PSY 3393 Experimental Projects Spring 2008

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1 PSY 3393 Experimental Projects Spring 2008 Dates Mar 4: Deadline for project 2 summary Mar 10-15: Spring Break Mar 20: Draft Intro for Project 2 due Dr. Peter Assmann Example topic outline for Project II Topic: The influence of labels on odor retention and identification Research question: Is it easier to recognize odors when they are assigned a label? DV: discrimination index, d' (d-prime) for odor recognition IV: presence versus absence of verbal label during the odor familiarization phase Reference: Bhalla M, Marcus KM, Cornwell JM (2000). Odor recognition and identification: effect of labels over time. Psychol Rep 86(2): Bhalla M, Marcus KM, Cornwell JM. Odor recognition and identification: effect of labels over time. Psychol Rep Apr;86(2): The effect of labels on recognition and identification of odors over time was assessed. 30 men and 30 women were presented 20 odors; half of the participants were also told a name for the odor as a label. Five min. and 60 min. later, all participants were given 20 odors (10 from the original set, 10 new) and asked whether each odor was new or old (odor recognition). The group given labels was also asked to recall the label provided (odor identification). Analysis indicated a significant effect of time on recognition. Significantly more odors were recognized at 5 min. than 60 min. The effect of label was also significant, with recognition being better for the Label condition than the No-Label condition. As for odor identification, women identified more labels than did men. Overall, odor recognition was better with labels soon after exposure, and the women were better at remembering the labels than the men. Bhalla M, Marcus KM, Cornwell JM. Odor recognition and identification: effect of labels over time. Psychol Rep Apr;86(2): Bhalla M, Marcus KM, Cornwell JM. Odor recognition and identification: effect of labels over time. Psychol Rep Apr;86(2): Dependent variables 1. Odor recognition - familiarization followed by test phase 2. Odor identification - recall the label provided Independent variables 1. Label vs. no label 2. Male vs. female participants 3. Time between familiarization and test phase (5 vs. 60 min) more odors recognized at 5 min. than 60 min recognition better for Label condition than No-Label women identified more labels than did men odor recognition was better with labels soon after exposure

2 Larsson M, Oberg C, Bäckman L. Recollective experience in odor recognition: influences of adult age and familiarity. Psychol Res Jan;70(1): We examined recollective experience in odor memory as a function of age, intention to learn, and familiarity. Young and older adults studied a set of familiar and unfamiliar odors with incidental or intentional encoding instructions. At recognition, participants indicated whether their response was based on explicit recollection (remembering), a feeling of familiarity (knowing), or guessing. The results indicated no age-related differences in the distribution of experiential responses for unfamiliar odors. By contrast, for familiar odors the young demonstrated more explicit recollection than the older adults, who produced more "know" and "guess" responses. Intention to learn was unrelated to recollective experience. In addition, the observed age differences in "remember" responses for familiar odors were eliminated when odor naming was statistically controlled. This suggests that age-related deficits in activating specific odor knowledge (i.e., odor names) play an important role for age differences in recollective experience of olfactory information. Larsson M, Oberg C, Bäckman L. Recollective experience in odor recognition: influences of adult age and familiarity. Psychol Res Jan;70(1): No age-related differences... for unfamiliar odors. For familiar odors the young demonstrated more explicit recollection than the older adults Older adults produced more "know" and "guess" responses. Intention to learn was unrelated to recollective experience. In addition, the observed age differences in "remember" responses for familiar odors were eliminated when odor naming was statistically controlled. This suggests that age-related deficits in activating specific odor knowledge (i.e., odor names) play an important role for age differences in recollective experience of olfactory information. Table to Graph Main effects and interactions Pictures Words Recall Recognition Percent correct Recall Task Pictures Words Recognition Pictures Words Recall Mean scores Recognition (column averages) (row averages) Main effect of stimulus type Main effect of task Speaker recognition Speaker recognition Compare adults and young children on a speaker recognition task. First, recruit about five people to make speech recordings (word lists or sentences). Use a subset of the recordings from each person to train the listeners. Have them practice listening to the sentences in random order until they can recognize the voices with 100% accuracy. Test them with various distortions Test them with various distortions Speech played backwards Speech shifted up or down in frequency Speech with background noise Compare performance of adults and 5-year olds Is there an overall effect of age? Do the distortions affect speaker recognition? Is there an interaction of age x distortion (are some distortions more harmful for one group than the other)?

