask appeared for 500ms; (b) the prime was then presented for 48ms; (c) a backward mask appeared for 96 ms; and (e) the mask(s)/target remained on the screen until the participant responded.

Anxiety Scale: The trait items in the Spielberg State-Trait Anxiety Inventory (SSTAI; Spielberger et al., 1983) were used.
Happiness Scale: The Oxford Happiness Questionnaire (OHQ; Hills & Argyle, 2002) was used.
Procedure
Participants were allocated to one of three groups, and sessions were run in groups of approximately 20 people. The task was preceded by 18 practice stimuli. Groups differed only in the instructions given relating to the judgement of meaning about the words: one group judged whether each word presented was negative in valence or not; one group judged whether each word presented was positive in valence or not; while one group judged whether each word presented represented somewhere or a place they could go (neutral emotional valence). Participants were asked to respond as quickly and as accurately as possible. The groups were further counterbalanced such that in one group, half the targets used related pairs and half did not, and the other group used the other half of the stimuli. Following this, they were told that after the main task had finished, that they would be presented with a list of questions, and that they should answer these based on their initial intuition without thinking too hard. The questions were from the two surveys, with the questions from the SSTAI (Spielberger et al., 1983) being presented first and the OHS second (Argyle et al., 1995). The experimental task and the two short surveys took about 15 minutes to complete.

Results
All data from the SSTAI and the OHS was initially processed by transforming the raw scores from all of the participants into z-scores. In the main task, all errors were discarded, as were responses in the meaning judgement task that were on stimuli that had a different meaning to the judgment (i.e., positive responses in a negative valence task). Reaction times (RTs) that were 3 or more SDs away from each participant’s mean were removed. The difference in reaction times between primed and control conditions was also calculated. The mean overall RTs appear in Figure 2.

Figure 2. Mean reaction times of judgements for primed and control word pairs a function of word valence. The error bars are 2 SE.

To examine the results, a 3 (Word Type – Positive/Negative/Neutral) × 2 (Prime Relatedness – Related/Different) ANOVA was conducted. The results showed there was a significant main effect of Priming, with related prime-target pairs being faster to process than control (unrelated) pairs, F(1, 117) = 10.23, p < .05. There was also a significant interaction between Prime Type and Stimuli type, with the negative stimuli appearing to show a bigger priming effect, F(2, 117) = 9.98, p < .005. To further examine the interaction, three t-tests were used to examine the size of the priming effect for each of the three stimuli types (negative, control and positive valence). Significant differences were found with the negative, t(39) = 4.73, p < .001, positive, t(29) = 2.65, p < .05, but not neutral words, t(39) = 1.58, p = .12.
To further examine the data, we first calculated the size of the priming effect displayed by each subject (the difference in reaction times between primed and control word pairs). We then correlated the anxiety and happiness scores with these priming effect scores. The results showed that the only correlations that even approached significance were with the anxiety scores and the negative stimuli (r = .31, p = .051) and the happiness scores and the negative stimuli (r = .28, p = .083).

Note to students: You are going to have to be very careful writing about these since they approach but are not significant —there is no “correct” way to do this, but you need to make sure you don’t just assume something that is close to significant is significant -- just that there appears to be a trend, and that it potentially could be just noise!
References
Deutsch, J. A., & Deutsch, D. (1963). Attention: Some theoretical considerations. Psychological Review, 70, 80-90.
Hills, P., & Argyle, M. (2002). The Oxford happiness questionnaire: A compact scale for the measurement of psychological well-being. Personality and Individual Differences, 33, 1073-1082.
Merikle, P. M., Smilek, D., & Eastwood, J. D. (2001). Perception without awareness: perspectives from cognitive psychology. Cognition, 79, 115-134.
Spielberger, C. D., Gorsuch, R. L., Lushene, R., Vagg, P. R., & Jacobs, G. A. (1983). Manual for the state-trait anxiety inventory. Palo Alto, CA: Consulting Psychologists press.

Additional Reading
Bodner, G., & Mason, M. E. J. (2003). Beyond spreading activation: An influence of relatedness proportion on masked semantic priming. Psychonomic Bulletin & Review, 10(3), 645-652.
Landauer, T. K., & Dumais, S. T. (1997). A solution to Plato's problem: The Latent Semantic Analysis theory of the acquisition, induction, and representation of knowledge. Psychological Review, 104, 211-240.