1. WHEN THE PROBE IS WILLING BUT THE MIND IS WEAK This research was supported by an NSERC operating grant For additional information please contact Marty Niewiadomski at martin@psych.utoronto.ca Marty Niewiadomski University of Toronto at Scarborough Steve Joordens University of Toronto at Scarborough Bill Hockley Wilfrid Laurier University A New Recognition Paradigm: THE WHAT Partial-item recognition THE HOW Study List –Present a list of words one at a time. Partial Item Recognition Test –48 “old” and 48 “new” test probes were presented one at a time. –All of the items had two letters removed. –All partial items could only be completed with one solution. –Subjects were asked to first generate the missing letters to complete the word, and then make a new/remember/know recognition decision for the completion THE WHY Reason # 1 – The paradoxical frequency effect in recall and recognition. In a recognition test, participants typically make more hits and fewer false alarms to low- frequency words compared to high frequency words (mirror effect). In a recall test, however, a general memory advantage favours high frequency items, as they tend to be recalled more often relative to low frequency words. Experiment 1 deals directly with this paradox. Reason # 2 – Beyond good encoding and environmental support – the role of context in recognition memory. Experiments 2-5 explore the roles of environmental support and context within the mirror effect. In all the Experiments, the partial-item recognition task helps to disambiguate the issues. A New Recognition Paradigm: THE WHAT Partial-item recognition THE HOW Study List –Present a list of words one at a time. Partial Item Recognition Test –48 “old” and 48 “new” test probes were presented one at a time. –All of the items had two letters removed. –All partial items could only be completed with one solution. –Subjects were asked to first generate the missing letters to complete the word, and then make a new/remember/know recognition decision for the completion THE WHY Reason # 1 – The paradoxical frequency effect in recall and recognition. In a recognition test, participants typically make more hits and fewer false alarms to low- frequency words compared to high frequency words (mirror effect). In a recall test, however, a general memory advantage favours high frequency items, as they tend to be recalled more often relative to low frequency words. Experiment 1 deals directly with this paradox. Reason # 2 – Beyond good encoding and environmental support – the role of context in recognition memory. Experiments 2-5 explore the roles of environmental support and context within the mirror effect. In all the Experiments, the partial-item recognition task helps to disambiguate the issues. –If subjects could not generate the appropriate letters, or made a mistake, the computer would fill in the blanks or correct them. ME__RY MEM_RY MEMORY 1=Remember OLD 2=Think OLD 3=NEW TEST LIST PARTIAL ITEM RECOGNITION EXPERIMENT 1 – FREQUENCY PARADOX METHOD Study list –60 words were presented one at a time. –Words were high frequency (mean = 143) or low frequency (mean = 6.9), blocked by frequency (blocks were counterbalanced and no block effect was observed in any experiments). –Half of the old and the new items were high frequency and half were low frequency. Presentation of old/new probes as well as word frequency was randomized at test. RESULTS Generation A generation advantage was observed for high- frequency items relative to low frequency items This advantage was present for both “old” and “new” items. Recognition A typical mirror pattern was observed between the new and old items. Furthermore, the recollective process usually associated with “remember” responses appears to be responsible for the “old” portion of the effect. EXPERIMENT 1 – FREQUENCY PARADOX METHOD Study list –60 words were presented one at a time. –Words were high frequency (mean = 143) or low frequency (mean = 6.9), blocked by frequency (blocks were counterbalanced and no block effect was observed in any experiments). –Half of the old and the new items were high frequency and half were low frequency. Presentation of old/new probes as well as word frequency was randomized at test. RESULTS Generation A generation advantage was observed for high- frequency items relative to low frequency items This advantage was present for both “old” and “new” items. Recognition A typical mirror pattern was observed between the new and old items. Furthermore, the recollective process usually associated with “remember” responses appears to be responsible for the “old” portion of the effect. overall This general pattern of results can be seen regardless of whether the items were generated or not. EXPERIMENTS 2-5: ENVIRONMENTAL SUPPORT AND THE MIRROR EFFECT IN RECOGNITION Two of the factors that influence memory are encoding and environmental support at test; the partial-item recognition task allows easy manipulation of the latter one. Simply removing letters from items at test decreases the amount of environmental support. These experiments used the partial-item recognition paradigm in three different settings: either two letters were removed, one letter was removed or no letters were removed (standard yes/no recognition). These conditions were tested in a between- subjects design (Exp 2-4) and in a within- subjects design (Exp. 5). This general pattern of results can be seen regardless of whether the items were generated or not. EXPERIMENTS 2-5: ENVIRONMENTAL SUPPORT AND THE MIRROR EFFECT IN RECOGNITION Two of the factors that influence memory are encoding and environmental support at test; the partial-item recognition task allows easy manipulation of the latter one. Simply removing letters from items at test decreases the amount of environmental support. These experiments used the partial-item recognition paradigm in three different settings: either two letters were removed, one letter was removed or no letters were removed (standard yes/no recognition). These conditions were tested in a between- subjects design (Exp 2-4) and in a within- subjects design (Exp. 5). TEST LIST INTACT SI_TER NEW OLD NE_ULA NEW OLD CO_KIE NEW OLD RE_ALL NEW OLD RE_SON NEW OLD PEOPLE NEW OLD SI_TER NEW OLD NE_ULA NEW OLD CO_KIE NEW OLD RE_ALL NEW OLD RE_SON NEW OLD PE_PLE NEW OLD TEST LIST 1 LETTER REMOVED TEST LIST 2 LETTERS REMOVED SI_TER NEW OLD NE_ULA NEW OLD CO_KIE NEW OLD RE_ALL NEW OLD RE_SON NEW OLD PE__LE NEW OLD non-generated generated RESULTS Between Subjects A typical mirror effect was observed in the intact condition (no letters removed). The “old” portion of the mirror effect was significantly attenuated in both partial-item conditions. Within Subjects No memory advantage was observed in the “old” portion of the effect, regardless whether the item had two, one, or no letters removed. CONCLUSIONS Experiment 1 shows a HF advantage for generation and a LF advantage for recognition, all within one experiment. Results of Experiments 2-5, show that good encoding and environmental support are not always sufficient to support recollection. Subjects may adopt a common strategy in dealing with partial recognition probes that results in decreased recollection. Recognition results are consistent with 2- Factor accounts of the mirror effect (e.g. Joordens & Hockley, 2000). RESULTS Between Subjects A typical mirror effect was observed in the intact condition (no letters removed). The “old” portion of the mirror effect was significantly attenuated in both partial-item conditions. Within Subjects No memory advantage was observed in the “old” portion of the effect, regardless whether the item had two, one, or no letters removed. CONCLUSIONS Experiment 1 shows a HF advantage for generation and a LF advantage for recognition, all within one experiment. Results of Experiments 2-5, show that good encoding and environmental support are not always sufficient to support recollection. Subjects may adopt a common strategy in dealing with partial recognition probes that results in decreased recollection. Recognition results are consistent with 2- Factor accounts of the mirror effect (e.g. Joordens & Hockley, 2000). between Ss – intact between Ss – 1 letter removed between Ss – 2 letters removed within Ss – 1 letter removed within Ss – 2 letters removed within Ss – intact