Influence of recall procedures on the modality effect with numbers and enumerated stimuli

Experiment 1 extended J. S. Nairne and W. L. McNabb's (1985) counting procedure for presenting numerical stimuli to examine the modality effect. The present authors presented participants with dots and beeps and instructed participants to count the items to derive to-be-remembered numbers. In addition, the authors presented numbers as visual and auditory symbols, and participants recalled items by using free-serial written recall. Experiment 1 demonstrated primacy effects, recency effects, and modality effects for visual and auditory symbols and for counts of dots and beeps. Experiment 2 replicated the procedure in Experiment 1 using strict-serial written recall instead of free-serial written recall. The authors demonstrated primacy and recency effects across all 4 presentation conditions and found a modality effect for numbers that the authors presented as symbols. However, the authors found no modality effect when they presented numbers as counts of beeps and dots. The authors discuss the implications of the results in terms of methods for testing modality effects.     

Effects of associatively significant posttrial stimuli on learning and memory

Pigeons were trained on a delayed conditional discrimination in which the choice between two simultaneously presented stimuli depended on how the trial started. Choice of one of the stimuli was reinforced if the trial had been initiated by presentation of a food sample and choice of the other was reinforced if no sample had been presented. Subsequently, test trials were administered on which an associatively significant stimulus was presented during the retention interval. This manipulation was intended to modulate the short-term retention of information about the food sample. It was found that performance on food sample test trials was enhanced by presentation of an excitor for food, disrupted by presentation of an inhibitor for food and unaffected by presentation of an associatively neutral stimulus. The impact of these posttrial stimuli was also assessed on the ability of the food sample to serve as a reinforcer. This was done by recording the development of responding to a keylight that signalled the food sample on these test trials. Compared to the associatively neutral stimulus, both the excitor and the inhibitor interfered with the development of keypecking. These results are discussed with regard to the issue of how posttrial events modulate associative learning.     

Output buffer storage and the modality of recall

In two experiments, subjects were presented with two lists of visual items simultaneously, both of which were to be recalled. The order of recall of the lists was manipulated. In Experiment 1, subjects were required to recall one list by speaking it and the other by writing it down. Prior knowledge of the particular mode of output required for each list resulted in significantly higher levels of recall than in a condition in which the output mode for each list was not known until after presentation. This result suggests that there may be at least two modality-specific output buffers. Experiment 2 employed the same method of presentation, but spoken recall of both lists was required. In addition, the priority of the lists was manipulated, and articulatory suppression was required in half of the trials. There was an effect of priority and of recall order, together with an interaction between the two. In contrast to the results of FitzGerald and Broadbent (1985a), however, who carried out a similar experiment but with written recall, articulatory suppression significantly reduced the priority and recall order interaction. It is concluded that there is one form of output buffer storage for written or manual output and one for spoken output.     

Effects of simultaneous interference upon free recall learning and retention

Learning and retention were examined under varying amounts of intratask interference during learning. All subjects were required to learn the same list of auditorily presented words while concurrently processing a visually presented interfering list. Differential amounts of interference were produced by varying the relatedness of the interfering list to the learning list. The common learning list consisted of four general categories that also contained members of more restricted subcategories. Some subjects were instructed about the existence and names of the subcategories. The results showed that interference lengthened learning but, in some cases, facilitated retention relative to control groups. Restricted category knowledge facilitated learning but had no effect on retention. There were no significant retention differences after I week, but after 5 weeks retention performance was significantly better for groups that learned under related interference conditions. The results were interpreted in terms of more elaborate encoding of the items in the high intratask interference conditions.     

Free recall and complexity of pictorial stimuli

In order to explore variables underlying primacy and recency effects in free recall of pictorial material, norms were developed using 120 subjects who rated the vividness and complexity of slides. Two experiments were then run in which two levels of each of these variables (extreme high and low ratings) were factorially combined. In the first experiment 24 subjects were shown three mixed lists, two short and one long (consisting of materials of all four combinations of vividness and complexity), and in the second experiment 12 subjects were shown four pure lists (consisting of materials of a single type). Analysis of variance showed list length in the mixed list experiment and complexity in both experiments to be strong determinants of recall. Greatest recall was for items of low complexity in short lists. Weak, but statistically significant, serial position effects were evident, particularly for less complex items. The effects of primacy and recency seem to decrease with increasing complexity of visual materials, perhaps because of the greater difficulty in rehearsing more complex pictures either verbally or iconically.     

Recency and the modality effect in immediate ordered recall

In immediate ordered recall, recency is the improved recall of the last item of a presentation, and the modality effect is the advantage for an acoustic presentation over a subvocalized visual presentation, primarily occurring at the last serial position. Experiment 1 tested grouped presentations. There was a modality effect for the first item of the last group, even though that item was at the third-to-last or fourth-to-last serial position. In Experiment 2, for vocalized presentations of syllables ending in a, recency was larger for staccato speech than legato speech; for subvocalized presentations, there was a substantial recency for the legato style. In Experiment 3, recency was larger for a set of syllables ending in ATE than for a set of syllables ending in AME. These results suggest that recency cannot be explained by the existence of a fixed-capacity store, auxiliary to the auditory short-term store, that retains only some types of presentations. It is suggested instead that recency might reflect an auxiliary method of using the information in the auditory short-term store.     