3 Face recognition Expertise in face recognition improves into adolescence To what extent can we detect small changes in facial features (e.g., spacing of the eyes, nose, mouth) Are there differences between 8-year olds and adults? Does this difference depend on familiarity with the type of face (e.g., human vs. monkey faces; Mondlach et al., Psy. Sci. 17: , 2006)? Using d' as dependent variable Recognition memory experiments Training set (e.g. 25 faces) Test set (e.g. 50 faces, 25 NEW and 25 OLD) In the test set, each item is presented and subjects are asked if the item is OLD (i.e., it was in the training set) or NEW (not in the training set). Using d' as dependent variable Record the number of hits (S answers yes (or OLD) and the item was in the training set). Record the number of false alarms (S answers yes but the item was not in the training set). Hypothetical Results Participant Hits False alarms 1 90/100 40/ /100 20/ /100 50/ /100 0/ /100 60/ /100 30/100 Hits: faces labelled as OLD (familiar) when they were OLD. False alarms: faces labelled as OLD when they were NEW. Correct rejections: faces labelled NEW when NEW. Misses: faces labelled NEW when OLD. SAS program D-prime (d') analysis title Program for computing d-prime ; data dprime; input id$ h fa; IF h=1 THEN zh=4; ELSE zh=probit(h); IF fa=0 THEN zfa=-4; ELSE zfa=probit(fa); dp=zh-zfa; cards; o o o o o o ; PROC print; run; Set a ceiling of 4 on z hits Set a floor of -4 on z false alarms Observer 5: 80% hits, 60% false alarms SAS output D-prime (d') analysis Program for computing d-prime Obs id h fa zh zfa d-prime 1 o o o o o o Using d-prime as the dependent variable (measure of sensitivity)

4 The literature review for a research paper is selective: it provides all and only the information the reader needs to know to explain why you are doing the study, what is already known and what questions remain. Explain what is unique about your study: the aspect that sets it apart from previous published studies. Explain how your approach differs from earlier studies, and why this new approach is important. Literature Review Step 1: Write an outline. Start with a general statement of what is already known, then focus on what is not well understood. This may be a controversy, a gap in the literature, or an unanswered question. Literature Review Step 2: Introduce your research question. Set this up so that readers are left with the impression that your research topic is the most interesting and logical question to ask. Draft version of the Introduction Step 3: Write a draft of the Introduction. You will need to re-write it several times as you develop your ideas and learn more about the topic. (You do not need to analyze the results before starting on this). Draft version of the paper Step 4: Write the remaining sections of the paper in a quick first draft. Fill in details later: add new material later to make things clearer, or provide additional background material, and delete phrases or sentences that do not directly relate to the central theme.

5 Each sentence in your Introduction should start with a topic sentence making an important point. Arrange the sentences in each paragraph in order of importance, with the most important points first. End your Introduction with a compelling rationale for your study. This should convince the reader that your study provides important new evidence, and that its topic is the logical next thing to investigate. Generally you should follow the writing style used by the papers in the field you are studying. If you use technical terms, define them the first time you use them. Write multiple drafts and proofread them (read them aloud). Eliminate wordy passages, unclear sentences, sentence fragments. Avoid repetition. Make sure each paragraph has a clear transition to the next paragraph. Provide a reference for each substantive finding or theoretical statement that is not your own. If you do not provide a reference, readers will assume that you (as the author) take credit for the concept or finding. Only cite references you have actually read. Only cite references with direct relevance to your paper. Follow the procedure for references in the APA manual.

6 ANOVA interactions Is there a serial position curve for odor memory? How would the serial position effect change if the odors were assigned labels (as compared to unlabeled odor stimuli)? Plot the interaction you might expect to see Describe the pattern in words Miles C, Hodder K. Serial position effects in recognition memory for odors: a reexamination. Mem Cognit Oct;33(7): Seven experiments examined recognition memory for sequentially presented odors. Following Reed (2000), participants were presented with a sequence of odors and then required to identify an odor from the sequence in a test probe comprising 2 odors. The pattern of results obtained by Reed (2000, although statistically marginal) demonstrated enhanced recognition for odors presented at the start (primacy) and end (recency) of the sequence: a result that we failed to replicate in any of the experiments reported here. Experiments 1 and 3 were designed to replicate Reed (2000), employing five-item and seven-item sequences, respectively, and each demonstrated significant recency, with evidence of primacy in Experiment 3 only. Experiment 2 replicated Experiment 1, with reduced interstimulus intervals, and produced a null effect of serial position. The ease with which the odors could be verbally labeled was manipulated in Experiments 4 and 5. Nameable odors produced a null effect of serial position (Experiment 4), and hard-to-name odors produced a pronounced recency effect (Experiment 5); nevertheless, overall rates of recognition were remarkably similar for the two experiments at around 70%. Articulatory suppression reduced recognition accuracy (Experiment 6), but recency was again present in the absence of primacy. Odor recognition performance was immune to the effects of an interleaved odor (Experiment 7), and, again, both primacy and recency effects were absent. There was no evidence of olfactory fatigue: Recognition accuracy improved across trials (Experiment 1). It is argued that the results of the experiments reported here are generally consistent with that body of work employing hard-toname visual stimuli, where recency is obtained in the absence of primacy when the retention interval is short.