Input and output modality effects in immediate serial recall

In immediate recall tasks, visual recency is substantially enhanced when output interference is low (Cowan, Saults, Elliott, & Moreno, 2002; Craik, 1969) whereas auditory recency remains high even under conditions of high output interference. This auditory advantage has been interpreted in terms of auditory resistance to output interference (e.g., Neath & Surprenant, 2003). In this study the auditory-visual difference at low output interference re-emerged when ceiling effects were accounted for, but only with spoken output. With written responding the auditory advantage remained significantly larger with high than with low output interference. These new data suggest that both superior auditory encoding and modality-specific output interference contribute to the classic auditory-visual modality effect.     

Presentation modality and mode of recall in verbal false memory

False memories were investigated for aurally and visually presented lists of semantically associated words. In Experiment 1, false written recall of critical intrusions was reliably lower following visual presentation compared with aural presentation. This presentation modality effect was attributed to the use of orthographic features during written recall to edit critical intrusions from visually presented lists. As predicted by this hypothesis, the modality effect was eliminated when the mode of recall was spoken rather than written. In Experiment 2, the modality effect in written recall was again replicated and then eliminated with an orienting task that ensured orthographic encoding even of aurally presented words. Thus, the modality effect appears to depend on using orthographic information to distinguish true from false verbal memories.     

Order of recall,output interference,and the modality effect

Summary In free recall, the order of recall following auditory and visual presentation differs; it tends to be forward for auditory but backward for visual. The first two experiments examined to what extent this difference in output order could account for the modality effect (i.e., a superior retention of auditorily as opposed to visually presented words). Order of recall was manipulated using postcued (Experiment 1) and precued (Experiment 2) procedures. Whereas the modality effect was unaffected with postcueing it was reduced to approximately half its size with precueing. It was concluded from these two studies that although output order cannot explain the whole modality effect, it does seem to play an important role for part of the effect in some situations. Experiments 3 and 4 used a mixed-mode and a probed recall procedure, respectively, to examine the role of output interference in modality experiments. The data suggested that output interference effects were non-monotonic; they were greater for visual than for auditory early in recall, but apparently no different later in recall. The two-store hypotheses (Murdock and Walker, 1969) was elaborated slightly to account for these results.This research was supported by Research Grants APA 146 from the National Research Council of Canada and OMHF 164 from the Ontario Mental Health Foundation. We would like to thank Doris Glavnov and Janet Metcalfe for help with the data analyses.     

Recency effects in delayed recall of mouthed stimuli

Auditory presentation leads to greater recency effects in recall than does visual presentation. This phenomenon (the modality effect) is found in both free and serial recall and in both immediate and delayed recall. Silent mouthing of visually presented stimuli also leads to enhanced recency effects in immediate serial recall. Two experiments reported here extend the generality of the mouthing effect by demonstrating that enhanced recency effects of mouthed stimuli occur in delayed serial and free recall. These results are inconsistent with theories that attribute the modality effect to a purely auditory sensory memory.     

Effects of stress on recall

Subjects in experimental conditions were exposed to a traumatic autopsy colour slide (labelled either as of New York Police Department (NYPD) or MGM studio origin) embedded in a neutral series of travel scenes, while control subjects saw a neutral target. Subjects in the high-stress condition showed a significant decrease in memory for neutral slides which followed the NYPD-labelled traumatic stimulus (p < 0.001). Results support evidence in the eyewitness memory field which indicate reduced recall under elevated levels of stress.     

Effects of postresponse visual stimuli on visual discrimination learning in the rhesus monkey

To learn more about the mechanism (or mechanisms) involved with postresponse stimulus processing during discrimination learning, a series of studies was conducted with monkeys to determine why the combined relevant and irrelevant stimuli impair learning more than irrelevant stimuli appearing alone. It was found that: (a) the greater size and complexity of the combination of stimuli were not responsible for the greater deficit, while the presence of the relevant stimuli (S^D and S^Δ) within the stimulus combination apparently was; (b) the more similar the postresponse irrelevant stimuli were to the relevant stimuli the greater the deficit that resulted; and (c) monkeys that had earlier learned to discriminate the relevant and irrelevant features of a combination showed no learning impairment when this same stimulus combination was later presented after the response during a new learning problem. These results were interpreted as evidence that: (1) processes associated with learning a discrimination problem do not end with the execution of a choice response; (2) postresponse stimuli produce greater impairment in discrimination learning when they are distorted versions of the relevant stimuli; and (3) the impairment resulting from postresponse irrelevant stimuli occurs primarily when this misinformation is processed and misperceived as being relevant to learning the discrimination problem.